Background: Inherited platelet deficiency and/or dysfunction may be more common in the general po... more Background: Inherited platelet deficiency and/or dysfunction may be more common in the general population than has previously been appreciated. In 2013 the Israeli Inherited Platelet Disorder (IPD) Registry was established. Methods: Clinical and laboratory data were collected to pre-specified registration forms. The study protocol was approved by the local hospital ethics committees. Results: To date we have included in the registry 89 patients (male 52%) from 79 families. Most patients (74%) have a not-yet specified inherited thrombocytopenia (n = 39) or non-specific platelet function disorder (n = 27). Full clinical data were available for 81 (91%) patients. The median (range) age at presentation and time of follow-up were 1.8 years (1 day-17.8 years) and 4.7 (0-26) years, respectively. The Pediatric Bleeding Questionnaire was available for 78 patients; abnormal bleeding score (≥2) was recorded in 47 (52.8%, 95% CI 42%-63.5%) patients and was less frequent in patients followed for isolated thrombocytopenia. Abnormal score was associated with a longer time of follow-up, OR 1.19 (95% CI 1.04-1.36). Conclusion: Long term follow-up of patients with IPDs is important as bleeding risks may increase with time. We expect that clinical and laboratory information of patients/families with IPDs gathered in a systemic format will allow for better diagnosis and treatment of these patients.
Journal of Pediatric Hematology Oncology, May 1, 2014
Hemophagocytic lymphohistiocytosis (HLH) denotes the common final pathway of a potentially fatal ... more Hemophagocytic lymphohistiocytosis (HLH) denotes the common final pathway of a potentially fatal hyperinflammatory condition of diverse etiologies. We describe the first case of documented HLH associated with human parechovirus 3. A monoallelic Ala91Val mutation was found in the PRF1 gene, but the contribution of this mutation to HLH remains controversial. The diagnosis, based on accepted criteria, was established early in the course of the disease and led to successful treatment and complete recovery. The awareness of this new association is clinically important in facilitating early treatment, preventing organ damage, and increasing the likelihood of complete recovery.
Mycoplasma pneumonia (M. pneumonia) is usually not considered among the several pathogens that in... more Mycoplasma pneumonia (M. pneumonia) is usually not considered among the several pathogens that induce immune thrombocytopenic purpura (ITP). We report a case of a child with a clinical diagnosis of severe ITP (as defined by the American Society of Hematology panel guidelines of 1994), that was associated with M. pneumonia pneumonia, and reviewed the few cases described in the English literature. A 7-year-old girl was admitted to the pediatric department with 1 day history of fever, purpura and petechiae on her legs, buttocks, arms, face, hard palate, oral mucous membranes and lips. Crepitations were heard over both lungs’ lower fields. Complete blood count revealed WBC of 22.3×103/ μL, Hemoglobin of 11.1 gr/dL, and platelet count of 2×103/μL. Red cells appeared normal on blood film with no features of microangiopathy. A chest X-ray demonstrated right middle lobe infiltrate. Presumptive diagnoses of ITP and RML pneumonia were made and treatment was initiated with one dose of IVIG 0.8 g/kg and daily IV Ceftriaxon at 50 mg/kg. Twelve hours after the IVIG administration, platelet count was 1.2×103/μL. Bone marrow examination revealed normal cellularity with young megakaryocytes, compatible with the diagnosis of ITP. Since there was no response to IVIG, Methylprednisolone 4 mg/ kg for 4 days was started. An extensive search of the literature for ITP or thrombocytopenia and pneumonia retrieved only 7 case reports. In all cases M. pneumonia was the only identified pathogen. Therefore, clarithromycin 15 mg/kg/d was added to the treatment regimen, prior to obtaining the serology results. Thereafter severe hemoptysis developed; the patient was admitted to the PICU and received 4 units of platelets and a second dose of IVIG. Hemoptysis resolved after another day, when the platelet count started to increase gradually, only to drop after the cessation of steroids. A second course of steroids at the same dose was begun and tapered off gradually over 21 days, while the platelet count steadily increased, exceeding 150×103/μL at 4 weeks from presentation. A positive Mycoplasma IgM titer at diagnosis and a 1:160 titer at 2 months confirmed the clinical diagnosis. The child is by now 20 months after the event with normal CBC. Several features of the 8 cases described (including our case) distinguish them from “classic” ITP: Thrombocytopenia occurred concomitantly with the infection as opposed to a few days to a few weeks interval between infection and ITP. Severe bleeding in 4 out of 8 patients including 2 with fatal intracranial hemorrhage in contrast to around 3% severe bleeding and around 1‰ fatal intracranial hemorrhage in “classic” ITP. Three of the authors who looked for specific anti-platelet antibodies were unable to demonstrate it, whereas such antibodies are found in many patients with ITP. Several mechanisms are suggested to explain these differences; though it remains unclear whether Mycoplasma associated thrombocytopenia represents a subset of ITP or constitutes a separate entity. We conclude that M. pneumonia should be looked for in any case of pneumonia and thrombocytopenia or ITP, and early specific anti-Mycoplasma therapy should be initiated to rapidly eliminate the causative agent. This may enhance recovery of the platelet count and decrease the rate of complications.
Introduction: Many premature and full-term newborns receive prophylactic platelet transfusions to... more Introduction: Many premature and full-term newborns receive prophylactic platelet transfusions to prevent bleeding, particularly the most prevalent one, i.e, intracranial hemorrhages. However, the platelet count threshold above which bleeding is prevented and the efficacy of platelet transfusion in thrombocytopenic neonates, have yet to be established. Therefore, inter-Neonatal Intensive Care Units (NICU) variations in treatment indications and practices are expected. Considerable inter-NICU variations will emphasize the need for guidelines on platelet transfusions to neonates and premature infants. Aims: To examine platelet products selection and indications for transfusion among neonatologists in Israel. Research and Methods: Electronic questionnaires addressing the choice of platelet products and the platelet count threshold for transfusion in various clinical settings were sent to 25 neonatal units. Results: All 25 neonatal units responded (100% response rate). There was considerable variation in product selection among the different neonatal units. Up to 24% of the participating units reported selecting nontraditional products. Variation was also found in thresholds for platelet transfusion - several units used high thresholds while others used low ones. Traditional guidelines were followed in up to 64% of cases in selected clinical scenarios. Conclusions: There is considerable variation in both platelet product selection and platelet count thresholds for transfusion among the different neonatal units. Discussion: A low threshold for platelet transfusion increases the risk for bleeding, whereas a high threshold increases the prevalence of complications from transfusion of blood products. Adherence to guidelines may prevent both such sequelae. Summary: Such variation in platelet transfusion among neonatologists emphasizes the need for an accepted policy. We recommend setting up a committee of neonatologists, pediatric hematologists and blood service experts which aims to establish an appropriate policy regarding the prevention of platelet transfusion sequelae in newborns.
