Revista Americana de Medicina Respiratoria, Jan 3, 2015
Split night. Usefulness and tolerance compared with full-night CPAP titration Introduction: The t... more Split night. Usefulness and tolerance compared with full-night CPAP titration Introduction: The treatment of choice for obstructive sleep apnea / hypopnea syndrome (OSAHS) is the use of continuous positive airway pressure (CPAP). Effective pressure correcting respiratory events must be determined individually for each patient regardless of the method used. It has been suggested that the split-night polysomnography (SNPSN) may not be appropriate to assess the severity of the disease and patients may have a lower adherence to CPAP. Objetives: To evaluate the utility SNPSG study performance. Materials and Methods: Patients with severe OSAHS were evaluated. They were divided into two groups, SNPSG and full night polysomnography (FNPSG). The success or failure of the CPAP titration was evaluated and both groups were compared by age, sex, body mass index (BMI), neck circumference, Epworth scale, respiratory perturbation index (PRI), basal and lowest saturation. Results: 314 patients were evaluated. SNPSG was conducted on 216 patients (68.8%) and FNPSG on 98 patients. Titration was effective and well tolerated in 159 (73.6%) of the patients undergoing PSGSN. In the group of FNPSG, a second study of titration was performed on 73 patients and 25 were absent. In this group Titulación de CPAP en noche partida
Pulmonary Artery Sarcoma Pulmonary artery sarcoma is a rare tumor with lethal prognosis. Its etio... more Pulmonary Artery Sarcoma Pulmonary artery sarcoma is a rare tumor with lethal prognosis. Its etiology is unknown; most frequently the pulmonary trunk and its main branches are affected. Magnetic reso- nance imaging with gadolinium and positron emission tomography are complementary studies that can guide the diagnosis, but this can only be established with the histologi- cal study. We present this case because of the low incidence and its importance in the differential diagnosis of pulmonary thromboembolism.
Introduction: Different COVID-19 vaccines were developed in a short time after the beginning of p... more Introduction: Different COVID-19 vaccines were developed in a short time after the beginning of pandemics, reducing mortality, especially in high risk population. This was demonstrated in several studies, mostly retrospective or based in mathematical models. The objective was to compare mortality in inpatients with COVID-19 related to vaccination. Methods: Longitudinal, prospective, comparative, observational study. Inpatients with COVID-19 diagnosis were included between 17/12/2021 and 23/02/22, in Hospital Nacional Prof. A Posadas and Hospital Interzonal General de Agudos Eva Perón. Results: Inpatients (245) were analyzed, finding an overall mortality of 25.3%, 16.8% in fully vaccinated patients (two or more doses with less than 150 days since the last dose until the COVID-19 test) and 31.9% in those with incomplete vaccination (unvaccinated, one dose or two or more doses with more than 150 days since the last dose) (p = 0.007), OR 2.31 (IC95; 1.25-4.28) for incomplete vaccination. Mortality was 32.2% in patients who developed pneumonia, 22.2% for fully vaccinated and 38% for incompletely vaccinated (p = 0.048), OR 2.15(IC95; 1.01-4.58). Mortality was associated with older age (70 vs. 59 years; p < 0.001), female sex (54.8% vs. 37.7%; p < 0.02) and oncologic disease (27.4 vs. 14.8%; p = 0.02). PESI score was higher in incompletely vaccinated (102.5 vs. 93, p = 0.05) and SOFA score was lower (2 vs. 3, p = 0.01). The necessary number to treat (NNT) to prevent one death was 7 patients for the overall sample (IC95;4-22) and 6 (IC95;3-106) for pneumonia. Discussion: This study constitutes a starting point for developing other investigations and raising awareness of medical community and people about the beneficial effects of vaccination.
