Comparison between antigenemia and a quantitative-competitive polymerase chain reaction for the diagnosis of cytomegalovirus infection after heart transplantation

Late cytomegalovirus (CMV) infections after kidney transplantation under the preemptive strategy: Risk factors and clinical aspects

BACKGROUND

Late cytomegalovirus infections (LCMV) after the cessation of prophylaxis are well described. We aimed to assess clinical and epidemiological data on late-occurring cytomegalovirus (CMV) infections in the absence of CMV prophylaxis in a cohort of kidney transplant patients.

METHODS

In a cohort of kidney transplant recipients not employing CMV-specific prophylaxis, patients with CMV infections occurring after 6 months of transplantation were compared to patients with CMV infections diagnosed within the first 6 months (early infections). The main objectives were to compare clinical outcomes and evaluate risk factors for late CMV infection.

RESULTS

A total of 556 patients were evaluated. Forty-three patients with LCMV infections were compared to 513 patients with early CMV infections. LCMV infections occurred after a median of 473 days of transplantation and had a more severe course, with a statistically significant higher rate of invasive disease and graft loss (60.5% vs 21.6% and 11.6% vs 3.1% respectively). Thirty-day mortality was twice as high for patients with LCMV, but did not reach statistical significance (9.3% vs 4.3%). By multivariate analysis, employment of antilymphocyte therapy early after transplantation and tacrolimus as initial immunosuppressive therapy were significantly protective for the occurrence of LCMV infections.

CONCLUSION

Late CMV infections in the absence of specific prophylaxis after kidney transplantation have a more severe outcome when compared to early infections and occur in patients less immunosuppressed early after transplantation.

A high level of urinary retinol-binding protein is associated with cytomegalovirus infection in kidney transplantation

The indirect effects of cytomegalovirus (CMV) viremia can be related to chronic changes in renal allograft structure, but its real impact in early and late graft function remains speculative. A total of 159 patients undergoing renal transplantation using a preemptive therapeutic strategy to prevent CMV disease were included in the present study. The patients were prospectively followed, with serial measurements of urinary retinol-binding protein (uRBP), a marker of proximal tubule injury. uRBP levels and their dynamic performance were compared according to CMV viremia and the 5-year estimated glomerular filtration rate (eGFR), as measured with the modification of diet in renal disease (MDRD) equation. CMV viremia was detected in 79.9% of the patients, with high uRBP levels being detected in 76.0% of these patients (compared with 40.7% in CMV-, P=0.005). High uRBP was associated with male recipients (P=0.02), the number of mismatches (P=0.02) and CMV infection (P=0.001). Five-year eGFR was worse in patients with high uRBP levels (50.3 ± 25.8 compared with 59.8 ± 26.4 ml/min, P=0.04). In a multivariate model, eGFR <60 ml/min was associated with donor age (P<0.001), the number of mismatches (P=0.04), thymoglobulin dose (P=0.02), the presence of and time with delayed graft function (DGF) (P=0.005 and P=0.04), 1-month tacrolimus levels (P=0.03), and uRBP levels after CMV treatment (P=0.01). Patients with CMV viremia in whom uRBP levels were normalized up to 3 months after treatment showed significantly better 5-year eGFR than those in whom uRBP remained high: 61.0 ± 24.2 compared with 42.3 ± 23.9 ml/min, P<0.001. CMV viremia was associated with high uRBP levels, which represent a profile of proximal tubule injury, and the dynamic performance of uRBP after treatment was associated with long-term kidney graft function.

