The economic impact of cytomegalovirus infection after liver transplantation

Pre-emptive treatment for cytomegalovirus viraemia to prevent cytomegalovirus disease in solid organ transplant recipients

BACKGROUND

Cytomegalovirus (CMV) is a significant cause of morbidity and death in solid organ transplant recipients. Pre-emptive treatment of patients with CMV viraemia using antiviral agents has been suggested as an alternative to routine prophylaxis to prevent CMV disease. This is an update of a Cochrane review first published in 2006 and updated in 2013.

OBJECTIVES

To determine the benefits and harms of pre-emptive treatment of CMV viraemia to prevent CMV disease and death (any cause) and the indirect effects of CMV infection (acute rejection, graft loss, opportunistic infections) in solid organ transplant recipients.

SEARCH METHODS

The Cochrane Kidney and Transplant Register of Studies was searched up to 17 December 2024 using search terms relevant to this review. Studies in the Register are identified through searches of CENTRAL, MEDLINE, and EMBASE, conference proceedings, the International Clinical Trials Registry Platform (ICTRP) Search Portal, and ClinicalTrials.gov.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) and quasi-RCTs comparing pre-emptive treatment with placebo, no specific treatment, or antiviral prophylaxis in solid organ transplant recipients.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed the eligibility of the identified studies, assessed the risk of bias, and extracted all data. Results were expressed as risk ratio (RR) and 95% confidence intervals (CI) for dichotomous outcomes. Statistical analyses were performed using a random-effects model. The certainty of evidence was assessed per outcome using the Grades of Recommendation, Assessment, Development and Evaluation (GRADE) approach.

MAIN RESULTS

In this update, we have included seven new studies, bringing the total number of included studies to 22 (1883 participants). Of these, seven investigated pre-emptive treatment versus placebo or standard care, 12 looked at pre-emptive treatment versus antiviral prophylaxis, one study investigated oral versus intravenous pre-emptive treatment, one investigated pre-emptive valganciclovir versus pre-emptive ganciclovir, and one investigated letermovir 40 mg twice/day versus 80 mg once/day. Studies were conducted in Australia, Brazil, the Czech Republic, Germany, Italy, Japan, Norway, Spain, South Korea, and the USA. Organ transplant recipients included kidney, liver, heart, lung, and kidney-pancreas. Thirteen studies were single-centre studies, six were multicentre, and three were unknown. The number of participants ranged from 12 to 296. Overall, selection bias was unclear (55%); performance, detection and attrition bias were high (91%, 63% and 95%, respectively), and reporting bias was low (55%). Compared with placebo or standard care, pre-emptive treatment probably reduces the risk of CMV disease (7 studies, 315 participants: RR 0.29, 95% CI 0.11 to 0.80; I2 = 54%; moderate-certainty evidence) but may result in little or no difference in death (any cause) (3 studies, 176 participants: RR 1.23, 95% CI 0.35 to 4.30; I2 = 0%; low-certainty evidence). Pre-emptive treatment may result in little or no difference in CMV organ involvement, CMV-associated symptoms, acute rejection, graft loss, other infections or leucopenia. Compared to prophylaxis, pre-emptive treatment may make little or no difference to the risk of developing CMV disease (11 studies, 1322 participants: RR 0.97, 95% CI 0.47 to 2.01; I2 = 54%; low-certainty evidence) and probably makes little or no difference to death (any cause) (9 studies, 1098 participants: RR 0.95, 95% CI 0.60 to 1.52; I2 = 0%; moderate-certainty evidence). Pre-emptive treatment may increase the risk of CMV infection (8 studies, 867 participants: RR 1.97, 95% CI 1.48 to 2.61; I2 = 66%; low-certainty evidence). The risk of leucopenia (7 studies, 869 participants: RR 0.57, 95% CI 0.38 to 0.87; I2 = 33%; moderate-certainty evidence) and neutropenia (5 studies, 859 participants: RR 0.63, 95% CI 0.44 to 0.90; I2 = 0% moderate certainty evidence) probably decreases with pre-emptive therapy. There may be little or no difference in the risks of acute rejection, graft loss, and infections other than CMV. Single studies were identified for comparisons between different pre-emptive treatments: 1) oral ganciclovir versus IV ganciclovir; 2) valganciclovir versus ganciclovir; 3) 40 mg twice/day versus 80 mg once/day. No differences between these treatment modalities in terms of CMV disease, death (any cause), or adverse events were identified.

AUTHORS' CONCLUSIONS

In this review, we have included seven new studies, yet the available evidence is overall of low certainty and the conclusions remain similar to the previous version of this review. Pre-emptive treatment probably reduces the risk of CMV disease compared with placebo or standard care. There were no clear differences between pre-emptive treatment and prophylaxis to prevent CMV disease or reduce the risk of death (any cause). The risk of CMV infection may be higher for patients receiving pre-emptive therapy, but the risk of adverse events, such as leucopenia, is probably lower.

A vaccine against cytomegalovirus: how close are we?

The pursuit of a vaccine against the human cytomegalovirus (HCMV) has been ongoing for more than 50 years. HCMV is the leading infectious cause of birth defects, including damage to the brain, and is a common cause of complications in organ transplantation. The complex biology of HCMV has made vaccine development difficult, but a recent meeting sponsored by the National Institute of Allergy and Infectious Diseases in September of 2023 brought together experts from academia, industry, and federal agencies to discuss progress in the field. The meeting reviewed the status of candidate HCMV vaccines under study and the challenges in clinical trial design in demonstrating efficacy against congenital CMV infection or the reduction of HCMV disease following solid organ transplantation or hematopoietic stem cell transplantation. Discussion in the meeting revealed that, with the numerous candidate vaccines that are under study, it is clear that a safe and effective HCMV vaccine is within reach. Meeting attendees achieved a consensus opinion that even a partially effective vaccine would have a major effect on the global health consequences of HCMV infection.

Antiviral medications for preventing cytomegalovirus disease in solid organ transplant recipients

BACKGROUND

The risk of cytomegalovirus (CMV) infection in solid organ transplant recipients has resulted in the frequent use of prophylaxis to prevent the clinical syndrome associated with CMV infection. This is an update of a review first published in 2005 and updated in 2008 and 2013.

OBJECTIVES

To determine the benefits and harms of antiviral medications to prevent CMV disease and all-cause death in solid organ transplant recipients.

SEARCH METHODS

We contacted the information specialist and searched the Cochrane Kidney and Transplant Register of Studies up to 5 February 2024 using search terms relevant to this review. Studies in the Register are identified through searches of CENTRAL, MEDLINE, and EMBASE, conference proceedings, the International Clinical Trials Registry Platform (ICTRP) Search Portal, and ClinicalTrials.gov.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) and quasi-RCTs comparing antiviral medications with placebo or no treatment, comparing different antiviral medications or different regimens of the same antiviral medications for CMV prophylaxis in recipients of any solid organ transplant. Studies examining pre-emptive therapy for CMV infection are studied in a separate review and were excluded from this review.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed study eligibility, risk of bias and extracted data. Summary estimates of effect were obtained using a random-effects model, and results were expressed as risk ratios (RR) and their 95% confidence intervals (CI) for dichotomous outcomes and mean difference (MD) and 95% CI for continuous outcomes. Confidence in the evidence was assessed using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach.

MAIN RESULTS

This 2024 update found four new studies, bringing the total number of included studies to 41 (5054 participants). The risk of bias was high or unclear across most studies, with a low risk of bias for sequence generation (12), allocation concealment (12), blinding (11) and selective outcome reporting (9) in fewer studies. There is high-certainty evidence that prophylaxis with aciclovir, ganciclovir or valaciclovir compared with placebo or no treatment is more effective in preventing CMV disease (19 studies: RR 0.42, 95% CI 0.34 to 0.52), all-cause death (17 studies: RR 0.63, 95% CI 0.43 to 0.92), and CMV infection (17 studies: RR 0.61, 95% CI 0.48 to 0.77). There is moderate-certainty evidence that prophylaxis probably reduces death from CMV disease (7 studies: RR 0.26, 95% CI 0.08 to 0.78). Prophylaxis reduces the risk of herpes simplex and herpes zoster disease, bacterial and protozoal infections but probably makes little to no difference to fungal infection, acute rejection or graft loss. No apparent differences in adverse events with aciclovir, ganciclovir or valaciclovir compared with placebo or no treatment were found. There is high certainty evidence that ganciclovir, when compared with aciclovir, is more effective in preventing CMV disease (7 studies: RR 0.37, 95% CI 0.23 to 0.60). There may be little to no difference in any outcome between valganciclovir and IV ganciclovir compared with oral ganciclovir (low certainty evidence). The efficacy and adverse effects of valganciclovir or ganciclovir were probably no different to valaciclovir in three studies (moderate certainty evidence). There is moderate certainty evidence that extended duration prophylaxis probably reduces the risk of CMV disease compared with three months of therapy (2 studies: RR 0.20, 95% CI 0.12 to 0.35), with probably little to no difference in rates of adverse events. Low certainty evidence suggests that 450 mg/day valganciclovir compared with 900 mg/day valganciclovir results in little to no difference in all-cause death, CMV infection, acute rejection, and graft loss (no information on adverse events). Maribavir may increase CMV infection compared with ganciclovir (1 study: RR 1.34, 95% CI: 1.10 to 1.65; moderate certainty evidence); however, little to no difference between the two treatments were found for CMV disease, all-cause death, acute rejection, and adverse events at six months (low certainty evidence).

