부산대학교 도서관

AIMS: Mast cells (MCs) are associated with fibrosis in various diseases. MCs comprise two phenotypes: the MCTC phenotype contains tryptase and chymase, whereas the MCT phenotype contains tryptase. Interleukin (IL)-4 promotes the development of MCTC from the MCT phenotype. The aim of this study was to determine the relationship between MC phenotypes and fibrosis in diffuse large B-cell lymphoma (DLBCL). METHODS AND RESULTS: We examined the distribution and density of MCs in 50 DLBCL and 20 reactive lymph nodes, and evaluated MC phenotypes and IL-4-expressing cells. To detect MCs, immunohistochemistry for tryptase and chymase was performed. The 50 DLBCLs were histologically divided into three groups: no fibrosis (32 cases), reticular type (eight cases) showing reticular fibrosis, and bundle type (10 cases) showing collagenous bundles. The density of tryptase-positive MCs was higher than that of chymase-positive MCs. The densities of tryptase-positive and chymase-positive MCs in fibrotic areas were significantly higher than those in the cellular areas in the reticular and bundle groups. Double immunostaining revealed that MCs in DLBCL comprised MCT and MCTC phenotypes. Chymase-positive MCs and T lymphocytes expressed IL-4. Although there were few chymase-positive MCs in reactive lymph nodes, the density of tryptase-positive MCs was not different from that in the ‘no fibrosis’ group. CONCLUSIONS: Tryptase-positive and chymase-positive MCs are associated with fibrosis in DLBCL.