Rising prevalence of diabetes in sub-Saharan Africa, coupled with continued malaria transmission,... more Rising prevalence of diabetes in sub-Saharan Africa, coupled with continued malaria transmission, has resulted more patients dealing with both communicable and non-communicable diseases. We previously reported that travelers with type 2 diabetes mellitus (T2DM) infected with Plasmodium falciparum were three times more likely to develop severe malaria than non-diabetics. Here we explore the biological basis for this by testing blood from uninfected subjects with type 1 and type 2 diabetes, ex vivo, for their effects on parasite growth and rosetting (binding of infected erythrocytes to uninfected erythrocytes). Rosetting was associated with type 2 diabetes, blood glucose and erythrocyte sedimentation rate (ESR), while parasite growth was positively associated with blood glucose, glycated hemoglobin (HbA1c), body mass index (BMI), fibrinogen and triglycerides. This study establishes a link between diabetes and malaria virulence assays, potentially explaining the protective effect of go...
Objective Co-aggregation of autoimmune diseases is common, suggesting partly shared etiologies. G... more Objective Co-aggregation of autoimmune diseases is common, suggesting partly shared etiologies. Genetic factors are believed to be important, but objective measures of environmental vs heritable influences on co-aggregation are absent. With a novel approach to twin studies, we aimed at estimating heritability and genetic overlap in seven organ-specific autoimmune diseases. Design Prospective twin cohort study. Methods We used a cohort of 110 814 twins to examine co-aggregation and heritability of Hashimoto’s thyroiditis, atrophic gastritis, celiac disease, Graves’ disease, type 1 diabetes, vitiligo and Addison’s disease. Hazard ratios (HR) were calculated for twins developing the same or different disease as compared to their co-twin. The differences between monozygotic and dizygotic twin pairs were used to estimate the genetic influence on co-aggregation. Heritability for individual disorders was calculated using structural equational modeling adjusting for censoring and truncation...
The Journal of Clinical Endocrinology & Metabolism, 2019
Context: Little is known of cardiovascular disease (CVD) in autoimmune Addison disease (AAD). Ina... more Context: Little is known of cardiovascular disease (CVD) in autoimmune Addison disease (AAD). Inadequate glucocorticoid replacement might potentially increase CVD risk. Objective: To examine CVD in AAD in subgroups of ischemic heart disease (IHD) and cerebrovascular disease (CeVD) and investigate the effects of glucocorticoid and mineralocorticoid dosing. Design, Setting, and Patients: In this cohort-control study, we used Swedish health registries from 1964 to 2013 to identify 1500 subjects with AAD and 13,758 matched controls. Incident CVD was analyzed from 2006 to 2013. Adjusted hazard ratios (aHRs) were calculated using Cox proportional hazard models. Glucocorticoid and mineralocorticoid doses were stratified to examine dose-related risks. Results: During 8807 person-years (PY), 94 events of first CVD (10.7/1000 PY) in patients with AAD occurred compared with 563 events during 80,163 PY (7.0/1000 PY) in controls. IHD was significantly more common in women (aHR, 2.15; 95% CI, 1.49 to 3.10) but not men (aHR, 1.16; 95% CI, 0.75 to 1.78) with AAD compared with controls. No increase in CeVD risk was detected (aHR, 0.88; 95% CI, 0.56 to 1.37, women; aHR, 0.88; 95% CI 0.53 to 1.50, men). CVD was associated with greater glucocorticoid and mineralocorticoid replacement doses in women but not men. Conclusion: The risk of IHD but not CeVD is increased in AAD, especially in women. The risk of CVD independently correlated with greater glucocorticoid and mineralocorticoid replacement doses in women. Our data suggest that close monitoring and early treatment of risk factors for CVD, among women in particular, might be warranted.
We report a case of a male patient with CTLA-4-deficiency presenting with pure red cell aplasia a... more We report a case of a male patient with CTLA-4-deficiency presenting with pure red cell aplasia and severe autoimmune enterocolitis that was successfully treated with the α 4 β 7 integrin-blocking monoclonal antibody vedolizumab.
Publisher Summary This chapter emphasizes on the synthesis of the glycophorin A polypeptide in th... more Publisher Summary This chapter emphasizes on the synthesis of the glycophorin A polypeptide in the K562 cell line and its intriguing posttranslational modifications, including N- and O-glycosylation, phosphorylation, and sulfation. The chapter also discusses its cell-free synthesis using glycophorin A mRNA obtained from K562 cells. The methods involve radioactive cell surface labeling of erythrocytes, radioactive metabolic labeling of K562 Cells, isolation of mRNA from K562 Cells, translation of mRNA in vitro, preparation of Lectin-Sepharose columns, preparation of anti-glycophorin A antiserum, Lectin-Sepharose affinity chromatography and immune precipitations, treatment of glycophorin A with endoglycosidase H, and polyacrylamide slab gel electrophoresis. The illustrative data and interpretation shows that tunicamycin inhibits N-glycosylation of proteins, and endoglycosidase H has no effect on either the lentil lectin- or wheat germ lectin-adsorbed molecules. The tunicamycin experiments clearly shows that the absence of the N-glycosidic oligosaccharide does not affect the intracellular migration of glycophorin A.
