A POLYMERASE CHAIN-REACTION TO DETECT A SPLICED LATE TRANSCRIPT OF HUMAN CYTOMEGALOVIRUS IN THE BLOOD OF BONE-MARROW TRANSPLANT RECIPIENTS

A reverse transcription (RT) nested polymerase chain reaction (PCR) pr ocedure is described for detecting RNA to a spliced late gene (SLG) of human cytomegalovirus (CMV), the product of which (175 bp) is easily differentiated in agarose gels from the product when the target is uns pliced viral RNA or DNA (258 bp). The SLG-RT-PCR has been compared aga inst a semi-quantitative PCR for CMV DNA in buffy-coat specimens colle cted weekly after bone marrow transplantation from 3 patients and agai nst the results of culturing these specimens for CMV both by conventio nal virus isolation, based on the detection of cytopathic effect, and by the early detection of infected cells by staining with virus-specif ic monoclonal antibodies. The detection of CMV RNA by SLG-RT-PCR corre lated well with the detection of infective virus but only when the res ults of both culture methods were combined, in that neither culture me thod alone was as sensitive as the SLG-RT-PCR. The presence of SLG RNA in the circulation is of value as a marker of active CMV infection.