Cytomegalovirus infection in renal transplantation: clinical aspects, management and the perspectives

Cytomegalovirus infection is one of most frequent infectious complications after renal transplantation, and can be classified as primo-infection, when the transmission occurs through the graft, or reactivation, when the recipient is cytomegalovirus seropositive. After transplantation, cytomegalovirus can appear as an infection, when the patient presents with evidence of viral replication without symptoms or disease, which has two clinical spectra: typical viral syndrome or invasive disease, which is a less common form. Their effects can be classified as direct, while the disease is developed, or indirect, with an increase of acute rejection and chronic allograft dysfunction risks. Diagnosis must be made based on viremia by one of the standardized methods: antigenemia or PCR, which is more sensitive. The risk factors related to infection after transplantation are the serologic matching (positive donor and negative recipient) and anti-lymphocyte antibody drugs. One of the strategies to reduce risk of disease should be chosen for patients at high risk: preemptive treatment or universal prophylaxis. Recent clinical research has described ganciclovir resistance as an emergent problem in management of cytomegalovirus infection. Two types of mutation that cause resistance were described: UL97 (most frequent) and UL54. Today, sophisticated methods of immunologic monitoring to detect specific T-cell clones against cytomegalovirus are used in clinical practice to improve the management of high-risk patients after renal transplantation.

A double-blinded, prospective study to define antigenemia and quantitative real-time polymerase chain reaction cutoffs to start preemptive therapy in low-risk, seropositive, renal transplanted recipients

BACKGROUND

Cytomegalovirus (CMV) disease occurs in 16% to 20% of low-risk, CMV-positive renal transplant recipients. The cutoffs for quantitative real-time polymerase chain reaction (qPCR) or phosphoprotein (pp65) antigenemia (pp65emia) for starting preemptive therapy have not been well established.

METHODS

We measured qPCR and pp65emia weekly from day 7 to day 120 after transplantation, in anti-CMV immunoglobulin G–positive donor and recipient pairs. Patients and physicians were blinded to the test results. Suspicion of CMV disease led to the order of new tests. In asymptomatic viremic patients, the highest pp65emia and qPCR values were used, whereas we considered the last value before diagnosis in those with CMV disease.

RESULTS

We collected a total of 1,481 blood samples from 102 adult patients. Seventeen patients developed CMV disease, 54 presented at least one episode of viremia that cleared spontaneously, and 31 never presented viremia. Five patients developed CMV disease after the end of the study period. The median (95% confidence interval) pp65emia and qPCR values were higher before CMV disease than during asymptomatic viremia (6 [9–82] vs. 3 [1–14] cells/10(6) cells; P<0.001 and 3,080 [1,263–15,605] vs. 258 [258–1,679] copies/mL; P=0.008, respectively). The receiver operating characteristic curve showed that pp65emia 4 cells/10(6) cells or greater showed a sensitivity and specificity to predict CMV disease of 69% and 81%, respectively (area, 0.769; P=0.001), with a positive predictive value of 37% and a negative predictive value of 93%. For qPCR 2,000 copies/mL or higher, the positive predictive value and negative predictive value were 57% and 91%, respectively (receiver operating characteristic area, 0.782; P=0.000).

CONCLUSION

With these cutoffs, both methods are appropriate for detecting CMV disease.

Comparison of quantitation of cytomegalovirus DNA by real-time PCR in whole blood with the cytomegalovirus antigenemia assay

Background

Quantitation of cytomegalovirus (CMV) DNA using real-time PCR has been utilized for monitoring CMV infection. However, the CMV antigenemia assay is still the 'gold standard' assay. There are only a few studies in Korea that compared the efficacy of use of real-time PCR for quantitation of CMV DNA in whole blood with the antigenemia assay, and most of these studies have been limited to transplant recipients.

Method

479 whole blood samples from 79 patients, falling under different disease groups, were tested by real-time CMV DNA PCR using the Q-CMV real-time complete kit (Nanogen Advanced Diagnostic S.r.L., Italy) and CMV antigenemia assay (CINA Kit, ArgeneBiosoft, France), and the results were compared. Repeatedly tested patients were selected and their charts were reviewed for ganciclovir therapy.

Results

The concordance rate of the two assays was 86.4% (Cohen's kappa coefficient value=0.659). Quantitative correlation between the two assays was a moderate (r=0.5504, P<0.0001). Among 20 patients tested repeatedly with the two assays, 13 patients were transplant recipients and treated with ganciclovir. Before treatment, CMV was detected earlier by real-time CMV DNA PCR than the antigenemia assay, with a median difference of 8 days. After treatment, the antigenemia assay achieved negative results earlier than real-time CMV DNA PCR with a median difference of 10.5 days.

