Cytomegalovirus transcripts in peripheral blood leukocytes of actively infected transplant patients detected by reverse transcription-polymerase chain reaction.

In an effort to examine human cytomegalovirus (CMV) infections on the transcript level in vivo, a reverse transcription-polymerase chain reaction (RT-PCR) for the detection of CMV mRNA in human peripheral blood leukocytes (PBL) was developed. Oligonucleotide primers were derived from the major immediate-early (MIE) and the pp150 genes of CMV, which allowed the exact differentiation between viral mRNA and DNA. With these primers, 8 renal transplant patients who revealed some evidence of active CMV infection were investigated. CMV-specific transcripts were found in 5 patients, all of them presenting MIE mRNA. pp150 transcripts were demonstrated in only one symptomatic patient who showed RNAemia for several weeks. These findings suggest that during active infection, CMV replicates in PBL and, furthermore, that a detailed analysis of mRNA patterns may make it possible to identify those patients at highest risk of developing symptomatic infection.