Evaluation of the role of YKL-40 in psoriasis and its connection to metabolic syndrome

Introduction:
Psoriasis is a prevalent skin inflammatory disorder with immune-mediated pathogenesis. Chitinase-3 like-protein-1 (YKL-40) is a glycoprotein with elevated expression levels in many human cancers and inflammatory diseases.

Objective:
The YKL-40 expression levels in psoriasis patients’ serum and skin tissue were investigated and compared with the patient’s clinical and histological information and metabolic syndrome variables.

Material and methods:
Enzyme-linked immunosorbent assay along with immunohistochemistry were performed to assess serum and tissue expression of YKL-40, respectively, in 35 psoriasis patients and 35 healthy controls. Moreover, carotid intima-media thickness and metabolic syndrome parameters were evaluated.

Results:
Patients with psoriasis had considerably increased serum and tissue expression of YKL-40 in comparison to healthy individuals. These levels in tissue and serum correlated with each other. YKL-40 immunohistochemical expression was also linked to elevated lipid profiles in psoriatic patients.

Conclusions:
As YKL-40 tissue expression was associated with the essential pathologic changes of psoriasis (increased cutaneous vascularity and inflammation), YKL-40 appeared to have a promising future in psoriasis. Furthermore, its association with elevated lipid profile in those patients suggests that YKL-40 may play a role in psoriasis and metabolic symdrome development. The elevated serum level was higher in patients and positively correlated to its tissue expression.