CLINICAL SIGNIFICANCE OF VIRAL LOAD IN THE DIAGNOSIS OF CYTOMEGALOVIRUS DISEASE AFTER LIVER TRANSPLANTATION (original) (raw)
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Journal of Clinical Virology, 2005
Background: Preemptive therapy required highly predictive tests for CMV disease. CMV antigenemia assay (pp65 Ag) has been commonly used for rapid diagnosis of CMV infection. Amplification methods for early detection of CMV DNA are under analysis. Objectives: To compare two diagnostic methods for CMV infection and disease in this population: quantitative PCR (qPCR) performed in two different samples, plasma and leukocytes (PMNs) and using a commercial diagnostic test (COBAS Amplicor Monitor Test) versus pp65 Ag. Study design: Prospective study conducted in liver transplant recipients from February 2000 to February 2001. Results: Analyses were performed on 164 samples collected weekly during early post-trasplant period from 33 patients. Agreements higher than 78% were observed between the three assays. Optimal qPCR cut-off values were calculated using ROC curves for two specific antigenemia values. For antigenemia ≥10 positive cells, the optimal cut-off value for qPCR in plasma was 1330 copies/ml, with a sensitivity (S) of 58% and a specificity (E) of 98% and the optimal cut-off value for qPCR-cells was 713 copies/5 × 10 6 cells (S:91.7% and E:86%). Using a threshold of antigenemia ≥20 positive cells, the optimal cut-off values were 1330 copies/ml for qPCR-plasma (S 87%; E 98%) and 4755 copies/5 × 10 6 cells for qPCR-cells (S 87.5%; E 98%). Prediction values for the three assays were calculated in patients with CMV disease (9 pts; 27%). Considering the assays in a qualitative way, the most sensitive was CMV PCR in cells (S: 100%, E: 54%, PPV: 40%; NPV: 100%). Using specific cut-off values for disease detection the sensitivity, specificity, PPV and NPV for antigenemia ≥10 positive cells were: 89%; 83%; 67%; 95%, respectively. For qPCR-cells ≥713 copies/5 × 10 6 cells: 100%; 54%; 33% and 100% and for plasma-qPCR ≥ 1330 copies/ml: 78%, 77%, 47%, 89% respectively. Conclusions: Optimal cut-off for viral load performed in plasma and cells can be obtained for the breakpoint antigenemia value recommended for initiating preemptive therapy with high specificities and sensitivities. Diagnostic assays like CMV pp65 Ag and quantitative PCR for CMV have similar efficiency and could be recommended as methods of choice for diagnosis and monitoring of active CMV infection after transplantation.
Journal of Medical Virology, 2004
cause of morbidity in solid organ recipients. Early markers to identify the progress of the infection and patients at high risk are required in order to apply a strategy of pre-emptive therapy. The efficacy of pre-emptive therapy relies on accurate laboratory tests to monitor CMV infection. The evaluation of CMV DNA kinetics by the polymerase chain reaction (PCR) is widely used for the management of CMV infection but markers predicting the progression of the infection and standardization of the technique are essential for the clinical interpretation of PCR results. A commercially available PCR system, the COBAS AMPLICOR Monitor (Roche Diagnostics, Brachburg, NJ), was used for the quantitation of CMV DNA in weekly blood samples (n ¼ 504) from 47 solid organ recipients in the first 6 months after transplantation. PCR results were evaluated according to the development of clinical disease in order to find a DNA threshold and time points predicting the progression of CMV infection.
Journal of Clinical Microbiology, 2002
A quantitative PCR test, the Cobas Amplicor CMV Monitor, was used for the monitoring of viral load in the peripheral blood of 27 individual liver transplant patients and correlated with cytomegalovirus (CMV) pp65 antigenemia. Altogether, 243 specimens were analyzed. During the first 3 months, 20 patients showed PCR positivity which correlated with pp65 antigenemia. Of those, 13 patients developed symptomatic CMV infection 27 to 52 days after transplantation, with a significantly higher peak viral load in PCR and in pp65 assay compared with the seven asymptomatic infections (median 10,200 versus 2,240 copies/ml, P < 0.05, and median 100 versus 30 pp65-positive cells/50,000 leukocytes, P < 0.01). Five were primary infections of D؉/R؊ cases (donor CMV seropositive and recipient seronegative) and demonstrated, except in one case, a high peak viral load (>10,000 copies/ml; range, 10,200 to 21,600 copies, and >50 positive cells, range, 50 to 800 cells). The peak viral loads of the six D؉/R؉ patients with symptomatic infection varied widely (range, 2,290 to 126,000 copies and 50 to 300 positive cells). Two D؊/R؉ patients developed symptomatic infection with a lower viral load (range, 1,120 to 6,510 copies and 25 to 100 positive cells). All symptomatic infections were successfully treated with ganciclovir. The asymptomatic infections all in D؉/R؉ patients with low copy numbers (<5,500 copies) were monitored until CMV disappeared. One of the seven PCR-negative patients had one sample with low antigenemia, but the subsequent specimens were all negative. The time-related correlation of the two methods was also good. In summary, quantitative PCR could equally well be used as the CMV pp65 assay for the monitoring of viral load in individual transplant patients.
