Evaluation of an automated real-time transcription-mediated amplification (TMA) assay for detection and quantification of cytomegalovirus DNA in different clinical specimens

Background

Reliable and fast detection and quantification of human cytomegalovirus (CMV) DNA in various diagnostic specimens is essential for care of immunocompromised or congenitally infected individuals.

Objectives

To evaluate the analytical and clinical performance of the Panther Aptima® CMV (Hologic) quantitative real-time transcription mediated amplification (TMA) assay.

Study design

Performance of the TMA assay run on the Hologic Panther Fusion was analysed for 32 proficiency testing samples and 21 quantitative reproducibility panel samples; additionally, we compared results of TMA assay and routine quantitative real-time PCR assays ("PCR-A"= Biomérieux CMV R-gene® or "PCR-B"= Laboratory-developed CMV-PCR) in 518 diagnostic specimens (254 plasma, 120 EDTA whole blood, 43 urine, 45 amniotic fluid and 56 breast milk) at two university hospital laboratories.

Results

All proficiency panel samples were correctly identified and quantified by the TMA assay; replicate testing of the reproducibility panel samples showed good reproducibility within and between the two laboratories. Sensitivity in plasma and WB was higher for the TMA assay detecting low-level CMV-DNAemia in samples tested negative by routine PCR. Quantitative CMV-DNAemia values correlated well between TMA and real-time PCR. Similarly, urine, AF and BM specimens showed a high rate of concordant results (91%, 98% and 98%, respectively) among TMA and PCR with good correlation of quantitative values.

Conclusion

The performance of the Aptima® CMV TMA assay for viral blood load testing compared well to established real-time PCRs. In addition, it can be useful for diagnostics in urine, amniotic fluid and breast milk specimens.