Evaluation of myofibroblasts in oral submucous fibrosis: correlation with disease severity

Oral submucous fibrosis (OSMF) is a chronic debilitating disease and a premalignant condition of the oral cavity characterized by generalized submucosal fibrosis. Myofibroblasts are contractile cells 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 organs like lungs, liver, kidney and skin. This study aims to evaluate the presence of myofibroblasts in various histological stages of OSMF.

Seventy cases of OSMF, which were further categorized histologically into early (35 cases) and advanced (35 cases), were subjected to immunohistochemistry using α-SMA antibody for detection of myofibroblasts. Fifteen normal oral mucosa specimens were also stained as controls.

The number of α-SMA-stained myofibroblasts in OSMF was significantly increased when compared to that of the normal controls (P<0.001). Additionally, a statistically significant increase in the myofibroblasts population between early and advanced stages was observed (P=0.000).

Our results corroborate the possibility that OSMF actually represents an abnormal healing process in response to chronic mechanical and chemical irritation because of areca nut chewing as demonstrated by the increased incidence of myofibroblasts in this disease. Furthermore, the progressive increase in myofibroblasts from early to advanced stages suggests their potential use as markers for evaluating the severity of OSMF.