Valganciclovir prophylaxis against cytomegalovirus impairs lymphocyte proliferation and activation in renal 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 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 Randomized Trial of Valganciclovir Prophylaxis Versus Preemptive Therapy in Kidney Transplant Recipients

SIGNIFICANCE STATEMENT

Although cytomegalovirus (CMV) infection is an important factor in the pathogenesis of kidney allograft rejection, previous studies have not determined the optimal CMV prevention strategy to avoid indirect effects of the virus. In this randomized trial involving 140 kidney transplant recipients, incidence of acute rejection at 12 months was not lower with valganciclovir prophylaxis (for at least 3 months) compared with preemptive therapy initiated after detection of CMV DNA in whole blood. However, prophylaxis was associated with a lower risk of subclinical rejection at 3 months. Although both regimens were effective in preventing CMV disease, the incidence of CMV DNAemia (including episodes with higher viral loads) was significantly higher with preemptive therapy. Further research with long-term follow-up is warranted to better compare the two approaches.

BACKGROUND

The optimal regimen for preventing cytomegalovirus (CMV) infection in kidney transplant recipients, primarily in reducing indirect CMV effects, has not been defined.

METHODS

This open-label, single-center, randomized clinical trial of valganciclovir prophylaxis versus preemptive therapy included kidney transplant recipients recruited between June 2013 and May 2018. After excluding CMV-seronegative recipients with transplants from seronegative donors, we randomized 140 participants 1:1 to receive valganciclovir prophylaxis (900 mg, daily for 3 or 6 months for CMV-seronegative recipients who received a kidney from a CMV-seropositive donor) or preemptive therapy (valganciclovir, 900 mg, twice daily) that was initiated after detection of CMV DNA in whole blood (≥1000 IU/ml) and stopped after two consecutive negative tests (preemptive therapy patients received weekly CMV PCR tests for 4 months). The primary outcome was the incidence of biopsy-confirmed acute rejection at 12 months. Key secondary outcomes included subclinical rejection, CMV disease and DNAemia, and neutropenia.

RESULTS

The incidence of acute rejection was lower with valganciclovir prophylaxis than with preemptive therapy (13%, 9/70 versus 23%, 16/70), but the difference was not statistically significant. Subclinical rejection at 3 months was lower in the prophylaxis group (13% versus 29%, P = 0.027). Both regimens prevented CMV disease (in 4% of patients in both groups). Compared with prophylaxis, preemptive therapy resulted in significantly higher rates of CMV DNAemia (44% versus 75%, P < 0.001) and a higher proportion of patients experiencing episodes with higher viral load (≥2000 IU/ml), but significantly lower valganciclovir exposure and neutropenia.

CONCLUSION

Among kidney transplant recipients, the use of valganciclovir prophylaxis did not result in a significantly lower incidence of acute rejection compared with the use of preemptive therapy.

CLINICAL TRIAL REGISTRY NAME AND REGISTRATION NUMBER

Optimizing Valganciclovir Efficacy in Renal Transplantation (OVERT Study), ACTRN12613000554763 .

Is Polyomavirus-Associated Nephropathy More Common in Kidney Transplant Recipients Exposed to Valganciclovir? A Retrospective Single Center Analysis

BACKGROUND

BK polyomavirus-associated nephropathy (PVAN) is a frequent complication in the early phase after kidney transplantation. The most important risk factor for PVAN is the intensity of immunosuppression. A recent study suggests that exposure to valganciclovir (VGC) could also be a risk factor.

METHODS

We performed a retrospective, single-center study to investigate the effect of valganciclovir exposure on the risk for PVAN during the first 100 days post transplant. Cytomegalovirus (CMV) seronegative recipients of a CMV seropositive donor kidney received VGC prophylaxis, whereas CMV seropositive recipients were managed by a pre-emptive CMV strategy. Cox regression analysis was used to identify risk factors for PVAN development with VGC treatment and strength of immunosuppressive therapy as time-dependent variables.