Autoimmune polyendocrine syndrome type 1 (APS1) is an autosomal recessive disorder with both endo... more Autoimmune polyendocrine syndrome type 1 (APS1) is an autosomal recessive disorder with both endocrine and non-endocrine features. Periodic gastrointestinal dysfunction occurs in 25-30% of APS1 patients. We aimed to identify an intestinal autoantigen. A human duodenal cDNA library was immunoscreened with serum samples from APS1 patients. A positive clone was identified and used for in-vitro transcription and translation, followed by immunoprecipitation with serum samples from 80 APS1 patients from Norway, Finland, and Sweden. Sections of normal and APS1-affected small intestine were immunostained with serum from APS1 patients and specific antibodies. An enzyme-inhibition assay was used to characterise the autoantibodies. We isolated a cDNA clone coding for tryptophan hydroxylase. 48% (38/80) of APS1 patients had antibodies to tryptophan hydroxylase, whereas no reactivity to this antigen was detected in patients with other autoimmune diseases (n=372) or healthy blood donors (n=70). 89% (17/19) of APS1 patients with gastrointestinal dysfunction were positive for antibodies to tryptophan hydroxylase, compared with 34% (21/61) of patients with no gastrointestinal dysfunction (p<0.0001). Serum from antibody-positive APS1 patients specifically immunostained tryptophan-hydroxylase-containing enterochromaffin cells in normal duodenal mucosa. No serotonin-containing cells were seen in duodenal biopsy samples from APS1 patients. Serum from antibody-positive APS1 patients almost completely inhibited activity of tryptophan hydroxylase. Tryptophan hydroxylase is an endogenous intestinal autoantigen in APS1, and there is an association between antibodies to the antigen and gastrointestinal dysfunction. Analysis of antibodies to tryptophan hydroxylase may be a valuable diagnostic tool to predict and monitor gastrointestinal dysfunction in APS1.
The Journal of Clinical Endocrinology & Metabolism, 2008
Background: It has been suggested that celiac disease is associated with thyroid disease. Earlier... more Background: It has been suggested that celiac disease is associated with thyroid disease. Earlier studies, however, have been predominately cross-sectional and have often lacked controls. There is hence a need for further research. In this study, we estimated the risk of thyroid disease in individuals with celiac disease from a general population cohort. Methods: A total of 14,021 individuals with celiac disease (1964–2003) and a matched reference population of 68,068 individuals were identified through the Swedish national registers. Cox regression estimated the risk of thyroid disease in subjects with celiac disease. Analyses were restricted to individuals with a follow-up of more than 1 yr and with no thyroid disease before study entry or within 1 yr after study entry. Conditional logistic regression estimated the odds ratio for subsequent celiac disease in individuals with thyroid disease. Results: Celiac disease was positively associated with hypothyroidism [hazard ratio (HR) =...
Autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy (APECED, or APS1), is a monogenic ... more Autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy (APECED, or APS1), is a monogenic autoimmune disease caused by mutations in the autoimmune regulator (AIRE) gene. The three main components of APECED are chronic mucocuteaneous candidiasis, hypoparathyroidism and adrenocortical insufficiency. However, several additional endocrine or other autoimmune disease components, or ectodermal dystrophies form the individually variable clinical picture of APECED. An important feature of APECED is a spectrum of well-characterized circulating autoantibodies, reacting against tissue-specific autoantigens. Aire deficient mice develop some characteristics of APECED phenotype. In order to investigate whether the Aire deficient mice produce autoantibodies similar to human APECED, we studied the reactivity of Aire mouse sera against mouse homologues of 11 human APECED antigens. None of the APECED antigens indicated elevated reactivity in the Aire knockout mouse sera, implying the absence of APECED associated autoantibodies in Aire deficient mice. These findings were supported by the failure of the autoantigens to activate mouse T-cells. Furthermore, Aire knockout mice did not express increased levels of antinuclear antibodies compared to wt mice. This study indicates that spontaneous induction of tissue-specific autoantibodies similar to APECED does not occur in the rodent model suggesting differences in the immunopathogenic mechanisms between mice and men.