Inherited bone marrow failure syndromes are rare genetic disorders characterized by bone marrow f... more Inherited bone marrow failure syndromes are rare genetic disorders characterized by bone marrow failure, congenital anomalies, and cancer predisposition. Available single disease registries provide reliable information regarding natural history, efficacy and side effects of treatments, and contribute to the discovery of the causative genes. However, these registries could not shed light on the true incidence of the various syndromes. We, therefore, established an Israeli national registry in order to investigate the relative frequency of each of these syndromes and their complications. Design and Methods Patients were registered by their hematologists in all 16 medical centers in Israel. We included patients with Fanconi anemia, severe congenital neutropenia, Diamond-Blackfan anemia, congenital amegakaryocytic thrombocytopenia, dyskeratosis congenita, Shwachman-Diamond syndrome, and thrombocytopenia with absent radii. Results One hundred and twenty-seven patients diagnosed between 1966 and 2007 were registered. Fifty-two percent were found to have Fanconi anemia, 17% severe congenital neutropenia, 14% Diamond-Blackfan anemia, 6% congenital amegakaryocytic thrombocytopenia, 5% dyskeratosis congenita, 2% Shwachman-Diamond syndrome, and 2% thrombocytopenia with absent radii. No specific diagnosis was made in only 2 patients. Of the thirty patients (24%) developing severe bone marrow failure, 80% had Fanconi anemia. Seven of 9 patients with leukemia had Fanconi anemia, as did all 6 with solid tumors. Thirty-four patients died from their disease; 25 (74%) had Fanconi anemia and 6 (17%) had severe congenital neutropenia. Conclusions This is the first comprehensive population-based study evaluating the incidence and complications of the different inherited bone marrow failure syndromes. By far the most common disease was Fanconi anemia, followed by severe congenital neutropenia and Diamond-Blackfan anemia. Fanconi anemia carried the worst prognosis, with severe bone marrow failure and cancer susceptibility. Diamond-Blackfan anemia had the best prognosis. The data presented provide a rational basis for prevention programs and longitudinal surveillance of the complications of inherited bone marrow failure syndromes.
Background: Rotavirus gastroenteritis is a prevalent childhood illness rarely complicated by seco... more Background: Rotavirus gastroenteritis is a prevalent childhood illness rarely complicated by secondary bacterial sepsis. Although there are case reports of septicemia after rotavirus infection, there are no recent reviews on this topic. Objectives: To add new cases of septicemia after rotavirus to the literature, review the few cases of septicemia after rotavirus that have been reported, calculate the incidence of septicemia in children hospitalized for rotavirus gastroenteritis, and discuss the characteristics of septicemia after rotavirus infection and implications for current pediatric practice. Methods: We identified children whose illness was complicated by septicemia from among all hospitalizations at our facility for rotavirus gastroenteritis from May 1999 through May 2010. We also review the few cases reported in the English literature. Results: We identified two cases of septicemia from among 632 hospitalizations for rotavirus gastroenteritis in this time period, for an incidence rate of 0.32%, which is comparable to other estimates in the English literature. The typical course for cases of bacterial superinfection involves a second peak of high fever; other clinical signs are variable. Conclusions: Septicemia after rotavirus gastroenteritis is a rare but dangerous entity. Early identification of a child developing bacterial superinfection after rotavirus, as in any case of sepsis, is of the utmost importance, as is obtaining blood cultures in a child with a rotavirus infection and a second fever spike.
Background: The worldwide introduction of pneumococcal conjugate vaccines (PCV) into National Imm... more Background: The worldwide introduction of pneumococcal conjugate vaccines (PCV) into National Immunization Programs resulted in rapid and substantial reduction of invasive pneumococcal disease (IPD) rates in children. However, the reduction of meningitis vs. non-meningitis IPD (nm-IPD) was not yet fully elucidated. We compared 7-valent and 13-valent PCV (PCV7 and PCV13) impact on pneumococcal-meningitis vs. nm-IPD in Israeli children <5 years. Methods: We conducted an ongoing nationwide, prospective, population-based, active surveillance. PCV7 and PCV13 were implemented in Israel in July 2009 and November 2010, respectively. All pneumococcal isolates (blood and/or CSF) from IPD episodes in children <5 years from July 2000 through June 2015 were included. Extrapolation for missing serotypes (34.7% of all isolates) was conducted. Results: 4163 IPD cases were identified; 3739 nm-IPD (89.8%) and 424 meningitis (10.2%). During the pre-PCV period (2000-2008), children <12 months constituted 52.1% and 33.7% of meningitis and nm-IPD, respectively (p < 0.001). The respective proportions of non-PCV13 serotypes (non-VT) were 18.2% vs. 10.1%, (p < 0.001). Comparing the last study year (2014-2015) to the mean of pre-PCV period, meningitis incidence in children <5 years decreased non-significantly by 27%, while nm-IPD decreased significantly by 69%. Dynamic rates of meningitis and nm-IPD caused by PCV13 serotypes were similar, with 93% and 95% overall reductions, respectively. However, non-VT increased in meningitis relatively to nm-IPD, mainly in children <24 months. Serotype 12F rose sharply and significantly since 2009-2010 through 2014-2015 (28.6% of all non-VT meningitis in children <24 m). Conclusions: The overall impact of PCV7/PCV13 in children <5 years in Israel was less prominent in meningitis than in nm-IPD. This could be attributed to the younger age of children with meningitis and differences in causative serotypes between the two groups, as the decline of the incidence of meningitis and nm-IPD caused by vaccine-serotypes is similar. Continuous monitoring of meningitis and nm-IPD is warranted.
S. Aviner *, M. Kalinin , R. Braunstein , M. Schlesinger a,b Department of Paediatrics, The Barzi... more S. Aviner *, M. Kalinin , R. Braunstein , M. Schlesinger a,b Department of Paediatrics, The Barzilai Medical Centre, Ashkelon, Israel b Faculty of Health Sciences, Ben-Gurion University of the Negev, The Barzilai Medical Center Campus, Ashkelon, Israel Paediatric Intensive Care Unit, Dana Children’s Hospital, Tel Aviv, Israel Sackler School of Medicine, Tel-Aviv University, Tel Aviv, Israel e Independent Statistical Consultant for Biomedical Studies, Tel Aviv, Israel
Induction of donor type chimerism in mildly prepared hosts without graft-versus-host disease (GvH... more Induction of donor type chimerism in mildly prepared hosts without graft-versus-host disease (GvHD) is a most desirable goal in bone morrow transplantation. We have recently demonstrated in a mouse model that donor veto cytotoxic T lymphocytes (CTLs) can facilitate the induction of donor type chimerism in sublethally irradiated recipients without causing GvHD if they are effectively depleted of alloreactivity against host cells by means of stimulation against a third party. We extend this approach to human cells, by preparing CTLs in two major steps: primary culture in the absence of interleukin 2, leading to death by neglect of antihost clones, and addition of interleukin 2 and subsequent dilution of antihost clones as a consequence of the expansion of the anti-third-party clones. CTLs prepared in this way specifically suppress host cytotoxic T cells directed against antigens of the donor, but not against fourth-party antigens, as demonstrated in a standard 51 Cr release assay. We conclude that human anti-third-party CTLs afford a new source of veto cells that are depleted of potential graft-versus-host-reactive clones. The cells generated by this approach could potentially be used to facilitate engraftment of allogeneic hematopoietic stem cells.
Langerhans cell histiocytosis (LCH) in premature babies is extremely rare as is a vesicular skin ... more Langerhans cell histiocytosis (LCH) in premature babies is extremely rare as is a vesicular skin rash, while gastrointestinal involvement is associated with a poor outcome. We report a case of LCH in a premature baby presented with isolated vesiculo‐papulo‐macular skin lesions and insidiously developed gastrointestinal symptoms, haematological and severe pulmonary involvement. We also reviewed a few cases of LCH in premature babies in the English language medical literature. LCH in preterm babies appears to be a severe systemic disease, usually lethal in‐utero or post delivery.Conclusion: Careful observation should be applied to newborns with skin‐only Langerhans cell histiocytosis in order to identify in time progression to potentially fatal systemic disease.
