Endocrine Abstracts

Background: Type 1 diabetes mellitus (T1DM) is caused by destruction of pancreatic beta cells. Children and adolescents with type 1 diabetes have an increased risk of developing other autoimmune diseases, most commonly autoimmune thyroiditis and celiac disease.

Objectives: To examine the frequency of individual human leukocyte antigen (HLA) alleles in people with T1DM and associated autoimmune (AI) diseases of the thyroid, digestive system, and skin, and to examine differences in gender and age at the time of diagnosis.

Subjects and Methods: Subjects were patients referred to the Clinical Institute of Transfusion Medicine for HLA typing. Data were collected in Clinical hospital center Osijek (HLA typing findings, associated autoimmune diseases of the thyroid gland, digestive system, and skin; age and sex).

Results: The study was conducted on 147 subjects with T1DM (51.7% women, 48,3% men). The AI disease of thyroid were most common (24,5%). Distribution of subjects by age groups differs significantly. The most common HLA alleles in men are HLA-DRB1*03, -DQA1*05, -DQB1*02, and in women HLA-DRB1*03, -DQA1*03, -DQB1*03(DQ8). Subjects with T1DM were more likely to have the DRB1*03-DQA1*05-DQB1*02 haplotype, and female subjects with T1DM were more likely to have the DRB1*08-DQA1*03-DQB1*03(DQ8) haplotype. There is a significant difference in the distribution of subjects with respect to the presence of autoimmune AI thyroid disease vs HLA-DRB1*03/*10,-DRB1*03(DQ8); AI of the digestive system disease relative to HLA-DRB1*01; AI skin disease vs HLA-DRB1*01, -DQB1*05.

Conclusion: Age is associated with an earlier diagnosis of T1DM, while gender is not. Individual HLA alleles have been associated with the earlier onset of T1DM and AI disease. The incidence of T1DM in the population is increasing and a proper understanding of the mechanism of occurrence is crucial to better diagnose and prevent the development of complications.

Key words: diabetes mellitus, type 1; histocompatibility antigens class II; autoimmune diseases