The impact of cytomegalovirus disease and asymptomatic infection on acute renal allograft rejection

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 .

Infection, Rejection, and the Connection

Solid organ transplantation is a life-saving treatment for people with end-stage organ disease. Immune-mediated transplant rejection is a common complication that decreases allograft survival. Although immunosuppression is required to prevent rejection, it also increases the risk of infection. Some infections, such as cytomegalovirus and BK virus, can promote inflammatory gene expression that can further tip the balance toward rejection. BK virus and other infections can induce damage that resembles the clinical pathology of rejection, and this complicates accurate diagnosis. Moreover, T cells specific for viral infection can lead to rejection through heterologous immunity to donor antigen directly mediated by antiviral cells. Thus, viral infections and allograft rejection interact in multiple ways that are important to maintain immunologic homeostasis in solid organ transplant recipients. Better insight into this dynamic interplay will help promote long-term transplant survival.

Female sex and advanced age are associated with invasive cytomegalovirus disease in solid organ transplant recipients

BACKGROUND

Limited data exist to describe sex-based differences in the severity of cytomegalovirus (CMV) infection after solid organ transplant (SOT). We sought to identify if a difference exists in likelihood of tissue-invasive disease between male and female SOT recipients and to understand how age affects this relationship.

METHODS

A retrospective cohort of 180 heart, liver, and kidney recipients treated for CMV was examined. A logistic regression model was developed to assess the relationship between female sex and CMV type (noninvasive vs. invasive). A secondary regression analysis looked at the relationship of invasive CMV with a variable combining sex with age above or below 50.

RESULTS

There were 37 cases of proven or probable invasive CMV, occurring in 30% of females versus 16% of males. After adjustment for potential confounders, females with CMV infection were significantly more likely to have invasive disease (odds ratio (OR) 2.69, 95% confidence interval (CI) 1.25-5.90, p = .01). Females 50 years or older were at particular risk compared with males under 50 years (adjusted OR 4.54, 95% CI 1.33-18.83, p = .02).

CONCLUSION

Female SOT recipients with CMV in our cohort were more likely than males to have tissue-invasive disease, with the highest risk among older females. Further prospective studies are warranted to explore underlying immunologic mechanisms.

Low dose thymoglobulin versus basiliximab in cytomegalovirus positive kidney transplant recipients: Effectiveness of preemptive cytomegalovirus modified strategy

BACKGROUND

We performed a retrospective trial to determine asymptomatic CMV reactivation and CMV disease in kidney allograft recipients with positive CMV serostatus.

METHODS

Preemptive modified strategy under low dose thymoglobulin versus basiliximab induction was evaluated. Patients were monitored by CMV-polymerase chain reaction (PCR); if the viral load was >4000copies/μl, they received valganciclovir adjusted for their renal function.

RESULTS

132 recipients were included in the study, 84 and 48 receiving basiliximab and thymoglobulin induction respectively, and followed up for 12 months. Asymptomatic CMV reactivation was significantly higher for thymoglobulin (77.1% vs. 16.7%, p<0.001). Treatment groups had similar rates of CMV disease (3.6% vs. 2.1%, p 0.538). The significant difference in asymptomatic CMV reactivation between two treatment groups did not have any impact on 1 year graft function (71±26ml/min vs. 74±19ml/min; p=0.475) and no histological differences in protocol biopsies were observed among patients with asymptomatic CMV reactivation vs those without CMV reactivation.

CONCLUSIONS

Due to the high asymptomatic CMV reactivation incidence in patients who received thymoglobulin induction, our results suggest that valganciclovir prophylaxis may be advantageous in CMV seropositive renal transplant recipients after low dose thymoglobulin induction. A preemptive strategy appeared to significantly reduce the likelihood of CMV disease in both groups. Rejection risk and negative impact in renal function associated with asymptomatic CMV reactivation was not found in our series.

