IDENTIFICATION OF ACTIVE CYTOMEGALOVIRUS-INFECTION BY ANALYSIS OF IMMEDIATE-EARLY, EARLY AND LATE TRANSCRIPTS IN PERIPHERAL-BLOOD CELLS OF IMMUNODEFICIENT PATIENTS

Owing to the persistence of viral DNA in leukocytes after primary CMV infection, detection of CMV DNA in these cells does not necessarily re present active infection. To identify CMV replication more precisely w e have analysed immediate-early, early and late CMV transcripts by RNA amplification. The assay seems to be specific for active infection si nce no RNA-derived PCR products were obtained from healthy seropositiv e persons. The late UL83 transcript was detected in 80% of the patient s with active CMV infections. Diagnosis of CMV replication by amplific ation of early and immediate-early transcripts was considerably less s ensitive. In the case of continual CMV DNA detection in blood leukocyt es by PCR without pp65 antigenemia the analysis of defined CMV transcr ipts would allow differentiation of active and non-active infection. I n two cases the RNA assay became negative prior to DNA PCR analysis an d pp65 antigen detection upon antiviral treatment, indicating that RNA amplification could be a suitable assay for early detection of the en d of viral replication. No strong correlation was found between RNA de tection and appearance of clinical symptoms. The development of CMV di sease probably depends more on the extent of the functional impairment of the immune system.