AGE-OF-ONSET RELATED HLA-DQA1 GENETIC-HETEROGENEITY OF INSULIN-DEPENDENT DIABETES-MELLITUS

Objective. To clarify whether there is an association of insulin-depen dent diabetes mellitus (IDDM) susceptibility with HLA-DQA1 locus in ad ult-onset IDDM. Patients and Methods. Possible heterogeneity in immuno genetic aspects was investigated by comparing the findings on relation ship between HLA-DQA1 52 Arg(+) and IDDM predisposition in three group s with different ages of IDDM onset (group A 14 years, group B 15-30 y ears, group C>31 years). Results. The frequency of HLA-DQA1 52 Arg(+) in group A (87.5%) was higher than that in control (53.9%, P<0.05) and in group B and C (P<0.05). The frequency of HLA-DQA1 52 Arg(+)/Arg(+) phenotype in group A (75%) was higher than that in group C (23.1%, P< 0.05). Conclusion. The contribution of HLA-DQA1 52 arginine to IDDM su sceptibility is heterogeneous. Further study is necessary to clarify t he immunogenetic entity of IDDM.