AUTHORS' CONCLUSIONS

Prophylaxis with antiviral medications reduces CMV disease and CMV-associated death, compared with placebo or no treatment, in solid organ transplant recipients. These data support the continued routine use of antiviral prophylaxis in CMV-positive recipients and CMV-negative recipients of CMV-positive organ transplants.

A Systematic Review and Meta-analysis of Optimized CMV Preemptive Therapy and Antiviral Prophylaxis for CMV Disease Prevention in CMV High-Risk (D+R-) Kidney Transplant Recipients

The optimal strategy for cytomegalovirus (CMV) disease prevention in CMV donor/recipient kidney transplant recipients remains uncertain. Conclusions of prior meta-analyses that CMV disease rates with preemptive therapy (PET) and universal prophylaxis (UP) were comparable may have been affected by inclusion of studies lacking key determinants of efficacy of the respective strategies.

Methods

We conducted a systematic review and meta-analysis of PET with weekly CMV polymerase chain reaction monitoring for ≥3 mo and UP with 6 mo of valganciclovir. PubMed and Embase databases were reviewed from January 1, 2010, to April 1, 2022. Risk of bias was assessed with 3 instruments (Cochrane RoB, Cochrane RoBINS-I, and an instrument for assessing risk in observational studies). The primary outcome was CMV disease incidence by 1-y posttransplant. Secondary outcomes by 1-y were graft loss, acute allograft rejection, and mortality. Results were synthesized using generalized linear mixed model meta-analysis. PET studies were stratified into low-threshold (LT) and high-threshold (HT) PET based on the viral load threshold for initiation of antiviral therapy.

Results

Twenty-five studies met inclusion criteria (6 PET, 19 UP). CMV disease incidence was significantly higher in HT (0.30 [95% confidence interval (CI), 0.22-0.39]) versus LT PET (0.06 [95% CI, 0.03-0.12]). LT PET was associated with a significantly lower CMV disease incidence (0.06 [95% CI, 0.03-0.12]) versus UP (0.21 [95% CI, 0.17-0.27]). Incidence of graft loss, acute allograft rejection, or mortality was not significantly different between LT PET and UP (P > 0.05 for all comparisons). Receipt of lymphocyte-depleting antibodies was not associated with a significant difference in CMV disease incidence (odds ratio = 1.34 [95% CI, 0.80-2.25]).

Conclusions

LT PET is associated with a significantly lower incidence of CMV disease compared to UP with similar rates of other clinical outcomes. These findings provide rationale and preliminary data for a randomized superiority trial of optimized LT-PET versus UP in donor seropositive recipient seronegative kidney transplant recipients.

Cost-effectiveness of Preemptive Therapy Versus Prophylaxis in a Randomized Clinical Trial for the Prevention of Cytomegalovirus Disease in Seronegative Liver Transplant Recipients With Seropositive Donors

BACKGROUND

The relative costs of preemptive therapy (PET) or prophylaxis for the prevention of cytomegalovirus (CMV) disease in high-risk donor CMV-seropositive/recipient-seronegative (D+/R-) liver transplant recipients have not been assessed in the context of a randomized trial.

METHODS

A decision tree model was constructed based on the probability of outcomes in a randomized controlled trial that compared valganciclovir as PET or prophylaxis for 100 days in 205 D+/R- liver transplant recipients. Itemized costs for each site were obtained from a federal cost transparency database. Total costs included costs of implementation of the strategy and CMV disease treatment-related costs. Net cost per patient was estimated from the decision tree for each strategy.

RESULTS

PET was associated with a 10% lower absolute rate of CMV disease (9% vs 19%). The cost of treating a case of CMV disease in our patients was $88 190. Considering cost of implementation of strategy and treatment-related cost for CMV disease, the net cost-savings per patient associated with PET was $8707 compared to prophylaxis. PET remained cost-effective across a range of assumptions (varying costs of monitoring and treatment, and rates of disease).

CONCLUSIONS

PET is the dominant CMV prevention strategy in that it was associated with lower rates of CMV disease and lower overall costs compared to prophylaxis in D+/R- liver transplant recipients. Costs were driven primarily by more hospitalizations and higher CMV disease-associated costs due to delayed onset postprophylaxis disease in the prophylaxis group.

Postoperative hyperglycemia may negatively impact cytomegalovirus infection in seropositive liver transplant recipients: a retrospective cohort study

The aim of the study was to evaluate the association between postoperative hyperglycemia and CMV infection. We analyzed 741 CMV seropositive recipients, of livers from seropositive living donors, who underwent preemptive CMV treatment without CMV prophylaxis. The primary outcome was early CMV infection within 1 month after surgery. Hyperglycemia was defined when mean postoperative blood glucose concentration was >180 mg/dl based on previous research and guidelines. Survival analysis was performed using the Fine and Gray model by accounting for the competing risk of CMV infection-unrelated death. Of the 741 recipients (hyperglycemic group, n = 287; nonhyperglycemic group, n = 454), 372 (50.2%) recipients developed cytomegalovirus (CMV) infection within 1 month after surgery. CMV infection risk was significantly higher in hyperglycemic group than in nonhyperglycemic group in univariable analysis [hazard ratio (HR) 1.34, 95% confidence interval (CI), 1.08-1.66; P = 0.007] and in multivariable analysis (HR 1.25, 95% CI 1.0-1.54; P = 0.038). CMV infection risk was also significantly associated with recipient age, graft ischemia time, model for end-stage liver disease score, and preoperative neutrophil-to-lymphocyte ratio (P < 0.05). In conclusion, preventing postoperative hyperglycemia appears to be an important factor decreasing the risk of CMV infection in seropositive liver transplant recipients undergoing preemptive CMV treatment.

Host Genetics of Cytomegalovirus Pathogenesis

Human cytomegalovirus (HCMV) is a ubiquitous herpes virus (human herpes virus 5) with the highest morbidity and mortality rates compared to other herpes viruses. Risk groups include very young, elderly, transplant recipient, and immunocompromised individuals. HCMV may cause retinitis, encephalitis, hepatitis, esophagitis, colitis, pneumonia, neonatal infection sequelae, inflammatory, and age-related diseases. With an arsenal of genes in its large genome dedicated to host immune evasion, HCMV can block intrinsic cellular defenses and interfere with cellular immune responses. HCMV also encodes chemokines, chemokine receptors, and cytokines. Therefore, genes involved in human viral defense mechanisms and those encoding proteins targeted by the CMV proteins are candidates for host control of CMV infection and reactivation. Although still few in number, host genetic studies are producing valuable insights into biological processes involved in HCMV pathogenesis and HCMV-related diseases. For example, genetic variants in the immunoglobulin GM light chain can influence the antibody responsiveness to CMV glycoprotein B and modify risk of HCMV-related diseases. Moreover, CMV infection following organ transplantation has been associated with variants in genes encoding toll-like receptors (TLRs), programmed death-1 (PD-1), and interleukin-12p40 (IL-12B). A KIR haplotype (2DS4+) is proposed to be protective for CMV activation among hematopoietic stem cell transplant patients. Polymorphisms in the interferon lambda 3/4 (IFNL3/4) region are shown to influence susceptibility to CMV replication among solid organ transplant patients. Interestingly, the IFNL3/4 region is also associated with AIDS-related CMV retinitis susceptibility in HIV-infected patients. Likewise, interleukin-10 receptor 1 (IL-10R1) variants are shown to influence CMV retinitis development in patients with AIDS. Results from genome-wide association studies suggest a possible role for microtubule network and retinol metabolism in anti-CMV antibody response. Nevertheless, further genetic epidemiological studies with large cohorts, functional studies on the numerous HCMV genes, and immune response to chronic and latent states of infection that contribute to HCMV persistence are clearly necessary to elucidate the genetic mechanisms of CMV infection, reactivation, and pathogenesis.

