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Quantification of CMV DNA in plasma by real-time PCR for management of allogenic stem cell transplant recipients

Abstract number: O252

Cardeñoso L., Agudo S., Moreno M.J., Rodrigo S., Muñoz O., Rivera V., López-Brea M.

The objective was to evaluate a quantitative real time PCR in plasma samples for monitoring active CMV infection in allogenic stem cell transplant (allo-SCT) patients and try a new strategy for the initiation of CMV preemptive therapy.

We studied 395 plasma samples obtained of 51 CMV infection episodes from 32 allo SCT patients between January 2007 and February 2009. 29 out of 32 received one or more course of preemptive therapy upon positive AG and/or TNAI-PCR results and 6 (19%) developed CMV end-organ disease (4 colitis and 2 neumonitis). All patients were monitored post-STC with antigenemia pp65 CINApool®, Argene (AG) and conventional quantitative PCR, COBAS® Amplicor® CMV after automatic extraction COBAS® Ampliprep® TNAI kit, Roche (TNAI-PCR). A positive sample was defined by AG geqslant R: gt-or-equal, slanted2/4×105 PMNs and/or TNAI-PCR geqslant R: gt-or-equal, slanted600 copies/mL.All samples were retrospectively tested using a real time PCR Affigene® CMV trender after automatic DNA extraction with NucliSENS® easyMAG®, bioMérieux (rt-PCR); data lower than 57 copies/ml were considered as negative. An episode was defined as the period between the first positive sample by antigenemia and/or TNAI-PCR, until the first negative sample by both techniques. Plasma samples were positive in 28.3%, 30.6% and 46% by AG, TNAI-PCR and rt-PCR, respectively. Rt-PCR detected 72% of AG positive samples vs 60% by TNAI-PCR. AG was not evaluable in 30 samples (7.5%). Sixteen samples (53%) were positive by rt-PCR vs 7 (23%) by TNAI-PCR. 12% of samples were only positive by rt-PCR. The range for rt-PCR was 63–2.77×104 copies/ml vs 608–2.7×104 copies/ml for TNAI-PCR. Episodes were detected in 46 (90%), 38 (82%) and 41 (89%) by AG, TNAI-PCR and rt-PCR, respectively. Six episodes (11.8%) were only detected by AG (all PCRs negative). Five episodes (10.9%) were detected only by PCR assays. Thirty-four episodes out of 51 episodes (66.7%) were detected by both PCR techniques, in 14 out of 34 (41.2%) were detected earlier by RT-PCR than TNAI-PCR (median = 7 days), and in 5 (14.7%) TNAI-PCR was earlier than Rt-PCR (median = 3 days). Concordance between PCRs assays was 79% (k = 0.6). Strategy based on the quantification of CMV DNA in plasma could be established in >153 copies/Ml (curve ROC, graphic 1) for triggering the initiation of CMV preemptive therapy in this clinical setting. Rt-PCR can be introduced to allow the more sensitive, rapid, and accurate diagnosis of CMV reactivation infection in SCT recipients, which allowed for preemptive therapy to be administered as early as possible.

Graphic 1. EASYMAG.

Session Details

Date: 10/04/2010
Time: 00:00-00:00
Session name: Abstracts 20th European Congress of Clinical Microbiology and Infectious Diseases
Subject:
Location: Vienna, Austria, 10 - 13 April 2010
Presentation type:
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