Establishment of cell lines capable of killing leukemia cells, in the absence of alloreactivity a... more Establishment of cell lines capable of killing leukemia cells, in the absence of alloreactivity against normal host cells, represents a most desirable goal in bone marrow transplantation (BMT) and cancer immunotherapy. By using a human 3 mouse chimeric model, we demonstrate that allogeneic anti-thirdparty cytotoxic T lymphocytes (CTLs) depleted of alloreactivity are endowed with a potent anti-B-cell chronic lymphocytic leukemia (B-CLL) reactivity. Likewise, CTL preparations generated from autologous T cells of the same patients with B-CLL exhibited comparable leukemia eradication, suggesting that the reactivity of allogeneic antithird-party CTLs is not mediated by residual antihost clones. This specificity was also exhibited in vitro, and annexin staining revealed that B-CLL killing is mediated by apoptosis. While the CTLs killing of third-party cells could be blocked by anti-CD3 antibody, the lysis of the B-CLL cells was not inhibited by this antibody, suggesting a T-cell receptor (TCR)-independent cytotoxicity. The role of cell contact leading to apoptosis of B-CLL cells is shown in transwell plates and by anti-lymphocyte function-associated antigen-1 (LFA-1)blocking antibody. Up-regulation of CD54 and the subsequent apoptosis of B-CLL cells depend on the initial LFA-1/ ICAM-1 (intercellular adhesion molecule 1) interaction. Taken together, these results suggest that allogeneic or autologous host nonreactive anti-thirdparty CTLs may represent a new therapeutic approach for patients with B-CLL. (Blood. 2005;105:3365-3371)
Establishment of cell lines capable of killing malignant cells, in the absence of alloreactivity ... more Establishment of cell lines capable of killing malignant cells, in the absence of alloreactivity against normal hematopoietic host cells, represents a most desirable goal in bone marrow transplantation (BMT) and in cancer immunotherapy. We have recently shown, that allogeneic anti third party CTLs depleted of alloreactivity against host cells, are endowed with a potent anti B-CLL reactivity in vitro and in-vivo (Arditi F et al. Blood. 2004 Jul 6, Epub ahead of print). While the ‘conventional’ killing of target cells of the stimulator cell origin could be blocked by anti-CD3 antibody (OKT3), the lysis of the B-CLL cells was not inhibited by this antibody, suggesting a TCR independent cytotoxicity. Annexin staining revealed that this killing is mediated by apoptosis. In the present study we extended our finding and investigated the potential of anti-third party CTLs to eradicate other B cell malignancies, testing in-vitro their capacity to kill 3 different B-cell lymphoma lines. Apoptosis of tumor cells was followed by annexin staining, and reduction in cell number was determined by cytofluorimetry of CD20+ positive cells. Human anti-third party CTLs were prepared as previously described by Arditi et al. and cultured for different periods with two human B cell Burkitt’s lymphoma lines (BL-44, and Namalwa) and one Mantle cell lymphoma line (Grantas). In order to avoid cross reactivity between the lymphoma lines and the stimulators used for preparing CTLs, their HLA Class 1 was deliberately mismatched. As previously found for B-CLL, in 4 different experiments the CTLs lysed a mean of 93%±8.4% of targets of stimulator origin within 4 hours. Upon addition of anti OKT3 antibody cytotoxicity was reduced to 25±26. In contrast, substantial killing of lymphoma lines was initially detected only after 24 hours and peaked at 72 hours (In 3 experiments a mean of 99%±0.5%, 80±20 and 62±31 was found for Grantas, Namlva and BL-44, respectively). This killing could be blocked by anti-LFA1 antibody when tested against the Grantas line targets (26±22% killing) but it was not inhibited by the OKT3 antibody (98%±2 killing), suggesting a TCR independent mechanism. The unique activation status of in-vitro expanded CTLs which express high levels of FasL and other death molecules might be responsible for the killing of B cell malignancies, provided initial binding is sufficiently prolonged, to allow for apoptosis to occur. Thus, adhesion mediated by LFA1 might contribute the additional avidity required to compensate for the lack of TCR recognition, so as to initiate close contact upon which the apoptotic machinery can be triggered. Taken together, these results suggest that the use of allogeneic host non-reactive anti-third party CTLs might be extended from B-CLL to include lymphoma patients. The potential of this surprisingly strong GVT reactivity as a new therapeutic approach should be further explored in preclinical models and for a wide range of hematopoietic malignancies.
In all, 15–30% of pediatric immune thrombocytopenia (ITP) patients will remain chronically thromb... more In all, 15–30% of pediatric immune thrombocytopenia (ITP) patients will remain chronically thrombocytopenic at 1 year post diagnosis. All attempts to classify patients at diagnosis have proven unsuccessful. We hypothesized that a different pathophysiology is responsible for non-chronic versus chronic pediatric ITP. We aimed to examine differences in the apoptotic markers’ presentation at diagnosis between non-chronic and chronic patients. Blood samples were collected from 42 pediatric patients with newly diagnosed ITP prior to initiation of treatment. We incubated patients’ sera with control platelets and compared the results among three research groups: healthy controls, chronic ITP, and non-chronic ITP patients. We measured apoptotic markers phosphatidylserine (PS) exposure and mitochondrial inner membrane potential (ΔΨm) by flow cytometry and the level of human apoptotic proteins by Human Apoptosis Array. We found increased platelet PS exposure and decreased ΔΨm in response to all ITP patients’ sera compared to control subjects. Human Apoptotic Array revealed an increased expression of five apoptotic proteins: BIM, CD40, IGFBP2, P21, and SMAC, following sera incubation of non-chronic pediatric ITP patients, compared to chronic patients’ sera, at diagnosis. Our data contribute to knowledge on apoptosis markers that may aid in predicting the prognosis of children with ITP. The key message of our article is that children with chronic ITP have a different apoptotic profile compared to non-chronic ITP. Addition to existing literature: This is the first study comparing apoptotic markers between children with chronic ITP to non-chronic ITP. Impact: Our findings indicate that, in the future, apoptotic markers may help to classify ITP patients into non-chronic versus chronic ones, at diagnosis. The key message of our article is that children with chronic ITP have a different apoptotic profile compared to non-chronic ITP. Addition to existing literature: This is the first study comparing apoptotic markers between children with chronic ITP to non-chronic ITP. Impact: Our findings indicate that, in the future, apoptotic markers may help to classify ITP patients into non-chronic versus chronic ones, at diagnosis.