Efficacy and safety of conventional antiviral agents in preventive strategies for cytomegalovirus infection after kidney transplantation: a systematic review and network meta-analysis

Cytomegalovirus (CMV) infection is common in kidney transplantation (KT). Antiviral-agents are used as universal prophylaxis. Our purpose aimed to compare and rank efficacy and safety. MEDLINE, Embase, SCOPUS, and CENTRAL were used from inception to September 2020 regardless language restriction. We included randomized clinical trials (RCTs) comparing the CMV infection/disease prophylaxis among antiviral-agents in adult KT recipients. Of 24 eligible RCTs, prophylactic valganciclovir (VGC) could significantly lower the overall CMV infection and disease risks than placebo with pooled risk differences (RDs) [95% confidence interval (CI)] of -0.36 (-0.54, -0.18) and -0.28 (-0.48, -0.08), respectively. Valacyclovir (VAC) and ganciclovir (GC) significantly decreased risks with the corresponding RDs of -0.25 (-0.32, -0.19) and -0.30 (-0.37, -0.22) for CMV infection and -0.26 (-0.40, -0.12) and -0.22 (-0.31, -0.12) for CMV disease. For subgroup analysis by seropositive-donor and seronegative-recipient (D+/R-), VGC and GC significantly lowered the risk of CMV infection/disease with RDs of -0.42 (-0.84, -0.01) and -0.35 (-0.60, -0.12). For pre-emptive strategies, GC lowered the incidence of CMV disease significantly with pooled RDs of -0.33 (-0.47, -0.19). VGC may be the best in prophylaxis of CMV infection/disease follow by GC. VAC might be an alternative where VGC and GC are not available.

Does Post-Transplant Cytomegalovirus Increase the Risk of Invasive Aspergillosis in Solid Organ Transplant Recipients? A Systematic Review and Meta-Analysis

Background: Cytomegalovirus (CMV) and invasive aspergillosis (IA) cause high morbidity and mortality in solid organ transplant (SOT) recipients. There are conflicting data with respect to the impact of CMV on IA development in SOT recipients. Methods: A literature search was conducted from existence through to 2 April 2021 using MEDLINE, Embase, and ISI Web of Science databases. This review contained observational studies including cross-sectional, prospective cohort, retrospective cohort, and case-control studies that reported SOT recipients with post-transplant CMV (exposure) and without post-transplant CMV (non-exposure) who developed or did not develop subsequent IA. A random-effects model was used to calculate the pooled effect estimate. Results: A total of 16 studies were included for systematic review and meta-analysis. There were 5437 SOT patients included in the study, with 449 SOT recipients developing post-transplant IA. Post-transplant CMV significantly increased the risk of subsequent IA with pORs of 3.31 (2.34, 4.69), I² = 30%. Subgroup analyses showed that CMV increased the risk of IA development regardless of the study period (before and after 2003), types of organ transplantation (intra-thoracic and intra-abdominal transplantation), and timing after transplant (early vs. late IA development). Further analyses by CMV definitions showed CMV disease/syndrome increased the risk of IA development, but asymptomatic CMV viremia/infection did not increase the risk of IA. Conclusions: Post-transplant CMV, particularly CMV disease/syndrome, significantly increased the risks of IA, which highlights the importance of CMV prevention strategies in SOT recipients. Further studies are needed to understand the impact of programmatic fungal surveillance or antifungal prophylaxis to prevent this fungal-after-viral phenomenon.

Clinical consequences of primary CMV infection after renal transplantation: a case-control study

The impact of primary cytomegalovirus infection (pCMV) on renal allograft function and histology is controversial. We evaluated the influence on incidence of acute rejection, allograft loss, allograft function and interstitial fibrosis/tubular atrophy (IF/TA). Retrospective case-control study, recipients transplanted between 2000 and 2014. Risk of acute rejection and allograft loss for those who experienced pCMV infection compared with those who did not, within an exposure period of two months after transplantation. Besides, its influence on allograft function and histology at one to three years after transplantation. Of 113 recipients experienced pCMV infection, 306 remained CMV seronegative. pCMV infection in the exposure period could not be proven as increasing the risk for acute rejection [HR = 2.18 (95% CI 0.80-5.97) P = 0.13] or allograft loss [HR = 1.11 (95%CI 0.33-3.72) P = 0.87]. Combination of pCMV infection and acute rejection posed higher hazard for allograft loss than acute rejection alone [HR = 3.69 (95% CI 1.21-11.29) P = 0.02]. eGFR(MDRD) values did not significantly differ at years one [46 vs. 50], two [46 vs. 51] and three [46 vs. 52]. No association between pCMV infection and IF/TA could be demonstrated [OR = 2.15 (95%CI 0.73-6.29) P = 0.16]. pCMV infection was not proven to increase the risk for acute rejection or allograft loss. However, it increased the risk for rejection-associated allograft loss. In remaining functioning allografts, it was not significantly associated with decline in function nor with presence of IF/TA.