Tuberculous pleurisy allows the study of human cells at the site of active Mycobacterium tubercul... more Tuberculous pleurisy allows the study of human cells at the site of active Mycobacterium tuberculosis infection. In this study, we found that among pleural fluid (PF) lymphocytes, natural killer (NK) cells are a major source of early gamma interferon (IFN-␥) upon M. tuberculosis stimulation, leading us to investigate the mechanisms and molecules involved in this process. We show that the whole bacterium is the best inducer of IFN-␥, although a high-molecular-weight fraction of culture filtrate proteins from M. tuberculosis H37Rv and the whole-cell lysate also induce its expression. The mannose receptor seems to mediate the inhibitory effect of mannosylated lipoarabinomannan, and Toll-like receptor 2 and 4 agonists activate NK cells but do not induce IFN-␥ like M. tuberculosis does. Antigen-presenting cells (APC) and NK cells bind M. tuberculosis, and although interleukin-12 is required, it is not sufficient to induce IFN-␥ expression, indicating that NK cell-APC contact takes place. Indeed, major histocompatibility complex class I, adhesion, and costimulatory molecules as well as NK receptors regulate IFN-␥ induction. The signaling pathway is partially inhibited by dexamethasone and sensitive to Ca 2؉ flux and cyclosporine. Inhibition of p38 and extracellular-regulated kinase mitogen-activated protein kinase pathways reduces the number of IFN-␥ ؉ NK cells. Phosphorylated p38 (p-p38) is detected in ex vivo PF-NK cells, and M. tuberculosis triggers p-p38 in PF-NK cells at the same time that binding between NK and M. tuberculosis reaches its maximum value. Thus, interplay between M. tuberculosis and NK cells/APC triggering IFN-␥ would be expected to play a beneficial role in tuberculous pleurisy by helping to maintain a type 1 profile.
Tuberculous pleuritis usually shows lymphocytic preponderance, but neutrophils are also present. ... more Tuberculous pleuritis usually shows lymphocytic preponderance, but neutrophils are also present. Therefore, pleuritis is a good model for the study of neutrophil fate at sites of active Mycobacterium tuberculosis infection. We have previously demonstrated in vitro that M. tuberculosis-induced neutrophil apoptosis involves p38 mitogen protein kinase activation through Toll-like receptor 2. Herein, we demonstrate that, in tuberculous pleuritis, neutrophil apoptosis increases together with the expression of Toll-like receptor 2 and phosphorylated p38 (p-p38) kinase. In addition, receptors associated with activation/apoptotis (CD11b, CD64, tumor necrosis factor receptor, and Fas ligand) are up-regulated, together with a loss of CD16 expression. However, neutrophils express CD86, CD83, and major histocompatibility complex class II antigens, acquiring dendritic cell (DC) characteristics. Therefore, the cytokine milieu in the pleural space may influence signaling pathways on activated neutrophils, thereby inducing apoptosis and inhibiting their proinflammatory capacity, as well as allowing them acquire DC characteristics that influence the immune response. Among the many clinical manifestations of tuberculosis (TB), pleuritis is of particular interest, since it resolves without therapy and patients are known to undergo a relatively effective immune response against Mycobacterium tuberculosis [1]. Pleuritis occurs in ∼10% of untreated individuals who have positive tuberculin test results [2]. However, tuberculous pleuritis may also develop as a complication of primary pulmonary TB [3]. Tuberculous pleuritis is caused by a severe delayed-type hypersensitivity reaction in response to the rupture of a subpleural focus of M. tuberculosis infection and subsequent escape of the bacteria or the antigens into the pleural space [2].