RESULTS

A total of 211 adults who received a kidney transplant between 2014 and 2019 were included. Eighteen (9%) developed PVAN. Multivariate regression analysis showed that women have a lower risk of developing PVAN (hazard ratio [HR] 0.08 (confidence interval [CI] 0.01-0.58), P = .013), whereas age was associated with an increased risk for PVAN (HR 1.04 for every additional year [CI 1.00-1.08], P = .029). There was a trend toward a lower risk of PVAN for patients on reduced immunosuppressive therapy (HR 0.44 [CI 0.15-1.24], P = .12). VGC use was not associated with the risk for PVAN (HR 0.99 [CI 0.35-2.78], P = .98).

CONCLUSIONS

In our study, VGC exposure was not associated with the risk for PVAN. Our study is the first to reassess in depth the hypothesis that VGC treatment increases the risk of PVAN. The unique strength of this study is the correction for the degree of immunosuppression and the statistical use of time-dependent covariates. This methodological approach can provide a foundation for further studies needed to confirm our findings.

Maribavir for the Management of Cytomegalovirus in Adult Transplant Recipients: A Review of the Literature and Practical Considerations

OBJECTIVE

To review the efficacy and safety of maribavir for management of cytomegalovirus (CMV) in solid organ transplant recipients.

DATA SOURCES

A literature search of PubMed and the Cochrane Controlled Trials Register (1960 to early July 2022) was performed using the following search terms: maribavir, 1263W94, and cytomegalovirus.

STUDY SELECTION AND DATA EXTRACTION

All relevant English-language studies were reviewed and considered, with a focus on phase 3 trials.

DATA SYNTHESIS

Maribavir, an orally available benzimidazole riboside with minimal adverse effects, was originally studied for universal prophylaxis in phase 3 trials but failed to demonstrate noninferiority over placebo and oral ganciclovir. It was effective for preemptive treatment in a dose-finding Phase 2 study. Maribavir is FDA approved for treatment of refractory/resistant CMV infection based on improved response rate at 8 weeks compared with investigator-assigned therapy (IAT) when initiated at median viral loads less than approximately 10 000 IU/mL (55.7% vs 23.9%, P < 0.001). Recurrence after 8-week treatment for refractory/resistant CMV was high (maribavir 50% vs IAT 39%). Significant drug interactions exist and must be managed by a pharmacotherapy expert to prevent harm.

RELEVANCE TO PATIENT CARE AND CLINICAL PRACTICE

The addition of maribavir to the antiviral armamentarium should improve the management of refractory/resistant CMV, allowing early transition from toxic, high-cost, intravenous agents such as foscarnet and outpatient management. Optimal timing of initiation, duration, and potential alternative uses are unclear.

CONCLUSION

Future studies are needed to fully elucidate the role of maribavir in the management of CMV after transplant.

Letermovir conversion after valganciclovir treatment in cytomegalovirus high-risk abdominal solid organ transplant recipients may promote development of cytomegalovirus-specific cell mediated immunity

PURPOSE

To evaluate the association of conversion from valganciclovir to letermovir on cytomegalovirus-specific cellular immunity.

METHODS

Adult patients were included if they received a kidney or liver transplant between 8/1/2018-12/31/20, developed symptomatic, high-level CMV viremia and were converted to letermovir 480 mg daily as monotherapy after treatment with ganciclovir-derivatives for a minimum of 4 weeks and had subsequent CMV cell-mediated immunity (CMI) testing via ICS assay by flow cytometry (Viracor Eurofins T Cell Immunity Panel).