Conclusions

Q-CMV real-time complete kit is a useful tool for early detection of CMV infection in whole blood samples in transplant recipients.

Clinical usefulness of plasma quantitative polymerase chain reaction assay: diagnosis of cytomegalovirus infection in kidney transplant recipients

BACKGROUND

Preemptive therapy is used to prevent cytomegalovirus (CMV) disease in transplant recipients. The CMV antigenemia assay, which has been commonly used as a predictive marker for preemptive therapy, requires intensive labor and immediate processing. We compared the cutoff value of plasma CMV polymerase chain reaction (PCR) with CMV antigenemia in kidney transplant recipients.

METHODS

We compared two diagnostic methods for CMV infection in kidney transplant recipients: quantitative PCR (qPCR) versus antigenemia. We evaluated the optimal cutoff value of plasma CMV qPCR by using receiver-operating characteristic curves for specific antigenemia values. All kidney transplant recipients from January 2004 to January 2005 were enrolled and followed with CMV antigenemia and plasma CMV qPCR.

RESULTS

The analyses were performed on 899 samples collected from 111 patients in the early posttransplant period, matching 84.1% of patients for the results of CMV antigenemia and plasma CMV qPCR. For patients with symptomatic CMV infection and disease, who showed ≥25 positive cells in the antigenemia assay, the cutoff value for qPCR was 17.8 copies/μL with a sensitivity of 97.1%, a specificity of 89.1%, and a positive predictive value of 26.6%.

CONCLUSIONS

Diagnostic assays for CMV such as CMV antigenemia and quantitative plasma PCR, showed similar diagnostic values. They are the methods of choice for the diagnosis and monitoring of active CMV infection after kidney transplantation. However, because of the relatively low positive predictive value of qPCR, this test may lead to unnecessary preemptive treatment in kidney transplant recipients.

[Evaluation of Biosewoom Real-Q Cytomegalovirus Quantification kit for Cytomegalovirus viral load measure]

BACKGROUND

Rapid and accurate laboratory tests are essential to detect cytomegalovirus (CMV) infections in solid organs and haematopoietic stem cell transplant recipients. We assessed the realtime quantitative PCR (RQ-PCR) technology for its usefulness in detecting CMV DNA.

METHODS

We evaluated the analytical performance of CMV RQ-PCR using Real-Q Cytomegalovirus Quantification kit (BioSewoom Inc., Korea). To evaluate its clinical utility, we also compared it to pp65 antigenemia test, an immunostaining method, on 343 samples of total 84 patients, including 63 transplant recipients.

RESULTS

The detection limit of RQ-PCR was 63 copies/mL and none of hepatitis B virus, hepatitis C virus, or human immunodeficiency virus showed a cross-reactivity with CMV. Total coefficient of variation (CV) was 10.4-19.5%. It detected CMV DNA in a linear range from 1 x 10(2) to 5 x 10(11) copies/mL (P<10(-13), R(2)=0.9994). The qualitative positive rates of pp65 antigenemia test and RQ-PCR were 4.7%, 16.3%, respectively and concordance rate between the two tests was 84.8% (Kappa=0.221, P<10(-6)). In comparison of quantitative results, the correlation between two tests was significant (r=0.45, P<10(-17)). In comparison among three groups by pp65 antigen level, CMV DNA level obtained with RQ-PCR increased significantly (P<10(-3) and P<10(-7), respectively).

CONCLUSIONS

The RQ-PCR is easier to perform than the immunostaining method, has good analytical performance and reflects the blood level of viral DNA well. It may be a new method substituting the pp65 antigenemia test. Further studies determining RQ-PCR value starting pre-emptive therapy will be required.