Cytomegalovirus Infection in Patients with Sepsis Due to Bloodstream Infections: Lower Risk and Better Outcomes in New versus Already Hospitalised Intensive Care Unit Admissions

Few studies have examined cytomegalovirus (CMV) reactivation exclusively in immunocompetent patients with sepsis due to bloodstream infections. In a cohort of CMV-seropositive critically ill otherwise non-immunosuppressed patients with sepsis due to bloodstream infection, weekly testing for CMV viraemia was performed. Outcomes were assessed at 30 days or until death/discharge from the intensive care unit (ICU). CMV viraemia developed in 20% (20/100) of the patients. Age ( P=0.044) and blood transfusions ( P=0.022) were significantly associated with CMV viraemia. There was no difference in the primary endpoint (mortality and/or multi-organ failure) between patients with and without CMV viraemia ( P=0.49). However, CMV viraemia was associated with significantly fewer ICU-free days ( P=0.023) and fewer ventilator-free days ( P=0.031). Patients hospitalised in the ICU for more than 48 hours prior to the onset of bloodstream infection were more likely to develop CMV viraemia ( P=0.006), have high-grade viraemia ( P=0.010), and fewer ICU-free days ( P=0.018) and ventilator-free days ( P=0.029) than those admitted within 48 hours of bloodstream infection. Thus, CMV reactivation was associated with fewer ICU- and ventilator-free days, however overall mortality was not affected. Patients already in the ICU at the onset of sepsis had higher risk of CMV reactivation and worse outcomes than new ICU-bound patients suggesting that a targeted approach for interventions for CMV could conceivably be directed towards those with a more protracted course of illness.

Synthetic DNA approach to cytomegalovirus vaccine/immune therapy

There is no licensed vaccine or cure for human cytomegalovirus (CMV), a ubiquitous β-herpes virus that infects 60-95 % of adults worldwide. Infection is a major cause of congenital abnormalities in newborns, contributes to development of childhood cerebral palsy and medulloblastoma, can result in severe disease in immunocompromised patients, and is a major impediment during successful organ transplantation. While CMV has been increasingly associated with numerous inflammatory diseases and cancers, only recently has it been correlated with increased risk of heart disease in adults, the number-one killer in the USA. These data, among others, suggest that subclinical CMV infection, or microinfection, in healthy individuals may play more of a causative role than an epiphenomenon in development of CMV-associated pathologies. Due to the myriad of diseases and complications associated with CMV, an efficacious vaccine would be highly valuable in reducing human morbidity and mortality as well as saving billions of dollars in annual health-care costs and disability adjusted life years (DALY) in the developing world. Therefore, the development of a safe efficacious CMV vaccine or immune therapy is paramount to the public health. This review aims to provide a brief overview on aspects of CMV infection and disease and focuses on current vaccine strategies. The use of new synthetic DNA vaccines might offer one such approach to this difficult problem.

Universal prophylaxis or preemptive strategy for cytomegalovirus disease after liver transplantation: a systematic review and meta-analysis

We systematically reviewed and meta-analyze the efficacy of universal prophylaxis (UP) and preemptive (PE) strategies (using ganciclovir or valganciclovir) in preventing cytomegalovirus (CMV) disease (CMD) among liver transplant recipients (LTRs). We performed an electronic search of MEDLINE, EMBASE and the Cochrane Database till December 2013. Studies that assessed UP or PE for preventing CMD in LTRs were included. The risk of bias was assessed using the Newcastle-Ottawa scale. The primary outcome was CMD, secondary outcomes being acute cellular rejection (ACR), graft loss (GL) and mortality. Due to the heterogeneity of comparative studies, an indirect comparison was performed. Pooled incidence rates with 95% confidence interval (CI) are calculated for each outcome using a random-effects model. Thirty-two studies involving 2456 LTRs were included. The majority of the studies were of low risk of bias. Irrespective of donor/recipient CMV sero-status, CMD was 10% with UP (95% CI: 6-14; I(2)  = 87%; 16 studies, n = 1581) and 7% with PE (95% CI: 3-10; I(2)  = 84%; 16 studies, n = 875) (mean difference 2.6; 95% CI: -3.25 to 8.45, p = 0.34). Likewise, ACR and mortality were similar with the two strategies. However, GL was significantly lower in the UP group, regardless of donor/recipient sero-status. In indirect comparison, the incidence of CMD, ACR and mortality in LTRs were similar with two strategies. Trials comparing the two strategies directly are needed.

Antiviral medications for preventing cytomegalovirus disease in solid organ transplant recipients

BACKGROUND

The risk of cytomegalovirus (CMV) infection in solid organ transplant recipients has resulted in the frequent use of prophylaxis with the aim of preventing the clinical syndrome associated with CMV infection. This is an update of a review first published in 2005 and updated in 2008.

OBJECTIVES

To determine the benefits and harms of antiviral medications to prevent CMV disease and all-cause mortality in solid organ transplant recipients.

SEARCH METHODS

We searched MEDLINE, EMBASE and the Cochrane Central Registry of Controlled Trials (CENTRAL) in The Cochrane Library to February 2004 for the first version of this review. The Cochrane Renal Group's specialised register was searched to February 2007 and to July 2011 for the first and current updates of the review without language restriction.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) and quasi-RCTs comparing antiviral medications with placebo or no treatment, comparing different antiviral medications and comparing different regimens of the same antiviral medications in recipients of any solid organ transplant. Studies examining pre-emptive therapy were excluded.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed study eligibility, risk of bias and extracted data. Results were reported as risk ratios (RR) or risk differences (RD) with 95% confidence intervals (CI) for dichotomous outcomes and by mean difference (MD) with 95% CI for continuous outcomes. Statistical analyses were performed using the random-effects model. Subgroup analysis and univariate meta-regression were performed using restricted maximum-likelihood to estimate the between study variance. Multivariate meta-regression was performed to investigate whether the results were altered after allowing for differences in drugs used, organ transplanted, and recipient CMV serostatus at the time of transplantation.

MAIN RESULTS

We identified 37 studies (4342 participants). Risk of bias attributes were poorly performed or reported with low risk of bias reported for sequence generation, allocation concealment, blinding and selective outcome reporting in 25% or fewer studies.Prophylaxis with aciclovir, ganciclovir or valaciclovir compared with placebo or no treatment significantly reduced the risk for CMV disease (19 studies; RR 0.42, 95% CI 0.34 to 0.52), CMV infection (17 studies; RR 0.61, 95% CI 0.48 to 0.77), and all-cause mortality (17 studies; RR 0.63, 95% CI 0.43 to 0.92) primarily due to reduced mortality from CMV disease (7 studies; RR 0.26, 95% CI 0.08 to 0.78). Prophylaxis reduced the risk of herpes simplex and herpes zoster disease, bacterial and protozoal infections but not fungal infection, acute rejection or graft loss.Meta-regression showed no significant difference in the relative benefit of treatment (risk of CMV disease or all-cause mortality) by organ transplanted or CMV serostatus; no conclusions were possible for CMV negative recipients of negative organs.Neurological dysfunction was more common with ganciclovir and valaciclovir compared with placebo/no treatment. In direct comparison studies, ganciclovir was more effective than aciclovir in preventing CMV disease (7 studies; RR 0.37, 95% CI 0.23 to 0.60) and leucopenia was more common with aciclovir. Valganciclovir and IV ganciclovir were as effective as oral ganciclovir. The efficacy and adverse effects of valganciclovir/ganciclovir did not differ from valaciclovir in three small studies. Extended duration prophylaxis significantly reduced the risk of CMV disease compared with three months therapy (2 studies; RR 0.20, 95% CI 0.12 to 0.35). Leucopenia was more common with extended duration prophylaxis but severe treatment associated adverse effects did not differ between extended and three month durations of treatment.

AUTHORS' CONCLUSIONS

Prophylaxis with antiviral medications reduces CMV disease and CMV-associated mortality in solid organ transplant recipients. These data suggest that antiviral prophylaxis should be used routinely in CMV positive recipients and in CMV negative recipients of CMV positive organ transplants.

Pre-emptive treatment for cytomegalovirus viraemia to prevent cytomegalovirus disease in solid organ transplant recipients

BACKGROUND

Cytomegalovirus (CMV) is a significant cause of morbidity and mortality in solid organ transplant recipients. Pre-emptive treatment of patients with CMV viraemia using antiviral agents has been suggested as an alternative to routine prophylaxis to prevent CMV disease. This is an update of a Cochrane review first published in 2005.

