Large Cell Lymphoma: Correlation of HIV Status and Prognosis with Differentiation Profiles Assessed by Immunophenotyping

Abstract

Diffuse large B cell lymphoma (DLBCL) and plasmablastic lymphoma (PBL) represent aggressive non-Hodgkin lymphomas, particularly in the setting of HIV infection. Since the introduction of highly active antiretroviral therapy (HAART), recent studies have documented improved survival outcome in patients with AIDS-related lymphomas. This study contributes a South African perspective by correlating the HIV status and prognosis of DLBCL and PBL with differentiation profiles assessed by immunophenotyping. Analysis of the morphologic, immunophenotypic and clinicopathologic features of 52 cases of DLBCL and 9 cases of de novo PBL was performed. The overall survival of patients with PBL was poorer than that of DLBCL (logrank p value 0.002). Despite HAART, the overall survival with DLBCL and HIV infection was significantly poorer than HIV negative patients with DLBCL (p value <0.001). Profound immunosuppression was evident in the HIV positive group as the mean CD4 count was 151 cells/mm(3) in DLBCL and 61 cells/mm(3) in PBL. HIV positive patients were significantly younger at presentation with greater likelihood of extranodal lymphoma. When Hans' and Muris' algorithmic stratification of DLBCL were applied, no statistical significance was demonstrated (p values 0.188 and 0.399 respectively). However, when Bcl-2 expression occurred in germinal center-type DLBCL (Hans' defined), improved survival was conferred by the germinal center immunophenotype (p value 0.007). The study demonstrates that DLBCL and PBL have significant potential for aggressive behaviour and poor outcome in the setting of profound immunosuppression due to HIV infection. Further studies are required to assess the effect of targeted-immunotherapy (Rituximab) in combination with recent amendment of the South African national antiretroviral treatment guidelines which has created tremendous potential for improved survival in patients with AIDS-related non-Hodgkin B-cell lymphomas.