Quantitation of cytomegalovirus DNA by real-time polymerase chain reaction in peripheral blood specimens of patients with solid organ transplants: Comparison with end-point PCR and pp65 antigen test

The polymerase chain reaction (PCR) for cytomegalovirus (CMV) DNA quantitation provides sensitive and specific data for detecting CMV as well as monitoring the infection and determining the appropriate antiviral strategy. A recently introduced real-time PCR assay for CMV DNA quantitation was applied on 158 peripheral blood leukocytes (PBLs) from 32 liver-transplanted patients with CMV asymptomatic infection and correlated with a commercial quantitative end-point PCR (COBAS AMPLICOR CMV Monitor) and CMV pp65 antigenemia. A good correlation was found between real-time PCR and pp65 antigen test (r2 = 0.691) and the two PCR assays (r2 = 0.761). Real-time PCR data were higher in pre-emptive treated patients (>20 pp65 + positive cells, median CMV DNA value: 3.8 log(10) copies/500,000 PBLs) than in not-treated ones (2.9 logs). According to pp65 levels of 0, 1-10, 11-20, 21-50, 51-100, and >100 positive cells/200,000 PBLs, median CMV DNA by real-time PCR was 2.6, 3.0, 3.6, 4.0, 4.2, and 4.8 logs, respectively, (CMV DNA levels by COBAS AMPLICOR: 2.8, 2.9, 3.8, 3.7, 3.9, and 4.0 logs). For samples with >20 pp65 + cells, real-time PCR gave significantly higher values than in groups with <20 pp65 + cells, whereas the COBAS AMPLICOR results showed a slower progression rate. Dilutions of CMV AD169 strain were used to probe real-time PCR reproducibility (between and intra-assay variability <2%) and sensitivity (100% detection rate at 10 copies/reaction, 28.5% with end-point PCR). In conclusion, real-time PCR significantly improves the study of CMV DNA dynamics due to a more reliable quantitation of CMV DNA for moderate and high DNA level compared to end-point PCR with better sensitivity and specificity. Real-time PCR provides more precise information for evaluating infection progress and assessing antiviral response, simplifying and accelerating the process of producing a reliable quantitation of CMV DNA for clinical purposes.

Analysis of a quantitative PCR assay for CMV infection in liver transplant recipients: an intent to find the optimal cut-off value

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-transplant 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 >or=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/5x10(6) cells (S:91.7% and E:86%). Using a threshold of antigenemia >or=20 positive cells, the optimal cut-off values were 1330 copies/ml for qPCR-plasma (S 87%; E 98%) and 4755 copies/5x10(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 >or=10 positive cells were: 89%; 83%; 67%; 95%, respectively. For qPCR-cells >or=713 copies/5x10(6) cells: 100%; 54%; 33% and 100% and for plasma-qPCR>or=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.

Decreased Cytomegalovirus infection after antilymphocyte therapy in sirolimus-treated renal transplant patients

Cytomegalovirus (CMV) infection is highly prevalent in transplant patients, especially in those submitted to a more intense immunosuppression. We monitored CMV infection in 34 patients during 60 days after antilymphocyte therapy without CMV prophylaxis. Six patients received sirolimus and 28 received no sirolimus as immunosuppression. During 60 days of follow-up time, 24/28 (86%) patients who did not use sirolimus developed CMV infection at a mean time of 32.43+/-13.67 days after antilymphocyte treatment. In contrast, no patient on sirolimus had CMV infection during the same follow-up (p<0.001). During a further 4-month follow-up, six patients on sirolimus-free therapy had recurrence of CMV, 46.5+/-18.5 days after the first episode. During this same period, one patient receiving sirolimus had one positive cell for CMV antigenemia, 169 days after antilymphocyte therapy. In conclusion, the use of sirolimus significantly reduced the incidence of CMV infection in patients treated with antilymphocyte antibodies.

Sequential cytomegalovirus antigenemia monitoring in kidney transplant patients treated with antilymphocyte antibodies

BACKGROUND

Antilymphocyte antibodies (ALA) use is related to disseminated cytomegalovirus (CMV) disease after kidney transplantation. Strict surveillance of CMV infection, preemptive antiviral treatment or concomitant ganciclovir and ALA use are proposed as an attempt to prevent related clinical complications. Our objective was to describe the pattern of CMV infection, based on sequential antigenemia detection, after ALA treatment.

