Evaluation of a Semiautomated System for the Quantitation of Human Adenovirus DNA from Clinical Samples

Human adenoviruses (HAdVs) cause severe disease in immunocompromised patients. Quantitation of HAdV DNA in peripheral blood is used to assess the risk of disseminated disease and to monitor response to therapy. The lower limit of detection, precision, and linearity of the semiautomated AltoStar adenovirus quantitative PCR (qPCR) was evaluated using reference HAdV-E4 in EDTA plasma and respiratory virus matrix. Qualitative and quantitative agreement was determined using 122 clinical EDTA plasma specimens previously tested using a laboratory-developed HAdV qPCR. The 95% lower limit of detection (LLOD) was 33 IU/mL (95% confidence interval [CI], 10 to 56) for EDTA plasma and 188 IU/mL (95% CI, 145 to 304) for respiratory swab matrix. In both matrices, the AltoStar HAdV qPCR was linear from 7.0 to 2.0 log₁₀ IU/mL. For the clinical specimens, overall agreement was 96.7% (95% CI, 91.8 to 99.1), positive percent agreement was 95.5% (95% CI, 87.6 to 98.5), and negative percent agreement was 98.2% (95% CI, 88.5 to 99.7). Passing-Bablok analysis of specimens quantifiable by both methods revealed a regression line of Y = 1.11 · X + 0.00; there was positive proportional bias (95% CI of the slope, 1.05 to 1.22) but no systematic bias (95% CI of the Y-intercept, -0.43 to 0.23) compared to the reference. The AltoStar platform provides accurate quantitation of HAdV DNA and provides a semiautomated option for the clinical monitoring of HAdV following transplantation. IMPORTANCE Accurate quantification of human adenovirus DNA in the peripheral blood plays a critical role in the management of adenovirus infections in transplant recipients. Many laboratories utilize in-house laboratory-based PCR assays for the quantification of human adenovirus, as there are few commercial options available. Here, we describe the analytical and clinical performance of the semiautomated AltoStar adenovirus quantitative PCR (Altona Diagnostics). This platform provides sensitive, precise, and accurate quantification of adenovirus DNA that is well suited for virological testing following transplantation. Prior to implementing a new quantitative test in the clinical laboratory, a rigorous evaluation is required to determine assay performance characteristics and to correlate results to current in-house methods of quantitation.