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Aim: Previous studies have reported an association between month of birth and incidence of type 1 diabetes. Using population‐based data, including almost all newly diagnosed children with type 1 diabetes in Sweden, we tested whether month of birth influences the risk of type 1 diabetes. Methods: For 8761 children diagnosed with type 1 diabetes between May 2005 and December 2016 in the Better Diabetes Diagnosis study, month of birth, sex and age were compared. Human leucocyte antigen (HLA) genotype and autoantibodies at diagnosis were analysed for a subset of the cohort (n = 3647). Comparisons with the general population used data from Statistics Sweden. Results: We found no association between month of birth or season and the incidence of type 1 diabetes in the cohort as a whole. However, boys diagnosed before 5 years were more often born in May (p = 0.004). We found no correlation between month of birth and HLA or antibodies. Conclusion: In this large nationwide study, the impact of month of birth on type 1 diabetes diagnosis was weak, except for boys diagnosed before 5 years of age, who were more likely born in May. This may suggest different triggers for different subgroups of patients with type 1 diabetes. [ABSTRACT FROM AUTHOR]

Introduction: Type I diabetes Mellitus (T1DM) is caused by autoimmune destruction of β-cells of pancreas. Two forms of T1DM are known called as 1A (autoimmune) and 1B (idiopathic). Aim: Aim was to study the prevalence of Anti-TTG IgA, AntiTPO, GADA, ZnT8 and IA-2 autoantibodies and HLA DR and DQ genes and its diagnostic value in T1DM. Materials and Methods: Thirty four T1DM patients, 59 type 2 diabetes mellitus (T2DM) patients and 28 healthy controls were included in study. Antibodies levels were estimated by ELISA and HLA typing was performed by SSP-PCR method. Result: The prevalence of various autoantibodies in T1DM were Anti-TTG 14.7%, Anti-TPO 17.65%, GADA 38.23%, ZnT8 11.76% and IA-2 5.88%. Only GADA and ZnT8 were significantly positive in T1DM. GADA (66.67%) and ZnT8 (33.33%) positivity was more in patients below 15 years age while levels of other antibodies were higher after 15 years age. All autoantibodies were detected in higher frequency in T1DM than in T2DM and controls. HLA DR and DQ typing showed highly significant increase in DRB1*0301 (61.76%, p=0.00) and DQB1*0201 (64.71%, p=0.00) in T1DM. Subjects with HLA DRB1*0301 and DQB1*0201 had 80-100% positive prevalence of GADA, ZnT8, IA-2, Anti-TTG and Anti-TPO autoantibodies. Conclusion: Combination of GADA antibody with DRB1 and DQB1 estimation improved diagnosis of T1A than insulin antigen specific antibodies alone.

Introduction: Type I diabetes Mellitus (T1DM) is caused by autoimmune destruction of β-cells of pancreas. Two forms of T1DM are known called as 1A (autoimmune) and 1B (idiopathic). Aim: Aim was to study the prevalence of Anti-TTG IgA, Anti- TPO, GADA, ZnT8 and IA-2 autoantibodies and HLA DR and DQ genes and its diagnostic value in T1DM. Materials and Methods: Thirty four T1DM patients, 59 type 2 diabetes mellitus (T2DM) patients and 28 healthy controls were included in study. Antibodies levels were estimated by ELISA and HLA typing was performed by SSP-PCR method. Result: The prevalence of various autoantibodies in T1DM were Anti-TTG 14.7%, Anti-TPO 17.65%, GADA 38.23%, ZnT8 11.76% and IA-2 5.88%. Only GADA and ZnT8 were significantly positive in T1DM. GADA (66.67%) and ZnT8 (33.33%) positivity was more in patients below 15 years age while levels of other antibodies were higher after 15 years age. All autoantibodies were detected in higher frequency in T1DM than in T2DM and controls. HLA DR and DQ typing showed highly significant increase in DRB1*0301 (61.76%, p=0.00) and DQB1*0201 (64.71%, p=0.00) in T1DM. Subjects with HLA DRB1*0301 and DQB1*0201 had 80-100% positive prevalence of GADA, ZnT8, IA-2, Anti-TTG and Anti-TPO autoantibodies. Conclusion: Combination of GADA antibody with DRB1 and DQB1 estimation improved diagnosis of T1A than insulin antigen specific antibodies alone. [ABSTRACT FROM AUTHOR]

