EVALUATION OF MUREX CMV DNA HYBRID CAPTURE ASSAY FOR DETECTION AND QUANTITATION OF CYTOMEGALOVIRUS-INFECTION IN PATIENTS FOLLOWING ALLOGENEIC STEM-CELL TRANSPLANTATION

Murex hybrid capture DNA assay (HCS) is a solution hybridization antib ody capture assay for detection and quantitation of cytomegalovirus (C MV) DNA in leukocytes. To determine whether CMV HCS is sensitive enoug h to initiate and monitor antiviral therapy after allogeneic stem cell transplantation (SCT), 51 consecutive SCT recipients were prospective ly screened for the appearance of CMV infection by HCS, PCR, and cultu re assays from blood samples. Preemptive antiviral therapy was initiat ed after the second positive PCR result in all patients, as previously reported, and HCS was not considered for clinical decision making. A total of 417 samples were analyzed. Of these, 21 samples were found to be positive by PCR and HCS, 88 samples were PCR positive but HCS nega tive, and 308 were negative by both assays. Concordance of results bet ween PCR and HCS and between HCS and blood culture was observed in 78. 9 and 95.9% of the samples assayed, respectively. PCR was found to be more sensitive than HCS, and HCS was more sensitive than the blood cul ture assay (P < 0.0001), Four patients with symptomatic CMV infection were PCR positive prior to the onset of CMV-related symptoms, whereas HCS detected CMV DNA in three patients prior to and one at onset of CM V disease. The numbers of genomes per milliliter of blood were higher in patients with symptomatic CMV infection than in those with asymptom atic CMV infection (P = 0.06), None of the HCS-negative patients devel oped CMV disease. Thus, all patients with CMV disease were correctly i dentified by HCS; however, the lower sensitivity limit of the HCS assa y may still be insufficient to allow diagnosis of CR IV infection earl y enough to prevent CMV disease in patients following allogeneic SCT.