Endothelins (ETs), potent vasoactive peptides, are present in many ocular tissues including the c... more Endothelins (ETs), potent vasoactive peptides, are present in many ocular tissues including the ciliary epithelium where active ET-1 is produced from the precursor Big ET-1 by a membrane-bound metalloprotease, endothelin-converting enzyme (ECE). Although the role of ocular ET's are uncertain, they are elevated in the aqueous humor of normal as well as glaucomatous eyes and have been shown to lower the intraocular pressure for prolonged periods of time. In the current study, an endothelin-converting enzyme-1 (ECE-1) has been identified and its activity has been studied in SV-40 transformed human non-pigmented ciliary epithelial (HNPE) cells. Western blotting using polyclonal antibodies against ECE-1, detected a 124 kDa protein in the plasma membrane but not in the cytosol. Further characterization of the enzymatic activity of ECE-1 (conversion of Big ET-1 to ET-1) using the plasma membrane fraction of HNPE cells was performed by a novel assay involving(125)I-Big ET-1 (substrate; 80 fmoles mg(-1)protein) and polyclonal antibodies specific for Big ET-1. Mean ECE-1 activity (expressed as fmoles(125)I-ET-1 produced mg protein(-1)time(-1)) increased linearly with time and was similar to that observed in rat lung tissue. ECE-1 activity was enhanced with increasing concentrations of substrate ((125)I-Big ET-1; 30-200 fmoles mg protein(-1)180 min(-1)) as well as with increasing concentrations of protein (5-20 microgram proteins at the substrate concentration of 80 fmoles mg protein(-1)180 min(-1)). Treatments with CGS-26303 (100 micrometer), an inhibitor of ECE-1 and thiorphan (2 mM; a metalloprotease inhibitor), significantly decreased ECE-1 activity. Furthermore, both, acidification of the reaction buffer (from pH 7.4 to 6.4) and the addition of a metal chelator, EGTA (2 mM) decreased ECE-1 activity by nearly 60%. These results suggest that the ECE-1 localized in HNPE cells, is a neutral pH-sensitive metalloprotease which is similar in its activity to that observed in lung tissue and is essential for the production of ET-1 in HNPE cells. The physiological importance of the unusual proteolytic processing by ECE-1 in ocular tissue may reflect on how ET regulates intraocular pressure.
Patients with autoimmune polyendocrine syndrome type I (APS I)suffer from endocrine and non-endoc... more Patients with autoimmune polyendocrine syndrome type I (APS I)suffer from endocrine and non-endocrine disorders due to mutations in the autoimmune regulator gene (AIRE). Mouse Aire is expressed both in thymic medullary epithelial cells and in peripheral antigen-presenting cells, suggesting a role in both central and peripheral tolerance. We here report that Aire-/dendritic cells (DC) activate naive T cells more efficiently than do Aire +/+ DC. Expression array analyses of Aire-/-DC revealed differential regulation of 68 transcripts, among which, the vascular cell adhesion molecule-1 (VCAM-1) transcript was up-regulated in Aire-/-DC. Concurrently, the expression of the VCAM-1 protein was up-regulated on both Aire-/-DC and monocytes from APS I patients. Blocking the interaction of VCAM-1 prevented enhanced Aire-/-DC stimulation of T cell hybridomas. We determined an increased number of DC in spleen and lymph nodes and of monocytes in the blood from Aire-/mice, and an increased number of blood monocytes in APS I patients. Our findings imply a role for Aire in peripheral DC regulation of T cell activation, and suggest that Aire participates in peripheral tolerance.
Patients with the autoimmune polyendocrine syndrome I (APS I) have high titers of neutralizing Ig... more Patients with the autoimmune polyendocrine syndrome I (APS I) have high titers of neutralizing IgG autoantibodies against type I interferons (IFNs), in particular IFN-ω. Until now, the most specific assay has been the antiviral interferon neutralizing assay (AVINA), which has the drawbacks of requiring a cytolytic virus, being cumbersome and difficult to standardise. We have developed a fast and reliable immunoassay based on radiolabelled IFN-ω for quantifying anti-IFN-ω antibodies. Sera from 48 APS I patients were analysed together with those from 5 control groups. All sera from APS I patients were positive for anti-IFN-ω, while, except one serum, all sera from the controls were negative. This method has the advantage over bioassays that it is readily adapted to high throughput. It provides an alternative, sensitive and specific diagnostic test for APS I, and an ideal screening tool to precede mutational analyses of the AIRE gene in suspected APS I cases.
reactive T and B-cells at peripheral lymphoid organs to generate pathogenic humoral autoimmunity,... more reactive T and B-cells at peripheral lymphoid organs to generate pathogenic humoral autoimmunity, and blocking CCL2 may have therapeutic potential in MG.
