Human herpesvirus 6 infection in neoplastic and normal brain tissue

The presence and variant distribution of human herpesvirus 6 (HHV-6) was in vestigated by a nested polymerase chain reaction (PCR) in 118 biopsies from patients affected by nervous tissue tumor (115 primary tumors and 3 metast asis) and in 31 autopsy samples from the brain of healthy individuals. HHV- 6 DNA sequences were detected in normal and neoplastic nervous tissue at a frequency of 32% and 37%, respectively. In both tissues, variant A was thre e times more frequent than the variant B. Peripheral blood lymphocytes (PBL s) derived from seven tumor affected patients contained the same variant as their respective brain sample, as judged by PCR. The expression of HHV-6 e ncoded immediate early protein p41 was detected by immunohistochemistry in neoplastic but not in normal brain. This may reflect viral reactivation fro m latency in immunocompromised patients. The seroepidemiological data indic ated a frequency distribution of anti-HHV-6 antibodies in patients with bra in tumors similar to that found in healthy donors. (C) 2001 Wiley-Liss, Inc .