The natural history and molecular heterogeneity of HIV-associated primary malignant lymphomatous effusions.

Abstract

Primary malignant lymphomatous effusions arising in individuals infected with the human immunodeficiency virus, type 1 (HIV-1) represent a rare subset of HIV-associated lymphomas. Previous studies have demonstrated that the malignant cells are monoclonal (as defined by rearrangement of the immunoglobulin gene), express cell surface CD38, and are infected with Epstein-Barr virus (EBV) and human herpes virus, type 8 (HHV-8). Despite these detailed molecular and immunophenotypic studies, clinical information on this disease entity is scant, prompting us to review the clinical features of eight cases seen at our institutions. All eight patients had total peripheral CD4+ lymphocytes < 200/microliter and presented with complaints related to body cavity distension. Routine laboratory values were nondiagnostic and yielded no prognostic information. Only two patients could tolerate and thus received chemotherapy with no obvious impact on their clinical course. The mean overall survival after diagnosis was 60 days (range 6-166 days). Four patients were examined at autopsy. The primary malignant lymphomatous effusion either was the immediate cause of death or contributed significantly to the death of only two. All four patients examined post mortem, however, had lymphomatous infiltration of serosal surfaces adjacent to the site of the primary malignant effusion. Molecular and immunologic studies performed on the malignant cells and effusion fluids revealed universal expression of cell surface CD38 and the presence of HHV-8 gene sequences, but in contrast with previous studies, only four had rearranged immunoglobulin genes or EBV present: IL-6 and IL-10 levels in the malignant effusion fluids were markedly elevated. In summary, this rare subset of HIV-associated lymphomas in our eight patients arose late in the course of HIV-associated disease, had a rapid clinical course, and was molecularly heterogeneous. A pathogenetic role for HHV-8 alone in this disease process is strengthened by our observation of four cases lacking EBV but containing HHV-8.