DETECTION RATE AND INTRATUMORAL VIRUS LOAD OF HUMAN-HERPESVIRUS-8 IN IMMUNODEFICIENCY-RELATED B-CELL LYMPHOID MALIGNANCIES

Human herpesvirus-8 (HHV-8), associated with Kaposi's sarcoma, primary effusion lymphoma, and Castleman's disease, has been found in circula ting B-cells and might have a causative role in B-cell malignancies as sociated with immunodeficiency syndromes. We determined the rate of de tection and intratumoral virus load of HHV-8 by means of a semiquantit ative approach in post-transplant lymphoproliferative diseases (PTLDs) , AIDS-related non-Hodgkin's lymphomas (NHLs), including both Burkitt' s lymphomas (BLs) and large cell lymphomas (LCLs), as well as in contr ol groups consisting of follicular hyperplasias (FHs) and HIV-negative LCLs. HHV-8 sequences were detected at a similar rate in HIV-negative PTLDs (24%), HIV-negative LCLs (22%) and HIV-negative FHs (17%). The detection rate was significantly higher in HIV-positive BLs (73%), HIV -positive LCLs (67%), and HIV-positive FHs (65%) supporting the view o f an epidemiological link between HHV-8 and HIV infections. The viral load was 10(2) genome copies per cell in the single case of primary ef fusion lymphoma included in the LCL group while it was 10(-3) copy per cell (median value; range: 10(-4)-10(-1)) in all the other HHV-8-posi tive samples. No significant difference of viral load was found accord ing to HIV status. The virus loads of PTLDs and HIV-positive LCLs were significantly higher than those observed in HIV-positive BLs and FHs, suggesting, to some extent, that the degree of immunodeficiency may i nfluence HHV-8 replication. However, with the exception of the single case of primary effusion lymphoma studied, the low intratumoral load o f HHV-8 strongly argues against a direct causative agent of the virus in the occurrence of PTLDs and AIDS-related NHLs. (C) 1997 Wiley-Liss, Inc.