Clinical Usefulness of Human Cytomegalovirus Antigenemia Assay after Kidney Transplantation

Background : This study was performed to determine the cut-off value and the predictability of symptomatic human cytomegalovirus (HCMV) infection according to the peak value of HCMV antigenemia assay in kidney transplant recipients. Materials and Methods : We reviewed the results of HCMV antigenemia assay (Chemicon, CA, USA) in patients who received kidney transplantation at our institution from May 2003 through May 2008, and investigated the existence and the type of HCMV infection by the medical record review. Patients who underwent the test only once during the episode or those who received ganciclovir for more than 48hrs before the test were excluded. The receiver-operator characteristic curve was drawn and the point showing maximum likelihood ratio (LR) was chosen as the cut-off value of symptomatic HCMV infection. Results : A total of 689 episodes were screened and 134 episodes were enrolled. Thirty-three (24.6 %) episodes were symptomatic HCMV infection, 23 (17.2%) episodes were associated with HCMV syndrome, and 10 (7.5%) episodes were tissue-invasive diseases. The maximum LR was 7.5 (95% confidence interval, 4.014.2) and the cut-off value was 29.5 cells/200,000 WBC. The sensitivity, specificity, positive predictive value, and negative predictive value were 66.7%, 91.1%, 71.0%, and 89.3%, respectively. Conclusions : The cut-off value of symptomatic HCMV infection by the peak value of HCMV antigenemia assay in our study was similar with previous results, although the sensitivity was relatively low.