ABSTRACT
BACKGROUND: Diffuse large B-cell lymphoma (DLBCL) is the most common type of malignant lymphoma which responds well to conventional chemotherapy. However, quite a few patients have a recurrence with more aggressive forms after completion of therapy. Multidrug resistance proteins (MRP) are related to this process in several ways such as cell cycle alteration and modulation of apoptosis. METHODS: We investigated the expression of P-glycoprotein (Gp), one of the well-known MRP, as well as apoptosis associated proteins in DLBCL. Immunohistochemical staining for Gp, p53, Bcl-2, Ki-67, active caspase 3 and FADD was done in forty DLBCL cases. The association between MRP and apoptosis associated proteins to clinical findings was also tested. RESULTS: Twenty-nine patients out of 40 (73%) with DLBCL were positive for Gp, and 26 cases (65%) had a strong positive for Gp. Gp expression was stronger in high-grade lesions than in low-grade lesions and was associated to Bcl-2 expression. However, we could not find an adverse impact of Gp expression on patients' overall survival or relapse free survival rate. CONCLUSIONS: Our study revealed a high frequency of expression for Gp in DLBCL with a possible relationship between the expressions of Gp to apoptosis associated proteins.