RESULTS

Seven patients met inclusion criteria; 87.5% were male and recipients of a kidney transplant. All patients were CMV high risk (D+/R-). Mean time from transplant to CMV disease was 200 ± 91 days. Peak viral load (VL) during CMV treatment was 540,341 ± 391,211 IU/mL. Patients received a mean of 30 ± 24 weeks (range: 4-78 weeks) of therapy with ganciclovir-derivatives at induction doses prior to letermovir introduction. The median absolute lymphocyte count (ALC) at letermovir initiation was 400/μL (IQR 575) and the median VL was 51.6 (range: ND-490) IU/mL. Most patients (n = 5/7, 71.4%) experienced an increase in VL 1 and/or 2 weeks after conversion to letermovir. All patients had positive CMI per ICS assay after conversion. Patients received a mean of 10.3 ± 6.9 weeks of letermovir prior to having a positive result. Median ALC at positivity was 900/μL. Immunosuppression was not further reduced from initiation of letermovir to demonstration of CMV CMI. No patient had progressive replication or breakthrough disease while maintained on letermovir and three patients (42.9%) underwent antiviral withdrawal without recurrence at the last follow-up.

CONCLUSION

In this case series of abdominal transplant recipients with severe or persistent CMV infection, patients developed CMV-specific CMI after conversion to letermovir monotherapy. These data suggest that using letermovir in place of valganciclovir for secondary prophylaxis may address the lack of efficacy previously seen with this approach, as well as the issues that plague antiviral withdrawal with systematic monitoring. Future prospective studies are needed to evaluate this effect in a more controlled research environment with serial CMI testing to elucidate the optimal duration of letermovir when used in this way.

CMV infection, valganciclovir exposure, and the risk of BK viremia and associated nephropathy after kidney transplantation: Is there a link?

BACKGROUND

Immunomodulatory effects attributable to cytomegalovirus (CMV) would predispose to BK polyomavirus (BKPyV) infection after kidney transplantation (KT), although available evidence is conflicting. It has been suggested that (val)ganciclovir therapy may increase the risk of BKPyV viremia and BKPyV-associated nephropathy (BKPyVAN) as a result of drug-induced T-cell impairment.

METHODS

We investigated whether CMV replication and/or (val)ganciclovir exposure (either as prophylaxis or treatment) were associated with the development of BKPyV viremia or BKPyVAN in a prospective cohort of 399 KT recipients. CMV infection (any level or high-level viremia and area under the curve of DNAemia) and (val)ganciclovir exposure (any duration of therapy and cumulative days of treatment) during the first post-transplant year were explored through separate landmark survival analyses.

RESULTS

Cumulative incidence of BKPyV viremia and BKPyVAN after a median follow-up of 551 days was 23.1% and 2.5%, respectively. One-year rates of CMV infection and (val)ganciclovir therapy were 47.4% and 54.1%, respectively. No differences were observed in BKPyV viremia- or BKPyVAN-free survival according to previous CMV infection or (val)ganciclovir exposure in any of the landmark analyses. Adjusted Cox models confirmed this lack of association.

CONCLUSION

Our findings do not confirm the existence of a relevant impact of CMV infection or (val)ganciclovir therapy on the risk of post-transplant BKPyV events.

Cytomegalovirus after kidney transplantation in 2020: moving towards personalized prevention

Cytomegalovirus (CMV)-related complications after kidney transplantation remain a substantial challenge. Rather than applying one preventive strategy to all at-risk patients, we can now adapt our strategy at the individual patient level. Antiviral prophylaxis or a strict pre-emptive strategy may be optimal for patients at the highest risk for CMV, while patients at lower risk may benefit particularly from pre-emptive monitoring and the administration of therapy only if needed. CMV-specific T-cell assays may be useful for further refining the pre-transplant determination of CMV risk, and for guiding decisions about antiviral therapy need or duration. An immunosuppressive regimen including a mammalian target of rapamycin inhibitor reduces CMV risk and may thus be an attractive option in some patients. New antiviral agents may further expand our therapeutic arsenal in the near future, and the prospects of CMV vaccination and adoptive T-cell therapy appear to be on the horizon.

