Lymphotropic virus infection of peripheral blood mononuclear cells in B-cell non-Hodgkin's lymphoma.

Some lymphotropic viruses such as Epstein-Barr virus (EBV) and human herpesvirus 6 (HHV-6) have been proposed as causative agents of B cell non-Hodgkin's lymphoma (NHL). More recently, the presence of hepatitis C virus (HCV), which is both a hepatotropic and lymphotropic virus, has been reported in one third of B cell NHL patients. The aim of this study was to investigate in a series of B cell NHL the prevalence of three lymphotropic viruses, i.e. EBV, HHV-6 and HCV, in peripheral blood mononuclear cells (PBMC). Eighteen unselected B cell NHL patients (10 men, 8 women; mean age 62 +/- 12 years, range 31-77 years; mean disease duration 1.8 +/- 1.4 years) and 40 age- and sex-matched healthy controls were included in the study. In all cases, an acquired-immunodeficiency-syndrome-related lymphoma was excluded. By means of the polymerase chain reaction technique, EBV DNA, HHV-6 DNA and HCV RNA were detected in PBMC. HCV genomic sequences were significantly more frequent in PBMC of NHL patients than in controls (33 vs. 2.5%; p < 0.01); on the other hand, in the same two groups EBV DNA (39 vs. 60%; p = not significant) and HHV-6 DNA (22 vs. 32%; p = not significant) were present in a comparable percentage of individuals in the same two groups. The infection of PBMC by HCV alone was present in the majority (5 of 6) of HCV-positive NHL. These data support the implication of HCV infection in a statistically significant number of B cell NHL, whereas a possible co-operation between HCV and other well-known lymphotropic viruses seems to be excluded.