Determination of Epstein-Barr virus (EBY) load by RT-PCR and cellular dilution

Epstein-Barr virus (EBV) is a ubiquitous human herpesvirus which establishe s life-long latency in the B-lymphocytes of infected individuals. Epstein-B arr virus is associated with Hodgkin's disease, AIDS-associated lymphoma an d post-transplant lymphoproliferative disease (PTLD). In PTLD, the onset of malignancy correlates with a rise in EBV load. The relationship between ma lignancy and EBV load in other EBV-associated malignancies is not known. Ep stein-Bar virus latency is associated with the expression of a limited set of viral transcripts. The most numerous of these are the EBERs (Epstein-Bar r early RNAs). The high copy number of the EBERs in each latently infected cell led the author to combine serial dilution of lymphocytes with reverse transcriptase polymerase chain reaction (RT-PCR) for EBER-1 as a means to r apidly quantitate EBV load. The highest viral load was seen in a bone marro w transplant patient, where one in 3906 lymphocytes harboured EBV. Elevated viral load was seen in two solid-organ transplant patients. Viral loads in healthy volunteers ranged from less than one in 1 x 10(6) to one in 6.25 x 10(4). Reverse transcriptase polymerase chain reaction for EBER-1 in seria l lymphocyte dilutions should allow the relationship of EBV load and malign ancy to be examined in a number of disease settings and should also provide a quantitative picture of the impact of anti-viral therapy. (C) 1998 Acade mic Press.