Celiac disease (CD) is a chronic inflammatory disease in the small intestine triggered by gluten uptake that occurs in genetically susceptible individuals. HLA-DQ2 protein encoded by HLA-DQA1*05 and DQB1*02 alleles is found in 90-95% of CD patients. All of the remaining patients carry HLA-DQ8 protein encoded by HLA-DQA1*03 and DQB1*03:02 alleles. Specific HLA-DQ genotypes define different risk for CD incidence. Presence of susceptible HLA-DQ genotypes does not predict certain disease development, but their absence makes CD very unlikely, close to 100%. Here we presented for the first time the distribution of HLA-DQ genotypes in the group of pediatric celiac patients from the University Children’s Hospital, Belgrade, Serbia and estimated risk for CD development that these genotypes confer. Seventy three celiac disease patients and 62 healthy individuals underwent genotyping for DQA1, DQB alleles and DRB1 allele. 94.5% of patients carried alleles that encode DQ2 protein variant and 2.7% carried alleles that encode DQ8 protein variant. Two patients carried single DQB1*02 allele. No patients were negative for all the alleles predisposing to CD. The highest HLA-DQ genotype risk for CD development was found in group of patients homozygous for DQ2.5 haplotype, followed by the group of heterozygous carriers of DQ2.5 haplotype in combination with DQB1*02 allele within the other haplotype. The lowest risk was observed in carriers of a single copy of DQB1*02 or DQA1*05 allele or other non-predisposing alleles. HLA genotyping, more informative than serological testing commonly used, proved to be a useful diagnostic tool for excluding CD development.

Immunogenetic studies have suggested that autoantibody production is commonly associated with particular human leukocyte antigens (HLA) class II genotypes in certain autoimmune diseases. The objective of this study was to investigate whether the production of anti-β2-glycoprotein I antibody (aβ2GPI) was associated with particular HLA-DQ alleles in patients with recurrent miscarriage (RM). The HLA-DQ genotypes in 126 patients with RM were determined using the polymerase chain reaction-sequence-specific primer method. Both the IgG and IgM isotypes of aβ2GPI were measured via enzyme-linked immunosorbent assay. Positive results for either IgG or IgM on two occasions within an interval of 12 weeks were defined as antiphospholipid antibody-positive. The frequencies of the HLA-DQA1*01:02 [odds ratio (OR) 3.4, 95% confidence interval (CI) 1.6-7.0, Pc = 0.018] and HLA-DQB1*02:01 alleles (OR 4.6,95% CI 2.1 -10.2, Pc = 9.18 X 10-4) were significantly increased in aβ2GPI-positive RM patients compared with aβ2GPI-negative RM patients. These results suggest that the HLA-DQA1*0102 and HLA-DQB1*0201 alleles may be involved in the production of aP2GPI in RM patients. [ABSTRACT FROM AUTHOR]

We selected 38 consecutive celiac disease (CD) patients (from a group of 316 consecutive CD patients) and 91 healthy blood donors, all of whom were HLA-DQ2 (DQA1*0501/DQB1*0201) negative, and investigated the presence of the classically associated alleles HLA-DQ8 and HLA-DRB4. We also studied the distribution of MICA transmembrane alleles in the two clinical forms of the disease. For this reason, these 38 DQ2-negative patients were subdivided into two groups: 18 typical CD patients and 20 atypical CD patients. No differences were found in the distribution of the DRB4 allele between DQ2-negative patients and controls. The HLA-DQ8 heterodimer (DQA1*03xx/DQB1*0302) was increased in CD patients (29%) compared with controls (10%), but no statistical differences were found. No differences were observed in the frequency of these alleles between either group of CD DQ2-negative patients. MICA-A5.1 was increased in atypical CD patients when compared with the typical forms of disease (Pc=0.03) and with healthy controls (Pc=0.002). No other MICA allele was found to be significantly increased in the groups under study. The presence of MICA-A5.1 in atypical CD DQ2-negative patients may indicate a possible role of this allele in the development of CD. [ABSTRACT FROM AUTHOR]

We studied nine consecutive DQ2-negative celiacs [from a group of 186 consecutive celiac disease (CD) patients] for the presence of the HLA-DQB1, DRB1, and DRBx alleles. HLA-DR53 was present in only 5 out of 9 (55%) of DQ2-negative patients. DRB4 (DR53) positivity –39% of chromosomes – among Spanish DQ2-negative CD patients is due to both DR4- and DR7-positive cases. Spanish DQ2-positive patients show a high frequency of DR7/DR11 heterozygous carriers of DRB4 (DR53). One-third of our DQ2-negative celiac patients have DRB1*04 (DR4). Six patients are DR4 negative: at least one of the DQ2 alleles (DQA1*0501/DQB1*02) is present in four cases, but none of the alleles of risk, including DR53, were found in the remainding two cases, both of whom carry DQB1*06 alleles (*0602/3 and 0604). The fact that half of our DQ2-negative patients lack DRB4 (DR53) leads us to believe that this gene is not an essential factor to confer CD susceptibility. [ABSTRACT FROM AUTHOR]