Essential Thrombocytosis (ET) is rare in children and its clinical course is considered to be dif... more Essential Thrombocytosis (ET) is rare in children and its clinical course is considered to be different from the adult disease. Unlike adults, most children with ET do not need treatment; however, children with extreme thrombocytosis present the treating physician with a therapeutic dilemma. We report a girl with a spontaneous resolution of extreme essential thrombocytosis. A 13 year old previously healthy girl presented to our ER with a 3 months history of intermittent mild abdominal pain with short episodes of diarrhea, intermittent episodes of paraesthesia in lower limbs and 3000 × 109/L platelets on CBC with pseudohyperkalemia of 6.4 mEq/L. Physical examination was unremarkable except for some diffuse mild tenderness on abdominal palpation. Laboratory work-up revealed normal WBC and Hb, Platelets 4100 × 109/L, mild microcytosis, Iron - 21.9 mcg/dL, transferin saturation 5.6%, serum potassium − 6.5 mEq/L, LDH 1000 IU. Liver, renal and thyroid function tests were within normal limits. PTT was mildly elevated 49.3 seconds (normal – 24.3–35), LAC-R mildly positive – 1.205 (0.8–1.20), KCT 58.2 sec. Anticardiolipin IgG −4.82 U/ml (negative), IgM - 11.24 U/ml (negative &amp;amp;lt; 7 U/ml). Anti dsDNA and Anti nuclear antibodies were negative. Studies for hypercoagulable state included Protein C, Antitrombin, Factor VIII, IX, XI, Factor V R506Q, and Apolipoprotein a; all were normal. A heterozygosity for PT G20210A was found, as well as homozygosity for MTHFR C667T with a normal level of Homocysteine (7.7mmole/L). Bone marrow aspiration showed increased cellularity of all cell lines, with many young megakaryocytes including some in clusters. No malignant cells were seen. Reticulin score on bone marrow biopsy was 0. Platelets function tests with adenosine di-phosphate and epinephrine were normal. Serum TPO level was 31.0 pg/ml (normal). A karyotype examination revealed a normal 46XX female. FISH for BCR/ABL was negative. DNA mutations for JAK2 on both the 12 and the14 exons and c-mpl mutations were not found. Spontaneous clone formation was normal. Helicobacter pylori IgG was 2.89 U/ml (normal) and stool was negative for parasites. Imaging studies included high resolution abdominal contrast CT scan, upper gastrointestinal tract imaging with gastrografin, Doppler sonography of splanchnic vessels and capsule endoscopy; all were interpreted as normal. Aspirin 75 mg/d was started without antimetabolite therapy. Abdominal pain and diarrhea gradually improved. After 3 month of antiagregant therapy, platelets count declined, gradually but steadily. One year after presentation the child is asymptomatic with platelet count of 600 × 109/L. The spontaneous remission of the extreme ET achieved by conservative treatment with no complications adds to the growing evidence, that childhood ET is a unique entity with different biology than adult ET, which might not need antimetabolite therapy.
Background and aims: Coe et al (2007) reported that maternal stress in monkeys during pregnancy i... more Background and aims: Coe et al (2007) reported that maternal stress in monkeys during pregnancy is a risk factor for iron deficiency in infancy. The purpose of the present study was to compare cord ferritin concentration in newborns whose mothers were resident in a war zone during the first trimester of pregnancy (stress group) to those of newborns whose mothers became pregnant after the war (control group). Methods: One-hundred forty healthy mothers with no perinatal complications were recruited for the study in the delivery room. Sixty-three mothers were resident in a war zone during the first trimester of pregnancy and 77 became pregnant after the war. Cord-blood samples were taken to assess neonate iron status. Mothers were interviewed one day after delivery. Assessments of subjective stress during pregnancy were measured by a visual analog scale. Results: Cord Ferritin levels were lower for the stress group compared with the control group (145.71±61.9 and 169.26±85.4; p=.06). A Q-Q plot of the distribution of cord ferritin showed a clear separation between the two groups beginning with the third centile. From the fourth centile on the ferritin cord concentrations in the control group were always above that of the stress group (p< .1 by Kolmogorov-Smirnov goodness-of-fit test). Hierarchic regression showed that subjective stress predicts cord Ferritin overall (β=-.18, p< .05), and specifically in the stress group (β=-.37, p,.01). Conclusion: Our findings indicate that maternal subjective long-term stress during the first trimester of pregnancy is associated with lower concentrations of cord serum Ferritin.
Induction of donor type chimerism under reduced intensity conditioning in the absence of GVHD rep... more Induction of donor type chimerism under reduced intensity conditioning in the absence of GVHD represents a major challenge in transplantation biology. Despite their remarkable potent veto activity, CD8 CTLs could not be used to enhance engraftment due to their GVH reactivity. To address this problem we developed a new approach for the generation of human host-nonreactive CTLs, based on stimulation of donor CD8 T cells against 3rd party stimulators under IL-2 deprivation. A major attribute of such anti-3rd party CTLs reported recently by our group is their ability to eradicate pathological B-CLL cells. This B-CLL killing was shown to be independent of TCR recognition and it was found to be mediated both by autologous and by allogeneic anti-3rd party CTLs. In the present study we demonstrate that anti-3rd party CTLs can also efficiently eradicate primary mantle lymphoma cells and Burkitt and mantle cell-lines. Furthermore, the use of lymphoma cell lines has enabled to define several aspects of the mechanism leading to their apoptosis. Thus, we found that anti-3rd party CTLs avidly bind to target lymphoma cells and form stable aggregates within the first minutes of contact. Conjugate formation as well as the actual killing of the tumor cells were effectively inhibited by blocking antibodies against LFA1 or ICAM1 but not against ICAM3. Moreover, effective inhibition was attained only when applying anti-LFA1 to the CTLs and anti-ICAM1 to the tumor cells (100%±10% and 72%±7% inhibition, respectively) but not vice-versa. Given the role of CD8-MHC class I interaction in veto mechanisms, we sought to evaluate its role in the killing of lymphoma cells by human anti-3rd party CTLs. Indeed, in 10 experiments survival of target lymphoma cells was increased from 50%±5% to 82%±1% upon addition of anti HLA-ABC Ab to the incubation with anti 3rd party CTLs. A similar survival increase to 77.5%±1% was found upon the addition of anti-CD8 Ab, suggesting that CD8 binding to MHC class I constant region is required for lymphoma cell killing. The important role of MHC class I was further established by comparing CTL-mediated killing of Daudi lymphoma cells lacking cell surface MHC class I expression and Daudi cells with reconstituted surface MHC class I due to stable β2-microglobulin overexpression (β2m-Daudi). Thus in contrast to the poor killing of Daudi cells which did not exceed 20%, the β2m-Daudi cell killing was comparable to that exhibited with burkitt lymphoma line expressing MHC class1 (56%±1% and 63%±3%, respectively in 4 experiments). Importantly, FACS analysis showed that, MHC I expression did not influence conjugate formation, but was rather involved in the induction of apoptosis (annexin V). Furthermore, a similar pattern was also found in vivo when β2m-Daudi or Daudi cells were infused into the peritoneum of SCID mice in the presence or absence of a 2.5-fold excess of anti 3rd party CTLs. In 3 experiments, FACS analysis of the cells recovered from the peritoneum showed that the CTLs killed 91% of the β2m-Daudi cells as opposed to 13% killing of the Daudi cells. Taken together, our results suggest that TCR independent killing of B cell malignancies by anti-3rd party CTLs is mediated via a rapid adhesion through ICAM1-LFA1 binding, followed by slow induction of apoptosis upon a critical interaction between CD8 on the CTL and MHC class I on the tumor cell.
Essential thrombocytosis (ET) is rare in children, sometimes difficult to be distinguished from s... more Essential thrombocytosis (ET) is rare in children, sometimes difficult to be distinguished from secondary thrombocytosis. This report concerns 2 children with extreme thrombocytosis of 4100 × 10(9)/L and 1644 × 10(9)/L with partial and complete remission at 3 months and 4 years from diagnosis, with a follow-up of 4 and 17 years, respectively, with no cytoreduction therapy. Diagnosis of ET was suggested according to accepted criteria. However, spontaneous remission of the thrombocytosis argues for the diagnosis of secondary thrombocytosis. These patients highlight the complexity of distinguishing childhood ET from secondary thrombocytosis and the need for cautious personalized decision on cytoreduction therapy.
