Expressions of CD1a and Ki-67 in psoriatic lesions before and after narrow-band ultraviolet B phototherapy

Abstract

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 CD1a-expressing dendritic cells and Ki-67-expressing keratinoeytes 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）. The PASI score significantly correlated with the expression level of Ki-67 （ r = 0.29, P 〈 0.05）, but unrelated to that of CD1a （r =-0.27, 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; CD1a^＋; Ki-67; Dendritic cells