Effects of Narrow Band Ultraviolet B on Serum Levels of Vascular Endothelial Growth Factor and Interleukin-8 in Patients with Psoriasis

The aim of this study was to investigate the effects of narrow band ultraviolet B (NB-UVB) therapy on serum levels of vascular endothelial growth factor (VEGF) and interleukin-8 (IL-8) in patients with psoriasis. Relevant Chinese and English scientific literature databases were searched to identify studies published before November, 2013 that included serum VEGF and IL-8 levels in patients with psoriasis. The studies retrieved from database searches were screened on the basis of predefined selection criteria, and data from finally selected studies were extracted for meta-analysis. Analyses were conducted using STATA 12.0 software. Our systematic search resulted in retrieval of 700 studies (500 studies in Chinese, 200 studies in English), and after a multistep screening process, 13 studies met the inclusion criteria and were enrolled for meta-analysis. The 13 studies contained a combined total of 400 patients with psoriasis and 221 healthy controls. The results of meta-analysis revealed that healthy controls exhibited significantly lower serum level of VEGF, compared to patients with psoriasis before therapy. After NB-UVB, VEGF levels were significantly decreased in patients with psoriasis, as compared to their pretherapy VEGF levels. Although no statistically significant differences were detected in IL-8 serum levels between patients with psoriasis and healthy controls before therapy, after NB-UVB therapy, the serum IL-8 levels in patients with psoriasis were markedly decreased. Corresponding reductions in the psoriasis area and severity index scores of patients with psoriasis were observed after NB-UVB treatment. Our results revealed that NB-UVB therapy significantly decreased the serum levels of VEGF and IL-8 in patients with psoriasis. Furthermore, VEGF and IL-8 levels correlated with disease status, indicating that they are sensitive biomarkers for evaluating the effectiveness of psoriasis therapy.