Evaluation of molecular techniques in prediction and diagnosis of cytomegalovirus disease in immunocompromised patients

Abstract

OBJECTIVES: To evaluate selected molecular tests in diagnosis and screening of cytomegalovirus (CMV) infection in immunosuppressed patients. DESIGN: Clinical and cost-effectiveness were assessed through a prospective two-stage trial of CMV screening regimes in a routine service setting. Different molecular test results were fed back to clinicians in each stage, plus antigenaemia results. The technical performance of the molecular methods was assessed through an independent masked comparison of each molecular test against the established (antigenaemia) test. Scientists performing a particular test were blind to the other test results for that sample. Diagnostic and therapeutic impact were recorded prospectively for all tests, to include any effect on diagnostic certainty, changes to CMV therapy and any other reported impact on patient management. The cost of each test was estimated under different laboratory conditions. Prospective patients undergoing CMV screening were compared with consecutive historical controls in the same unit. Towards the end of the study, a survey of all UK virology laboratories was undertaken to identify current CMV screening practice and test preferences. In addition, all UK renal transplant surgeons and haematology transplant centres were surveyed in order to identify current clinical practice and perceptions of the benefits of CMV screening. SETTING: Study patients were recruited from University Hospital Wales (UHW), Cardiff. Staff in the Cardiff Public Health Laboratory Service virology laboratory performed the tests. PARTICIPANTS: A consecutive series of transplant patients was recruited to the prospective study over a 42-month period, totalling 98 renal and 140 haematology patients. A consecutive series of historical controls was identified, with 199 renal and 136 haematology patients who underwent transplants in the UHW during the 29 months prior to the prospective CMV screening trial.