PATIENTS AND METHODS

Thirty renal transplant patients were prospectively screened for CMV infection after ALA treatment. CMV antigenemia (pp65 antigen detection) was monitored twice a week in the first month and weekly until 60 days after the beginning of ALA therapy. Any positive value of antigenemia was considered CMV infection.

RESULTS

Twenty-eight (93.3%) patients were CMV positive (IgG) before transplantation. The mean duration of ALA treatment was 12.1+/-2.4 days. Positive antigenemia was detected in 24 (80%) patients, a mean of 52.5+/-15 days after transplant and 44.7+/-14 days after the beginning of ALA treatment. The median antigenemia count was 7 positive cells/300,000 neutrophils (range: 1-227). Antigenemia preceded clinical symptoms by 5.8 days (0-28 days). Eighteen (75%) of 24 positive patients received ganciclovir treatment: 8 patients (26.7%) for viral syndrome, 2 patients (33.3%) for invasive disease, and 8 patients (26.7%) as part of preemptive therapy, asymptomatic with high antigenemia values. Six pp65-positive patients with low counts were followed up until a negative result and remained asymptomatic without any specific treatment.

CONCLUSION

CMV infection was frequent after ALA treatment in this group and generally occurred late after completion of treatment. Antigenemia was a reliable tool to guide preemptive treatment in these patients, and such strategy is an alternative option compared to the prophylactic use of ganciclovir with ALA treatment.

CYTOMEGALOVIRUS INFECTION IN ORGAN-TRANSPLANT RECIPIENTS: DIAGNOSTIC VALUE OF PP65 ANTIGEN TEST, QUALITATIVE POLYMERASE CHAIN REACTION (PCR) AND QUANTITATIVE TAQMAN PCR

BACKGROUND

The human cytomegalovirus (CMV) is a major cause of morbidity and mortality in transplant patients. In this study, we compared the diagnostic value of pp65 antigen test, qualitative nested polymerase chain reaction (PCR), and quantitative Taqman PCR in predicting the clinical outcome of CMV infection.

METHODS

A total of 169 samples derived from 59 organ-transplant recipients (kidney n= 46, liver n= 11, kidney and pancreas n= 2) were analyzed. Peripheral blood leukocytes (PBL) were isolated using dextran gradient centrifugation, and 2 x 10 cells were analyzed for pp65 antigen by immunofluorescence. A crude DNA extract obtained from the same number of cells was used for qualitative nested PCR and quantitative Taqman PCR analysis. RESULTS.: The correlation coefficient of pp65 antigen test and Taqman PCR was R= 0.699 (P = 0.001). With cut-off values for pp65 antigen test set at greater than 10 positive nuclei per 2 x 10 PBL, sensitivity was 91%, and positive predictive value (PPV) was 70%. When the corresponding cut-off value for Taqman PCR was applied (>125000 genome copies per 2 x 10 PBL), a sensitivity of 83% and a PPV of 68% were found. Both assays allowed for the monitoring of successful antiviral therapy. Although qualitative nested PCR was highly sensitive (95%), it was less useful in predicting CMV disease (PPV 47%) and in therapy control.

CONCLUSION

Our data show that pp65 antigen test and Taqman PCR are almost equivalent in the monitoring of CMV infection and disease when identical cell numbers are used for both assays.

Cytomegalovirus Infection in Heart-Transplant Recipients in a Central Region of Italy

Cytomegalovirus (CMV) infection occurs very often after solid organ transplantation and is often a life-threatening complication of long-term immunosoppressive therapy. Actually it is unknown which type of drug is indicated to control the infection in immunocompromised patients. We studied 10 consecutive patients who had undergone heart-transplantation and in which CMV infection was the commonest post-transplant infectious disease. Our results suggest a careful monitoring of IgG seropositivity in heart transplant patients, especially when it is not possible to know the serum status of the donor.