Objectives Primary adrenocortical insufficiency is mostly caused by an autoimmune destruction of ... more Objectives Primary adrenocortical insufficiency is mostly caused by an autoimmune destruction of the adrenal cortex. The disease may appear isolated or as a part of an autoimmune polyendocrine syndrome (APS). APS1 is a rare hereditary disorder with a broad spectrum of clinical manifestations. In APS2, primary adrenocortical insufficiency is often combined with autoimmune thyroid disease and/or type 1 diabetes. We analysed mortality and cancer incidence in primary adrenocortical insufficiency patients during 40 years. Data were compared with the general Swedish population. Design and patients A population based cohort study including all patients with autoimmune primary adrenocortical insufficiency (3299) admitted to Swedish hospitals 1964-2004. Measurements Mortality risk was calculated as the standardized mortality ratio (SMR) and cancer incidence as the standardized incidence ratio (SIR). Results A more than 2-fold increased mortality risk was observed in both women (SMR 2•9, 95% CI 2•7-3•0) and men (SMR 2•5, 95% CI 2•3-2•7). Highest risks were observed in patients diagnosed in childhood. SMR was higher in APS1 patients (SMR 4•6, 95% CI 3•5-6•0) compared with patients with APS2 (SMR 2•1, 95% CI 1•9-2•4). Cancer incidence was increased (SIR 1•3, 95% CI 1•2-1•5). When tumours observed during the first year of follow-up were excluded, only the cancer risk among APS1 patients remained increased. Cause-specific cancer incidence analysis revealed significantly higher incidences of oral cancer, nonmelanoma skin cancer, and male genital system cancer among patients. Breast cancer incidence was lower than in the general population. Conclusions Our study shows a reduced life expectancy and altered cancer incidence pattern in patients with autoimmune primary adrenocortical insufficiency.
Objective Pituitary adenomas occur rarely in childhood and adolescence. Pituitary adenoma predisp... more Objective Pituitary adenomas occur rarely in childhood and adolescence. Pituitary adenoma predisposition (PAP) has been recently associated with germline mutations in the aryl hydrocarbon receptor interacting protein (AIP) gene. The aim of the study was to examine the proportion of germline AIP mutations in apparently sporadic paediatric pituitary adenomas. Design Genomic DNA was analysed for mutations in the AIP gene, by PCR amplification and direct sequencing. Patients A population-based cohort consisting of 36 apparently sporadic paediatric pituitary adenoma patients, referred to two medical centres in Italy, was included in the study. Patients were either less than 18 years at diagnosis, or showed clinical evidence of adenoma development before the age of 18 years. Results A heterozygous in-frame deletion Y248del (c.742_744delTAC) was identified in one GH-secreting adenoma patient. Loss of heterozygosity (LOH) analysis of tumour DNA revealed the loss of the wild-type allele. First degree relatives carrying the mutation were clinically unaffected. Conclusions While mutations were absent in non-GH-secreting adenoma patients, germline AIP mutations can be found in children and adolescents with GH-secreting tumours, even in the absence of family history. The present study reports the AIP mutation analysis results on patients of a single ethnic origin. Clearly, further studies are needed to improve our knowledge on the role of AIP in paediatric pituitary adenomas.
Variants in the gene encoding the enzyme glutamic acid decarboxylase like 1 (GADL1) have been ass... more Variants in the gene encoding the enzyme glutamic acid decarboxylase like 1 (GADL1) have been associated with response to lithium therapy. Both GADL1 and the related enzyme cysteine sulfinic acid decarboxylase (CSAD) have been proposed to be involved in the pyridoxal-5 0-phosphate (PLP)-dependent biosynthesis of taurine. In the present study, we compared the catalytic properties, inhibitor sensitivity and expression profiles of GADL1 and CSAD in brain tissue. In mouse and human brain we observed distinct patterns of expression of the PLP-dependent decarboxylases CSAD, GADL1 and glutamic acid decarboxylase 67 (GAD67). CSAD levels were highest during prenatal and early postnatal development; GADL1 peaked early in prenatal development, while GAD67 increased rapidly after birth. Both CSAD and GADL1 are being expressed in neurons, whereas only CSAD mRNA was detected in astrocytes. Cysteine sulfinic acid was the preferred substrate for both mouse CSAD and GADL1, although both enzymes also decarboxylated cysteic acid and aspartate. In silico screening and molecular docking using the crystal structure of CSAD and in vitro assays led to the discovery of eight new enzyme inhibitors with partial selectivity for either CSAD or GADL1. Lithium had minimal effect on their enzyme activities. In conclusion, taurine biosynthesis in vertebrates involves two structurally related PLP-dependent decarboxylases (CSAD and GADL1) that have partially overlapping catalytic properties but different tissue distribution, indicating divergent physiological roles. Development of selective enzyme inhibitors targeting these enzymes is important to further dissect their (patho)physiological roles.
