IL-12, IL-17 and IL-23gene polymorphisms in alopecia areata

Alopecia areata is a nonscarring hair loss on the scalp and/or body. Although etiopathogenesis is unknown, it is thought to be an autoimmune disease with genetic predisposition and environmental triggers, mediated by T cells. In this study our aim is to investigate IL-12 (1188A/C), IL-17 (A7488G) and IL-23 (+2199A/C) gene polymorphisms and to compare the clinical parameters in patients with alopecia areata. In the study, 100 patients with alopecia areata and 71 volunteers with no personal and family history of alopecia areata were enrolled. IL-12 (1188A/C), IL-17 (A7488G) and IL-23 (+2199A/C) gene polymorphisms were determined by PCR-RFLP (Polymerase chain reaction-restriction fragment length polymorphism) method both in patient and control groups. There were no significant differences in the polymorphisms of IL-12 (1188A/C) and IL-23 (+2199A/C) genes between patients and healty controls. In patients with alopecia areata IL-17 (A7488G) GG genotype was significantly increased than control group (p=0,021), GA genotype was significantly (p=0.014) decreased. Groups of patients according to disease severity compared with IL-17 (A7488G) AA genotype was significantly (p= 0.024) higher in the group with mild to severe illness, GG genotype was significantly (p=0.029) lower. Patient groups compared according to the presence of autoimmune diseases IL-17 (A7488G) AA genotype was significantly (p=0.027) higher in the patients without autoimmune disease than in the patients with autoimmune disease. In conclusion, IL-17 (A7488G) GG genotype may contribute to susceptibility to alopecia areata, GA genotype may be a protective factor against alopesia areata. IL-17 (A7488G) GG genotype may be a risk factor for increasing the severity of disease, AA genotype may be a protective factor against the severity of disease and development of autoimmune diseases. Key Words: Alopecia Areata, Polymorphism, IL-12, IL-17, IL-23