Quantitation of cytomegalovirus DNA by the polymerase chain reaction as a predictor of disease in solid organ transplantation

Cytomegalovirus (CMV) infection is an important 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 = 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. Week 4 from transplantation was the earliest time point to note a significant difference between those patients who eventually developed CMV disease (n = 30) and those who remained asymptomatically infected (n = 17). At week 4, viral loads were significantly higher in patients who developed CMV disease than in asymptomatic infections (median value: 4 log(10)/10(6) leukocytes vs. 2.8, P < 0.0001). At week 4, a DNA level >/=4 log(10)/10(6) leukocytes was associated with a 45.37 odds ratio for CMV disease. Any increase >/=1 log from the first DNA detection to week 4 correlated with the clinical progression of CMV infection (odds ratio 1.74). In those patients who were treated with anti-CMV therapy, a >97% reduction of the baseline viral load was associated with a complete therapeutic success. In conclusion, CMV infection is a highly dynamic process and the quantitation of CMV DNA by PCR is a powerful marker to control successfully the infection, but a strict follow-up of the recipient and standardized PCR tests are mandatory for the best management of the infection.

Asymptomatic Cytomegalovirus Retinitis after Cardiac Transplantation

PURPOSE

To determine the prevalence and the risk factors of cytomegalovirus (CMV) retinitis after cardiac transplantation in visually asymptomatic patients.

METHODS

Ophthalmoscopic examinations including fundus fluorescein angiography were performed in asymptomatic patients who had cardiac transplantation at Ege University Hospital between April 1998 and June 2002 to screen for evidence of diagnostic CMV retinitis lesions to determine the prevalence in this population.

RESULTS

Thirteen patients (aged 40 +/- 12.6) who had cardiac transplantation underwent ophthalmoscopic examination 2-50 months (23.5 +/- 16.2 months; mean +/- SD) after transplantation. All recipients had positive serology to CMV before transplantation. During the study period, 3 patients developed asymptomatic CMV reactivation. One patient developed CMV disease (pneumonia). All of the patients were visually asymptomatic during the study period. Two patients (15%) had a history of diabetes mellitus and chronic severe arterial hypertension. Seven recipients (53%) had been heavy cigarette smokers and 3 patients (23%) had hyperlipidemia. Two (15%) of 13 patients with arterial hypertension and diabetes had evidence of asymptomatic active CMV retinitis. These patients were treated with intravenous ganciclovir.

CONCLUSIONS

Active cytomegalovirus retinitis lesions were found in 2 (15%) of 13 cardiac transplantation patients who had no visual symptoms. We think that the patients with systemic microvascular risk factors such as diabetes, hypertension and smoking should be screened closely for the development of CMV retinitis after cardiac transplantation even if the patients have no visual symptoms.

Monitoring of human cytomegalovirus infections in heart transplant recipients by pp65 antigenemia

BACKGROUND

Rapid diagnostic techniques offer the opportunity of early diagnosis of human cytomegalovirus (CMV) infection in immunocompromized patients at risk of developing CMV disease and syndrome. The use of CMV pp65 antigenemia as a predictor of CMV syndrome and disease in heart transplant recipient after induction therapy was studied retrospectively.

METHODS

One hundred and nineteen consecutive heart transplant recipients treated with induction therapy who survived more then 14 d were monitored for CMV infection. Ninety-four recipients were seropositive for CMV. Twenty-five recipients were seronegative for CMV and received grafts from seropositive donors. Pre-emptive therapy was used in seropositive patients when CMV pp65 antigenemia was greater than 50 antigen-positive cells per 2 x 10(5) peripheral blood leukocytes (PBL); prophylactic therapy was done only in seronegative recipient matched with seropositive donor.

