Immunohistochemical analysis of the antiapoptotic Mcl-1 and Bcl-2 proteins in follicular lymphoma

Abstract

In the present study, we investigated the expression of Mcl-1 and Bcl-2 by immunohistochemistry in 85 patients of grades 1-3 and transformed follicular lymphoma (FL). In lymphoma tissue, centroblasts uniformly expressed high levels of Mcl-1 (Mcl-1hi) whereas centrocytes demonstrated low Mcl-1 expression (Mcl-1lo). Bcl-2 expression in centroblasts/centrocytes was reciprocal to Mcl-1 staining in most cases. A high number of Mcl-1 hi centroblasts in tissue sections (≥200/high-power field) correlated with poor overall survival (P < 0·001), independent of the International Prognostic Index and FL grade. This suggests that the number of centroblasts with strong Mcl-1 staining is associated with clinical outcome in FL patients. © 2006 Blackwell Publishing Ltd.