ABSTRACT
[ ABSTRACT] AIM:To investigate the distribution of mast cells ( MCs) and the expression of transforming growth factor-β(TGF-β) on tryptase positive MCs in different types of human periapical diseases.METHODS:Total 78 cases of specimens were involved in this study, including healthy control, periapical cyst and periapical granuloma.The tissue sam-ples were fixed in 10% formalin for at least 48 h, stained with hematoxylin and eosin for histopathological examination, stained with toluidine blue staining for identifying MCs and MCs degranulation, and stained with double immunofluores-cence for identification of tryptase-TGF-βdouble positive MCs.RESULTS:The density of tryptase-TGF-βdouble positive MCs in the periapical lesions was significantly higher than that in the healthy controls ( P<0.01) .The number of TGF-βpositive MCs in the periapical cyst was significantly higher than that in the periapical granuloma ( P<0.01 ) .Compared with toluidine blue staining, the number of MCs with double immunofluorescence staining significantly increased ( P <0.01).CONCLUSION:The TGF-βpositive MCs may play an important role in the pathogenesis of human chronic peria-pical diseases, particularly in the formation of fibrous tissue in periapical cyst.Double immunofluorescence staining is more sensitive than the traditional toluidine blue staining for identifying MCs.