Caurio CFB, Allende OS, Kist R, Santos KL, Vasconcellos ICS, Rozales FP, Lana DFD, Praetzel BM, Alegretti AP, Pasqualotto AC. Clinical validation of an in-house quantitative real time PCR assay for cytomegalovirus infection using the 1st WHO International Standard in kidney transplant patients.
ACTA ACUST UNITED AC 2021;
43:530-538. [PMID:
33970997 PMCID:
PMC8940123 DOI:
10.1590/2175-8239-jbn-2020-0214]
[Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2020] [Accepted: 01/18/2021] [Indexed: 12/01/2022]
Abstract
Introduction:
Cytomegalovirus (CMV) is one of the most common agents of infection in solid
organ transplant patients, with significant morbidity and mortality.
Objective:
This study aimed to establish a threshold for initiation of preemptive
treatment. In addition, the study compared the performance of antigenemia
with qPCR results.
Study design:
This was a prospective cohort study conducted in 2017 in a single kidney
transplant center in Brazil. Clinical validation was performed by comparing
in-house qPCR results, against standard of care at that time (Pp65 CMV
Antigenemia). ROC curve analysis was performed to determine the ideal
threshold for initiation of preemptive therapy based on the qPCR test
results.
Results:
Two hundred and thirty two samples from 30 patients were tested with both
antigenemia and qPCR, from which 163 (70.26%) were concordant (Kappa
coefficient: 0.435, p<0.001; Spearman correlation:
0.663). PCR allowed for early diagnoses. The median number of days for the
first positive result was 50 (range, 24-105) for antigenemia and 42 (range,
24-74) for qPCR (p<0.001). ROC curve analysis revealed
that at a threshold of 3,430 IU/mL (Log 3.54), qPCR had a sensitivity of
97.06% and a specificity of 74.24% (AUC 0.92617 ± 0.0185,
p<0.001), in the prediction of 10 cells/105
leukocytes by antigenemia and physician's decision to treat.
Conclusions:
CMV Pp65 antigenemia and CMV qPCR showed fair agreement and a moderate
correlation in this study. The in-house qPCR was revealed to be an accurate
method to determine CMV DNAemia in kidney transplant patients, resulting in
positive results weeks before antigenemia.
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