YKL-40 immunoexpression as a prognosticator of mycosis fungoides.

Abstract

YKL-40 is a 40 kDa chitinase-like glycoprotein that is predicted to contribute to the pathogenesis of several inflammatory and neoplastic conditions. To assess YKL-40 immunoexpression in different stages of mycosis fungoides (MF) to find out if YKL-40 is playing a possible role in disease pathophysiology and progression. This work included 50 patients with different stages of MF diagnosed on the basis of clinical, histopathological, and both CD4 and CD8 immunophenotyping, in addition to 25 normal control skin. The Immune Reactive Score (IRS) of YKL-40 expression was determined in all specimens and statistically analyzed. YKL-40 expression reported a significant rise in MF lesions compared to control skin. Among MF specimens, the mildest expression was observed in the early patch stage followed by the plaque stage, while the strongest was in tumor stages. Positive correlations were discovered between IRS of YKL-40 expression in MF specimens and patients' age, disease chronicity, clinical staging, and TNMB classification. YKL-40 might participate in MF pathophysiology, and the highest expression is associated with advanced stages of the disease and poor outcomes. Therefore, it might be of value as a prognosticator for monitoring high-risk MF patients and follow-up assessment of treatment success.