Background: Inherited platelet deficiency and/or dysfunction may be more common in the general po... more Background: Inherited platelet deficiency and/or dysfunction may be more common in the general population than has previously been appreciated. In 2013 the Israeli Inherited Platelet Disorder (IPD) Registry was established. Methods: Clinical and laboratory data were collected to pre-specified registration forms. The study protocol was approved by the local hospital ethics committees. Results: To date we have included in the registry 89 patients (male 52%) from 79 families. Most patients (74%) have a not-yet specified inherited thrombocytopenia (n = 39) or non-specific platelet function disorder (n = 27). Full clinical data were available for 81 (91%) patients. The median (range) age at presentation and time of follow-up were 1.8 years (1 day-17.8 years) and 4.7 (0-26) years, respectively. The Pediatric Bleeding Questionnaire was available for 78 patients; abnormal bleeding score (≥2) was recorded in 47 (52.8%, 95% CI 42%-63.5%) patients and was less frequent in patients followed for isolated thrombocytopenia. Abnormal score was associated with a longer time of follow-up, OR 1.19 (95% CI 1.04-1.36). Conclusion: Long term follow-up of patients with IPDs is important as bleeding risks may increase with time. We expect that clinical and laboratory information of patients/families with IPDs gathered in a systemic format will allow for better diagnosis and treatment of these patients.
Journal of Pediatric Hematology Oncology, May 1, 2014
Hemophagocytic lymphohistiocytosis (HLH) denotes the common final pathway of a potentially fatal ... more Hemophagocytic lymphohistiocytosis (HLH) denotes the common final pathway of a potentially fatal hyperinflammatory condition of diverse etiologies. We describe the first case of documented HLH associated with human parechovirus 3. A monoallelic Ala91Val mutation was found in the PRF1 gene, but the contribution of this mutation to HLH remains controversial. The diagnosis, based on accepted criteria, was established early in the course of the disease and led to successful treatment and complete recovery. The awareness of this new association is clinically important in facilitating early treatment, preventing organ damage, and increasing the likelihood of complete recovery.
Mycoplasma pneumonia (M. pneumonia) is usually not considered among the several pathogens that in... more Mycoplasma pneumonia (M. pneumonia) is usually not considered among the several pathogens that induce immune thrombocytopenic purpura (ITP). We report a case of a child with a clinical diagnosis of severe ITP (as defined by the American Society of Hematology panel guidelines of 1994), that was associated with M. pneumonia pneumonia, and reviewed the few cases described in the English literature. A 7-year-old girl was admitted to the pediatric department with 1 day history of fever, purpura and petechiae on her legs, buttocks, arms, face, hard palate, oral mucous membranes and lips. Crepitations were heard over both lungs’ lower fields. Complete blood count revealed WBC of 22.3×103/ μL, Hemoglobin of 11.1 gr/dL, and platelet count of 2×103/μL. Red cells appeared normal on blood film with no features of microangiopathy. A chest X-ray demonstrated right middle lobe infiltrate. Presumptive diagnoses of ITP and RML pneumonia were made and treatment was initiated with one dose of IVIG 0.8 g/kg and daily IV Ceftriaxon at 50 mg/kg. Twelve hours after the IVIG administration, platelet count was 1.2×103/μL. Bone marrow examination revealed normal cellularity with young megakaryocytes, compatible with the diagnosis of ITP. Since there was no response to IVIG, Methylprednisolone 4 mg/ kg for 4 days was started. An extensive search of the literature for ITP or thrombocytopenia and pneumonia retrieved only 7 case reports. In all cases M. pneumonia was the only identified pathogen. Therefore, clarithromycin 15 mg/kg/d was added to the treatment regimen, prior to obtaining the serology results. Thereafter severe hemoptysis developed; the patient was admitted to the PICU and received 4 units of platelets and a second dose of IVIG. Hemoptysis resolved after another day, when the platelet count started to increase gradually, only to drop after the cessation of steroids. A second course of steroids at the same dose was begun and tapered off gradually over 21 days, while the platelet count steadily increased, exceeding 150×103/μL at 4 weeks from presentation. A positive Mycoplasma IgM titer at diagnosis and a 1:160 titer at 2 months confirmed the clinical diagnosis. The child is by now 20 months after the event with normal CBC. Several features of the 8 cases described (including our case) distinguish them from “classic” ITP: Thrombocytopenia occurred concomitantly with the infection as opposed to a few days to a few weeks interval between infection and ITP. Severe bleeding in 4 out of 8 patients including 2 with fatal intracranial hemorrhage in contrast to around 3% severe bleeding and around 1‰ fatal intracranial hemorrhage in “classic” ITP. Three of the authors who looked for specific anti-platelet antibodies were unable to demonstrate it, whereas such antibodies are found in many patients with ITP. Several mechanisms are suggested to explain these differences; though it remains unclear whether Mycoplasma associated thrombocytopenia represents a subset of ITP or constitutes a separate entity. We conclude that M. pneumonia should be looked for in any case of pneumonia and thrombocytopenia or ITP, and early specific anti-Mycoplasma therapy should be initiated to rapidly eliminate the causative agent. This may enhance recovery of the platelet count and decrease the rate of complications.
Introduction: Many premature and full-term newborns receive prophylactic platelet transfusions to... more Introduction: Many premature and full-term newborns receive prophylactic platelet transfusions to prevent bleeding, particularly the most prevalent one, i.e, intracranial hemorrhages. However, the platelet count threshold above which bleeding is prevented and the efficacy of platelet transfusion in thrombocytopenic neonates, have yet to be established. Therefore, inter-Neonatal Intensive Care Units (NICU) variations in treatment indications and practices are expected. Considerable inter-NICU variations will emphasize the need for guidelines on platelet transfusions to neonates and premature infants. Aims: To examine platelet products selection and indications for transfusion among neonatologists in Israel. Research and Methods: Electronic questionnaires addressing the choice of platelet products and the platelet count threshold for transfusion in various clinical settings were sent to 25 neonatal units. Results: All 25 neonatal units responded (100% response rate). There was considerable variation in product selection among the different neonatal units. Up to 24% of the participating units reported selecting nontraditional products. Variation was also found in thresholds for platelet transfusion - several units used high thresholds while others used low ones. Traditional guidelines were followed in up to 64% of cases in selected clinical scenarios. Conclusions: There is considerable variation in both platelet product selection and platelet count thresholds for transfusion among the different neonatal units. Discussion: A low threshold for platelet transfusion increases the risk for bleeding, whereas a high threshold increases the prevalence of complications from transfusion of blood products. Adherence to guidelines may prevent both such sequelae. Summary: Such variation in platelet transfusion among neonatologists emphasizes the need for an accepted policy. We recommend setting up a committee of neonatologists, pediatric hematologists and blood service experts which aims to establish an appropriate policy regarding the prevention of platelet transfusion sequelae in newborns.