Background: Pandemic influenza A (H1N1) has emerged rapidly in Argentina since May 2009. Prelimin... more Background: Pandemic influenza A (H1N1) has emerged rapidly in Argentina since May 2009. Preliminary comparisons with seasonal influenza suggest that H1N1 disproportionately affects younger patients, generally causing mild disease, but in a minority of cases can be lethal. Objective: The aim of this study was to develop a clinical tool for the initial management of patients with influenza-like syndrome, within the context of the novel H1N1 virus epidemic, to detect patients who need further investigation (e.g., chest X-ray study) for the diagnosis of pneumonia. Methods: We prospectively studied 1090 consecutive patients with influenza-like syndrome for a period of 15 days. Based on the presence of inspiratory crackles and the level of transcutaneous pulse oximetry, we selected 217 patients requiring chest X-ray study, and pneumonia was confirmed in all of these patients. Results: Among the patients with pneumonia, 132 viral diagnostic tests were available, from which specimens tested by real-time reverse-transcriptase polymerase-chain reaction (RTPCR) were positive for H1N1 in 61 patients (46%). Comparison between RTPCRpositive and RTPCR-negative patients did not show any significant difference. Eighty-seven randomly selected patients with influenza-like syndrome, but without crackles and with O 2 saturation > 96%, received chest X-ray studies; none demonstrated pulmonary infiltrates. Conclusion: Within the context of an influenza epidemic with the new H1N1 virus, the use of two simple and accessible clinical signs permits a rapid differentiation between those patients requiring close monitoring vs. those with mild and self-resolving disease.
ABSTRACTTuberculous pleurisy allows the study of human cells at the site of activeMycobacterium t... more ABSTRACTTuberculous pleurisy allows the study of human cells at the site of activeMycobacterium tuberculosisinfection. In this study, we found that among pleural fluid (PF) lymphocytes, natural killer (NK) cells are a major source of early gamma interferon (IFN-γ) uponM. tuberculosisstimulation, leading us to investigate the mechanisms and molecules involved in this process. We show that the whole bacterium is the best inducer of IFN-γ, although a high-molecular-weight fraction of culture filtrate proteins fromM. tuberculosisH37Rv and the whole-cell lysate also induce its expression. The mannose receptor seems to mediate the inhibitory effect of mannosylated lipoarabinomannan, and Toll-like receptor 2 and 4 agonists activate NK cells but do not induce IFN-γ likeM. tuberculosisdoes. Antigen-presenting cells (APC) and NK cells bindM. tuberculosis, and although interleukin-12 is required, it is not sufficient to induce IFN-γ expression, indicating that NK cell-APC contact takes place. ...
ABSTRACTPolymorphonuclear neutrophils (PMN) exposed toMycobacterium tuberculosisdisplay bacterici... more ABSTRACTPolymorphonuclear neutrophils (PMN) exposed toMycobacterium tuberculosisdisplay bactericidal responses and produce inflammatory proteins. This PMN-mediated inflammatory response is regulated by an activation of the apoptotic program, which collaborates to avoid tissue injury. In vitro, circulating PMN from patients with tuberculosis (TB) show an increased spontaneous apoptosis, andM. tuberculosis-induced activation accelerates the PMN apoptosis. In this study, we evaluated the mechanisms involved in spontaneous andM. tuberculosis-induced apoptosis. We demonstrate that apoptosis of PMN is not induced by lipoarabinomannan or by a whole-cell lysate ofM. tuberculosisand that neither tumor necrosis factor alpha nor CD11b, CD14, and Fcγ receptors are involved. Apoptosis of PMN from patients with active TB (TB-PMN) is induced by the interaction with the wholeM. tuberculosisvia Toll-like receptor 2 (TLR2), and, in contrast to spontaneous apoptosis, it involves the p38 mitogen-activa...
