Immunohistochemical evaluation of myofibroblasts using alpha-smooth muscle actin in oral submucous fibrosis

Abstract

Introduction: Oral submucous fibrosis (OSMF) is a chronic debilitating disease and a premalignant condition of the oral cavity characterized by generalized submucosal fibrosis with a multifactorial etiology. Myofibroblasts are a unique group of cells phenotypically intermediate between smooth muscle cells and fibroblast exhibiting contractile properties, expressing α-smooth muscle actin (α-SMA) and are considered primary producers of extracellular matrix after injury. Their accumulation has been established as a marker of progressive fibrosis in various organs. The aim of the present study is to evaluate and compare the myofibroblasts in various histological grades of OSMF. Materials and Method: Fifteen cases of OSMF, which were further categorized histologically into early (5 cases), moderately advanced (5 cases) and advanced (5 cases), were subjected to immunohistochemical evaluation using α-SMA antibody for detection of myofibroblasts. Fifteen benign mucosal proliferation specimens were also stained for comparison. Results: The number of myofibroblasts in OSMF was significantly increased when compared to that of benign mucosal proliferations (P < 0.05). Additionally, a statistically significant increase in the myofibroblasts population between early and advanced stages was observed (P < 0.05). Conclusions: The results of the present study showed that expression of myofibroblasts within the OSMF group showed a progressive increase from the early OSMF through moderate OSMF and the advanced OSMF group indicating that myofibroblasts could serve as effective prognostic marker for disease progression in oral submucous fibrosis.

Keywords

• myofibroblasts
• oral submucous fibrosis
• α-sma