OBJECTIVES

This review was conducted to evaluate the efficacy of pre-emptive treatment with antiviral medications in preventing symptomatic CMV disease.

SEARCH METHODS

For this update, we searched the Cochrane Renal Group's Specialised Register (to 16 January 2013) through contact with the Trials' Search Co-ordinator using search terms relevant to this review.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) of pre-emptive treatment compared with placebo, no specific treatment or with antiviral prophylaxis in solid organ transplant recipients.

DATA COLLECTION AND ANALYSIS

Four authors assessed the quality and extracted all data. Analyses used a random-effects model and results were expressed as risk ratio (RR) and 95% confidence intervals (CI).

MAIN RESULTS

We identified 15 eligible studies (1098 participants). Of these, six investigated pre-emptive treatment versus placebo or treatment of CMV when disease occurred (standard care), eight looked at pre-emptive treatment versus antiviral prophylaxis, and one reported on oral versus intravenous pre-emptive treatment.Assessment of risk of bias identified that the processes reported for sequence generation and allocation concealment were at low risk of bias in only five and three studies, respectively. All studies were considered to be at low risk of attrition bias, and seven studies were considered to be at low risk of bias for selective reporting. Only one study reported adequate blinding of participants and personnel; no study reported blinding of outcome assessment.Compared with placebo or standard care, pre-emptive treatment significantly reduced the risk of CMV disease (6 studies, 288 participants: RR 0.29, 95% CI 0.11 to 0.80) but not acute rejection (3 studies, 185 participants: RR 1.21, 95% CI 0.69 to 2.12) or all-cause mortality (3 studies, 176 participants: RR 1.23, 95% CI 0.35 to 4.30). Comparative studies of pre-emptive therapy versus prophylaxis showed no significant differences in preventing CMV disease between pre-emptive and prophylactic therapy (7 studies, 753 participants: RR 1.00, 95% CI 0.36 to 2.74) but there was significant heterogeneity (I² = 63%). Leucopenia was significantly less common with pre-emptive therapy compared with prophylaxis (6 studies, 729 participants: RR 0.42, 95% CI 0.20 to 0.90). Other adverse effects did not differ significantly or were not reported. There were no significant differences in the risks of all-cause mortality, graft loss, acute rejection and infections other than CMV.

AUTHORS' CONCLUSIONS

Few RCTs have evaluated the effects of pre-emptive therapy to prevent CMV disease. Pre-emptive therapy is effective compared with placebo or standard care. Despite the inclusion of five additional studies in this update, the efficacy of pre-emptive therapy compared with prophylaxis to prevent CMV disease remains unclear due to significant heterogeneity between studies. Additional head-to-head studies are required to determine the relative benefits and harms of pre-emptive therapy and prophylaxis to prevent CMV disease in solid organ transplant recipients.

Evaluation of valganciclovir pharmacokinetics in lung transplant recipients

BACKGROUND

Valganciclovir is commonly used for cytomegalovirus prevention after lung transplantation. The pharmacokinetic profile of valganciclovir in lung transplant patients has not been well described or linked to efficacy and safety.

METHODS

This prospective, randomized, crossover study determined the steady-state pharmacokinetic profile of 2 different doses of valganciclovir in lung transplant recipients and compared these profiles with intravenous ganciclovir.

RESULTS

Ten patients were evaluated. Patients were 56.8 ± 3.4 years old and had a mean creatinine clearance of 69 ± 9 ml/min. Oral bioavailability of ganciclovir after administration of valganciclovir was 59%, and mean half-life was 3.73 ± 1.15 hours. The maximal concentration after intravenous 5 mg/kg ganciclovir was significantly higher than after 450 mg valganciclovir (8.37 ± 3.03 mg/liter vs. 5.3 ± 2.09 mg/liter, respectively; p = 0.02) and similar to 900 mg valganciclovir (7.93 ± 3.97 mg/liter; p = 0.78). A higher area under the curve at 0-24 hours (AUC(0-24)) was found with 900 mg valganciclovir compared with intravenous 5 mg/kg/day ganciclovir (47.8 ± 19.7 vs 32.9 ± 10.8 mg · hour/liter, respectively; p = 0.049). The AUC(0-24) for 450 mg valganciclovir twice daily was 45.5 ± 22.9 mg · hour/liter.

CONCLUSION

Valganciclovir at 900 mg/day resulted in the equivalent of a mean daily dose of 7.7 mg/kg intravenous ganciclovir. Higher systemic ganciclovir exposures occurred after 900 mg/day valganciclovir compared with intravenous 5 mg/kg/day ganciclovir. Valganciclovir therapeutic drug monitoring may be warranted in select lung transplant patients to avoid increased toxicity.

Cytomegalovirus incidence between everolimus versus mycophenolate in de novo renal transplants: pooled analysis of three clinical trials

Everolimus (EVR) in heart and renal transplant (RTx) recipients may be associated with a decreased incidence of cytomegalovirus (CMV). A detailed analysis of the association between EVR versus mycophenolic acid (MPA) and CMV events has not been reported. CMV data from 2004 de novo RTx recipients from three-randomized, prospective, EVR studies A2309 (N = 833), B201 (N = 588) and B251 (N = 583) were retrospectively analyzed to identify differences between two EVR dosing groups and MPA. EVR groups received 1.5 mg/day, or 3 mg/day with either standard (SD-CsA) or reduced dose cyclosporine (RD-CsA). Controls received MPA with SD-CsA. CMV prophylaxis was as per center practice. CMV incidence (infection/syndrome, disease, viremia) was captured per local center evaluations. Kaplan-Meier analyses demonstrated that freedom from CMV viremia and infection/syndrome was significantly greater for EVR versus MPA for recipients without CMV prophylaxis. Among recipients who received prophylaxis, freedom from viremia was greater for EVR 3.0 mg; freedom from infection/syndrome was greater for EVR 3.0 and 1.5 mg. Although freedom from organ involvement was numerically greater for EVR, it was not statistically significant. This analysis documents significant reductions in the incidence of CMV infection/syndrome and viremia in EVR-treated de novo RTx recipients, especially those who did not receive CMV prophylaxis versus MPA.

The 'indirect' effects of cytomegalovirus infection

Cytomegalovirus (CMV) remains the most important infection in the immunocompromized host even in the era of effective therapy. CMV is usually acquired early in life and can be transmitted by contact with infected body fluids. In the immunocompetent population, primary infection is almost always of little clinical consequence. However, CMV infection in immunocompromized patients, especially those naive to CMV exposure, can cause tissue invasive disease, severe symptoms and/or death. However, beyond these direct effects, increasing in vitro evidence is accumulating that suggests CMV has many other effects on the host's immune response which may explain some of the detrimental consequences for the immunosuppressed patient, and may also be partially responsible for a variety of conditions in immunocompetent individuals. In its latent state, CMV employs several mechanisms to evade detection by the host's immune system. The virus also employs other methods to take advantage of activation of the immune system and replicate in sites of inflammation. This review focuses on the immunosuppressive and inflammatory mechanisms that have been attributed to CMV and will relate them to some of the clinical sequellae that have been associated with the indirect effects of CMV infection.

Assessing the economic merits of managing cytomegalovirus infection in organ and stem cell transplantation

Two preventative approaches exist to manage cytomegalovirus (CMV), a common infection in recipients of organ and stem cell transplants: prophylaxis--the prevention of viraemia--and pre-emptive therapy--the prevention of manifestation of disease in patients who have viraemia. Economic evaluation may provide a helpful framework to inform the choice between these two approaches. However, several issues arise. Direct comparisons of prophylaxis and pre-emptive therapy are rare and there are few epidemiological data that depict the full natural history of CMV infection and disease. There is a need for large, prospective randomised trials that directly compare these two strategies and are of sufficient duration to assess their overall impact on direct and indirect effects of CMV as well as patient quality of life. These methodological issues are relevant to the economic evaluation of preventative measures in other clinical settings and highlight the need for a rigorous evaluative framework to best inform decision making about the optimal strategy for patients.

Antiviral medications for preventing cytomegalovirus disease in solid organ transplant recipients

BACKGROUND

The risk of cytomegalovirus (CMV) infection in solid organ transplant recipients has resulted in the frequent use of prophylaxis with the aim of preventing the clinical syndrome associated with CMV infection.

OBJECTIVES

To determine the benefits and harms of antiviral medications to prevent CMV disease and all-cause mortality in solid organ transplant recipients.