Polymorphonuclear neutrophils (PMN) modulate the adaptive immune response through interactions wi... more Polymorphonuclear neutrophils (PMN) modulate the adaptive immune response through interactions with immature dendritic cells (iDC) while spontaneous apoptotic neutrophils (PMNapo) may have an inhibitory effect on DC functions. We investigate the effect exerted by PMNapo in DC maturation and the role of Mycobacterium tuberculosis (Mtb)-induced PMNapo in the cross-presentation of mycobacterial antigens. We demonstrate that Mtb triggers the maturation of iDC while it is impaired by the presence of PMNapo, which abrogate Mtb-induced expression of costimulatory and HLA class II molecules, reducing IL-12 and IFN-c release by DC and partially inhibiting Mtb-driven lymphocyte proliferation. This inhibitory effect is not observed in already Mtb-matured DC, and it involves a direct interaction between DC and PMNapo, as supernatants from PMNapo cultures do not reveal this effect. Although PMNapo do not alter Mtb/DC-SIGN interaction, they affect the intracellular signals leading to DC maturation without requiring their entry into DC. Phagocytosis of Mtb-induced PMNapo by iDC leads to lymphoproliferation, which is significantly reduced by blocking CD36 and not DC-SIGN on iDC. Therefore, cross-presentation of Mtb antigens is taking place. Our findings suggest that the inflammatory milieu is subjected to a fine balance between non-infected and Mtb-induced PMNapo: non-infected PMNapo limiting inflammation and Mtb-induced PMNapo generating a specific immune activity.
Lower lung field tuberculosis. Tuberculosis (TB) that affects lower lung fields (LLFTB) is infreq... more Lower lung field tuberculosis. Tuberculosis (TB) that affects lower lung fields (LLFTB) is infrequent in the adult population and is generally associated with immunodeficiency. The objective of our study was to determine the incidence of llfTB in our patients population and compare the characteristics of these patients with those who presented TB of typical pulmonary localization. We studied 42 patients with llfTB retrospectively between 2004 and 2008 and compared them to 84 patients with TB of typical localization (control group). HIV-positive patients were excluded. LLFTB represented 6% of the pulmonary TB cases. No significant differences were found with respect to age, sex, the presence of cavities in chest x-rays, days of evolution, and albumin levels. LLFTB had a significantly greater proportion of comorbilities (p < 0.001), the presence of con - densation (p < 0.001), and unilateral involvement (p < 0.001), with a higher number of hospital admissions (p = 0.02). The observation that only 16 of the 42 patients with llfTB (38%) had a notable comorbility is important. Thus, llfTB can be present without associated comorbilities and must be suspected in pneumonias that have a torpid evolution regardless of pulmonary localization.
Revista Americana de Medicina Respiratoria, Jan 3, 2015
Split night. Usefulness and tolerance compared with full-night CPAP titration Introduction: The t... more Split night. Usefulness and tolerance compared with full-night CPAP titration Introduction: The treatment of choice for obstructive sleep apnea / hypopnea syndrome (OSAHS) is the use of continuous positive airway pressure (CPAP). Effective pressure correcting respiratory events must be determined individually for each patient regardless of the method used. It has been suggested that the split-night polysomnography (SNPSN) may not be appropriate to assess the severity of the disease and patients may have a lower adherence to CPAP. Objetives: To evaluate the utility SNPSG study performance. Materials and Methods: Patients with severe OSAHS were evaluated. They were divided into two groups, SNPSG and full night polysomnography (FNPSG). The success or failure of the CPAP titration was evaluated and both groups were compared by age, sex, body mass index (BMI), neck circumference, Epworth scale, respiratory perturbation index (PRI), basal and lowest saturation. Results: 314 patients were evaluated. SNPSG was conducted on 216 patients (68.8%) and FNPSG on 98 patients. Titration was effective and well tolerated in 159 (73.6%) of the patients undergoing PSGSN. In the group of FNPSG, a second study of titration was performed on 73 patients and 25 were absent. In this group Titulación de CPAP en noche partida
Pulmonary Artery Sarcoma Pulmonary artery sarcoma is a rare tumor with lethal prognosis. Its etio... more Pulmonary Artery Sarcoma Pulmonary artery sarcoma is a rare tumor with lethal prognosis. Its etiology is unknown; most frequently the pulmonary trunk and its main branches are affected. Magnetic reso- nance imaging with gadolinium and positron emission tomography are complementary studies that can guide the diagnosis, but this can only be established with the histologi- cal study. We present this case because of the low incidence and its importance in the differential diagnosis of pulmonary thromboembolism.