Inherited bone marrow failure syndromes are rare genetic disorders characterized by bone marrow f... more Inherited bone marrow failure syndromes are rare genetic disorders characterized by bone marrow failure, congenital anomalies, and cancer predisposition. Available single disease registries provide reliable information regarding natural history, efficacy and side effects of treatments, and contribute to the discovery of the causative genes. However, these registries could not shed light on the true incidence of the various syndromes. We, therefore, established an Israeli national registry in order to investigate the relative frequency of each of these syndromes and their complications. Design and Methods Patients were registered by their hematologists in all 16 medical centers in Israel. We included patients with Fanconi anemia, severe congenital neutropenia, Diamond-Blackfan anemia, congenital amegakaryocytic thrombocytopenia, dyskeratosis congenita, Shwachman-Diamond syndrome, and thrombocytopenia with absent radii. Results One hundred and twenty-seven patients diagnosed between 1966 and 2007 were registered. Fifty-two percent were found to have Fanconi anemia, 17% severe congenital neutropenia, 14% Diamond-Blackfan anemia, 6% congenital amegakaryocytic thrombocytopenia, 5% dyskeratosis congenita, 2% Shwachman-Diamond syndrome, and 2% thrombocytopenia with absent radii. No specific diagnosis was made in only 2 patients. Of the thirty patients (24%) developing severe bone marrow failure, 80% had Fanconi anemia. Seven of 9 patients with leukemia had Fanconi anemia, as did all 6 with solid tumors. Thirty-four patients died from their disease; 25 (74%) had Fanconi anemia and 6 (17%) had severe congenital neutropenia. Conclusions This is the first comprehensive population-based study evaluating the incidence and complications of the different inherited bone marrow failure syndromes. By far the most common disease was Fanconi anemia, followed by severe congenital neutropenia and Diamond-Blackfan anemia. Fanconi anemia carried the worst prognosis, with severe bone marrow failure and cancer susceptibility. Diamond-Blackfan anemia had the best prognosis. The data presented provide a rational basis for prevention programs and longitudinal surveillance of the complications of inherited bone marrow failure syndromes.
Background: Rotavirus gastroenteritis is a prevalent childhood illness rarely complicated by seco... more Background: Rotavirus gastroenteritis is a prevalent childhood illness rarely complicated by secondary bacterial sepsis. Although there are case reports of septicemia after rotavirus infection, there are no recent reviews on this topic. Objectives: To add new cases of septicemia after rotavirus to the literature, review the few cases of septicemia after rotavirus that have been reported, calculate the incidence of septicemia in children hospitalized for rotavirus gastroenteritis, and discuss the characteristics of septicemia after rotavirus infection and implications for current pediatric practice. Methods: We identified children whose illness was complicated by septicemia from among all hospitalizations at our facility for rotavirus gastroenteritis from May 1999 through May 2010. We also review the few cases reported in the English literature. Results: We identified two cases of septicemia from among 632 hospitalizations for rotavirus gastroenteritis in this time period, for an incidence rate of 0.32%, which is comparable to other estimates in the English literature. The typical course for cases of bacterial superinfection involves a second peak of high fever; other clinical signs are variable. Conclusions: Septicemia after rotavirus gastroenteritis is a rare but dangerous entity. Early identification of a child developing bacterial superinfection after rotavirus, as in any case of sepsis, is of the utmost importance, as is obtaining blood cultures in a child with a rotavirus infection and a second fever spike.
Background: The worldwide introduction of pneumococcal conjugate vaccines (PCV) into National Imm... more Background: The worldwide introduction of pneumococcal conjugate vaccines (PCV) into National Immunization Programs resulted in rapid and substantial reduction of invasive pneumococcal disease (IPD) rates in children. However, the reduction of meningitis vs. non-meningitis IPD (nm-IPD) was not yet fully elucidated. We compared 7-valent and 13-valent PCV (PCV7 and PCV13) impact on pneumococcal-meningitis vs. nm-IPD in Israeli children <5 years. Methods: We conducted an ongoing nationwide, prospective, population-based, active surveillance. PCV7 and PCV13 were implemented in Israel in July 2009 and November 2010, respectively. All pneumococcal isolates (blood and/or CSF) from IPD episodes in children <5 years from July 2000 through June 2015 were included. Extrapolation for missing serotypes (34.7% of all isolates) was conducted. Results: 4163 IPD cases were identified; 3739 nm-IPD (89.8%) and 424 meningitis (10.2%). During the pre-PCV period (2000-2008), children <12 months constituted 52.1% and 33.7% of meningitis and nm-IPD, respectively (p < 0.001). The respective proportions of non-PCV13 serotypes (non-VT) were 18.2% vs. 10.1%, (p < 0.001). Comparing the last study year (2014-2015) to the mean of pre-PCV period, meningitis incidence in children <5 years decreased non-significantly by 27%, while nm-IPD decreased significantly by 69%. Dynamic rates of meningitis and nm-IPD caused by PCV13 serotypes were similar, with 93% and 95% overall reductions, respectively. However, non-VT increased in meningitis relatively to nm-IPD, mainly in children <24 months. Serotype 12F rose sharply and significantly since 2009-2010 through 2014-2015 (28.6% of all non-VT meningitis in children <24 m). Conclusions: The overall impact of PCV7/PCV13 in children <5 years in Israel was less prominent in meningitis than in nm-IPD. This could be attributed to the younger age of children with meningitis and differences in causative serotypes between the two groups, as the decline of the incidence of meningitis and nm-IPD caused by vaccine-serotypes is similar. Continuous monitoring of meningitis and nm-IPD is warranted.
S. Aviner *, M. Kalinin , R. Braunstein , M. Schlesinger a,b Department of Paediatrics, The Barzi... more S. Aviner *, M. Kalinin , R. Braunstein , M. Schlesinger a,b Department of Paediatrics, The Barzilai Medical Centre, Ashkelon, Israel b Faculty of Health Sciences, Ben-Gurion University of the Negev, The Barzilai Medical Center Campus, Ashkelon, Israel Paediatric Intensive Care Unit, Dana Children’s Hospital, Tel Aviv, Israel Sackler School of Medicine, Tel-Aviv University, Tel Aviv, Israel e Independent Statistical Consultant for Biomedical Studies, Tel Aviv, Israel
Induction of donor type chimerism in mildly prepared hosts without graft-versus-host disease (GvH... more Induction of donor type chimerism in mildly prepared hosts without graft-versus-host disease (GvHD) is a most desirable goal in bone morrow transplantation. We have recently demonstrated in a mouse model that donor veto cytotoxic T lymphocytes (CTLs) can facilitate the induction of donor type chimerism in sublethally irradiated recipients without causing GvHD if they are effectively depleted of alloreactivity against host cells by means of stimulation against a third party. We extend this approach to human cells, by preparing CTLs in two major steps: primary culture in the absence of interleukin 2, leading to death by neglect of antihost clones, and addition of interleukin 2 and subsequent dilution of antihost clones as a consequence of the expansion of the anti-third-party clones. CTLs prepared in this way specifically suppress host cytotoxic T cells directed against antigens of the donor, but not against fourth-party antigens, as demonstrated in a standard 51 Cr release assay. We conclude that human anti-third-party CTLs afford a new source of veto cells that are depleted of potential graft-versus-host-reactive clones. The cells generated by this approach could potentially be used to facilitate engraftment of allogeneic hematopoietic stem cells.
Langerhans cell histiocytosis (LCH) in premature babies is extremely rare as is a vesicular skin ... more Langerhans cell histiocytosis (LCH) in premature babies is extremely rare as is a vesicular skin rash, while gastrointestinal involvement is associated with a poor outcome. We report a case of LCH in a premature baby presented with isolated vesiculo‐papulo‐macular skin lesions and insidiously developed gastrointestinal symptoms, haematological and severe pulmonary involvement. We also reviewed a few cases of LCH in premature babies in the English language medical literature. LCH in preterm babies appears to be a severe systemic disease, usually lethal in‐utero or post delivery.Conclusion: Careful observation should be applied to newborns with skin‐only Langerhans cell histiocytosis in order to identify in time progression to potentially fatal systemic disease.
