Serum YKL-40 in patients with psoriasis vulgaris treated by narrow-band UVB phototherapy

Background: Psoriasis is a common chronic and immune-mediated inflammatory skin disease. Objectives: This study aimed to investigate the serum levels of Chitinase-3-like protein 1 (YKL-40) in patients with psoriasis vulgaris before and after narrow-band ultraviolet B (NB-UVB) phototherapy. Methods: This study was designed as a cross-sectional case-control. This study included 30 patients with psoriasis vulgaris and 20 healthy individuals. Psoriasis Area and Severity Index (PASI) score were used to evaluate the patients with psoriasis vulgaris before and after treatment. All patients were treated 2 times per week for 3 months with NB-UVB phototherapy. Enzyme-linked immunosorbent assay (ELISA) was used to assess serum levels of YKL-40 of the healthy control subjects and psoriatic patients before and after treatment by NB-UVB phototherapy. Results: The serum level of YKL-40 was significantly higher in patients with psoriasis vulgaris versus healthy control subjects (p value<.001). There were significant reductions in the serum levels of YKL-40 and PASI scores after 3 months of treatment with NB-UVB phototherapy in patients with psoriasis vulgaris (p value<.001). Conclusions: This study concluded that NB-UVB phototherapy for three months in patients with psoriasis vulgaris was an essential method for decreasing the serum levels of YKL-40 and PASI scores.