Introduction: Different COVID-19 vaccines were developed in a short time after the beginning of p... more Introduction: Different COVID-19 vaccines were developed in a short time after the beginning of pandemics, reducing mortality, especially in high risk population. This was demonstrated in several studies, mostly retrospective or based in mathematical models. The objective was to compare mortality in inpatients with COVID-19 related to vaccination. Methods: Longitudinal, prospective, comparative, observational study. Inpatients with COVID-19 diagnosis were included between 17/12/2021 and 23/02/22, in Hospital Nacional Prof. A Posadas and Hospital Interzonal General de Agudos Eva Perón. Results: Inpatients (245) were analyzed, finding an overall mortality of 25.3%, 16.8% in fully vaccinated patients (two or more doses with less than 150 days since the last dose until the COVID-19 test) and 31.9% in those with incomplete vaccination (unvaccinated, one dose or two or more doses with more than 150 days since the last dose) (p = 0.007), OR 2.31 (IC95; 1.25-4.28) for incomplete vaccination. Mortality was 32.2% in patients who developed pneumonia, 22.2% for fully vaccinated and 38% for incompletely vaccinated (p = 0.048), OR 2.15(IC95; 1.01-4.58). Mortality was associated with older age (70 vs. 59 years; p < 0.001), female sex (54.8% vs. 37.7%; p < 0.02) and oncologic disease (27.4 vs. 14.8%; p = 0.02). PESI score was higher in incompletely vaccinated (102.5 vs. 93, p = 0.05) and SOFA score was lower (2 vs. 3, p = 0.01). The necessary number to treat (NNT) to prevent one death was 7 patients for the overall sample (IC95;4-22) and 6 (IC95;3-106) for pneumonia. Discussion: This study constitutes a starting point for developing other investigations and raising awareness of medical community and people about the beneficial effects of vaccination.
Tuberculous pleurisy allows the study of human cells at the site of active Mycobacterium tubercul... more Tuberculous pleurisy allows the study of human cells at the site of active Mycobacterium tuberculosis infection. In this study, we found that among pleural fluid (PF) lymphocytes, natural killer (NK) cells are a major source of early gamma interferon (IFN-␥) upon M. tuberculosis stimulation, leading us to investigate the mechanisms and molecules involved in this process. We show that the whole bacterium is the best inducer of IFN-␥, although a high-molecular-weight fraction of culture filtrate proteins from M. tuberculosis H37Rv and the whole-cell lysate also induce its expression. The mannose receptor seems to mediate the inhibitory effect of mannosylated lipoarabinomannan, and Toll-like receptor 2 and 4 agonists activate NK cells but do not induce IFN-␥ like M. tuberculosis does. Antigen-presenting cells (APC) and NK cells bind M. tuberculosis, and although interleukin-12 is required, it is not sufficient to induce IFN-␥ expression, indicating that NK cell-APC contact takes place. Indeed, major histocompatibility complex class I, adhesion, and costimulatory molecules as well as NK receptors regulate IFN-␥ induction. The signaling pathway is partially inhibited by dexamethasone and sensitive to Ca 2؉ flux and cyclosporine. Inhibition of p38 and extracellular-regulated kinase mitogen-activated protein kinase pathways reduces the number of IFN-␥ ؉ NK cells. Phosphorylated p38 (p-p38) is detected in ex vivo PF-NK cells, and M. tuberculosis triggers p-p38 in PF-NK cells at the same time that binding between NK and M. tuberculosis reaches its maximum value. Thus, interplay between M. tuberculosis and NK cells/APC triggering IFN-␥ would be expected to play a beneficial role in tuberculous pleurisy by helping to maintain a type 1 profile.
