LAUSR

Introduction: Cytomegalovirus (CMV) remains a major cause of morbidity and mortality among solid organ transplant recipients, despite remarkable advances in its diagnosis, prevention and treatment [1]. The two methods that are currently used to monitor CMV infection and disease in these patients are the pp65 antigenemia assay and the quantitative nucleic acid test (QNAT) [2]. The purpose of this study is to compare two different types of QNAT (the Roche COBAS AmpliPrep/COBAS TaqMan CMV test, which is available commercially, and a laboratory-developed RT-PCR test) and one CMV pp65 antigenemia assay. Materials and methods: A total of 49 samples from 32 transplant recipients (28 renal and 4 cardiac transplants) were submitted to these three methodologies. Results: The results showed a significant agreement (concordance rates between 81.6% and 71.4%, and Cohen’s kappa coefficient values between 0.456 and 0.602, p < 0.001) and a moderate to high, significant (p < 0.01), correlation between these methods (Spearman’s coefficient value of 0.769 for pp65 antigenemia and COBAS, 0.546 for pp65 antigenemia and RT-PCR “in-house”, and 0.736 for COBAS and RT-PCR “in-house” comparison). The unexpected good results obtained with antigenemia is a consequence of decades of laboratory’s and operators’ experience with this technique. In addition, one third (33.3%) of all antigenemia positive samples had 1 or 2 positive cells. Discussion and conclusions: The results from this study showed significant agreement and correlation between the three methodologies. Therefore, we conclude that these can be used successfully for monitoring solid organ transplant recipients.