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.

Impacts of Interleukin-18 Polymorphisms on the Incidence of Delayed-Onset Cytomegalovirus Infection in a Cohort of Kidney Transplant Recipients

Background

The incidence of cytomegalovirus (CMV) infection in solid organ transplant recipients may be reduced by antiviral prophylaxis, but this strategy may lead to delayed-onset CMV infection. The proinflammatory cytokine interleukin (IL)-18 plays a major role in viral host defense responses. This study examines the impacts of 2 single-nucleotide polymorphisms (SNPs) in the promoter region of the IL-18 gene, -607C/A (rs1946518) and -137G/C (rs187238), on the incidence of delayed-onset CMV infection in patients undergoing kidney transplant.

Methods

This retrospective study analyzed 2 IL-18 SNPs in consecutive adult kidney transplant recipients using real-time polymerase chain reaction with TaqMan probes. Participants were enrolled over the period 2005–2013 and stratified according to their IL-18 SNP genotype. The concordance index (Harrell’s c-index) was used as a measure of the discriminatory power of the predictive models constructed with bootstrapping to correct for optimistic bias.

Results

Seven hundred nine patients received transplants in the study period, and 498 met selection criteria. Cytomegalovirus infection and disease incidence were 38% and 7.5%, respectively. In multivariate competing risk regression models, carriers of the -607C/-137G haplotype who received prophylaxis showed a higher incidence of CMV replication after antiviral agent discontinuation (hazard ratio = 2.42 [95% confidence interval, 1.11–5.26]; P = .026), whereas CMV disease was not observed in those given prophylaxis who were noncarriers of this polymorphism (P = .009).

Conclusions

Our findings suggest that the -607C/-137G IL-18 haplotype is associated with a higher incidence of postprophylaxis CMV replication. The prior identification of this polymorphism could help select alternative measures to prevent delayed-onset CMV infection in these patients.

Persistent primary cytomegalovirus infection in a kidney transplant recipient: Multi-drug resistant and compartmentalized infection leading to graft loss

Cytomegalovirus (CMV) is one of the most common opportunistic infections after transplantation. To prevent CMV infections, universal prophylaxis and pre-emptive therapy with ganciclovir or its prodrug valganciclovir is applied. However, prolonged antiviral therapy may result in drug-resistance emergence. We describe a case of a 43-year-old CMV-seronegative patient who underwent kidney transplantation from a CMV-seropositive donor and developed CMV disease despite valganciclovir prophylaxis. CMV viral load increased even though valgangiclovir dose was augmented and immunosuppressive therapy reduced. CMV genotyping revealed mutations in the viral UL97 protein kinase, explaining ganciclovir-resistant CMV infection. The viral load failed to respond to foscavir, cidofovir and CMV-neutralizing immunoglobulins. Kidney allograft dysfunction developed 3 months post-transplantation with a histopathologic diagnosis of CMV nephropathy and potentially concomitant T-cell mediated rejection. A transplantectomy was performed on day 164 post-transplantation since the patient had uncontrollable CMV disease associated with a circulating multidrug-resistant DNA polymerase-mutant virus. Detailed monitoring in this patient demonstrated hallmarks of complicated CMV disease: (i) relatively rapid evolution of drug-resistant CMV mutants in the setting of persistent high blood viral loads, (ii) emergence of viral drug-resistance linked to acute graft rejection, (iii) transient and, thereafter, lack of response to various anti-CMV treatments, (iv) compartmentalization and heterogeneity of CMV viral populations, (v) possible differential ability of viral mutants to cause disease in the graft, and (vi) detection of minor viral variants by next generation sequencing. Translational research platforms that provide rapid molecular genotyping for detection of CMV drug-resistance are essential in guiding CMV disease management in high-risk transplant recipients.

