Immunohistochemical evaluation of cyclooxygenase‐2 and mast cell density in periapical lesions

Abstract

AbstractAimPeriapical granuloma (PG) and cyst (PC) are formed as a protective response consequent to pulpal infection leaching through the apical foramen and lateral canals. Various inflammatory mediators like mast cells and cyclooxygenase (COX)‐2 are involved in this intricate process. This pilot study aimed to evaluate and compare the immunoexpression of tryptase and COX‐2 in periapical granuloma and periapical cyst, and also correlate them with intensity of inflammatory infiltrate and thickness of cystic epithelial lining.MethodologyAn observational and cross‐sectional study was conducted on paraffin‐embedded tissue sections of 50 PGs and 50 PCs submitted for morphological and immunohistochemical analysis using anti‐tryptase and anti‐COX‐2 antibodies. The mean number of mast cells (total, granulated and degranulated), mean COX‐2 expression and inflammatory score was calculated. The data obtained were analysed using Mann Whitney U, Student's T, Chi‐square and Spearman correlation test (p < .05).ResultsThe inflammatory score, total mast cells and COX‐2 expression were similar in PGs and PCs (p = .352, .339 and .352) however, the degranulated mast cells were highly significant in PC while granulated mast cells were highly significant in PG respectively (p < .001 in both). Although a non‐significant correlation existed between COX‐2 and total mast cells in both groups but, total mast cells were significantly correlated with epithelial thickness in PC (p = .029).ConclusionsMast cells and cyclooxygenase‐2 proved to be independent inflammatory markers in periapical lesions. Further studies should be planned on mast cell and COX‐2 inhibitors as treatment modalities of periapical lesions.