DEFB1 gene polymorphisms modify vitiligo extent and response to NB‐UVB phototherapy

Human beta defensin‐1(hBD‐1); an antimicrobial peptide, has immune regulatory effects which may be involved in autoimmunity. The aims were to evaluate the association between defensin beta 1 (DEFB1) (‐44 C/G) and (‐20 G/A) gene polymorphisms with the risk of vitiligo development, the extent of the disease and the response to NB‐UVB treatment in a sample of Egyptian population. 178 active nonsegmental vitiligo patients and 182 control subjects were included in this prospective case control study. Vitiligo extent was evaluated using vitiligo area scoring index (VASI). Gene polymorphisms in all participants were studied by RFLP PCR technique. Patients were treated by three narrowband UVB (NB‐UVB) treatment sessions per week. After 12 weeks, the patients were reevaluated clinically to assess the extent of the disease using VASI scoring again and to evaluate the type of repigmentation, if any. AA genotype of DEFB1 (‐20G/A) has a protective role against vitiligo development, while (DEFB1 ‐44 C/G) GG genotype and G allele increase the risk of vitiligo development about two folds. Patients carrying polymorphism in DEFB1 (‐20G/A) only showed the lowest VASI scores (14.23 ± 2.77) and the highest percentage of improvement (66.12 ± 18.01%), while patients carrying polymorphism in DEFB1(‐44 C/G) only showed the highest baseline VASI scores (38.87 ± 6.7) and the lowest therapeutic response (23.79 ± 19.42%) among all patients groups. Different DEFB1 gene polymorphisms may modify the risk of vitiligo development, the disease extent and the response to NB‐UVB phototherapy.