Tuberculous pleuritis usually shows lymphocytic preponderance, but neutrophils are also present. ... more Tuberculous pleuritis usually shows lymphocytic preponderance, but neutrophils are also present. Therefore, pleuritis is a good model for the study of neutrophil fate at sites of active Mycobacterium tuberculosis infection. We have previously demonstrated in vitro that M. tuberculosis-induced neutrophil apoptosis involves p38 mitogen protein kinase activation through Toll-like receptor 2. Herein, we demonstrate that, in tuberculous pleuritis, neutrophil apoptosis increases together with the expression of Toll-like receptor 2 and phosphorylated p38 (p-p38) kinase. In addition, receptors associated with activation/apoptotis (CD11b, CD64, tumor necrosis factor receptor, and Fas ligand) are up-regulated, together with a loss of CD16 expression. However, neutrophils express CD86, CD83, and major histocompatibility complex class II antigens, acquiring dendritic cell (DC) characteristics. Therefore, the cytokine milieu in the pleural space may influence signaling pathways on activated neutrophils, thereby inducing apoptosis and inhibiting their proinflammatory capacity, as well as allowing them acquire DC characteristics that influence the immune response. Among the many clinical manifestations of tuberculosis (TB), pleuritis is of particular interest, since it resolves without therapy and patients are known to undergo a relatively effective immune response against Mycobacterium tuberculosis [1]. Pleuritis occurs in ∼10% of untreated individuals who have positive tuberculin test results [2]. However, tuberculous pleuritis may also develop as a complication of primary pulmonary TB [3]. Tuberculous pleuritis is caused by a severe delayed-type hypersensitivity reaction in response to the rupture of a subpleural focus of M. tuberculosis infection and subsequent escape of the bacteria or the antigens into the pleural space [2].
Background: Pandemic influenza A (H1N1) has emerged rapidly in Argentina since May 2009. Prelimin... more Background: Pandemic influenza A (H1N1) has emerged rapidly in Argentina since May 2009. Preliminary comparisons with seasonal influenza suggest that H1N1 disproportionately affects younger patients, generally causing mild disease, but in a minority of cases can be lethal. Objective: The aim of this study was to develop a clinical tool for the initial management of patients with influenza-like syndrome, within the context of the novel H1N1 virus epidemic, to detect patients who need further investigation (e.g., chest X-ray study) for the diagnosis of pneumonia. Methods: We prospectively studied 1090 consecutive patients with influenza-like syndrome for a period of 15 days. Based on the presence of inspiratory crackles and the level of transcutaneous pulse oximetry, we selected 217 patients requiring chest X-ray study, and pneumonia was confirmed in all of these patients. Results: Among the patients with pneumonia, 132 viral diagnostic tests were available, from which specimens tested by real-time reverse-transcriptase polymerase-chain reaction (RTPCR) were positive for H1N1 in 61 patients (46%). Comparison between RTPCRpositive and RTPCR-negative patients did not show any significant difference. Eighty-seven randomly selected patients with influenza-like syndrome, but without crackles and with O 2 saturation > 96%, received chest X-ray studies; none demonstrated pulmonary infiltrates. Conclusion: Within the context of an influenza epidemic with the new H1N1 virus, the use of two simple and accessible clinical signs permits a rapid differentiation between those patients requiring close monitoring vs. those with mild and self-resolving disease.
ABSTRACTTuberculous pleurisy allows the study of human cells at the site of activeMycobacterium t... more ABSTRACTTuberculous pleurisy allows the study of human cells at the site of activeMycobacterium tuberculosisinfection. In this study, we found that among pleural fluid (PF) lymphocytes, natural killer (NK) cells are a major source of early gamma interferon (IFN-γ) uponM. tuberculosisstimulation, leading us to investigate the mechanisms and molecules involved in this process. We show that the whole bacterium is the best inducer of IFN-γ, although a high-molecular-weight fraction of culture filtrate proteins fromM. tuberculosisH37Rv and the whole-cell lysate also induce its expression. The mannose receptor seems to mediate the inhibitory effect of mannosylated lipoarabinomannan, and Toll-like receptor 2 and 4 agonists activate NK cells but do not induce IFN-γ likeM. tuberculosisdoes. Antigen-presenting cells (APC) and NK cells bindM. tuberculosis, and although interleukin-12 is required, it is not sufficient to induce IFN-γ expression, indicating that NK cell-APC contact takes place. ...