Antiviral treatment approaches for cytomegalovirus prevention in kidney transplant recipients: A systematic review of randomized controlled trials

Various CMV anti-viral (AV) preventive strategies have been utilized in KTRs. We examined efficacy, safety and costs of CMV-AV prevention strategies in KTRs using a systematic literature review (SLR) of randomized controlled trials (RCTs) publications indexed in MEDLINE and Embase (from inception to November 2018). Thirty RCTs met inclusion criteria with 22 unique AV preventive strategies. Prophylaxis was associated with significantly lower rates of CMV infection/disease (CMVi/d) compared to no prophylaxis (pooled odds ratio, pOR with 95% confidence interval (CI): CMVi: 0.33; 0.19, 0.57; CMVd: 0.27; 0.19; 0.39). Preemptive therapy (PET) had lower rates of CMVd (0.29; 0.11, 0.77), and medical costs compared to no PET. Prophylaxis had significantly lower rates of early CMVi/d, and higher rates of late CMVi and hematological adverse events (leukopenia, 2.93; 1.22, 7.04), and similar overall medical costs compared to PET. Studies involving head-to-head comparison of different prophylaxis approaches showed mixed findings with respect to optimum dose, duration and route of administration on CMV outcomes. Although there was heterogeneity across populations and interventions, both prophylaxis and PET strategies reduced CMVi/d compared to no prophylaxis/PET and had differential safety profile in terms of hematological adverse events. For comprehensiveness we did not limit study inclusion based on date; the wide time-period may have contributed to the heterogeneity in prevention approaches which subsequently made pooling studies a challenge. Despite demonstrated efficacy of prophylaxis/PET, our findings highlight the potential need of a novel intervention with a better safety profile and perhaps improved outcomes.

Exploring failure of antimicrobial prophylaxis and pre-emptive therapy for transplant recipients: a systematic review

OBJECTIVES

Infections remain a threat for solid organ and stem cell transplant recipients. Antimicrobial prophylaxis and pre-emptive therapy have improved survival of these patients; however, the failure rates of prophylaxis are not negligible. The aim of this systematic review is to explore the reasons behind failure of antimicrobial prophylaxis and pre-emptive therapy.

SETTING

This systematic review included prospective randomised controlled trials and prospective single-arm studies.

PARTICIPANTS

The studies included were on prophylaxis and pre-emptive therapy of opportunistic infections in transplant recipients. Studies were included from databases MEDLINE, CENTRAL and Embase published until October first 2018.

PRIMARY AND SECONDARY OUTCOME MEASURES

Primary outcome measures were breakthrough infections, adverse events leading to stopping of treatment, switching medication or dose reduction. Secondary outcome measures were acquired resistance to antimicrobials, antifungals or antivirals and death.

RESULTS

From 3317 identified records, 30 records from 24 studies with 2851 patients were included in the systematic review. Seventeen focused on prophylactic and pre-emptive treatment of cytomegalovirus and seven studies on invasive fungal infection. The main reasons for failure of prophylaxis and pre-emptive therapy were adverse events and breakthrough infections, which were described in 54% (13 studies) and 38% (9 studies) of the included studies, respectively. In 25%, six of the studies, a detailed description of patients who experienced failure of prophylaxis or pre-emptive therapy was unclear or lacking.

CONCLUSIONS

Our results show that although failure is reported in the studies, the level of detail prohibits a detailed analysis of failure of prophylaxis and pre-emptive therapy. Clearly reporting on patients with a negative outcome should be improved. We have provided guidance on how to detect failure early in a clinical setting in accordance to the results from this systematic review.

PROSPERO REGISTRATION NUMBER

CRD42017077606.

