HLA Class II Differentiates Between Thyroid and Polyglandular Autoimmunity.

The HLA class II genes are susceptibility genes for autoimmune endocrine diseases; however, scarce data are available pertaining to the determinants of genetic susceptibility to polyglandular autoimmunity (PGA). A total of 300 consecutive and unselected patients with either PGA or monoglandular autoimmune thyroid disease (AITD) and 100 healthy control subjects were genotyped for the HLA class II DRB1, -DQA1, and -DQB1 alleles. Compared to patients with AITD and controls, the HLA-DRB1*03 (pc =0.001), *04 (pc<0.001), -DQA1*03 (pc<0.001), and -DQB1*02 (pc =0.001) alleles were increased in patients with PGA. When dividing patients with Hashimoto's thyroiditis (HT) into those with PGA (PGA-HT) v…