SEARCH STRATEGY

We searched the Cochrane Central Register of Controlled Trials, MEDLINE, EMBASE, reference lists and abstracts from conference proceedings without language restriction. Date of last search: February 2007

SELECTION CRITERIA

Randomised controlled trials (RCTs) and quasi-RCTs comparing antiviral medications with placebo or no treatment, comparing different antiviral medications and comparing different regimens of the same antiviral medications in recipients of any solid organ transplant.

DATA COLLECTION AND ANALYSIS

Statistical analyses were performed using the random effects model and results expressed as relative risk (RR) for dichotomous outcomes with 95% confidence intervals (CI). Subgroup analysis and univariate meta-regression were performed using restricted maximum-likelihood to estimate the between study variance. Multivariate meta-regression was performed to investigate whether the results were altered after allowing for differences in drugs used, organ transplanted and recipient CMV serostatus at the time of transplantation.

MAIN RESULTS

Thirty four studies (3850 participants) were identified. Prophylaxis with aciclovir, ganciclovir or valaciclovir compared with placebo or no treatment significantly reduced the risk for CMV disease (19 studies; RR 0.42, 95% CI 0.34 to 0.52), CMV infection (17 studies; RR 0.61, 95% CI 0.48 to 0.77), and all-cause mortality (17 studies; RR 0.63, 95% CI 0.43 to 0.92) primarily due to reduced mortality from CMV disease (7 studies; RR 0.26, 95% CI 0.08 to 0.78). Prophylaxis reduced the risk of herpes simplex and herpes zoster disease, bacterial and protozoal infections but not fungal infection, acute rejection or graft loss. Meta-regression showed no significant difference in the relative benefit of treatment (risk of CMV disease or all-cause mortality) by organ transplanted or CMV serostatus; no conclusions were possible for CMV negative recipients of negative organs. In direct comparison studies, ganciclovir was more effective than aciclovir in preventing CMV disease (7 studies; RR 0.37, 95% CI 0.23 to 0.60). Valganciclovir and IV ganciclovir were as effective as oral ganciclovir.

AUTHORS' CONCLUSIONS

Prophylaxis with antiviral medications reduces CMV disease and CMV-associated mortality in solid organ transplant recipients. They should be used routinely in CMV positive recipients and in CMV negative recipients of CMV positive organ transplants.

Programmed death-1 expression in liver transplant recipients as a prognostic indicator of cytomegalovirus disease

Immunological parameters that distinguish solid-organ transplant (SOT) recipients at risk for life-threatening cytomegalovirus (CMV) disease are being actively pursued to aid posttransplant management. A candidate marker is programmed death (PD)-1 receptor, whose overexpression has been associated with disease progression during persistent viral infections. To determine whether levels of this negative regulator of T cell activity are altered in SOT recipients with symptoms of CMV disease, a comparative PD-1 expression analysis was done in healthy, CMV-positive individuals and in liver transplant recipients. PD-1 levels were measured among the total population of CD8(+) and CD8(+) T cells binding to CMV-specific major histocompatibility complex class I tetramers. Minimal PD-1 expression was found in the healthy, CMV-positive cohort, and symptomatic SOT recipients had significantly higher PD-1 levels. PD-1 up-regulation was significantly associated with incipient and overt CMV disease and with viremia. Our findings suggest that PD-1 could be developed as a prognostic tool to predict CMV disease and guide therapeutic interventions.

Update on Pharmacoeconomics in Transplantation

Purpose

To provide current information on pharmacoeconomic outcomes in transplantation for the past 6 years.

Methods

An extensive literature search was undertaken using PubMed and other authenticated Internet sources. Key words used to elicit pertinent studies were “pharmacoeconomics,” “transplantation,” “cost-effectiveness,” “cost-benefit,” “cost-minimization” and “cost-utility” analyses. Studies included in the review contain updated pharmacoeconomic data generated during the past 6 years on economic, clinical, and humanistic outcomes. These data are used to describe and analyze the cost of drug therapy used in transplantation.

Results

Background information is included in the review to provide a context from which to evaluate new study material. Data extracted from the studies include significant findings and study limitations. Data were stratified into understanding pharmacoeconomic methods and their application to transplantation, maintenance and induction therapies, and management of and costs associated with adverse events and quality-of-life issues.

Conclusions

Continued evolution of pharmacoeconomic analysis is needed so that optimal care can be provided in the most cost-effective manner. Pharmacoeconomic study, done rationally and logically, is an indispensable tool in determining optimal transplantation regimens.

Temporal trends in early clinical outcomes and health care resource utilization for liver transplantation in the United States

INTRODUCTION

Procedures such as liver transplantation, which entail large costs while benefiting only a small percentage of the population, are being increasingly scrutinized by third-party payors. The purpose of our study was to conduct a longitudinal analysis of the early clinical outcomes and health care resource utilization for liver transplantation in the United States.

METHODS

The Nationwide Inpatient Sample database was used to conduct a longitudinal analysis of the clinical outcome and resource utilization data for liver transplantation procedures in adult recipients performed in the United States over three time periods (Period I: 1988-1993; Period II: 1994-1998: Period III: 1999-2003).

RESULTS

Compared to Period I, adult liver transplant recipients were more likely to be male, older, and non-White in Period III. Recipients were more likely to have at least one major comorbidity preoperatively than in Period I. The in-hospital mortality rate after liver transplantation decreased significantly from Period I to Period III, but the major intraoperative and postoperative complication rates increased over the same time period. Mean length of hospital stay decreased over the 15-year period, but the percentage of patients with a non-routine discharge status increased.

CONCLUSION

Our findings indicate that the rate of postoperative complications and non-routine discharges after liver transplantation is increasing. However, these negative changes in the cost-outcomes relationship for liver transplantation are balanced by improving postoperative survival rates and reductions in the length of hospital stay.

Effect of antiviral chemoprophylaxis on adverse clinical outcomes associated with cytomegalovirus after liver transplantation

OBJECTIVE

To assess t he association be tweencytomegalovirus (CMV) serology of donor and recipient and adverse outcomes afterliver transplantation in the era of effective antiviral chemoprophylaxis.

PATIENTS AND METHODS

We performed a retrospective cohort study of 193 consecutive patients undergoing their first liver transplantation between February 1998 and July 2000 with targeted and preemptive ganciclovir chemoprophylaxis. Patients were divided into 4 groups by CMV serology of donor and recipient: donor-/recipient-; donor-/recipient+; donor+/recipient+; and donor+/recipient-. Survival to the end points of retransplantation, death, or survival to 1 year after transplantation (whichever occurred first) was assessed. Rates of bacterial, fungal, and CMV Infection and of CMV disease were recorded and compared.

RESULTS

No significant differences were observed in the rates of retransplantation, death, or survival to 1 year among the 4 groups of patients. Despite significantly higher rates of CMV infection in the donor+ groups, there were no differences in the rates of bacterial or fungal Infection or of CMV disease. Rejection occurred least frequently in the donor-/recipient- group.

CONCLUSION

The adverse effects of CMV on outcomes after liver transplantation have been diminished in the era of effective antiviral chemoprophylaxis.

Antivirals in the transplant setting

Over the past quarter of a century, antiviral drugs have moved from an experimental adventure in transplant patients to a situation where they are used routinely to prevent diseases caused by several viruses. Furthermore, they have significantly reduced several medical complications of transplantation, such as graft rejection, thereby implicating viruses as components of their pathogenesis. By controlling these major complication, the development of these antiviral drugs and their prodrugs, has therefore greatly facilitated the clinical expansion of transplantation, allowing life saving procedures to be offered to more patients who could potentially benefit. This article will briefly summaries which viruses are important following transplantation and outline the evidence-base from randomized controlled clinical trails for the deployment of antiviral drugs to prevent viral diseases.

Pre-emptive treatment for cytomegalovirus viraemia to prevent cytomegalovirus disease in solid organ transplant recipients

BACKGROUND

Cytomegalovirus (CMV) is a significant cause of morbidity and mortality in solid organ transplant recipients. Pre-emptive treatment with antiviral agents of patients with CMV viraemia has been widely adopted as an alternative to routine prophylaxis to prevent CMV disease.

OBJECTIVES

This review was conducted to evaluate the efficacy of pre-emptive treatment in preventing symptomatic CMV disease.

SEARCH STRATEGY

The Cochrane Central Register of Controlled Trials (CENTRAL, in The Cochrane Library Issue 2, 2005), MEDLINE (1966 to February 2005), EMBASE (1980 to February 2005) and reference lists and conference proceedings were searched.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) of pre-emptive treatment versus placebo, no treatment or antiviral prophylaxis in solid organ transplant recipients.