Transplant International, 1994
A polymerase chain reaction (PCR) test for CMV DNA was evaluated for clinical usefulness. Leukocytes and serum were sampled from 36 patients who had recently undergone organ transplantation. Clinical symptoms, virus culture, and IgG and IgM antibodies were used to identify, in retrospect, patients with CMV disease certified beyond all doubt, with probable disease, with asymptomatic infection, or without infection. PCR tests for CMV DNA in leukocytes (BC-PCR) and serum (SE-PCR) were then evaluated. BC-PCR was positive in all patients with certified CMV disease but also in 31 YO of the samples from patients ___ ~
Journal of Clinical Microbiology, 2003
Early and accurate monitoring of cytomegalovirus (CMV) infection in solid-organ transplant recipients is of major importance. We have assessed the potential benefit of an ultrasensitive plasma-based PCR assay for renal transplant recipients. The pp65 CMV antigen (pp65 Ag) assay using leukocytes was employed as a routine test for the monitoring of CMV in 23 transplant recipients. We compared the pp65 antigenemia with the CMV load quantified by an ultrasensitive PCR (US-PCR) with a limit of detection of 20 CMV DNA copies/ml of plasma. CMV infection was detected in 215 (67%) of 321 plasma samples by the US-PCR compared with 124 (39%) of 321 samples by the pp65 Ag assay. The US-PCR assay permitted the detection of CMV infection episodes following transplantation a median of 12 days earlier than the pp65 Ag assay. Moreover, during CMV infection episodes, DNA detection by the US-PCR was consistently positive, whereas false negative results were frequently observed with the pp65 Ag assay. We found a good correlation between the two assays, and the peak viral loads were significantly higher in patients with CMV-related complications (median, 5,000 DNA copies/ml) than in those without symptoms (1,160 DNA copies/ml) (P ؍ 0.048). In addition, patients that did not require preemptive therapy based on the results of the pp65 assay had CMV loads significantly lower (median, 36 DNA copies/ml) than those that needed treatment (median, 4,703 DNA copies/ml) (P < 0.001). These observations provided cutoff levels that could be applied in clinical practice. The ultrasensitive plasmabased PCR detected CMV infection episodes earlier and provided more consistent results than the pp65 Ag assay. This test could improve the monitoring of CMV infection or reactivation in renal transplant recipients.
Clinical and Diagnostic Virology, 1996
Backgrotmd: Rapid laboratory methods for the early detection of cytomegalovirus (CMV) are needed for the prevention of CMV disease in transplant recipients. These methods should not only be able to detect the virus but also he highly predictive for CMV disease. Ob~'tive: The clinical value of a simple and rapid nested plasma polymerase chain reaction (PCR) was evaluated by comparing the results with CMV pp65 antigen detection in leukocytes (CMV antigenemia assay), virus isolation from leukocytes, CMV IgG and IgM antibody response and clinical data. Study design: A total of 471 EDTA blood samples were collected from 85 kidney transplant patients during a 3-4 month period after transplantation. CMV DNA was amplified directly from 10/~1 of plasma while 150 000 separated leukocytes were stained for CMV pp65 antigen by each of two monoclonal antibodies. A total of one million leukocytes were used for virus isolation. The PCR protocol used in the present study involves a simple alkaline lysis technique for isolating DNA directly from plasma which is easy and rapid to perform. Results: Twenty-eight patients developed symptomatic CMV infection while asymptomatic infection occurred in 29 patients. CMV pp65 antigen detection had a 75% sensitivity and a 57% positive predictive value for CMV disease development, compared with 64% and 79% sensitivity and 49% and 46% positive predictive value for CMV DNA and viremia, respectively. The median time until detection of CMV in patients with symptomatic CMV infection was 2t days after transplantation, compared with 49 days in asymptomatic patients by any of the methods used. Early
Journal of Clinical Microbiology, 2003
In order to evaluate the LightCycler-based PCR (LC-PCR) as a diagnostic assay technique, a classical pp65 antigenemia assay and the commercially available COBAS Amplicor CMV Monitor (CACM) assay were compared to the LC-PCR assay for the detection and quantitation of cytomegalovirus (CMV) load in 404 parallel specimens of peripheral blood from 66 patients after solid organ transplantation. A good correlation existed among these three assays (r Х 0.6, P < 0.0001). The LC-PCR assay was the most sensitive (54% of specimens positive) compared to the CACM (48.6%) and the pp65 antigenemia (26%) assays. The LC-PCR assay detected all samples found positive by using both the CMV pp65 antigenemia assay and the CACM assay. The LC-PCR also had the widest dynamic range (from 250 to 10 7 DNA copies/ml of plasma). No cross-reactions were found among CMV and Epstein-Barr virus, varicella-zoster virus, or herpes simplex virus in the LC-PCR by using amplification with specifically designed primer pairs. Precision, expressed as the coefficient of variation, was <3% with standard DNA from cell cultures and between 6.55 and 14.1% with clinical specimens in repeat LC-PCR runs. One run of the LC-PCR took half of the time required for the semiautomated CACM procedure. Because of its sensitivity, specificity, cost-effectiveness, and simplicity, the LC-PCR assay could replace the pp65 antigenemia and the CACM assays as the preferred technique for the surveillance, diagnosis, and monitoring of response of CMV diseases in high-risk populations.
