Objective: YKL-40 is an inflammatory glycoprotein associated with atherosclerosis, cardiovascular disease, diabetes or metabolic syndrome which are common comorbidities in psoriasis. The aim of the study was to assess serum YKL-40 level in psoriasis and elucidate possible associations with disease activity, inflammatory or metabolic parameters and treatment.
Methods: A total of 37 individuals with active plaque-type psoriasis and 15 healthy controls were enrolled. Blood samples were collected before and after 2 weeks of therapy. Serum YKL-40 concentrations were evaluated by enzyme-linked immunosorbent assay (ELISA). The results were correlated with Psoriasis Area and Severity Index (PASI), body mass index (BMI), inflammatory and biochemical markers, lipid profile and topical therapy.
Results: Median YKL-40 serum levels were significantly increased in psoriatic patients in comparison to the controls (p < .0001). No significant correlations between investigated protein and metabolic parameters as BMI (p = .19), glucose (p = .32) nor lipids levels were found. Significant positive relation with CRP (p = .003) or alanine aminotransferase (p = .04) and no correlation with PASI (p = .2) were noted. Serum YKL-40 level remained unchanged (p = .5) after topical treatment, despite clinical improvement.
Conclusions: YKL-40 might be a biomarker of psoriasis and inflammation in psoriatic patients, but not a reliable indicator of metabolic conditions, severity of psoriasis nor efficacy of the treatment.
Keywords: Psoriasis; YKL-40; anthralin; atherosclerosis; cardiovascular disease; topical treatment.