Objective: To investigate a possible association of DRB1, DQA1 and DQB1 alleles with the chronic autoimmune thyroiditis (AT) development in patients with diabetes mellitus type 1 (DM1) manifested between 18 to 40 years of age. Patients and methods: In 118 patients with DM1 (age at DM1 diagnosis 28.0 (6.9) years, duration of DM1 14.0 (6.3) years) HLA-DRB1, -DQA1 and -DQB1 alleles were analysed by sequence specific oligonucleotide probes and sequence specific primers. AT was present in 53 (44.9%) of these patients (ultrasonography, positive titres of specific thyroid autoantibodies and/or elevation of TSH). Statistics: Chi-square test, t-test. Data given as mean (SD) or percent. Results: Females were significantly more often affected by AT (37F:16M in AT-positive group, vs. 26F:39M in AT-negative group, p<0.0015), the mean age at DM1 diagnosis as well as duration of DM1 was not different in both groups. We observed higher phenotype frequency of DQB1*0301 (18.9% vs. 7.7%, p<0,07) and DQB1*0201/*0201 (homozygote) (9% vs. 2%, p=0.05), and lower frequency of DRB1*03 antigen (35.9% vs. 52.3%, p<0.08) in AT-positive group, all of borderline significance. The frequencies of the most frequent haplotypes DRB1*04-DQA*0301-DQB1*0302 (54.7% vs. 49.2%, n.s.), DRB1*03-DQA1*0501-*DQB1*0201 (35.8% vs. 50.8%. n.s.), and DRB1*01-DQA1*0101-DQB1*0501 (15.1% vs. 24.6%, n.s.) were similar in AT-positive and AT-negative group.
Conclusions: No significant association of HLA-DRB1-DQA1-DQB1 haplotype with chronic autoimmune thyroiditis development was observed in patients with DM1 manifested between 18 and 40 years of age.
Supported by Research Intention of Ministry of Health, Czech Republic No: MZ 00000023761, approved by the Ethical Committee of the Institute of Endocrinology.
24 - 26 Mar 2003
British Endocrine Societies