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

Abstract

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.

Estimation of tissue level of human beta‐defensin 1 in vitiligo before and after narrowband ultraviolet B phototherapy: A case‐control study

“…This comes in contrast to the study of Ochoa‐Ramírez et al, 4 who reported that HBD‐1 levels were lower in patients with active vitiligo in comparison to patients with stable vitiligo; that is probably because HBD‐1 was measured in serum reflecting the systemic activity of the disease, not lesional skin that could be either stable or active. This is strongly supported by the well‐established HBD‐1 gene polymorphism in vitiligo 4,5 (Tables ).…”

“…Genotype frequencies of HBD‐1 were studied in vitiligo patients. Both the ‐44CG genotype and G‐allele frequencies were higher in patients with vitiligo, conferring an increased risk of developing vitiligo 4,5 . Therefore, the goal of this study was to assess the tissue level of HBD‐1 in vitiligo patients in comparison to its level in healthy controls to verify its role in the pathogenesis of vitiligo.…”

Human beta-defensin 1 circulating level and gene polymorphism in non-segmental vitiligo Egyptian patients

“…In agreement with this result, Ochoa-Ramírez et al 25 observed that there was a predominance of GG genotype at position-20 in vitiligo patients than controls. Also, Salem et al 30 studied 50 Egyptian NSV patients and revealed that the DEFB1 (−20G/A) AA genotype and A allele had significantly lower frequencies in vitiligo patients and exerted a protective effect against vitiligo development.…”

Precision medicine and personalized approach in vitiligo

“…Similarly, polymorphism in human beta defensin, an antimicrobial peptide has also been found to govern response to phototherapy. AA genotype of DEFB1 (−20G/A) has a protective role against vitiligo development, while (DEFB1 −44 C/G) GG genotype not only doubles the risk of vitiligo, but also portends a poor response to NB‐UVB 13 …”

“…AA genotype of DEFB1 (−20G/A) has a protective role against vitiligo development, while (DEFB1 −44 C/G) GG genotype not only doubles the risk of vitiligo, but also portends a poor response to NB-UVB. 13 2.3 | Micro RNAs (miRNAs) and therapeutic targets miRNAs are long noncoding messsenger RNA (mRNAs) which modulate cellular differentiation, proliferation and apoptosis, including immune cell and melanocyte development and function, thus playing a role in vitiligo pathogenesis.…”