YKL-40 tissue expression in lichen planus

Background Lichen planus (LP) is an idiopathic chronic inflammatory disease of the skin, mucous membranes, and nails. The exact pathogenesis of LP is still unclear. Chitinase-3-like protein 1 (YKL-40) is one of the 18 glycosyl hydrolases, but lacks enzymatic activity. Recent studies have shown that YKL-40 is present at sites of inflammation and tissue remodeling, triggers immune responses, and attracts eosinophils and T cells. Objective To clarify a suggested role of YKL-40 in LP inflammation. Patients and methods This case–control study included 30 cutaneous LP patients and 30 healthy volunteers serving as controls. About 4-mm punch-skin biopsies were taken from skin lesions in LP patients and healthy skin from controls. Skin biopsies were examined for YKL-40 using PCR technique. Results The expression of YKL-40 in LP lesions (5.12±1.02 pg/ml) was significantly higher than their expression in control-tissue biopsies (1.02±0.05 pg/ml) (P<0.001). No significant relation was detected between the expression of YKL-40, type of LP, and the disease duration. Conclusion We can conclude that upregulation of YKL-40 could point to a possible role in the pathogenesis of LP.