Endocrine autoimmunity in patients with Latent Autoimmune Diabetes in Adults (LADA) - association with HLA genotype

Introduction: Latent autoimmune diabetes in adults (LADA) is a slow-developing form of autoimmune diabetes, characterised by the presence of type 1 diabetes-associated autoantibody and presentation at diagnosis similar to patients with type 2 diabetes. The aim of this study was to determine the prevalence of auto-antibodies related to endocrine autoimmune diseases in patients with LADA and to assess their association with HLA genotype. Material and methods: We evaluated the presence of anti-thyroglobulin (ATG), anti-thyroid peroxidase (ATPO), anti-tissue transglutaminase IgA (ATTA), and anti 21 hydroxylase (A21H) in 70 patients with LADA, 69 with Type 2 diabetes, and in 50 healthy controls HLA genotype was assed in subpopulation of sluclied subjects. Results: The presence of ATPO (28.6 vs. 10%); ATG (28.6 vs. 14%) was higher in patients with LADA in comparison to healthy controls and ATPO in comparison to patients with type 2 diabetes (38.6 vs. 17.4 %). In patients with LADA the presence of autoimmune thyroid autoantibodies was associated with newly diagnosed subclinical hypothyroidism; almost 7% of patients presented with high TSH. The presence of A21H (2.86 vs. 5.8 vs. 6.1%) and ATTA (2.86 vs. 4.3 vs. 6.0%) was not different between groups. Patients with high TSH level were positive for DQA1*0301 and DRB1*04 HLA genotype: DQB1*0201 and DQB1*02 were higher in patients positive for ATTA. Conclusions: Patients with LADA have higher prevalence of thyroid autoimmune diseases. In patients with LADA similarly to type 1 genotype DQA1* 0301 seems to CONFER susceptibility to thyroid autoimmunity, and DQB1*0201 to celiac disease.