Assessment of YKL-40 as a Potential Biomarker of the Disease Severity in Psoriatic Patients with or without Psoriatic Arthritis Treated with Methotrexate

Abstract

Abstract Introduction Psoriasis is an inflammatory disease of a complex pathogenesis with its typical cutaneous symptoms are papules& plaques covered with silvery scales and arthritis is one of its most common complications. The biological role of chitinase-3-like protein 1 (YKL-40) remains unknown. It is suggested that this protein takes part in processes such as proliferation, inflammation, angiogenesis and tissue remodelling. Aim To investigate the serum level of YKL-40 in psoriatic patients with or without psoriatic arthritis and to study the effect of treatment with methotrexate on the serum levels of YKL-40. Material and methods The study was performed on 40 patients with psoriasis vulgaris with or without psoriatic arthritis. All patients showed the clinical signs of psoriasis vulgaris with or without psoriatic arthritis. The diagnosis of cutaneous psoriasis was made clinically based on the characteristic lesions and scored according to Psoriasis Area and Severity Index (PASI) and, additionally, the Body Surface Area (BSA). Psoriatic arthritis patients had fulfilled the diagnostic criteria defined by the classification of Psoriatic Arthritis (CASPAR) criteria. The severity of psoriatic arthritis was assessed using DAPSA Score. Blood samples were taken to measure the serum concentration of YKL-40. Results YKL-40 serum levels were significantly higher in patients with psoriatic arthritis, compared to patients with psoriasis only & a significant reduction inYKL-40 levels in both groups, psoriasis patients with and without psoriatic arthritis, after receiving methotrexate treatment. There was a positive correlation between serum YKL-40 and PASI. Conclusions YKL-40 can be a useful biomarker for assessment of the disease severity in psoriatic patients with or without psoriatic arthritis. It also detects the efficacy of treatment with methotrexate.