Could α MSH-MIFT Axis and IDH2 be Considered Promising Predictors of Non-segmental Vitiligo Response to NB-UVB Phototherapy?

Background: The search for objective factors that help in predicting the response of vitiligo treatment is very important.

Objective: We sought to evaluate the effect of NB-UVB phototherapy on both the alpha melanocyte stimulating hormone-microphthalmia-associated transcription factor (α-MSH-MIFT) axis, and isocitrate dehydrogenase 2 (IDH2) in non-segmental vitiligo (NSV).

Methods: This prospective clinical trial included 50 NSV patients and 50 healthy control subjects. α-MSH tissue levels as well as MITF and IDH2 immunostaining were assessed in normal and vitiliginous skin biopsies before treatment and then in the repigmented areas following 24 NB-UVB phototherapy treatment sessions using ELISA technique and immunohistochemical study, respectively.

Results: There was a significant negative correlation between baseline VASI scores and the tissue levels of α-MSH (=0.006) and the expression of both MITF (<0.00001) and IDH-2 (= 0.001). The mean α-MSH tissue levels increased significantly after treatment (<0.001). Tissue expression of both MTIF and IDH-2 was significantly upregulated following treatment (-value <0.001). The percentage of improvement showed a significant positive correlation with the studied markers (<0.00001).

Conclusion: α-MSH- MIFT axis and the antioxidant protein IDH2 are promising objective markers of non-segmental vitiligo severity, and are suggested as predictors of vitiligo response to treatment.