Cytomegalovirus prevention strategies and the risk of BK polyomavirus viremia and nephropathy

Polyomavirus BK (BKV) is the cause of polyomavirus-associated nephropathy resulting in premature graft loss. There are limited data regarding the role of cytomegalovirus (CMV) infection and its prevention in developing BKV viremia and PVAN. In a prospective study, we analyzed 207 consecutive renal transplant recipients previously enrolled in 2 randomized trials evaluating different CMV prevention regimens with routine screening for BKV and CMV. Of these, 59 received valganciclovir and 100 valacyclovir prophylaxis; 48 patients were managed by preemptive therapy. At 3 years, the incidence of BKV viremia and PVAN was 28% and 5%, respectively. CMV DNAemia developed in 55% and CMV disease in 6%. Both BKV viremia (42% vs 23% vs 21%, P = .006) and PVAN (12% vs 2% vs 2%, P = .011) were increased in patients treated with valganciclovir prophylaxis compared to valacyclovir and preemptive therapy. Using multivariate Cox proportional hazard regression, valganciclovir prophylaxis was independent predictor of BKV viremia (hazard ratio [HR] = 2.38, P = .002) and PVAN (HR = 4.73, P = .026). In contrast, the risk of subsequent BKV viremia was lower in patients with antecedent CMV DNAemia (HR = 0.50, P = .018). These data suggest valganciclovir prophylaxis may be associated with increased risk of BKV viremia and PVAN. CMV DNAemia did not represent a risk for BKV.

GCV/VCVG prophylaxis against CMV DNAemia in pediatric renal transplant patients: A systematic review and meta-analysis

CMV disease continues to stand as a significant threat to the longevity of renal transplants in children. More pediatric recipients are CMV-negative with CMV-positive donor serologies resulting in a HR mismatch. The length of prophylaxis with GCV or VGCV required to optimally prevent recurrence of CMVDNAemia remains unknown. This study is a meta-analysis comparing GCV/VGCV prophylaxis regimens provided for <6 months, from 6 to <12 months, and ≥12 months after transplant in order to prevent CMVDNAemia. The search conducted involved PubMed, EMBASE, ISI Web of Science, and Cochrane Central Register from inception through December 2017. Search terms Kidney Transplantation, CMV, GCV, and VGCV provided 204 studies for abstract review. Studies excluded were those which did not itemize pediatric data separately, single case reports, and duplicate studies. Pooled analysis of five retrospective studies and one prospective study identified that there is no statistically significant difference in the incidence of CMV DNAemia when comparing <6 months of prophylaxis and >12 months of prophylaxis (23% and 15%, respectively, P = 0.23). Regardless of the length of prophylaxis, there was no statistical difference in the incidence of CMV DNAemia in the HR patients (6 to <12 months vs <6 months, P = 0.62; 6 to <12 months vs ≥12 months, P = 0.78; ≥12 months vs <6 months, P = 0.83). This study identifies no optimal length of prophylaxis for HR mismatch pediatric renal transplant patients as many develop CMV DNAemia.

The Third International Consensus Guidelines on the Management of Cytomegalovirus in Solid-organ Transplantation

Despite recent advances, cytomegalovirus (CMV) infections remain one of the most common complications affecting solid organ transplant recipients, conveying higher risks of complications, graft loss, morbidity, and mortality. Research in the field and development of prior consensus guidelines supported by The Transplantation Society has allowed a more standardized approach to CMV management. An international multidisciplinary panel of experts was convened to expand and revise evidence and expert opinion-based consensus guidelines on CMV management including prevention, treatment, diagnostics, immunology, drug resistance, and pediatric issues. Highlights include advances in molecular and immunologic diagnostics, improved understanding of diagnostic thresholds, optimized methods of prevention, advances in the use of novel antiviral therapies and certain immunosuppressive agents, and more savvy approaches to treatment resistant/refractory disease. The following report summarizes the updated recommendations.

Less renal allograft fibrosis with valganciclovir prophylaxis for cytomegalovirus compared to high-dose valacyclovir: a parallel group, open-label, randomized controlled trial

BACKGROUND

Cytomegalovirus (CMV) prophylaxis may prevent CMV indirect effects in renal transplant recipients. This study aimed to compare the efficacy of valganciclovir and valacyclovir prophylaxis for CMV after renal transplantation with the focus on chronic histologic damage within the graft.

