Evaluation and comparison of three high throughput assays (Alinity m CMV, Aptima CMV Quant and cobas CMV) for quantifying CMV DNA in plasma samples

Abstract

Background: Cytomegalovirus (CMV) can cause symptomatic CMV syndrome or tissue-invasive CMV disease in immunocompromised individuals, including solid-organ transplant and hematopoietic stem cell transplant recipients. In these populations, monitoring of CMV load is essential, assessing both risk of disease and response to antiviral therapy. High throughput commercial assays are currently available for CMV quantitation, but they are often evaluated independently, with few studies comparing these assays. This study evaluated CMV quantitative assays for use with the Roche cobas 6800, Abbott Alinity m and Hologic Panther platforms using stored patient plasma.

Methods: Analytical evaluation was performed using the 1st WHO international standard for human CMV for Nucleic Acid Amplification Techniques (cobas and Alinity m) or the Hologic CMV QC Calibrator 6 (Aptima). Parallel testing of 136 clinical plasma samples was performed across the three platforms.

Results: Linearity for each assay ranged from 98.6 % to 99.96 % and precision and limit of quantitation were as expected with little variation between platforms. 136 clinical plasma samples were evaluated with similar agreement observed between each assay. The greatest positive agreement was between the Aptima Quant and Alinity m assays (95.6 %, 95 % CI 89-98.6 %) and the lowest between the Aptima Quant and cobas assays (94.1 %, 87.4-97.5 %).

Conclusions: All assays were sensitive and accurate when quantifying CMV, and performance across all 3 assays was comparable for monitoring CMV viral loads in patient plasma.

Keywords: CMV quantitation; CMV viral load; Cytomegalovirus; High through-put automated platform; Performance evaluation.