Rising prevalence of diabetes in sub-Saharan Africa, coupled with continued malaria transmission,... more Rising prevalence of diabetes in sub-Saharan Africa, coupled with continued malaria transmission, has resulted more patients dealing with both communicable and non-communicable diseases. We previously reported that travelers with type 2 diabetes mellitus (T2DM) infected with Plasmodium falciparum were three times more likely to develop severe malaria than non-diabetics. Here we explore the biological basis for this by testing blood from uninfected subjects with type 1 and type 2 diabetes, ex vivo, for their effects on parasite growth and rosetting (binding of infected erythrocytes to uninfected erythrocytes). Rosetting was associated with type 2 diabetes, blood glucose and erythrocyte sedimentation rate (ESR), while parasite growth was positively associated with blood glucose, glycated hemoglobin (HbA1c), body mass index (BMI), fibrinogen and triglycerides. This study establishes a link between diabetes and malaria virulence assays, potentially explaining the protective effect of go...
Objective Co-aggregation of autoimmune diseases is common, suggesting partly shared etiologies. G... more Objective Co-aggregation of autoimmune diseases is common, suggesting partly shared etiologies. Genetic factors are believed to be important, but objective measures of environmental vs heritable influences on co-aggregation are absent. With a novel approach to twin studies, we aimed at estimating heritability and genetic overlap in seven organ-specific autoimmune diseases. Design Prospective twin cohort study. Methods We used a cohort of 110 814 twins to examine co-aggregation and heritability of Hashimoto’s thyroiditis, atrophic gastritis, celiac disease, Graves’ disease, type 1 diabetes, vitiligo and Addison’s disease. Hazard ratios (HR) were calculated for twins developing the same or different disease as compared to their co-twin. The differences between monozygotic and dizygotic twin pairs were used to estimate the genetic influence on co-aggregation. Heritability for individual disorders was calculated using structural equational modeling adjusting for censoring and truncation...
The Journal of Clinical Endocrinology & Metabolism, 2019
Context: Little is known of cardiovascular disease (CVD) in autoimmune Addison disease (AAD). Ina... more Context: Little is known of cardiovascular disease (CVD) in autoimmune Addison disease (AAD). Inadequate glucocorticoid replacement might potentially increase CVD risk. Objective: To examine CVD in AAD in subgroups of ischemic heart disease (IHD) and cerebrovascular disease (CeVD) and investigate the effects of glucocorticoid and mineralocorticoid dosing. Design, Setting, and Patients: In this cohort-control study, we used Swedish health registries from 1964 to 2013 to identify 1500 subjects with AAD and 13,758 matched controls. Incident CVD was analyzed from 2006 to 2013. Adjusted hazard ratios (aHRs) were calculated using Cox proportional hazard models. Glucocorticoid and mineralocorticoid doses were stratified to examine dose-related risks. Results: During 8807 person-years (PY), 94 events of first CVD (10.7/1000 PY) in patients with AAD occurred compared with 563 events during 80,163 PY (7.0/1000 PY) in controls. IHD was significantly more common in women (aHR, 2.15; 95% CI, 1.49 to 3.10) but not men (aHR, 1.16; 95% CI, 0.75 to 1.78) with AAD compared with controls. No increase in CeVD risk was detected (aHR, 0.88; 95% CI, 0.56 to 1.37, women; aHR, 0.88; 95% CI 0.53 to 1.50, men). CVD was associated with greater glucocorticoid and mineralocorticoid replacement doses in women but not men. Conclusion: The risk of IHD but not CeVD is increased in AAD, especially in women. The risk of CVD independently correlated with greater glucocorticoid and mineralocorticoid replacement doses in women. Our data suggest that close monitoring and early treatment of risk factors for CVD, among women in particular, might be warranted.
We report a case of a male patient with CTLA-4-deficiency presenting with pure red cell aplasia a... more We report a case of a male patient with CTLA-4-deficiency presenting with pure red cell aplasia and severe autoimmune enterocolitis that was successfully treated with the α 4 β 7 integrin-blocking monoclonal antibody vedolizumab.
Publisher Summary This chapter emphasizes on the synthesis of the glycophorin A polypeptide in th... more Publisher Summary This chapter emphasizes on the synthesis of the glycophorin A polypeptide in the K562 cell line and its intriguing posttranslational modifications, including N- and O-glycosylation, phosphorylation, and sulfation. The chapter also discusses its cell-free synthesis using glycophorin A mRNA obtained from K562 cells. The methods involve radioactive cell surface labeling of erythrocytes, radioactive metabolic labeling of K562 Cells, isolation of mRNA from K562 Cells, translation of mRNA in vitro, preparation of Lectin-Sepharose columns, preparation of anti-glycophorin A antiserum, Lectin-Sepharose affinity chromatography and immune precipitations, treatment of glycophorin A with endoglycosidase H, and polyacrylamide slab gel electrophoresis. The illustrative data and interpretation shows that tunicamycin inhibits N-glycosylation of proteins, and endoglycosidase H has no effect on either the lentil lectin- or wheat germ lectin-adsorbed molecules. The tunicamycin experiments clearly shows that the absence of the N-glycosidic oligosaccharide does not affect the intracellular migration of glycophorin A.