METHODS

From November 2007 through April 2012, adult renal transplant recipients were randomized, in an open-label, single-center study, at a 1:1 ratio to 3-month prophylaxis with valganciclovir (n = 60) or valacyclovir (n = 59). The primary endpoint was moderate-to-severe interstitial fibrosis and tubular atrophy assessed by protocol biopsy at 3 years evaluated by a single pathologist blinded to the study group. The analysis was conducted in an intention-to-treat population.

RESULTS

Among the 101 patients who had a protocol biopsy specimen available, the risk of moderate-to-severe interstitial fibrosis and tubular atrophy was significantly lower in those treated with valganciclovir (22% versus 34%; adjusted odds ratio, 0.31; 95% confidence interval, 0.11-0.90; P = 0.032 by multivariate logistic regression). The incidence of CMV disease (9% versus 2%; P = 0.115) and CMV DNAemia (36% versus 42%; P = 0.361) were not different at 3 years.

CONCLUSIONS

Valganciclovir prophylaxis, as compared with valacyclovir, was associated with a reduced risk of moderate-to-severe interstitial fibrosis and tubular atrophy in patients after renal transplantation.

TRIAL REGISTRATION

Australian New Zealand Clinical Trials Registry ( ACTRN12610000016033 ). Registered on September 26, 2007.

Bone marrow suppression and associated consequences in patients after heart transplantation: A 6-year retrospective review

AIMS

To evaluate the incidence of bone marrow suppression and consequences of MMF dose adjustment in patients within the first year after heart transplantation.

METHODS

Group I (n=47) was treated with a regimen currently used in patients after heart transplantation (mycophenolatemofetil - MMF, valganciclovir - VGC and trimethoprim/sulfamethoxazole - TMP-SMX). Group II (n=47) received only MMF of potentially myelotoxic medications. The myelotoxic effect and need for dose modification were assessed. The incidence of rejections and infectious episodes associated with MMF adjustment were analyzed during the first 12 months in Group I.

RESULTS

There was a significantly greater proportion of patients with leukopenia (leukocyte count < 4 x 10^9/L) at 3 months after orthotopic heart transplantation in Group I compared with Group II (19.1% vs 2.1%; P = 0.02). The difference in lymphopenia (lymphocyte count < 0.8 x 10^9/L) at 3 months follow-up was highly significant (38.3 % vs 6.4 %; P = 0.0002). MMF was modified due to bone marrow suppression or severe infection in 63.8% patients in Group I and in only 8.5% of patients in Group II (P < 0.001). Reducing or stopping MMF was not associated with increased rejections. In Group I, at least 1 episode of higher degree cellular or humoral rejection occurred in 35% of patients with the standard MMF dosage compared with only 26% in patients with modified MMF (P = 0.0534).

CONCLUSIONS

Addition of VGC+TMP-SMX to current immunosuppressive medication regimen in patients after heart transplantation is associated with significant lymphocytopenia and leukopenia. Importantly, modification of immunosuppressive prophylaxis (reducing or stopping MMF) leads to normalization of blood count without increased incidence of rejections.

Randomized trial of valganciclovir versus valacyclovir prophylaxis for prevention of cytomegalovirus in renal transplantation

BACKGROUND AND OBJECTIVES

Both valganciclovir and high-dose valacyclovir are recommended for cytomegalovirus prophylaxis after renal transplantation. A head-to-head comparison of both regimens is lacking. The objective of the study was to compare valacyclovir prophylaxis with valganciclovir, which constituted the control group.

DESIGN, SETTINGS, PARTICIPANTS, & MEASUREMENTS

In a randomized, open-label, single-center trial, recipients of renal transplants (recipient or donor cytomegalovirus-seropositive) were randomly allocated (1:1) to 3-month prophylaxis with valacyclovir (2 g four times daily) or valganciclovir (900 mg daily). Enrollment occurred from November of 2007 to April of 2012. The primary end points were cytomegalovirus DNAemia and biopsy-proven acute rejection at 12 months. Analysis was by intention to treat.