RESULTS

High-level CMV pp65 antigenemia (50 antigen-positive cells 2 x 10(5) PBL) occurred in 34% (41 of 119) of patients at a median of 44 d following transplantation. In seropositive recipients, 16% (15 of 94) of patients developed CMV invasive disease or syndrome, and in seronegative recipients 20% (5 of 25) of patients developed CMV disease or syndrome. Sixty-six per cent (62 of 94) of CMV seropositive patients were identified as not requiring pre-emptive therapy. In seropositive and seronegative recipients, the sensibility and negative predictive value of the cut-off level of 50 antigen positive cell for CMV disease and syndrome was 100%. The specificity was 79% and positive predictive value was 49%.

CONCLUSION

Because of the excellent sensibility and negative predictive value of the cut-off level of 50 antigen positive cell per 2 x 10(5) PBL, application of pre-emptive therapy guided by high level of CMV pp65 antigenemia in the context of induction therapy allow to omit antiviral therapy in many at risk patients. In the context of pre-emptive and prophylactic therapy, the cut-off level of 50 antigen positive cell do not allow to predict with accuracy the development of CMV disease or syndrome.

Real-time PCR assay compared to nested PCR and antigenemia assays for detecting cytomegalovirus reactivation in adult T-cell leukemia-lymphoma patients

We analyzed the efficiency of the quantitative real-time PCR assay for cytomegalovirus (CMV) reactivation in adult T-cell leukemia-lymphoma (ATL) patients and compared the results with those obtained with qualitative nested PCR and antigenemia assays. The viral load obtained by the real-time PCR assay closely paralleled the number of antigen-positive cells obtained with the antigenemia assay. Real-time PCR revealed that a large number of DNA copies could be present even in samples assessed as negative or low in antigen-positive cells (0 to 10 antigen-positive cells/50,000 cells) by antigenemia assay. CMV copy numbers did not differ between the negative and low-antigen-positive groups. When the input concentration for real-time PCR assay was 2,500 to 5,000 copies/ml, the positivity rate for the nested PCR assay was 47.3%, while the positivity rate was more than 90% at an input concentration of >/=50,000 copies/ml. Real-time PCR is more sensitive than the antigenemia and nested PCR assays. Moreover, real-time PCR was able to detect CMV reactivation earlier than the antigenemia and nested PCR assays through the use of longitudinal analysis in four ATL patients with CMV pneumonia. In longitudinal assessments, analysis of the results suggested that a cutoff level of 5,000 copies/ml might be used to initiate treatment. Real-time PCR is more suitable for monitoring CMV reactivation in ATL patients than the antigenemia and nested PCR assays. CMV viral loads of 5,000 copies/ml are proposed as the cutoff for initiating antiviral therapy in ATL patients.

Occult herpes family viral infections are endemic in critically ill surgical patients

OBJECTIVE

Herpes family viruses have been recognized as pathogens for many years in immunosuppressed transplant or human immunodeficiency virus patients, but they have garnered little attention as potential pathogens in the nonimmunosuppressed critically ill. The objective of this study was to define the prevalence of and risk factors for development of herpes family virus infection in chronic critically ill surgical patients.

DESIGN

Prospective epidemiologic study.

SETTING

A 38-bed surgical intensive care unit in a major university hospital.

PATIENTS

Nonimmunosuppressed intensive care unit patients in intensive care unit for >/=5 days.

INTERVENTIONS

None; patients received no antiviral treatment during the study.

MEASUREMENTS AND MAIN RESULTS

Weekly cultures for cytomegalovirus (CMV) and herpes simplex virus, viral serologies, and T-cell counts were performed. The prevalence (95% confidence interval) of positive respiratory cultures for herpes simplex or CMV was 35% (22-49%); 15% (5-25%) cultured positive for CMV, 23% (11-35%) cultured positive for herpes simplex virus, and one patient's respiratory secretions culturing positive for both CMV and herpes simplex virus. The prevalence of CMV viremia was only 5.8% (1-10%). CMV+ patients had longer hospital admissions, intensive care unit admissions, and periods of ventilator dependence than CMV- patients, despite having comparable severity of illness scores. CMV+ patients also had significantly higher numbers of blood transfusions, prevalence of steroid exposure, and prevalence of hepatic dysfunction, and all were immunoglobulin G positive at the beginning of the study. In contrast, herpes simplex virus-positive patients had lengths of hospital admissions, lengths of intensive care unit admissions, and periods of ventilator dependence comparable with patients without viral infections (p >.05).