DATA COLLECTION AND ANALYSIS

Two authors assessed the quality and extracted all data. Analysis was with a random-effects model and results expressed as relative risk (RR) and 95% confidence intervals (CI).

MAIN RESULTS

Ten eligible trials (476 patients) were identified, six of pre-emptive treatment versus placebo or treatment of CMV when disease occurred (standard care), three of pre-emptive treatment versus antiviral prophylaxis and one of oral versus intravenous pre-emptive treatment. Compared with placebo or standard care, pre-emptive treatment significantly reduced the risk of CMV disease (six trials, 288 patients: RR 0.29, 95% CI 0.11 to 0.80) but not acute rejection (three trials, 185 patient: RR 1.06, 95% CI 0.64 to 1.76) or all-cause mortality (two trials, 176 patients: RR 1.23, 95% CI 0.35 to 4.30). Comparative trials of pre-emptive therapy versus prophylaxis showed no significant difference in the risks of CMV disease, acute rejection or all-cause mortality.

AUTHORS' CONCLUSIONS

Few RCTs have evaluated the effects of pre-emptive therapy to prevent CMV disease. Pre-emptive therapy is effective compared with placebo or standard care, but additional head-to-head trials are required to determine the relative benefits and harms of pre-emptive therapy and prophylaxis to prevent CMV disease in solid organ transplant recipients.

Human cytomegalovirus vaccine: time to look for alternative options

In 1999, the Institute of Medicine (IOM) of the National Academy of Sciences (USA) assigned the highest priority for a vaccine to prevent congenital human cytomegalovirus (HCMV) infection, on the basis of the life-time cost to the health care system and the impact of the virus on human suffering. Subsequently, this priority was also endorsed by the US National Vaccine Program Office, which proposed a series of recommendations including support for increased funding by government agencies for HCMV vaccine research. Despite numerous attempts over the past three decades, successful licensure of a HCMV vaccine formulation remains elusive. Here we review the current status of HCMV vaccine studies and, based on our recent understanding of immune regulation of HCMV infection, we argue that a more realistic goal for vaccine strategies should be preventing HCMV disease rather than infection.

Impact of cytomegalovirus prophylaxis on rejection following orthotopic liver transplantation

With improved cytomegalovirus (CMV) prophylaxis, CMV disease after liver transplantation has decreased dramatically, and patient and graft survival have improved. We examined the impact of CMV prophylaxis on biopsy proven rejection after orthotopic liver transplantation by analyzing data on 192 liver recipients over 5 years (1994-1999). Risk factors assessed for biopsy proven rejection including donor and recipient age, CMV serostatus; CMV prophylaxis; immunosuppression; bacteremia and blood product use were examined over a 2-year follow-up. Multivariate analysis of risk factors for rejection showed that bacteremia (HR 3.57, 95% CI 1.39-9.36, P=0.008), donor age (HR 1.20, 95% CI 1.06-1.36, per 10 year increase, P=0.004), and use of cyclosporine as initial immunosuppression compared to tacrolimus (HR 1.98, 95% CI 1.27-3.09, P=0.003) were associated with increased risk; ganciclovir prophylaxis for 3 months (HR 0.51, 95% CI 0.33 to 0.79, P=0.003) and recipient age (HR 0.78; 95% CI 0.63-0.96, for each 10 year increase, P=0.03) were associated with decreased risk. We conclude that, the use of CMV prophylaxis with ganciclovir significantly reduces the incidence of biopsy proven rejection in liver transplant recipients.

Antiviral medications for preventing cytomegalovirus disease in solid organ transplant recipients

BACKGROUND

The risk of cytomegalovirus (CMV) infection in solid organ transplant recipients has resulted in the frequent use of prophylaxis with the aim of preventing the clinical syndrome associated with CMV infection.

OBJECTIVES

To determine the benefits and harms of antiviral medications to prevent CMV disease and all-cause mortality in solid organ transplant recipients.

SEARCH STRATEGY

We searched the Cochrane Central Register of Controlled Trials, MEDLINE, EMBASE, reference lists and abstracts from conference proceedings without language restriction.

SELECTION CRITERIA

Randomised and quasi-randomised controlled trials comparing antiviral medications with placebo or no treatment, trials comparing different antiviral medications and trials comparing different regimens of the same antiviral medications in recipients of any solid organ transplant.

DATA COLLECTION AND ANALYSIS

Two reviewers independently assessed trial quality and extracted data from each trial. Statistical analyses were performed using the random effects model and results expressed as relative risk (RR) for dichotomous outcomes with 95% confidence intervals (CI). Subgroup analysis and univariate meta-regression were performed using restricted maximum-likelihood to estimate the between study variance. Multivariate meta-regression was performed to investigate whether the results were altered after allowing for differences in drugs used, organ transplanted and recipient CMV serostatus at the time of transplantation.

MAIN RESULTS

Thirty two trials (3737 participants) were identified. Prophylaxis with aciclovir, ganciclovir or valaciclovir compared with placebo or no treatment significantly reduced the risk for CMV disease (19 trials; RR 0.42, 95% CI 0.34 to 0.52), CMV infection (17 trials; RR 0.61, 95% CI 0.48 to 0.77), and all-cause mortality (17 trials; RR 0.63, 95% CI 0.43 to 0.92) primarily due to reduced mortality from CMV disease (seven trials; RR 0.26, 95% CI 0.08 to 0.78). Prophylaxis reduced the risk of herpes simplex and herpes zoster disease, bacterial and protozoal infections but not fungal infection, acute rejection or graft loss. Meta-regression showed no significant difference in the risk of CMV disease or all-cause mortality by organ transplanted or CMV serostatus; no conclusions were possible for CMV negative recipients of negative organs. In direct comparison trials, ganciclovir was more effective than aciclovir in preventing CMV disease (seven trials; RR 0.37, 95% Cl 0.23 to 0.60). Valganciclovir and intravenous ganciclovir were as effective as oral ganciclovir.

AUTHORS' CONCLUSIONS

Prophylaxis with antiviral medications reduces CMV disease and CMV-associated mortality in solid organ transplant recipients. They should be used routinely in CMV positive recipients and in CMV negative recipients of CMV positive organ transplants.

Quality assurance, efficiency indicators and cost-utility of the evaluation workup for liver transplantation

We report the results of a retrospective review of the outpatient pretransplantation workup for United Network for Organ Sharing (UNOS) 3 patients adopted at a liver transplantation (LT) center and illustrate the efficiency indicators used for quality evaluation and cost-analysis. A single-center, pre-LT evaluation workup was performed on an outpatient basis at a cost per patient evaluation of 2,770 Euros (). Objective measures were: the number of patients admitted to and excluded from each phase of the algorithm; the rate of patients admitted to pre-LT evaluation out of the total of referred patients (the referral efficiency rate); the rate of waitlisted patients out of those admitted to pre-LT evaluation (the evaluation efficiency rate); the rate of waitlisted patients out of those referred for LT (the process efficiency rate); and the cost per waitlisted patient, as the ratio of the cost per patient evaluation to the evaluation efficiency rate. From January 1, 1996, to October 1, 2004, 1,837 patients were referred for LT on an outpatient basis. Based on preemptive evaluation of the available clinical data, 412 patients (22.4%) were excluded from pre-LT evaluation and 1,425 (77.6%) were admitted to preliminary consultation. Among these, 603 (42.3%) were excluded from and 822 (57.7%) were admitted to pre-LT evaluation with a referral efficiency rate of 44.7% (822 of 1,837). Out of the patients evaluated for LT, 484 were waitlisted with a cost-utility and evaluation efficiency rate of 58.8% each (484 of 822). Of the 1,837 patients originally addressed for LT 484 were waitlisted, yielding a process efficiency rate of 26.3% (484 of 1,837) and a cost per waitlisted patient of 4,710.8. In conclusion, the 3 indicators allowed monitoring of the efficiency of the pre-LT evaluation algorithm. The current process efficiency rate at our center is low (26.3%), but avoiding early referrals we might increase it to 31.6%, with a 12% net saving on costs per waitlisted patient (from 4,710.8 to 4,165.4).

Indirect Outcomes Associated with Cytomegalovirus (Opportunistic Infections, Hepatitis C Virus Sequelae, and Mortality) in Liver-Transplant Recipients with the Use of Preemptive Therapy for 13 Years

BACKGROUND

The effect of preemptive therapy on indirect sequelae associated with cytomegalovirus (CMV) in liver-transplant recipients has not been clearly delineated.

METHODS

Thirteen years of outcome with the use of preemptive therapy were assessed in a cohort of 216 consecutive liver-transplant recipients.

