Clinical evaluation of Roche COBAS^® AmpliPrep/COBAS^® TaqMan^® CMV test using nonplasma samples

Abstract

Cytomegalovirus (CMV) infection is a leading cause of loss of hearing, vision, and mental retardation in congenitally infected children. It is also associated with complications of organ transplant and opportunistic HIV coinfection. The Roche COBAS AmpliPrep/COBAS TaqMan CMV test is an FDA-approved test that measures CMV DNA viral load in plasma for the diagnosis and management of patients at risk of CMV-associated diseases. Besides plasma, CMV is often found in bronchoalveolar lavage (BAL), cerebrospinal fluid (CSF), and urine. Thus, monitoring of CMV for critical care of patients in these nonplasma samples becomes necessary. The objective of this study was to conduct an analytic and clinical feasibility study of the Roche CMV test in BAL, CSF, and urine. The lower limit of detection, analytic measurement range, assay sensitivity, specificity, and precision were determined. Results of this study showed that the lower limit of detections were 50, 100, and 300 IU/mL for BAL, CSF, or urine, respectively. The analytic measurement ranges were from log 2.48 to log 5.48. The assay specificity was 94.4% for BAL and 100% for CSF and urine. The assay precision was all within the acceptable range. The performance of Roche test was further compared with 2 comparators including the RealTime CMV assay (Abbott Molecular) and a CMV Quantitative Polymerase Chain Reaction test (Vela Diagnostics). There was a general positive correlation between the Roche method and the Abbott or the Vela method. Overall, this study suggests that the Roche CMV test is suitable for the quantification of CMV viral load DNA in the described nonplasma samples.

Increasing Cytomegalovirus Detection Rate from Respiratory Tract Specimens by a New Laboratory-Developed Automated Molecular Diagnostic Test

“…However, the ability of various commercial kits to manually extract CMV DNA from spiked human specimens varies [ 34 ]. Further, compared to other clinical specimens, respiratory tract specimens have been reported to account for the highest CMV PCR detection rate [ 18 , 19 , 35 ], for which similar results were found in this study ( Table 2 and Table 3 ). Comparison of the sensitivities of different extraction protocols in various clinical specimens for CMV PCR requires further investigation.…”

“…According to a recent study, LOD for the commercial CMV DNA standard, detected using Roche CAP/CTM CMV platform in BAL, is lower than that in CSF and urine [ 18 ]. Costa et al (28th European Congress of Clinical Microbiology and Infectious Disease in 2018, abstract P0496) reported an LOD for CMV ELITe platform of 57 IU/mL for amniotic fluid, 151 IU/mL for urine, and 44 IU/mL for saliva.…”

“…However, commercial automated extraction combined with real-time PCR platforms (In Vitro Diagnostics, IVD), such as Roche Cobas AmpliPrep/TaqMan 48, Abbott m2000SP/2000RT and QIAGEN QIAsymphony/Rotor Gene-Q, have only been validated for the detection of CMV DNA in blood samples [ 15 , 16 , 17 ]. Few assays for non-blood specimens have been validated and reported [ 18 , 19 ]. Considering the matrix complexity of non-blood specimens, the performance of CMV PCR testing of such specimens should be validated to ensure the quality of assays.…”

Performance evaluation of the Alinity m system for quantifying cytomegalovirus DNA in samples of the respiratory, gastrointestinal, and urinary tract

“…Another small study compared RealTi m e CMV as reference assay to Roche CAP/CTM CMV evaluating 17 BAL samples. Fourteen samples were quantified by both assays resulting in a mean bias of 0.93 Log IU/mL (CAP/CTM - RealTi m e) ( 25 ). Overall, a number of influencing factors including pulmonary hemorrhage, preceding antiviral therapy, amount of cells in the BAL sample, CMV prevalence, or quantitation differences between PCR assays as shown above make interpretation of CMV DNA loads in BAL challenging and complicate the definition of a universal threshold ( 5 ).…”