Performance evaluation of the Aptima CMV quant assay using plasma and non-plasma samples.

BACKGROUND: Cytomegalovirus (CMV) infection has a major negative impact on transplantation and is associated with increased morbidity and mortality in this patient population. Quantitation of CMV infections using a molecular test is the preferred method for monitoring patients post-transplant. For this analysis, we compared the Aptima CMV Quant Assay (Aptima CMV) on the Panther system to the ELITech MGB Alert® CMV 3.0 ASR (MGB CMV) run on the ELITe InGenius®. METHODS: The analytical performance of the assay was assessed using commercially available CMV reference panels that meet the 1st WHO International Standard for Human Cytomegalovirus for nucleic acid amplification techniques. The clinical performance of the assay was determined using 249 plasma and non-plasma samples. RESULTS: The 95% LOD of the Aptima assay was determined to be 50 IU/mL and 200 IU/mL for the MGB CMV assay. A strong linear correlation with the reference panel (R2 = 0.9945), excellent reproducibility, and accuracy (R2 = 0.986) over the detection range of the assay was observed. Of the 249 clinical samples tested, only 17 (6.8%) yielded discordant results which were at or near the lower limit of quantification of the assays. Although the Aptima CMV assay demonstrated excellent concordance of qualitative results to the MGB CMV assay for all samples, the MGB CMV quantified CMV DNA at an average of 0.5 Log IU/mL higher than Aptima CMV. CONCLUSION: The Aptima CMV assay is both sensitive and accurate in quantifying CMV in both plasma and non-plasma specimens on the fully automated Panther system.