Establishment of cell lines capable of killing leukemia cells, in the absence of alloreactivity a... more Establishment of cell lines capable of killing leukemia cells, in the absence of alloreactivity against normal host cells, represents a most desirable goal in bone marrow transplantation (BMT) and cancer immunotherapy. By using a human 3 mouse chimeric model, we demonstrate that allogeneic anti-thirdparty cytotoxic T lymphocytes (CTLs) depleted of alloreactivity are endowed with a potent anti-B-cell chronic lymphocytic leukemia (B-CLL) reactivity. Likewise, CTL preparations generated from autologous T cells of the same patients with B-CLL exhibited comparable leukemia eradication, suggesting that the reactivity of allogeneic antithird-party CTLs is not mediated by residual antihost clones. This specificity was also exhibited in vitro, and annexin staining revealed that B-CLL killing is mediated by apoptosis. While the CTLs killing of third-party cells could be blocked by anti-CD3 antibody, the lysis of the B-CLL cells was not inhibited by this antibody, suggesting a T-cell receptor (TCR)-independent cytotoxicity. The role of cell contact leading to apoptosis of B-CLL cells is shown in transwell plates and by anti-lymphocyte function-associated antigen-1 (LFA-1)blocking antibody. Up-regulation of CD54 and the subsequent apoptosis of B-CLL cells depend on the initial LFA-1/ ICAM-1 (intercellular adhesion molecule 1) interaction. Taken together, these results suggest that allogeneic or autologous host nonreactive anti-thirdparty CTLs may represent a new therapeutic approach for patients with B-CLL. (Blood. 2005;105:3365-3371)
Establishment of cell lines capable of killing malignant cells, in the absence of alloreactivity ... more Establishment of cell lines capable of killing malignant cells, in the absence of alloreactivity against normal hematopoietic host cells, represents a most desirable goal in bone marrow transplantation (BMT) and in cancer immunotherapy. We have recently shown, that allogeneic anti third party CTLs depleted of alloreactivity against host cells, are endowed with a potent anti B-CLL reactivity in vitro and in-vivo (Arditi F et al. Blood. 2004 Jul 6, Epub ahead of print). While the ‘conventional’ killing of target cells of the stimulator cell origin could be blocked by anti-CD3 antibody (OKT3), the lysis of the B-CLL cells was not inhibited by this antibody, suggesting a TCR independent cytotoxicity. Annexin staining revealed that this killing is mediated by apoptosis. In the present study we extended our finding and investigated the potential of anti-third party CTLs to eradicate other B cell malignancies, testing in-vitro their capacity to kill 3 different B-cell lymphoma lines. Apoptosis of tumor cells was followed by annexin staining, and reduction in cell number was determined by cytofluorimetry of CD20+ positive cells. Human anti-third party CTLs were prepared as previously described by Arditi et al. and cultured for different periods with two human B cell Burkitt’s lymphoma lines (BL-44, and Namalwa) and one Mantle cell lymphoma line (Grantas). In order to avoid cross reactivity between the lymphoma lines and the stimulators used for preparing CTLs, their HLA Class 1 was deliberately mismatched. As previously found for B-CLL, in 4 different experiments the CTLs lysed a mean of 93%±8.4% of targets of stimulator origin within 4 hours. Upon addition of anti OKT3 antibody cytotoxicity was reduced to 25±26. In contrast, substantial killing of lymphoma lines was initially detected only after 24 hours and peaked at 72 hours (In 3 experiments a mean of 99%±0.5%, 80±20 and 62±31 was found for Grantas, Namlva and BL-44, respectively). This killing could be blocked by anti-LFA1 antibody when tested against the Grantas line targets (26±22% killing) but it was not inhibited by the OKT3 antibody (98%±2 killing), suggesting a TCR independent mechanism. The unique activation status of in-vitro expanded CTLs which express high levels of FasL and other death molecules might be responsible for the killing of B cell malignancies, provided initial binding is sufficiently prolonged, to allow for apoptosis to occur. Thus, adhesion mediated by LFA1 might contribute the additional avidity required to compensate for the lack of TCR recognition, so as to initiate close contact upon which the apoptotic machinery can be triggered. Taken together, these results suggest that the use of allogeneic host non-reactive anti-third party CTLs might be extended from B-CLL to include lymphoma patients. The potential of this surprisingly strong GVT reactivity as a new therapeutic approach should be further explored in preclinical models and for a wide range of hematopoietic malignancies.
In all, 15–30% of pediatric immune thrombocytopenia (ITP) patients will remain chronically thromb... more In all, 15–30% of pediatric immune thrombocytopenia (ITP) patients will remain chronically thrombocytopenic at 1 year post diagnosis. All attempts to classify patients at diagnosis have proven unsuccessful. We hypothesized that a different pathophysiology is responsible for non-chronic versus chronic pediatric ITP. We aimed to examine differences in the apoptotic markers’ presentation at diagnosis between non-chronic and chronic patients. Blood samples were collected from 42 pediatric patients with newly diagnosed ITP prior to initiation of treatment. We incubated patients’ sera with control platelets and compared the results among three research groups: healthy controls, chronic ITP, and non-chronic ITP patients. We measured apoptotic markers phosphatidylserine (PS) exposure and mitochondrial inner membrane potential (ΔΨm) by flow cytometry and the level of human apoptotic proteins by Human Apoptosis Array. We found increased platelet PS exposure and decreased ΔΨm in response to all ITP patients’ sera compared to control subjects. Human Apoptotic Array revealed an increased expression of five apoptotic proteins: BIM, CD40, IGFBP2, P21, and SMAC, following sera incubation of non-chronic pediatric ITP patients, compared to chronic patients’ sera, at diagnosis. Our data contribute to knowledge on apoptosis markers that may aid in predicting the prognosis of children with ITP. The key message of our article is that children with chronic ITP have a different apoptotic profile compared to non-chronic ITP. Addition to existing literature: This is the first study comparing apoptotic markers between children with chronic ITP to non-chronic ITP. Impact: Our findings indicate that, in the future, apoptotic markers may help to classify ITP patients into non-chronic versus chronic ones, at diagnosis. The key message of our article is that children with chronic ITP have a different apoptotic profile compared to non-chronic ITP. Addition to existing literature: This is the first study comparing apoptotic markers between children with chronic ITP to non-chronic ITP. Impact: Our findings indicate that, in the future, apoptotic markers may help to classify ITP patients into non-chronic versus chronic ones, at diagnosis.