CONCLUSIONS

There is a significant prevalence (22-49%) of occult active herpes family viruses in chronic critically ill surgical patients. The clinical significance of these viral infections is unknown, although CMV+ patients have significantly higher morbidity rates than CMV- patients. Several factors suggest pathogenicity, but further study is needed to define causality.

Nonmyeloablative transplantation with or without alemtuzumab: comparison between 2 prospective studies in patients with lymphoproliferative disorders

Although nonmyeloablative conditioning regimen transplantations (NMTs) induce engraftment of allogeneic stem cells with a low spectrum of toxicity, graft-versus-host disease (GVHD) remains a significant cause of morbidity and mortality. In vivo T-cell depletion, using alemtuzumab, has been shown to reduce the incidence of GVHD. However, this type of maneuver, although reducing GVHD, may have an adverse impact on disease response, because NMTs exhibit their antitumor activity by relying on a graft-versus-malignancy effect. To explore the efficacy of alemtuzumab compared with methotrexate (MTX) for GVHD prophylaxis, we have compared the results in 129 recipients of a sibling NMT enrolled in 2 prospective studies for chronic lymphoproliferative disorders. Both NMTs were based on the same combination of fludarabine and melphalan, but the United Kingdom regimen (group A) used cyclosporin A plus alemtuzumab, whereas the Spanish regimen (group B) used cyclosporin A plus MTX for GVHD prophylaxis. Patients receiving alemtuzumab had a higher incidence of cytomegalovirus (CMV) reactivation (85% versus 24%, P <.001) and a significantly lower incidence of acute GVHD (21.7% versus 45.1%, P =.006) and chronic GVHD (5% versus 66.7%, P <.001). Twenty-one percent of patients in group A and 67.5% in group B had complete or partial responses 3 months after transplantation (P <.001). Eighteen patients in group A received donor lymphocyte infusions (DLIs) to achieve disease control. At last follow-up there was no difference in disease status between the groups with 71% versus 67.5% (P =.43) of patients showing complete or partial responses in groups A and B, respectively. No significant differences were observed in event-free or overall survival between the 2 groups. In conclusion, alemtuzumab significantly reduced GVHD but its use was associated with a higher incidence of CMV reactivation. Patients receiving alemtuzumab often required DLIs to achieve similar tumor control but the incidence of GVHD was not significantly increased after DLI.

Oral valganciclovir: a new option for treatment of cytomegalovirus infection and disease in immunocompromised hosts

Immunocompromised hosts are at increased risk of cytomegalovirus (CMV) infection and serious CMV disease. CMV infection is an important cause of morbidity among patients infected with HIV and after solid organ transplantation (SOT) and may cause life-threatening disease in allogeneic stem cell transplant (SCT) recipients. The introduction into clinical use of potent antiviral compounds and of rapid detection assays for CMV during the past two decades has allowed development of strategies for the prevention and treatment of disease caused by CMV in these groups of immunocompromised patients. At present, the antiviral drugs ganciclovir, foscarnet and cidofovir are commonly used in the treatment of CMV infection and disease. However, these agents have a poor oral bioavailability and, for systemic use, require iv. administration for most indications. Valganciclovir is an oral prodrug of ganciclovir, with a 10-fold greater bioavailability than oral ganciclovir. Studies of the pharmacokinetics of valganciclovir among HIV-infected CMV-seropositive patients and liver transplant recipients suggest that this oral compound has the potential to replace both oral and iv. ganciclovir in many situations if it is shown to be as efficacious and safe as those ganciclovir formulations in immunodeficient patients. In the first part of this review, currently established approaches to the management of CMV infection and disease in SCT and SOT recipients and HIV-infected patients are discussed to highlight possible indications for future valganciclovir use; in the second part, data from human studies of valganciclovir are presented.