Autoimmune polyendocrine syndrome type 1 (APS1) is an autosomal recessive disorder with both endo... more Autoimmune polyendocrine syndrome type 1 (APS1) is an autosomal recessive disorder with both endocrine and non-endocrine features. Periodic gastrointestinal dysfunction occurs in 25-30% of APS1 patients. We aimed to identify an intestinal autoantigen. A human duodenal cDNA library was immunoscreened with serum samples from APS1 patients. A positive clone was identified and used for in-vitro transcription and translation, followed by immunoprecipitation with serum samples from 80 APS1 patients from Norway, Finland, and Sweden. Sections of normal and APS1-affected small intestine were immunostained with serum from APS1 patients and specific antibodies. An enzyme-inhibition assay was used to characterise the autoantibodies. We isolated a cDNA clone coding for tryptophan hydroxylase. 48% (38/80) of APS1 patients had antibodies to tryptophan hydroxylase, whereas no reactivity to this antigen was detected in patients with other autoimmune diseases (n=372) or healthy blood donors (n=70). 89% (17/19) of APS1 patients with gastrointestinal dysfunction were positive for antibodies to tryptophan hydroxylase, compared with 34% (21/61) of patients with no gastrointestinal dysfunction (p<0.0001). Serum from antibody-positive APS1 patients specifically immunostained tryptophan-hydroxylase-containing enterochromaffin cells in normal duodenal mucosa. No serotonin-containing cells were seen in duodenal biopsy samples from APS1 patients. Serum from antibody-positive APS1 patients almost completely inhibited activity of tryptophan hydroxylase. Tryptophan hydroxylase is an endogenous intestinal autoantigen in APS1, and there is an association between antibodies to the antigen and gastrointestinal dysfunction. Analysis of antibodies to tryptophan hydroxylase may be a valuable diagnostic tool to predict and monitor gastrointestinal dysfunction in APS1.
The Journal of Clinical Endocrinology & Metabolism, 2008
Background: It has been suggested that celiac disease is associated with thyroid disease. Earlier... more Background: It has been suggested that celiac disease is associated with thyroid disease. Earlier studies, however, have been predominately cross-sectional and have often lacked controls. There is hence a need for further research. In this study, we estimated the risk of thyroid disease in individuals with celiac disease from a general population cohort. Methods: A total of 14,021 individuals with celiac disease (1964–2003) and a matched reference population of 68,068 individuals were identified through the Swedish national registers. Cox regression estimated the risk of thyroid disease in subjects with celiac disease. Analyses were restricted to individuals with a follow-up of more than 1 yr and with no thyroid disease before study entry or within 1 yr after study entry. Conditional logistic regression estimated the odds ratio for subsequent celiac disease in individuals with thyroid disease. Results: Celiac disease was positively associated with hypothyroidism [hazard ratio (HR) =...
Autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy (APECED, or APS1), is a monogenic ... more Autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy (APECED, or APS1), is a monogenic autoimmune disease caused by mutations in the autoimmune regulator (AIRE) gene. The three main components of APECED are chronic mucocuteaneous candidiasis, hypoparathyroidism and adrenocortical insufficiency. However, several additional endocrine or other autoimmune disease components, or ectodermal dystrophies form the individually variable clinical picture of APECED. An important feature of APECED is a spectrum of well-characterized circulating autoantibodies, reacting against tissue-specific autoantigens. Aire deficient mice develop some characteristics of APECED phenotype. In order to investigate whether the Aire deficient mice produce autoantibodies similar to human APECED, we studied the reactivity of Aire mouse sera against mouse homologues of 11 human APECED antigens. None of the APECED antigens indicated elevated reactivity in the Aire knockout mouse sera, implying the absence of APECED associated autoantibodies in Aire deficient mice. These findings were supported by the failure of the autoantigens to activate mouse T-cells. Furthermore, Aire knockout mice did not express increased levels of antinuclear antibodies compared to wt mice. This study indicates that spontaneous induction of tissue-specific autoantibodies similar to APECED does not occur in the rodent model suggesting differences in the immunopathogenic mechanisms between mice and men.