ABSTRACTPolymorphonuclear neutrophils (PMN) exposed toMycobacterium tuberculosisdisplay bacterici... more ABSTRACTPolymorphonuclear neutrophils (PMN) exposed toMycobacterium tuberculosisdisplay bactericidal responses and produce inflammatory proteins. This PMN-mediated inflammatory response is regulated by an activation of the apoptotic program, which collaborates to avoid tissue injury. In vitro, circulating PMN from patients with tuberculosis (TB) show an increased spontaneous apoptosis, andM. tuberculosis-induced activation accelerates the PMN apoptosis. In this study, we evaluated the mechanisms involved in spontaneous andM. tuberculosis-induced apoptosis. We demonstrate that apoptosis of PMN is not induced by lipoarabinomannan or by a whole-cell lysate ofM. tuberculosisand that neither tumor necrosis factor alpha nor CD11b, CD14, and Fcγ receptors are involved. Apoptosis of PMN from patients with active TB (TB-PMN) is induced by the interaction with the wholeM. tuberculosisvia Toll-like receptor 2 (TLR2), and, in contrast to spontaneous apoptosis, it involves the p38 mitogen-activa...
Polymorphonuclear neutrophils (PMN) modulate the adaptive immune response through interactions wi... more Polymorphonuclear neutrophils (PMN) modulate the adaptive immune response through interactions with immature dendritic cells (iDC) while spontaneous apoptotic neutrophils (PMNapo) may have an inhibitory effect on DC functions. We investigate the effect exerted by PMNapo in DC maturation and the role of Mycobacterium tuberculosis (Mtb)-induced PMNapo in the cross-presentation of mycobacterial antigens. We demonstrate that Mtb triggers the maturation of iDC while it is impaired by the presence of PMNapo, which abrogate Mtb-induced expression of costimulatory and HLA class II molecules, reducing IL-12 and IFN-c release by DC and partially inhibiting Mtb-driven lymphocyte proliferation. This inhibitory effect is not observed in already Mtb-matured DC, and it involves a direct interaction between DC and PMNapo, as supernatants from PMNapo cultures do not reveal this effect. Although PMNapo do not alter Mtb/DC-SIGN interaction, they affect the intracellular signals leading to DC maturation without requiring their entry into DC. Phagocytosis of Mtb-induced PMNapo by iDC leads to lymphoproliferation, which is significantly reduced by blocking CD36 and not DC-SIGN on iDC. Therefore, cross-presentation of Mtb antigens is taking place. Our findings suggest that the inflammatory milieu is subjected to a fine balance between non-infected and Mtb-induced PMNapo: non-infected PMNapo limiting inflammation and Mtb-induced PMNapo generating a specific immune activity.
Lower lung field tuberculosis. Tuberculosis (TB) that affects lower lung fields (LLFTB) is infreq... more Lower lung field tuberculosis. Tuberculosis (TB) that affects lower lung fields (LLFTB) is infrequent in the adult population and is generally associated with immunodeficiency. The objective of our study was to determine the incidence of llfTB in our patients population and compare the characteristics of these patients with those who presented TB of typical pulmonary localization. We studied 42 patients with llfTB retrospectively between 2004 and 2008 and compared them to 84 patients with TB of typical localization (control group). HIV-positive patients were excluded. LLFTB represented 6% of the pulmonary TB cases. No significant differences were found with respect to age, sex, the presence of cavities in chest x-rays, days of evolution, and albumin levels. LLFTB had a significantly greater proportion of comorbilities (p < 0.001), the presence of con - densation (p < 0.001), and unilateral involvement (p < 0.001), with a higher number of hospital admissions (p = 0.02). The observation that only 16 of the 42 patients with llfTB (38%) had a notable comorbility is important. Thus, llfTB can be present without associated comorbilities and must be suspected in pneumonias that have a torpid evolution regardless of pulmonary localization.
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