Expressions of CDla and Ki-67 in psoriatic lesions before and after narrow-band ultraviolet B phototherapy

Objective To investigate the effect of narrow-band ultraviolet B phototherapy on the expression of CDla and Ki-67 in psoriatic lesions. Methods The expression and distribution of CDla and Ki-67 antigens were detected by immunohistochemistry in involved and uninvolved psoriatic skin of 27 patients before and after ultraviolet B phototherapy. Psoriasis area and severity index (PASI) was assessed to evaluate the severity of disease. Results The count of CDla-expressing dendritic cells and Ki-67-expressing keratinocytes per square millimeter under high power field was higher in untreated involved psoriatic epidermis than that in uninvolved psoriatic epidermis and involved psoriatic epidermis after narrow-band UVB therapy (15 ±4 vs 9 ± 3 and 9 ± 3, 53 ± 12 vs 22 ± 6 and 25 ±1, all P 0.05). Conclusions Narrow-band UVB may improve psoriasis via modulating the immune system of skin. The expression level of Ki-67 in psoriatic epidermis is associated with PASI. Key words: Psoriasis; Ultraviolet rays; Immune system; CDla+; Ki-67; Dendritic cells