RESULTS

In total, 119 patients were assigned to valacyclovir (n=59) or valganciclovir prophylaxis (n=60). Cytomegalovirus DNAemia developed in 24 (43%) of 59 patients in the valacyclovir group and 18 (31%) of 60 patients in the valganciclovir group (adjusted hazard ratio, 1.35; 95% confidence interval, 0.71 to 2.54; P=0.36). The incidence of cytomegalovirus disease was 2% with valacyclovir and 5% with valganciclovir prophylaxis (adjusted hazard ratio, 0.21; 95% confidence interval, 0.01 to 5.90; P=0.36). Significantly more patients with valacyclovir prophylaxis developed biopsy-proven acute rejection (18 of 59 [31%] versus 10 of 60 [17%]; adjusted hazard ratio, 2.49; 95% confidence interval, 1.09 to 5.65; P=0.03). The incidence of polyomavirus viremia was higher in the valganciclovir group (18% versus 36%; adjusted hazard ratio, 0.43; 95% confidence interval, 0.19 to 0.96; P=0.04).

CONCLUSIONS

Valganciclovir shows no superior efficacy in cytomegalovirus DNAemia prevention compared with valacyclovir prophylaxis. However, the risk of biopsy-proven acute rejection is higher with valacyclovir.

The efficacy and cost-effectiveness of valacyclovir in cytomegalovirus prevention in solid organ transplantation

Prevention of cytomegalovirus infection using antiviral prophylaxis or the pre-emptive therapy approach is an integral part of management of patients after solid organ transplantation. Regarding renal transplantation, valacyclovir is currently the only antiviral agent recommended for prophylaxis as an alternative to valganciclovir. This review article discusses studies documenting the efficacy and safety of valacyclovir prophylaxis as well as those comparing valacyclovir with other prophylactic regimens or with pre-emptive therapy. Also addressed are the economic aspects supporting the cost-effectiveness of valacyclovir prophylaxis and demonstrating lower costs compared with other cytomegalovirus preventive strategies.

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.

Herpes viruses and HIV-1 drug resistance mutations influence the virologic and immunologic milieu of the male genital tract

OBJECTIVES

To further understand the role that chronic viral infections of the male genital tract play on HIV-1 dynamics and replication.

DESIGN

Retrospective, observational study including 236 paired semen and blood samples collected from 115 recently HIV-1 infected antiretroviral naive men who have sex with men.

METHODS

In this study, we evaluated the association of seminal HIV-1 shedding to coinfections with seven herpes viruses, blood plasma HIV-1 RNA levels, CD4 T-cell counts, presence of transmitted drug resistance mutations (DRMs) in HIV-1 pol, participants' age and stage of HIV-infection using multivariate generalized estimating equation methods. Associations between herpes virus shedding, seminal HIV-1 levels, number and immune activation of seminal T-cells was also investigated (Mann-Whitney).

RESULTS

Seminal herpes virus shedding was observed in 75.7% of individuals. Blood HIV-1 RNA levels (P < 0.01) and seminal cytomegalovirus (CMV) and human herpes virus (HHV)-8 levels (P < 0.05) were independent predictors of detectable seminal HIV-1 RNA; higher seminal HIV-1 levels were associated with CMV and Epstein-Barr virus (EBV) seminal shedding, and absence of DRM (P < 0.05). CMV and EBV seminal shedding was associated with higher number of seminal T-lymphocytes, but only presence of seminal CMV DNA was associated with increased immune activation of T-lymphocytes in semen and blood.

CONCLUSION

Despite high median CD4 T-cells numbers, we found a high frequency of herpes viruses seminal shedding in our cohort. Shedding of CMV, EBV and HHV-8 and absence of DRM were associated with increased frequency of HIV-1 shedding and/or higher levels of HIV-1 RNA in semen, which are likely important cofactors for HIV-1 transmission.