Significance of reverse transcription polymerase chain reaction in the detection of human cytomegalovirus gene transcripts in thoracic organ transplant recipients

BACKGROUND: Cytomegalovirus disease is a major cause of morbidity in transplant recipients. We have evaluated the clinical value of detecting viral mRNA transcripts for the diagnosis of active infection leading to disease in recipients of thoracic organ transplants.

METHODS: Blood samples from 10 transplant recipients were analyzed before transplantation and weekly after transplantation for 12 weeks. The profile of viral immediate-early, early, and late gene expression was determined by the reverse transcription polymerase chain reaction and compared with cytomegalovirus (pp65) antigenemia and host antibody status (serologic study).

RESULTS: Two patients showed no active cytomegalovirus infection, one had asymptomatic infection detected serologically and seven patients had development of symptomatic infection with a significant serologic change. Viral immediate-early mRNA transcript was detectable in all 10 patients, including the two with no active infection. Early and late gene expression occurred in seven patients who were all antigenemia positive and in whom disease developed. Of the seven patients with development of antigenemia, six showed viral early and late gene expression before pp65 antigenemia, whereas one patient showed antigenemia before early and late gene expression.

CONCLUSION: We have shown that the detection of viral early and late gene expression by reverse transcription polymerase chain reaction can act as diagnostic markers of cytomegalovirus disease with expression of early gene preceding the detection of antigenemia in most cases. In contrast, viral immediate early gene expression did not correlate with clinical infection. This diagnostic approach could be useful in the treatment of thoracic organ transplant recipients.