Use of CMV transcripts for monitoring of CMV infections in transplant recipients
International Journal of Antimicrobial Agents, 2000
The development of the nucleic acid sequence-based amplification (NASBA) technology has allowed qualitative determination of human cytomegalovirus (HCMV) immediate-early (IE) and late (pp67) transcripts for monitoring of HCMV infections in the post transplantation period. pp67-mRNA NASBA was shown to be less sensitive than pp65 antigenemia and leukoDNAemia, yet more sensitive than viremia in (i) detecting HCMV infection in both patients and blood samples and (ii) anticipating diagnosis of HCMV infection in solid organ (heart, lung) transplant recipients (SOTR). Use of pp67-mRNA NASBA, as a parameter for initiation of pre-emptive therapy, could be employed as an alternative to detecting antigenemia or DNAemia in SOTR, whereas in bone marrow transplant recipients (BMTR) its use would be too risky because of the delayed detection of HCMV infection. On the other hand, IE-mRNA NASBA was shown to be largely superior to the other assays both in detecting HCMV infection in patients and blood samples and in anticipating diagnosis of HCMV infection. This appears particularly useful in BMTR, where early initiation of antiviral treatment is mandatory in order to prevent the appearance of HCMV interstitial pneumonia. Pre-emptive therapy in BMTR, however, if based upon IE-mRNA NASBA would imply treatment of a greater number of patients as compared with antigenemia-or DNAemia-guided treatment. The clinical usefulness of this approach should be evaluated in prospective trials in the near future, pp67-mRNA NASBA in SOTR with reactivated HCMV infections and IE-mRNA NASBA in BMTR could represent two new virologic parameters to be used as a cutoff for pre-emptive therapy control of HCMV infections in the post-transplant period. Viral transcripts are more direct markers of viral replication in vivo and their disappearance indicates block of the replication process. : S 0 9 2 4 -8 5 7 9 ( 0 0 ) 0 0 2 7 9 -X
Transplantation proceedings, 2000
T HE MAJORITY of the adult human population is seropositive for cytomegalovirus (CMV), a member of the -herpesvirus family. Normally, infection of immunocompetent individuals does not cause disease. In contrast, infection of immunocompromised individuals, such as patients with AIDS and transplant recipients, can cause severe complications and can even lead to death. Therefore, early detection of active CMV infection is necessary to start effective antiviral treatment. Nucleic Acid Sequence-Based Amplification (NASBA) has been developed for the specific amplification of RNA. 1 In previous studies, 2,3 we evaluated the diagnostic value of monitoring the expression of the CMV immediate early (IE) 1 and late pp67 mRNA using NASBA, in peripheral blood cells of kidney transplant (Tx) patients. The IE 1 mRNA is expressed directly after entrance of the virus into a cell, while pp67 mRNA is expressed in a late stage in the replication cycle. NASBA results were compared to the techniques that are routinely being used for the detection of CMV: pp65-antigenemia, virus culture, and serology. From this study it was concluded that IE NASBA is a very sensitive assay that detects the onset of CMV infection significantly earlier than the other assays. This is especially valuable for patients that are at risk for symptomatic CMV infection, i.e., seronegative patients with an organ of a seropositive donor and/or intense immunesuppression. The sensitivity and specificity values of pp67 NASBA were comparable to those of the antigenemia assay. We set up a similar study to evaluate the diagnostic value of IE and pp67 NASBA for liver Tx patients. The liver Tx patients are usually severely ill, immunesuppression is more intense compared to the kidney Tx patients and they often have anti-rejection therapy. The results for IE NASBA are presented in this report. The evaluation of pp67 NASBA is still in progress.