Diagnosis and monitoring of human cytomegalovirus infection in transplant recipients

In the last decade, transplantology has become the treatment of choice for a large number of malignant diseases or organ dysfunctions. Transplants are classified into two main groups: solid organ transplants (SOT) and haematopoietic stem cell transplants (HSCT). Human cytomegalovirus (HCMV) infection is the most common viral complication in both SOT and HSCT recipients within 3 months of transplant. Major risk factors for HCMV infection are the mismatch between donor and recipient antibody status, and the immunosuppressive regimen. Clinical manifestations range from asymptomatic infections to severe HCMV disease involving lung, gastrointestinal tract, liver, retina, central and peripheral nervous systems. Diagnosis is based mainly upon detection and quantification of virus in blood by determination of viraemia, antigenaemia, DNAaemia, and RNAaemia. In addition, detection of the emergence of resistance to HCMV-specific antiviral drugs such as ganciclovir and foscarnet, may be achieved by performing phenotypic and genotypic assays. Monitoring of HCMV infections in both SOT and HSCT recipients allows timely adoption of pre-emptive (presymptomatic) therapy strategies, which have led to almost complete disappearance of HCMV disease in both transplantation settings. In parallel, sustained treatment with specific antiviral drugs must elicit monitoring of antiviral drug resistance to permit a timely shift to an alternative drug. In conclusion, diagnostic and therapeutic tools now available allow almost complete control of HCMV infections in different transplantation settings. (C) 2001 Lippincott Williams & Wilkins.