RESULTS

The incidence of major infections (31% vs. 44.3%), bacterial infections (31% vs. 39.2%), bacteremia (19% vs. 29.1%), or fungal infections (3.4% vs. 7.6%) did not differ significantly for patients with CMV infection who received preemptive therapy compared with those who never developed CMV infection and did not receive antiviral prophylaxis for CMV (P>0.20 for all variables). The rate of opportunistic infections also did not differ when patients were stratified by primary CMV infection, reactivation infection, or no CMV infection. Recurrent hepatitis C virus (HCV) hepatitis occurred in 55.6% of the patients with CMV treated with preemptive therapy and 49.8% of those without CMV infection (P>0.20). The probability of survival at 6 months, 12 months, 2 years, and 3 years was also comparable for the two groups.

CONCLUSIONS

Liver-transplant recipients with CMV infection, including high-risk R-/D+ patients, when followed using the preemptive therapy approach had no significant difference in meaningful outcomes such as opportunistic superinfections, HCV recurrence rates, rejection, and survival when compared with the patients in whom CMV infection never developed and who did not receive antiviral prophylaxis for CMV.

Viral prophylaxis in organ transplant patients

Viral pathogens have emerged as the most important microbial agents having deleterious effects on solid organ transplant (SOT) recipients. Antiviral chemoprophylaxis involves the administration of medications to abort transmission of, avoid reactivation of, or prevent progression to disease from, active viral infection. Cytomegalovirus (CMV) is the major microbial pathogen having a negative effect on SOT recipients. CMV causes infectious disease syndromes, augments iatrogenic immunosuppression and is commonly associated with opportunistic superinfection. CMV has also been implicated in the pathogenesis of rejection. Chemoprophylactic regimens for CMV have included oral aciclovir (acyclovir) at medium and high doses, intravenous and oral ganciclovir, and the prodrugs valaciclovir (valacyclovir) and valganciclovir. CMV prophylactic strategies should be stratified, with the highest-risk patients receiving the most 'potent' prophylactic regimens. Herpes simplex virus (HSV) reactivation in SOT recipients is more frequent, may become more invasive, takes longer to heal, and has greater potential for dissemination to visceral organs than it does in the immunocompetent host. Prophylactic regimens for CMV are also effective chemoprophylaxis against HSV; in the absence of CMV prophylaxis, aciclovir, valaciclovir or famciclovir should be used as HSV prophylaxis in seropositive recipients. Primary varicella-zoster virus (VZV) after SOT is rare and most commonly seen in the paediatric transplant population because of VZV epidemiology. Zoster occurs in 5-15% of patients, usually after the sixth post-transplant month. Prophylactic regimens for zoster are neither practical nor cost effective after SOT because of the late onset of disease and low proportion of affected individuals. All SOT recipients should receive VZV immune globulin after contact with either varicella or zoster. Epstein-Barr virus has its most significant effect in SOT as the precipitating factor in the development of post-transplant lymphoproliferative disorders. Antiviral agents that could be effective are the same as those used for CMV, but indications for and effectiveness of prophylaxis are poorly established. Hepatitis B virus (HBV) and hepatitis C virus (HCV) are important pathogens in the SOT population as indications for transplantation. So-called 'prophylaxis' for recurrent HBV and HCV after liver transplantation is controversial, suppressive rather than preventive, and potentially lifelong. Influenza infection after SOT is acquired by person-to-person contact. During epidemic periods of influenza, transplant populations experience a relatively high frequency of infection, and influenza may affect immunosuppressed SOT recipients more adversely than immunocompetent individuals. Antiviral medications for prevention of influenza are administered as post-exposure prophylaxis to SOT recipients, in addition to yearly vaccine, in circumstances such as influenza epidemics and nosocomial outbreaks, and after exposure to a symptomatic individual during 'flu season'.

Valganciclovir: oral prevention and treatment of cytomegalovirus in the immunocompromised host

Herpes virus infections, particularly those caused by cytomegalovirus (CMV), lead to significant and, sometimes severe, clinical problems for the immunocompromised host. As effective agents have become available, several treatment and prevention strategies have evolved over the past decade, first in intra-venous form and more recently, as oral preparations. Valganciclovir, the valine ester of ganciclovir, is an orally administered, potent, antiviral agent active against all herpes viruses. When taken orally, valganciclovir has much-improved bioavailability compared with oral ganciclovir and achieves ganciclovir exposures similar to intravenous ganciclovir. Clinical trials evaluating the safety and efficacy of valganciclovir for the treatment of new AIDS-associated CMV retinitis showed equivalency to intravenous ganciclovir and prevented progression of quiescent disease. In solid organ recipients, once-daily valganciclovir has been proven equivalent to oral ganciclovir for the prevention of CMV infection. The high bioavailability and convenient dosing formulation make valganciclovir an attractive option for these indications.

Human cytomegalovirus: clinical aspects, immune regulation, and emerging treatments

After initial infection, human cytomegalovirus remains in a persistent state with the host. Immunity against the virus controls replication, although intermitent viral shedding can still take place in the seropositive immunocompetent person. Replication of cytomegalovirus in the absence of an effective immune response is central to the pathogenesis of disease. Therefore, complications are primarily seen in individuals whose immune system is immature, or is suppressed by drug treatment or coinfection with other pathogens. Although our increasing knowledge of the host-virus relationship has lead to the development of new pharmacological strategies for cytomegalovirus-associated infections, these strategies all have limitations-eg, drug toxicities, development of resistance, poor oral bioavailability, and low potency. Immune-based therapies to complement pharmacological strategies for the successful treatment of virus-associated complications should be prospectively investigated.

Late-Onset Cytomegalovirus Disease in Liver Transplant Recipients Despite Antiviral Prophylaxis1

BACKGROUND

The incidence and impact of cytomegalovirus (CMV) disease that occurs despite CMV prophylaxis among liver transplant recipients have been incompletely defined.

METHODS

The incidence and risk factors for CMV disease during the first posttransplant year in a cohort of liver transplant recipients who received antiviral prophylaxis with oral ganciclovir were retrospectively analyzed using Cox proportional-hazard regression models.

RESULTS

CMV disease developed in 19 of 259 recipients (7% [95% confidence interval 0.04-0.11]) at a median of 4.5 months posttransplant, included syndrome (63%) or tissue-invasive disease (37%), and was independently associated with an increased risk of mortality during the first posttransplant year (hazard ratio 14 [95% confidence interval 3.8-54], P=0.0007). The incidence was higher (10/38 [26%] vs. 8/180 [4.5%], P<0.0001) in seronegative recipients (R-) of an organ from a seropositive donor (D+) compared with seropositive (R+) patients, respectively. D+R- status was the only variable significantly associated with CMV disease in multivariate analysis.

CONCLUSIONS

Late CMV disease develops in a substantial proportion of D+R- recipients after prophylaxis is discontinued, is not accurately predicted by patient factors, and is associated with increased mortality. New strategies to identify D+R- patients at risk and to reduce the incidence and impact of late CMV disease in this group are warranted.

Cytomegalovirus and lung transplantation

Cytomegalovirus (CMV) infection remains a serious problem in lung transplant recipients. Development of potent oral antiviral agents, molecular techniques for the detection of infection and its response to therapy and the emergence of isolates with antiviral resistance have had significant impacts on the approach to CMV in these patients. This article discusses the following issues as part of a comprehensive CMV management strategy in lung transplant recipients: (1) Prevention strategies in the era of potent oral antiviral agents, (2) the role of new diagnostic techniques in the management of CMV, (3) treatment regimens for established CMV infection or disease, (4) the potential impact of treatment of CMV on the indirect effects on long-term allograft function, and (5) the incidence, risk factors for and impact of ganciclovir resistance following lung transplantation.

Aciclovir or ganciclovir universal prophylaxis of cytomegalovirus infection in liver transplantation: an economic analysis

BACKGROUND

Cytomegalovirus (CMV) following orthotopic liver transplantation can result in significant morbidity and mortality. Prophylaxis with oral aciclovir (ACV) or ganciclovir (GCV) for all transplant recipients (universal prophylaxis) may be beneficial, but which agent is more cost-effective is unknown.

METHODS

A single centre, retrospective study of all patients who had OLT at the Western Australian Liver Transplantation Service was performed. Patients received ACV from 1992 to 1998, and GCV from 1999 to 2001. A comparative cost-effectiveness analysis for the two groups was performed based on the mean total cost of the number of cases of CMV infection and disease as the clinical end-point.

