Association between HLA-DQA2 Allele and Alopecia Areata

Background and purpose: Alopecia areata (AA), also known as spot baldness, is an autoimmune disease in which hair is lost from some or all areas of the body. Genetic factors are known to play a role in the onset of this disease. The HLA complex genes are primarily involved in AA. In present study, effect of HLA-DQA2 allele frequency was analyzed in Iranian AA patients and control samples. The study group comprised 30 patients with Alopecia areata and 15 healthy controls. Genomic DNA was extracted from whole blood using DNG plus method. Polymerase chain reaction with sequence specific primers technique (PCR-SSP) was performed to detect HLA-DQA2. The association between HLA-DQA2 allele and some risk factors such as family history, anemia, and the onset of the disease was analyzed. Patients included 13 females and 17 males (mean age 26.3 ±12.5 years) and the controls were five females and 10 males (mean age 30.1±5.8 years). The frequency of HLA-DQA2 allele in AA patients (93.33%) was not significant compared to that of the controls (76.66%) (OR 0.94, 95% CI =0.018-1.018, p>0.05). No association was found between the disease and family history of AA (OR=0.09; 95% CI=0.01-0.119, P= 0), and onset of disease (OR =1.015; 95% CI=0.95-1.07, p=0.607). But significant correlation was observed between AA disease and anemia (OR =0.017; 95% CI=0.02-0.179, p=0.001). This study did not show strong correlation between HLA-DQA2 allele and developing Alopecia areata. The HLA-DQA2 allele was associated with anemia, but not related to family history and the onset of disease.