Evaluation of the COBAS Amplicor HCMV Monitor for early detection and monitoring of human cytomegalovirus infection after allogeneic stem cell transplantation

Abstract

Early diagnosis of human cytomegalovirus (HCMV) infection and the introduction of preemptive antiviral therapy have reduced HCMV-related mortality after allogeneic stem cell transplantation. A critical goal remains stratifying risk profiles and minimizing potential harm owing to antiviral overtreatment. We compared the commercially available standardized COBAS Amplicor CMV Monitor (CACM) to an in-house PCR assay, for the monitoring of HCMV infection. Seventy-two patients were surveyed by an in-house PCR of whole blood, quantitative viral load assessment by CACM and virus culture assays in a prospective and a retrospective study. A high concordance between CACM and PCR was documented. The viral load at onset correlated with the peak viral load (Spearman rank correlation R ¼ 0.634, P ¼ 0.0004). In patients developing HCMV disease, both viral loads were in trend higher (P ¼ 0.823, respectively P ¼ 0.053), and the viremic episodes longer (P ¼ 0.015), as compared to asymptomatically HCMV-infected patients. The serological pre-transplant status was the major risk factor for the development of HCMV disease, showing highest risk for seropositive patients receiving a seronegative graft, whereas donor type (related or unrelated) and graft type (bone marrow or peripheral blood mobilized stem cells) did not have an influence. HCMV infection proved to be a risk factor for the development of non-viral opportunistic infections (P ¼ 0.002).

Quantification of DNA in Plasma by an Automated Real-Time PCR Assay (Cytomegalovirus PCR Kit) for Surveillance of Active Cytomegalovirus Infection and Guidance of Preemptive Therapy for Allogeneic Hematopoietic Stem Cell Transplant Recipients

“…In our center, preemptive therapy is initiated upon a positive antigenemia result (Ն1 pp65-positive cells/200,000 PMNLs) with an incidence of CMV disease lower than 5% (34). The occurrence of two consecutive positive PCR tests performed on whole blood has also been shown to be a clinically safe approach for triggering the initiation of preemptive therapy (7,21). Currently, however, there are no consensus criteria for the initiation of anti-CMV preemptive therapy on the basis of a quantitative PCR monitoring strategy in this clinical setting.…”

“…In fact, discrepant results have been published on this subject. (1,4,6,9,10,19,21,27,31,35,38,39,40). Recent data on the performance of several highly sensitive real-time PCRs, both laboratory-developed and commercial assays (5,20,22), however, demonstrate that both plasma and whole blood are equally suitable for monitoring active CMV infection in Allo-SCT recipients.…”

Prospective comparison of PCR-based vs late mRNA-based preemptive antiviral therapy for HCMV infection in patients after allo-SCT

“…3 However, this improvement is associated with an overtreatment of at least 50% of the patients with potentially toxic antiviral compounds. 10 Different diagnostic strategies to improve patient stratification for preemptive antiviral therapy have been proposed, 11 including measurement of viral-load kinetics, 12 and assessment of active viral replication by the detection of HCMV RNA in clinical samples. 13 More recently, a new diagnostic method based on the amplification of HCMV RNA in blood samples has been commercialized (NucliSens CMV pp67, bioMerieux bv, Boxtel, the Netherlands).…”

The effect of quantification standards used in real-time CMV PCR assays on guidelines for initiation of therapy in allogeneic stem cell transplant patients

“…4 Different institutions have developed their own assays and local guidelines, and these vary depending on the specimen type (whole blood, plasma or a leukocyte preparation) and the design of the assay. Approaches have included treatment after one 5 or two positive PCR tests, 3 when the CMV viral load reaches a threshold value 6 , or a combination of these. 7 The recent publication by Verkruyse et al 6 of their experience and recommendations at the Washington University School of Medicine, clearly different from that of the National Institutes of Health Clinical Research Center (NIH), prompted us to undertake the present study.…”

“…Quantitative polymerase chain reaction (qPCR) assays and the CMV pp65 antigenemia test are used commonly to detect reactivation of CMV and guide pre-emptive therapy before disease onset. [1][2][3] Although qPCR assays are gaining popularity, guidelines for antiviral therapy based on these results are lacking. The CDC, Infectious Disease Society of America, and the American Society of Blood and Marrow Transplantation guidelines published in the year 2000, mention only non-quantitative PCR.…”