[Comparison of the results of quantitative polymerase chain reaction for cytomegalovirus among laboratories].

While cytomegalovirus (CMV) antigenemia assay is generally used for the monitoring of CMV reactivation/diseases, plasma real-time polymerase chain reaction (PCR) can also be a promising methodology and it can be performed by commercially available laboratories. In this study, the results of plasma real-time PCR performed by three laboratories were compared with those of CMV antigenemia. In CMV antigenemia-positive patients (N=11), the results of PCR were positive in all cases examined by two laboratories, while one laboratory yielded positive results only in 6 patients. One of the 2 CMV antigenemia-negative patients yielded positive PCR results at two laboratories, but one laboratory did not show positive results. A per-sample analysis showed that, of 84 CMV antigenemia-negative samples, PCR yielded negative results in 44 samples, positive results in 11 samples at three laboratories and at one or two laboratories in the remaining samples. Of the 36 CMV antigenemia-positive samples, PCR yielded positive results in 21 samples at three laboratories and positive results in the remaining samples at one or two laboratories. Although copy number of CMV-DNA evaluated by PCR at 3 laboratories showed a significant correlation with CMV antigenemia values, median copy number of CMV-DNA showed significant differences among the laboratories. Based on these findings, it is suggested that plasma real-time PCR has a higher sensitivity than CMV antigenemia in detecting CMV reactivation. However, the results varied significantly among the laboratories, suggesting that standardization of the methods is warranted.