Human retrovirus type 5 sequences in non-Hodgkin's lymphoma of T cell origin

DNA of a recently described fifth exogenous retrovirus (HRV-5) has been fou nd in blood samples from patients with autoimmune diseases and lymphoma. We analyzed HRV-5 sequence in DNA extracted from whole blood of 17 patients w ith T cell non-Hodgkin's lymphoma (NHL) and 186 patients with hematological malignancies other than NHL, using a sensitive PCR technique. While all sa mples of patients with hematological malignancies other than NHL were negat ive, 2 of the 17 patients with T cell NHL were HRV-5 DNA positive. Both HRV -5-positive patients had T cell NHL of high-grade malignancy (stage IV) and diffuse distribution of the lymphoma, including infiltration of bone marro w or lung and pleura. The difference in HRV-5 DNA detection frequency betwe en NHL and control groups is significant (p value of 0.0004 judged by the F isher exact test). These data, together with our previous finding of HRV-5 DNA in three B cell NHL cases, are compatible with an association between H RV-5 and NHL, of both T cell and B cell origin.