Endothelins (ETs), potent vasoactive peptides, are present in many ocular tissues including the c... more Endothelins (ETs), potent vasoactive peptides, are present in many ocular tissues including the ciliary epithelium where active ET-1 is produced from the precursor Big ET-1 by a membrane-bound metalloprotease, endothelin-converting enzyme (ECE). Although the role of ocular ET's are uncertain, they are elevated in the aqueous humor of normal as well as glaucomatous eyes and have been shown to lower the intraocular pressure for prolonged periods of time. In the current study, an endothelin-converting enzyme-1 (ECE-1) has been identified and its activity has been studied in SV-40 transformed human non-pigmented ciliary epithelial (HNPE) cells. Western blotting using polyclonal antibodies against ECE-1, detected a 124 kDa protein in the plasma membrane but not in the cytosol. Further characterization of the enzymatic activity of ECE-1 (conversion of Big ET-1 to ET-1) using the plasma membrane fraction of HNPE cells was performed by a novel assay involving(125)I-Big ET-1 (substrate; 80 fmoles mg(-1)protein) and polyclonal antibodies specific for Big ET-1. Mean ECE-1 activity (expressed as fmoles(125)I-ET-1 produced mg protein(-1)time(-1)) increased linearly with time and was similar to that observed in rat lung tissue. ECE-1 activity was enhanced with increasing concentrations of substrate ((125)I-Big ET-1; 30-200 fmoles mg protein(-1)180 min(-1)) as well as with increasing concentrations of protein (5-20 microgram proteins at the substrate concentration of 80 fmoles mg protein(-1)180 min(-1)). Treatments with CGS-26303 (100 micrometer), an inhibitor of ECE-1 and thiorphan (2 mM; a metalloprotease inhibitor), significantly decreased ECE-1 activity. Furthermore, both, acidification of the reaction buffer (from pH 7.4 to 6.4) and the addition of a metal chelator, EGTA (2 mM) decreased ECE-1 activity by nearly 60%. These results suggest that the ECE-1 localized in HNPE cells, is a neutral pH-sensitive metalloprotease which is similar in its activity to that observed in lung tissue and is essential for the production of ET-1 in HNPE cells. The physiological importance of the unusual proteolytic processing by ECE-1 in ocular tissue may reflect on how ET regulates intraocular pressure.
Patients with autoimmune polyendocrine syndrome type I (APS I)suffer from endocrine and non-endoc... more Patients with autoimmune polyendocrine syndrome type I (APS I)suffer from endocrine and non-endocrine disorders due to mutations in the autoimmune regulator gene (AIRE). Mouse Aire is expressed both in thymic medullary epithelial cells and in peripheral antigen-presenting cells, suggesting a role in both central and peripheral tolerance. We here report that Aire-/dendritic cells (DC) activate naive T cells more efficiently than do Aire +/+ DC. Expression array analyses of Aire-/-DC revealed differential regulation of 68 transcripts, among which, the vascular cell adhesion molecule-1 (VCAM-1) transcript was up-regulated in Aire-/-DC. Concurrently, the expression of the VCAM-1 protein was up-regulated on both Aire-/-DC and monocytes from APS I patients. Blocking the interaction of VCAM-1 prevented enhanced Aire-/-DC stimulation of T cell hybridomas. We determined an increased number of DC in spleen and lymph nodes and of monocytes in the blood from Aire-/mice, and an increased number of blood monocytes in APS I patients. Our findings imply a role for Aire in peripheral DC regulation of T cell activation, and suggest that Aire participates in peripheral tolerance.
Patients with the autoimmune polyendocrine syndrome I (APS I) have high titers of neutralizing Ig... more Patients with the autoimmune polyendocrine syndrome I (APS I) have high titers of neutralizing IgG autoantibodies against type I interferons (IFNs), in particular IFN-ω. Until now, the most specific assay has been the antiviral interferon neutralizing assay (AVINA), which has the drawbacks of requiring a cytolytic virus, being cumbersome and difficult to standardise. We have developed a fast and reliable immunoassay based on radiolabelled IFN-ω for quantifying anti-IFN-ω antibodies. Sera from 48 APS I patients were analysed together with those from 5 control groups. All sera from APS I patients were positive for anti-IFN-ω, while, except one serum, all sera from the controls were negative. This method has the advantage over bioassays that it is readily adapted to high throughput. It provides an alternative, sensitive and specific diagnostic test for APS I, and an ideal screening tool to precede mutational analyses of the AIRE gene in suspected APS I cases.
reactive T and B-cells at peripheral lymphoid organs to generate pathogenic humoral autoimmunity,... more reactive T and B-cells at peripheral lymphoid organs to generate pathogenic humoral autoimmunity, and blocking CCL2 may have therapeutic potential in MG.
