Quantification of cytomegalovirus (CMV) viral load by the hybrid capture assay allows for early detection of CMV disease in lung transplant recipients

Background: We prospectively compared the hybrid capture system (HCS) assay with conventional cell culture and shell vial assay for the detection of c ytomegalovirus (CMV) infection and disease in the lung transplant populatio n. Methods: Between January 1999 and February 2000, 34 lung transplant patient s at Loyola University Medical Center, who were considered to be at risk fo r CMV disease, underwent surveillance testing for CMV cell culture, shell v ial assay and HCS assay according to a pre-determined schedule. In addition , bronchoscopy with bronchoalveolar lavage (BAL) and transbronchial biopsy were performed at regular intervals and for clinical indications. All BAL s amples were sent for CMV cultures and biopsy specimens were analyzed for hi stopathologic evidence of CMV by immunoperoxidase staining using antibody t o early immediate nuclear antigen. Results: Ten patients developed CMV disease/syndrome during the course of t he study. The sensitivity, specificity, positive predictive value and negat ive predictive value were > 90% for the HCS assay. The sensitivity of the H CS assay (90%) was statistically significantly higher than the sensitivity of either the SV assay (40%) or the cell culture (50%). In addition, the HC S assay was able to detect CMV 50 67 days prior to clinical evidence of CMV disease and an average of 36 days prior to the other detection techniques. Conclusion: The HCS assay is a sensitive diagnostic technique able to relia bly detect CMV disease earlier than other diagnostic methods in the lung tr ansplant population. Future studies may be able to evaluate whether pre-emp tive anti-viral therapy targeted to specific viral loads using the HCS assa y will be beneficial in preventing morbidity associated with CMV disease.