Class II HLA genotype in fulminant type 1 diabetes: A nationwide survey with reference to glutamic acid decarboxylase antibodies

Aims/Introduction: Fulminant type 1 diabetes is a subtype of type 1 diabetes characterized by a remarkably abrupt onset of insulin‐deficient hyperglycemia within a few days. The aim of the present study was to clarify characteristic class II HLA genotypes in a large number of patients with fulminant type 1 diabetes to date. Materials and Methods: We analyzed the HLA‐DRB1 and DQB1 genotypes, and their haplotypes in 207 patients with fulminant type 1 diabetes and 325 control subjects in the Japanese population. Results: The frequencies of the DRB1*04:05‐DQB1*04:01 and DRB1*09:01‐DQB1*03:03 haplotypes were significantly higher, and those of the DRB1*01:01‐DQB1*05:01, DRB1*15:02‐DQB1*06:01 and DRB1*08:03‐DQB1*06:01 haplotypes were significantly lower in patients with fulminant type 1 diabetes than in the control subjects. Combination analysis showed that the frequencies of homozygotes with DRB1*04:05‐DQB1*04:01 odds ratio (OR) 7.0] and DRB1*09:01‐DQB1*03:03 (OR 9.5) were significantly higher in patients with fulminant type 1 diabetes. Within a limited portion of patients with fulminant type 1 diabetes with antibodies to glutamic acid decarboxylase (GADab; n = 25), the frequency of DRB1*09:01‐DQB1*03:03, but not DRB1*04:05‐DQB1*04:01, was significantly higher than in control subjects (44.0% vs 13.7%; Pc < 0.05, OR 5.0). Correction to last line of Results, added after online publication 29 July 2011: “OR 5.1” is changed to “OR 5.0”.] Conclusions: Our large‐scale study showed the characteristic class II HLA genotypes in fulminant type 1 diabetes, and implicated that genetic contribution to disease susceptibility is distinct between GADab‐positive and GADab‐negative fulminant type 1 diabetes. (J Diabetes Invest, doi: 10.1111/j.2040‐1124.2011.00139.x, 2012)