Cytomegalovirus Infection in Transplant Recipients: Applications of PCR

Abstract

Objective: Various laboratory methods for detection of cytomegalovirus (CMV) are available, but all suffer from limited sensitivity and specificity or are prone to sampling errors. With the highly sensitive polymerase chain reaction (PCR) active CMV infection is difficult to confirm, so schemes have been devised to improve the diagnostic significance of CMV PCR. Data Sources: Recent literature, including original articles by the authors, on laboratory diagnosis of CMV infection in transplant patients is reflected on. Selection Criteria: CMV PCR applications in the transplant setting, particularly renal transplantation, are discussed with respect to specific risks for CMV infection in this group of patients. Results: CMV PCR from leukocytes usually becomes positive earlier than antigenemia. Repeatedly positive qualitative PCR over time as well as quantitative PCR increase the predictive value for symptomatic CMV infection in seropositive transplant recipients, with PCR being less hampered by delayed sample processing than antigenemia. CMV PCR from leukocytes of healthy seropositive blood donors remains continuously negative. To date PCR data on the role of CMV in graft rejection are controversial. Conclusions: Qualitative CMV PCR is best of all useful to screen seronegative transplant recipients. Quantitative PCR is superior to antigenemia when analyzing samples processed with delay. PCR screening of blood products for CMV is not reasonable. The utility of PCR to recognize CMV-associatedgraft rejection is unclear.