RESULTS

The ACV group comprised of 55 patients and there were 24 in the GCV group. The incidence of CMV disease was 7% and 4% for the ACV and GCV groups, respectively (P > 0.05). For CMV infection it was 16% and 8%, respectively (P > 0.05). GCV prevented more cases of CMV infection and disease than ACV but at an incremental cost of dollars A20,000 (dollars US10,172) per case prevented. Overall, ACV was more cost-effective than GCV by dollars A2200 (dollars US1119) per person. The cost benefit of ACV was derived principally through a reduced pharmaceutical cost. Both agents were well tolerated without development of antiviral resistance.

CONCLUSIONS

Universal prophylaxis of CMV infection-following liver transplantation with aciclovir is more cost-effective than with ganciclovir.

[Efficacy preemptive therapy with ganciclovir for the prevention of cytomegalovirus disease in liver transplant recipients]

BACKGROUND AND OBJECTIVE

In liver transplant recipients the most frequent infection is that produced by cytomegalovirus (CMV). One of the methods to reduce the incidence of that infection is the CMV pp65 antigenemia-guided preemptive therapy with intravenous ganciclovir.

PATIENTS AND METHOD

Liver transplant recipients were tested for CMV antigenemia at days 14, 28, 45, 60, 90 and 180 postransplantation and when clinically indicated. Patients showing > 50/200.000 leukocytes received ganciclovir 5 mg/kg/12 h for 14 days. Risk factors for active CMV disease where studied.

RESULTS

182 CMV seropositive patients where included in the study. 16 patients with > 50/200.000 leukocytes received ganciclovir as preemptive therapy. CMV disease appeared in 9/182 patients (4.9%): 2/16 who received PT and 7/166 among those who did not receive preemptive therapy. The only factor associated with increased incidence of CMV disease was to have missing samples for CMV antigenemia during the follow up (p < 0.0042; OR = 8,17; 95% CI, 1.94-34.36).

CONCLUSIONS

Ganciclovir antigenemia-guided preemptive therapy is associated with a low incidence of CMV disease. Bad adherence to the protocol of antigenemia samples increases the risk for CMV disease.

Impact of donor infections on outcome of orthotopic liver transplantation

Infection occurs when microbial agents enter the host, either through airborne transmission or by direct contact of a substance carrying the infectious agent with the host. Human body fluids, solid organs, or other tissues often are ideal vectors to support microbial agents and can transmit infections efficiently from donor to recipient. In the case of blood transfusion and tissue transplantation, the main consequence of such a transmission is infection of the recipient. However, in the case of solid-organ transplantation, and particularly for liver transplantation, donor infections are not only transmitted to the recipient, the donor infection also may affect the donated liver's preservability and subsequent function in the recipient irrespective of the systemic consequences of the infection. In addition, solid organ recipients of infected organs are less able to respond to the infectious agent because of their immunosuppressive treatment. Thus, transmission of infections from organ donor to liver recipient represents serious potential risks that must be weighed against a candidate's mortality risk without the transplant. However, the ever-increasing gap between the number of donors and those waiting for liver grafts makes consideration of every potential donor, regardless of the infection status, essential to minimize waiting list mortality. In this review, we will focus on assessing the risk of transmission of bacterial, fungal, viral, and parasitic infectious agents from cadaveric liver donors to recipients and the effect such a transmission has on liver function, morbidity, and mortality. We will also discuss risk-benefit deliberations for using organs from infected donors for certain types of recipients. These issues are critically important to maximize the use of donated organs but also minimize recipient morbidity and graft dysfunction.

Cytomegalovirus infection in solid organ transplantation: economic implications

Cytomegalovirus (CMV) is a pathogen, commonly encountered in the recipients of solid organ transplantation and is an important cause of morbidity and mortality in these patients. CMV infection and disease have been shown to increase the cost of care in transplant recipients and several different strategies of prevention have been shown to be effective in clinical trials. A systematic review of published information on the economic impact of CMV in solid organ transplantation was performed; both clinical- and decision-analysis-based studies were reviewed. Clinical studies have shown that CMV infection and disease is associated with increased length of hospital stay and overall costs. Decision-analysis-based studies suggest that in general, antiviral chemoprophylaxis against CMV in transplant recipients is a cost-effective intervention compared with other established healthcare interventions such as strategies for colorectal cancer screening. Prophylaxis with oral or parenteral ganciclovir is probably the most cost-effective strategy; however, restricting prophylaxis to high-risk groups (such as donor seropositive/recipient seronegative status and the use of an antilymphocyte antibody) or chemoprophylaxis for an extended period does not improve cost effectiveness. Pre-emptive therapy is an evolving strategy for prevention of CMV disease in transplant recipients and is rapidly gaining in popularity. Well-designed trials incorporating prospective cost data and comparing pre-emptive therapy versus conventional antiviral prophylaxis are needed to establish the superiority of one strategy over the other.

Economic impact of cytomegalovirus in solid organ transplantation

Cytomegalovirus (CMV) infection has a direct effect on morbidity in solid organ transplantation patients, and indirect effects related to the development of opportunistic infections, allograft rejection, and patient mortality. Although intuitively it follows that costs attributable to CMV infections would be increased, direct proof has remained elusive. Accumulating evidence suggests, however, that CMV infection has a significant impact on the costs to transplantation programs, particularly in seronegative recipients of seropositive allografts (D+/R-), and additional costs may be incurred through the effects on CMV potentiating the risks of various opportunistic infections leading to graft rejection.

Preemptive strategy for ganciclovir administration against cytomegalovirus in liver transplantation recipients

In utilizing a preemptive strategy to minimize the occurrence of symptomatic cytomegalovirus (CMV) infection following liver transplant, only patients with proven CMV activity by direct detection are treated. We applied the following preemptive strategy for CMV infection to 49 sequential liver transplant recipients between 1998 and 2001. Patients were monitored for CMV activity using CMV p65 antigen assay for the first 10 months of the study. Thereafter, we changed the detection method to a quantitative PCR for plasma CMV-DNA. All patients were monitored post transplant, weekly for the first 3 months and then monthly. Only patients with detected CMV activity were treated with ganciclovir. Patients were divided into four groups, based on donor (D) and recipient (R) CMV status. In seven out of 49 patients (14.3%) CMV activity was detected: four in group D+/R-, and three in group D-/R-. Five out of these seven patients had asymptomatic CMV infection. Symptomatic CMV infection developed only in two of these seven patients, to give total rate of 4.1% (2/49). All seven patients developed CMV IgG antibody. 'Transient' CMV replication detected by PCR in five patients in group D+/R+ was not defined as infection. No patients developed organ-invasive CMV disease. The cost of anti-CMV treatment using the preemptive strategy was $1000/patient/1st year. Using preemptive strategy, early detection of CMV infection was achieved, allowing timely treatment. The use of ganciclovir for CMV infection in only 4.3% of the patients should have a positive impact on minimizing the risk of ganciclovir-resistant virus, and should reduce the cost of CMV prevention strategies.

The economic value of valacyclovir prophylaxis in transplantation

Cytomegalovirus (CMV) infection and disease, with its extensive direct and indirect consequences, adds considerably to the cost of patient management in both solid organ and bone marrow transplantation. Antiviral prophylaxis for CMV infection can offer cost advantages over preemptive therapy and "wait-and-treat" approaches. Valacyclovir has demonstrated efficacy for CMV prophylaxis in renal, heart, and bone marrow transplantation and is cost-effective when compared with placebo in renal transplant recipients at high risk of CMV infection. In reducing CMV infection and disease, valacyclovir prophylaxis appears to be associated with reductions in indirect effects of CMV (acute graft rejection, other opportunistic infections) and, if these effects are considered, the potential exists for even greater savings to be made with valacyclovir therapy. Benefits of valacyclovir in transplantation extend beyond CMV to other herpesviruses and may be increased in some clinical situations by prolonging prophylaxis beyond 3 months.

Beta-herpesvirus challenges in the transplant recipient

Cytomegalovirus (CMV) has major consequences after allogeneic stem cell and solid organ transplantation. CMV may cause significant morbidity and mortality, and monitoring to detect reactivation to reduce disease or management of end organ disease is associated with increased resource utilization. Two other members of the beta-herpesvirus family, human herpesvirus (HHV) type 6 and HHV-7, are increasingly recognized as important pathogens in transplant recipients, either by direct infection (e.g., encephalitis, hepatitis, or pneumonitis) or via interaction with CMV. In addition to direct effects of CMV infection, such indirect effects as an increased risk for bacterial and fungal infections or impaired graft acceptance and function are important research topics. Diagnosis and treatment of CMV infection is currently more advanced than for HHV-6 and HHV-7.