Evaluation of Performance Characteristics of the Aptima CMV Quant Assay for the Detection and Quantitation of CMV DNA in Plasma Samples.

Quantification of Cytomegalovirus (CMV) DNA has become the standard of care in the diagnosis and management of CMV infection in transplant recipients. The objective of the study was to evaluate performance characteristics of the Aptima CMV Quant assay in comparison to Abbott RealTi m e CMV assay, Qiagen Artus CMV RGQ MDx assay, and Roche cobas CMV test using plasma samples. The performance of the Aptima assay was evaluated by comparing the Exact Diagnostics CMV verification panel and positive controls, Hologic CMV internal reproducibility panel, and SeraCare CMV DNA qualification panel to the RealTi m e assay. Clinical agreement was evaluated using 389 clinical plasma samples comparing the Aptima assay to three comparator assays. The Aptima assay demonstrated good linearity and strong linear correlation between the assays (R 2 = 0.99); the intra- and interassay reproducibility was excellent overall (SD = 0.09 to 0.14 and SD = 0.04 to 0.14, respectively); 95% limit of detection (LOD) is 32 IU/mL and LOQ is 45 IU/mL. The SeraCare qualification panel yielded a strong linear correlation (R 2 = 0.99). A total of 262 positive samples were analyzed to compare Aptima and Realti m e assays using Deming regression and Bland-Altman analysis and demonstrated a mean bias of 0.092 Log 10 IU/mL. Artus (85) and cobas (159) positive samples were compared to the Aptima assay using Deming regression and Bland-Altman analyses and showed mean bias of 0.184 and -0.208 Log 10 IU/mL, respectively. The findings demonstrate that the Aptima assay is sensitive and accurate in quantifying CMV in plasma specimens on the fully automated Panther system and that the results were comparable to the other FDA-approved CMV assays.