Clinical evaluation of a new recombinant antigen-based cytomegalovirus immunoglobulin M immunoassay in liver transplant recipients

Background. Human cytomegalovirus (CMV) is a significant cause of morbidity and mortality among transplant recipients. Monitoring transplant recipient s by CMV IgM serology has been questioned by several studies due to the rep orted insensitivity of serologic tests relative to antigen detection method s. Methods. In this retrospective study, we have evaluated the performance of the new recombinant antigen-based Abbott AxSYM CMV IgM assay and compared i t with CMV culture technique in a cohort of 40 liver transplant recipients who did not receive antiviral prophylaxis, Results. The sensitivity, specificity, and positive and negative predictive values for detection of CMV disease by the AxSYM CMV IgM assay were 90.0%, 60.0%, 69.2%, and 85.7%, respectively, and by culture the values were 100% , 55.0%, 69.0%, and 100%, respectively. Detection of CMV IgM occurred befor e or at the time of CMV disease in only R+ recipients. Conclusion, Although this assay is a sensitive test for CMV-specific IgM, d etection of CMV IgM preceded detection of virus by culture in patients only when the liver transplant recipient was CMV immune before transplantation (R+).