Objectives Primary adrenocortical insufficiency is mostly caused by an autoimmune destruction of ... more Objectives Primary adrenocortical insufficiency is mostly caused by an autoimmune destruction of the adrenal cortex. The disease may appear isolated or as a part of an autoimmune polyendocrine syndrome (APS). APS1 is a rare hereditary disorder with a broad spectrum of clinical manifestations. In APS2, primary adrenocortical insufficiency is often combined with autoimmune thyroid disease and/or type 1 diabetes. We analysed mortality and cancer incidence in primary adrenocortical insufficiency patients during 40 years. Data were compared with the general Swedish population. Design and patients A population based cohort study including all patients with autoimmune primary adrenocortical insufficiency (3299) admitted to Swedish hospitals 1964-2004. Measurements Mortality risk was calculated as the standardized mortality ratio (SMR) and cancer incidence as the standardized incidence ratio (SIR). Results A more than 2-fold increased mortality risk was observed in both women (SMR 2•9, 95% CI 2•7-3•0) and men (SMR 2•5, 95% CI 2•3-2•7). Highest risks were observed in patients diagnosed in childhood. SMR was higher in APS1 patients (SMR 4•6, 95% CI 3•5-6•0) compared with patients with APS2 (SMR 2•1, 95% CI 1•9-2•4). Cancer incidence was increased (SIR 1•3, 95% CI 1•2-1•5). When tumours observed during the first year of follow-up were excluded, only the cancer risk among APS1 patients remained increased. Cause-specific cancer incidence analysis revealed significantly higher incidences of oral cancer, nonmelanoma skin cancer, and male genital system cancer among patients. Breast cancer incidence was lower than in the general population. Conclusions Our study shows a reduced life expectancy and altered cancer incidence pattern in patients with autoimmune primary adrenocortical insufficiency.
Objective Pituitary adenomas occur rarely in childhood and adolescence. Pituitary adenoma predisp... more Objective Pituitary adenomas occur rarely in childhood and adolescence. Pituitary adenoma predisposition (PAP) has been recently associated with germline mutations in the aryl hydrocarbon receptor interacting protein (AIP) gene. The aim of the study was to examine the proportion of germline AIP mutations in apparently sporadic paediatric pituitary adenomas. Design Genomic DNA was analysed for mutations in the AIP gene, by PCR amplification and direct sequencing. Patients A population-based cohort consisting of 36 apparently sporadic paediatric pituitary adenoma patients, referred to two medical centres in Italy, was included in the study. Patients were either less than 18 years at diagnosis, or showed clinical evidence of adenoma development before the age of 18 years. Results A heterozygous in-frame deletion Y248del (c.742_744delTAC) was identified in one GH-secreting adenoma patient. Loss of heterozygosity (LOH) analysis of tumour DNA revealed the loss of the wild-type allele. First degree relatives carrying the mutation were clinically unaffected. Conclusions While mutations were absent in non-GH-secreting adenoma patients, germline AIP mutations can be found in children and adolescents with GH-secreting tumours, even in the absence of family history. The present study reports the AIP mutation analysis results on patients of a single ethnic origin. Clearly, further studies are needed to improve our knowledge on the role of AIP in paediatric pituitary adenomas.
Variants in the gene encoding the enzyme glutamic acid decarboxylase like 1 (GADL1) have been ass... more Variants in the gene encoding the enzyme glutamic acid decarboxylase like 1 (GADL1) have been associated with response to lithium therapy. Both GADL1 and the related enzyme cysteine sulfinic acid decarboxylase (CSAD) have been proposed to be involved in the pyridoxal-5 0-phosphate (PLP)-dependent biosynthesis of taurine. In the present study, we compared the catalytic properties, inhibitor sensitivity and expression profiles of GADL1 and CSAD in brain tissue. In mouse and human brain we observed distinct patterns of expression of the PLP-dependent decarboxylases CSAD, GADL1 and glutamic acid decarboxylase 67 (GAD67). CSAD levels were highest during prenatal and early postnatal development; GADL1 peaked early in prenatal development, while GAD67 increased rapidly after birth. Both CSAD and GADL1 are being expressed in neurons, whereas only CSAD mRNA was detected in astrocytes. Cysteine sulfinic acid was the preferred substrate for both mouse CSAD and GADL1, although both enzymes also decarboxylated cysteic acid and aspartate. In silico screening and molecular docking using the crystal structure of CSAD and in vitro assays led to the discovery of eight new enzyme inhibitors with partial selectivity for either CSAD or GADL1. Lithium had minimal effect on their enzyme activities. In conclusion, taurine biosynthesis in vertebrates involves two structurally related PLP-dependent decarboxylases (CSAD and GADL1) that have partially overlapping catalytic properties but different tissue distribution, indicating divergent physiological roles. Development of selective enzyme inhibitors targeting these enzymes is important to further dissect their (patho)physiological roles.
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Papers by Olle Kämpe