Impact of automated nucleic acid extraction platforms on plasma Cytomegalovirus DNA loads quantitated by real-time PCR normalized to the 1st WHO international standard.

Introduction: The extent to which commercially available nucleic acid extraction platforms impact the magnitude of Cytomegalovirus (CMV) DNA loads measured in plasma specimens by 1st WHO standard-normalized real-time PCR assays is uncertain.

Methods: This retrospective study compares the performance of Abbott m2000sp, Qiagen QIAsymphony SP, and KingFisher Flex platforms using plasma samples from allogeneic hematopoietic stem cell transplant recipients and plasma spiked with the CMV AD169 strain. The Abbott RealTime CMV PCR assay was used for CMV DNA quantitation.

Results: Maximum differences in CMV DNA loads quantified in plasma from 11 allo-HSCT and spiked plasma over a wide range of viral DNA concentrations (2.0-4.0 log₁₀ IU/ml) were ≤0.5 log₁₀ IU/ml.

Conclusions: The CMV DNA extraction efficiency of the platforms evaluated varies. The impact of these variations on CMV DNA loads quantified in plasma may not be clinically relevant.