HLA in Czech adult patients with autoimmune diabetes mellitus: comparison with Czech children with type 1 diabetes and patients with type 2 diabetes

Summary Type 1 diabetes results from an autoimmune insulitis, associated with HLA class II alleles. The evidence about HLA allele association is not clear in patients diagnosed after 35 years of age. In this study we have analyzed HLA alleles of DQB1 and DRB1 genes by sequence specific primer (SSP)‐PCR technique in adult patients with disease onset after 35 years of age. Two hundred and eighty‐one patients were divided into three groups according to the insulin therapy, the level of C peptide (CP), and GAD antibodies (anti‐GAD). Group 1 (type 1 diabetes in adults) was characterized by CP less than 200 pmol/L and anti‐GAD more or less than 50 ng/mL (n = 80). All of them had insulin therapy within 6 months after diagnosis. Group 2 latent autoimmune diabetes mellitus in adults (LADA) was defined by a minimum 6‐month‐long phase after diagnosis without insulin therapy, and was characterized by CP more than 200 pmol/L and anti‐GAD more than 50 ng/mL (n = 70). Group 3 (type 2 diabetes) was characterized by CP more than 200 pmol/L and anti‐GAD less than 50 ng/mL (n = 131). None ever had insulin therapy. In group 1, there was increased frequency of DRB1*04 (45.0% vs. controls 14.1%, OR = 5.0, P < 0.0005) and DQB1*0302 alleles (43.3% vs. controls 11.1%, OR = 6.1, P