HMB-45 Study Before and After Narrow-Band (311 nm) Ultraviolet B Treatment in Vitiligo

Vitiligo is an acquired disease in which the loss of functional melanocytes results in depigmented macules and patches. Over the years, wide arrays of markers for melanocytes have been described, including human melanoma black 45 (HMB-45). Narrow-band ultraviolet B (NB-UVB) therapy is one of the therapeutic modalities for vitiligo. We sought to detect HMB-45 staining after 30 sessions of NB-UVB therapy in vitiligo and perivitiliginous skin. All the participants were planned to have 30 sessions of NB-UVB therapy with 724 lamps (FS, 72 T, 12-HO Daavlin MED) at 311 nm wavelengths. The patients underwent skin sampling from lesional and perilesional area before and after 30 sessions of treatment. The skin biopsies were sent to the laboratory for light microscopy and immunohistochemical study. The evaluation of HMB-45 was based on the quantitative method, measuring the number of positive stained cells. Clinical response was defined as repigmentation in three categories: more than 75%; between 40% and 75%; and less than 40%. The data were analyzed using SPSS (version 17). Twenty-nine patients completed the study. The Wilcoxon test showed a meaningful relation between HMB-45 staining before and after NB-UVB treatment in perilesional skin. We did not find a meaningful relation between HMB-45 staining before and after treatment regarding the mean age, gender, mean duration of disease, and initial lesional area (P = 0.55, P = 0.41, P = 0.55, and P = 0.87, respectively). After 30 sessions of NB-UVB therapy, repigmentation was less than 40% in 8 (27.6%), 40 - 75% in 7 (24.1%), and more than 75% in 6 patients. The HMB-45 stain strength significantly changed after treatment in perilesional skin.