Essential Thrombocytosis (ET) is rare in children and its clinical course is considered to be dif... more Essential Thrombocytosis (ET) is rare in children and its clinical course is considered to be different from the adult disease. Unlike adults, most children with ET do not need treatment; however, children with extreme thrombocytosis present the treating physician with a therapeutic dilemma. We report a girl with a spontaneous resolution of extreme essential thrombocytosis. A 13 year old previously healthy girl presented to our ER with a 3 months history of intermittent mild abdominal pain with short episodes of diarrhea, intermittent episodes of paraesthesia in lower limbs and 3000 × 109/L platelets on CBC with pseudohyperkalemia of 6.4 mEq/L. Physical examination was unremarkable except for some diffuse mild tenderness on abdominal palpation. Laboratory work-up revealed normal WBC and Hb, Platelets 4100 × 109/L, mild microcytosis, Iron - 21.9 mcg/dL, transferin saturation 5.6%, serum potassium − 6.5 mEq/L, LDH 1000 IU. Liver, renal and thyroid function tests were within normal limits. PTT was mildly elevated 49.3 seconds (normal – 24.3–35), LAC-R mildly positive – 1.205 (0.8–1.20), KCT 58.2 sec. Anticardiolipin IgG −4.82 U/ml (negative), IgM - 11.24 U/ml (negative &amp;amp;lt; 7 U/ml). Anti dsDNA and Anti nuclear antibodies were negative. Studies for hypercoagulable state included Protein C, Antitrombin, Factor VIII, IX, XI, Factor V R506Q, and Apolipoprotein a; all were normal. A heterozygosity for PT G20210A was found, as well as homozygosity for MTHFR C667T with a normal level of Homocysteine (7.7mmole/L). Bone marrow aspiration showed increased cellularity of all cell lines, with many young megakaryocytes including some in clusters. No malignant cells were seen. Reticulin score on bone marrow biopsy was 0. Platelets function tests with adenosine di-phosphate and epinephrine were normal. Serum TPO level was 31.0 pg/ml (normal). A karyotype examination revealed a normal 46XX female. FISH for BCR/ABL was negative. DNA mutations for JAK2 on both the 12 and the14 exons and c-mpl mutations were not found. Spontaneous clone formation was normal. Helicobacter pylori IgG was 2.89 U/ml (normal) and stool was negative for parasites. Imaging studies included high resolution abdominal contrast CT scan, upper gastrointestinal tract imaging with gastrografin, Doppler sonography of splanchnic vessels and capsule endoscopy; all were interpreted as normal. Aspirin 75 mg/d was started without antimetabolite therapy. Abdominal pain and diarrhea gradually improved. After 3 month of antiagregant therapy, platelets count declined, gradually but steadily. One year after presentation the child is asymptomatic with platelet count of 600 × 109/L. The spontaneous remission of the extreme ET achieved by conservative treatment with no complications adds to the growing evidence, that childhood ET is a unique entity with different biology than adult ET, which might not need antimetabolite therapy.
Background and aims: Coe et al (2007) reported that maternal stress in monkeys during pregnancy i... more Background and aims: Coe et al (2007) reported that maternal stress in monkeys during pregnancy is a risk factor for iron deficiency in infancy. The purpose of the present study was to compare cord ferritin concentration in newborns whose mothers were resident in a war zone during the first trimester of pregnancy (stress group) to those of newborns whose mothers became pregnant after the war (control group). Methods: One-hundred forty healthy mothers with no perinatal complications were recruited for the study in the delivery room. Sixty-three mothers were resident in a war zone during the first trimester of pregnancy and 77 became pregnant after the war. Cord-blood samples were taken to assess neonate iron status. Mothers were interviewed one day after delivery. Assessments of subjective stress during pregnancy were measured by a visual analog scale. Results: Cord Ferritin levels were lower for the stress group compared with the control group (145.71±61.9 and 169.26±85.4; p=.06). A Q-Q plot of the distribution of cord ferritin showed a clear separation between the two groups beginning with the third centile. From the fourth centile on the ferritin cord concentrations in the control group were always above that of the stress group (p< .1 by Kolmogorov-Smirnov goodness-of-fit test). Hierarchic regression showed that subjective stress predicts cord Ferritin overall (β=-.18, p< .05), and specifically in the stress group (β=-.37, p,.01). Conclusion: Our findings indicate that maternal subjective long-term stress during the first trimester of pregnancy is associated with lower concentrations of cord serum Ferritin.
Induction of donor type chimerism under reduced intensity conditioning in the absence of GVHD rep... more Induction of donor type chimerism under reduced intensity conditioning in the absence of GVHD represents a major challenge in transplantation biology. Despite their remarkable potent veto activity, CD8 CTLs could not be used to enhance engraftment due to their GVH reactivity. To address this problem we developed a new approach for the generation of human host-nonreactive CTLs, based on stimulation of donor CD8 T cells against 3rd party stimulators under IL-2 deprivation. A major attribute of such anti-3rd party CTLs reported recently by our group is their ability to eradicate pathological B-CLL cells. This B-CLL killing was shown to be independent of TCR recognition and it was found to be mediated both by autologous and by allogeneic anti-3rd party CTLs. In the present study we demonstrate that anti-3rd party CTLs can also efficiently eradicate primary mantle lymphoma cells and Burkitt and mantle cell-lines. Furthermore, the use of lymphoma cell lines has enabled to define several aspects of the mechanism leading to their apoptosis. Thus, we found that anti-3rd party CTLs avidly bind to target lymphoma cells and form stable aggregates within the first minutes of contact. Conjugate formation as well as the actual killing of the tumor cells were effectively inhibited by blocking antibodies against LFA1 or ICAM1 but not against ICAM3. Moreover, effective inhibition was attained only when applying anti-LFA1 to the CTLs and anti-ICAM1 to the tumor cells (100%±10% and 72%±7% inhibition, respectively) but not vice-versa. Given the role of CD8-MHC class I interaction in veto mechanisms, we sought to evaluate its role in the killing of lymphoma cells by human anti-3rd party CTLs. Indeed, in 10 experiments survival of target lymphoma cells was increased from 50%±5% to 82%±1% upon addition of anti HLA-ABC Ab to the incubation with anti 3rd party CTLs. A similar survival increase to 77.5%±1% was found upon the addition of anti-CD8 Ab, suggesting that CD8 binding to MHC class I constant region is required for lymphoma cell killing. The important role of MHC class I was further established by comparing CTL-mediated killing of Daudi lymphoma cells lacking cell surface MHC class I expression and Daudi cells with reconstituted surface MHC class I due to stable β2-microglobulin overexpression (β2m-Daudi). Thus in contrast to the poor killing of Daudi cells which did not exceed 20%, the β2m-Daudi cell killing was comparable to that exhibited with burkitt lymphoma line expressing MHC class1 (56%±1% and 63%±3%, respectively in 4 experiments). Importantly, FACS analysis showed that, MHC I expression did not influence conjugate formation, but was rather involved in the induction of apoptosis (annexin V). Furthermore, a similar pattern was also found in vivo when β2m-Daudi or Daudi cells were infused into the peritoneum of SCID mice in the presence or absence of a 2.5-fold excess of anti 3rd party CTLs. In 3 experiments, FACS analysis of the cells recovered from the peritoneum showed that the CTLs killed 91% of the β2m-Daudi cells as opposed to 13% killing of the Daudi cells. Taken together, our results suggest that TCR independent killing of B cell malignancies by anti-3rd party CTLs is mediated via a rapid adhesion through ICAM1-LFA1 binding, followed by slow induction of apoptosis upon a critical interaction between CD8 on the CTL and MHC class I on the tumor cell.
Essential thrombocytosis (ET) is rare in children, sometimes difficult to be distinguished from s... more Essential thrombocytosis (ET) is rare in children, sometimes difficult to be distinguished from secondary thrombocytosis. This report concerns 2 children with extreme thrombocytosis of 4100 × 10(9)/L and 1644 × 10(9)/L with partial and complete remission at 3 months and 4 years from diagnosis, with a follow-up of 4 and 17 years, respectively, with no cytoreduction therapy. Diagnosis of ET was suggested according to accepted criteria. However, spontaneous remission of the thrombocytosis argues for the diagnosis of secondary thrombocytosis. These patients highlight the complexity of distinguishing childhood ET from secondary thrombocytosis and the need for cautious personalized decision on cytoreduction therapy.
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Papers by Shraga Aviner