Prospective comparison of cytomegalovirus quantification in whole blood and plasma samples among hematopoietic stem cell transplant and kidney transplant recipients

Background

Cytomegalovirus (CMV) induces multi-organ pathogenesis in hematopoietic stem cell transplant (HSCT) and kidney transplant (KT) recipients. Effective management involves systematic monitoring for CMV reactivation by quantitative real-time PCR, allowing timely preemptive intervention. However, the optimal blood compartment for CMV surveillance remains undetermined.

Objective

The aim of the study was to compare the quantification of CMV DNA in paired plasma and whole blood samples.

Study design

From June and October 2022, we conducted a prospective study with 390 sets of paired plasma and whole blood specimens collected from 60 HSCT and 24 KT recipients. CMV DNA levels were compared between the cobas® CMV assay on the automated cobas® 6800 system for plasma and the reference assay, Abbott RealTime CMV assay on the m2000 RealTime platform for whole blood.

Results

The sensitivity and specificity of CMV quantification in plasma using the cobas® CMV assay were 90.0 % (95 %CI: 81.5 to 95.9) and 94.8 % (95 %CI: 91.8 to 96.8), respectively, compared to whole blood quantification with the Abbott assay. The overall agreement between these two strategies was 0.89 (95 %CI: 0.86–0.91). In samples with quantifiable results, a correlation was observed between the two methods (R² = 0.62, 95 %CI: 0.65–0.87, p < 0.0001). CMV loads were significantly higher in whole blood, with a mean bias of 0.42 log₁₀ IU/mL (95 %CI: -0.32–1.15).

Conclusion

The cobas® CMV assay in plasma showed significant concordance with the Abbott RealTime CMV assay in whole blood, confirming the relevance of plasma samples for CMV monitoring in HSCT and KT recipients.