Analysis of Expression of Myofibroblasts in Oral Submucous Fibrosis: An Immunohistochemistry Study

Background: Oral submucous fibrosis (OSMF) is a chronic disease that produces tissue fibrosis and is considered to be a potentially malignant disorder. The exact pathogenesis and malignant conversion mechanism of this disorder are still unknown. Myofibroblasts have been implicated as one of the possible pathological mechanisms responsible for the pathophysiology of OSMF. The present study was conducted to evaluate the expression of myofibroblasts (MF) in normal mucosa and different grades of OSMF. Materials & Methods: The sample consisted of a total of 80 specimens. The study group included specimens from clinically and histopathologically confirmed OSMF patients. The specimens were divided into four groups. Group 1 consisted of 19 specimens of grade III OSMF. Group II had 20 specimens of grade II OSMF, Group 3 with 21 specimens of grade I OSMF, and Group 4 constituted a control group of 20 normal epithelium specimens. Two sections each from all the four groups were obtained. While one section was stained with H and E, the other section was stained immunohistochemically using alpha-smooth muscle antibody. For analysis, the expression of myofibroblasts was categorized as strong, moderate, weak, or absent. All the results were recorded and subjected to statistical analysis. Results: In OSMF patients, irrespective of the grade, the expression of myofibroblast was strong in 28.33 percent of the patients, while it was moderate and weak in 30.00 percent and 40.00 percent of the patients, respectively. Expression of myofibroblast was noted to be significantly increased in grade III OSMF patients as compared to controls as well as grade I OSMF patients (p-value <0.05). Conclusion: Myofibroblasts expression is significantly raised in OSMF patients. The expression can also be correlated within different grades of OSMF where advanced stages show comparatively high expression of these smooth muscles like fibroblasts. Hence, we suggest that myofibroblasts could be assessed as markers for analyzing the progression of OSMF.