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.

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

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

New therapies for human cytomegalovirus infections

The recent approval of letermovir marks a new era of therapy for human cytomegalovirus (HCMV) infections, particularly for the prevention of HCMV disease in hematopoietic stem cell transplant recipients. For almost 30 years ganciclovir has been the therapy of choice for these infections and by today's standards this drug exhibits only modest antiviral activity that is often insufficient to completely suppress viral replication, and drives the selection of drug-resistant variants that continue to replicate and contribute to disease. While ganciclovir remains the therapy of choice, additional drugs that inhibit novel molecular targets, such as letermovir, will be required as highly effective combination therapies are developed not only for the treatment of immunocompromised hosts, but also for congenitally infected infants. Sustained efforts, largely in the biotech industry and academia, have identified additional highly active lead compounds that have progressed into clinical studies with varying levels of success and at least two have the potential to be approved in the near future. Some of the new drugs in the pipeline inhibit new molecular targets, remain effective against isolates that have developed resistance to existing therapies, and promise to augment existing therapeutic regimens. Here, we will describe some of the unique features of HCMV biology and discuss their effect on therapeutic needs. Existing drugs will also be discussed and some of the more promising candidates will be reviewed with an emphasis on those progressing through clinical studies. The in vitro and in vivo antiviral activity, spectrum of antiviral activity, and mechanism of action of new compounds will be reviewed to provide an update on potential new therapies for HCMV infections that have progressed significantly in recent years.

Effects of Granulocyte and Monocyte Adsorptive Apheresis in Renal Transplantation Recipients With Concomitant Cytomegalovirus Infection

BACKGROUND

Granulocyte and monocyte adsorptive apheresis (GMAA) is widely used as a treatment for active ulcerative colitis (UC) in Japan. Much attention has been paid to the possibility of GMAA for the treatment and control of cytomegalovirus (CMV) reactivation in patients with refractory UC and concomitant CMV infection. In this study, the effects of the combination of GMAA and antiviral therapy were examined in renal transplant recipients with concomitant CMV infection.

METHODS

Combination therapy of GMAA and antiviral drugs was performed 9 times in 7 renal transplant recipients with concomitant CMV infection. Four of the cases were positive for CMV-IgG, and 3 were negative. The clinical presentation of CMV infection was viremia in 6 cases and disease (CMV retinitis) in 1 case. CMV infection was diagnosed by using an antigenemia assay (C7-HRP). GMAA session was performed once, and the duration of the session was 120 min. Immediately after the GMAA session, ganciclovir was administered at 5 mg/kg/body weight. CMV infection was monitored based on C7-HRP and CMV-DNA in the peripheral blood samples.

RESULTS

All cases became negative for C7-HRP and CMV-DNA within 21 days (median, 14 days; range, 3-21 days) and 17 days (median, 6 days; range, 3-17 days), respectively, after starting the combination therapy. No side effects of GMAA were observed.

CONCLUSIONS

This case series found that GMAA in combination with antiviral drugs may shorten the duration of treatment against CMV infection in renal transplant recipients. Further studies in a larger number of patients are required to confirm these results.

Easier Control of Late-Onset Cytomegalovirus Disease Following Universal Prophylaxis Through an Early Antiviral Immune Response in Donor-Positive, Recipient-Negative Kidney Transplants

Universal prophylaxis for cytomegalovirus (CMV) prevention is viable but, compared with a preemptive strategy, leads to higher incidence of late-onset disease (LOD) associated with poor patient and graft survival. The purpose of this study was to compare LOD with early onset disease (EOD), with a focus on the highest risk kidney transplant recipients (KTRs): CMV seronegative recipients transplanted from seropositive donors (D+R-). Since CMV control depends on both antiviral treatment and specific immune response, we also compared Vδ2-negative (Vδ2(neg) ) γδ T cell expansion involved in CMV infection resolution. EOD was defined as occurring <3 mo and LOD as occurring >3 mo after transplantation. Depending on the period, universal prophylaxis or preemptive treatment was used. Overall, 168 D+R- KTRs were included between 2003 and 2011. LOD was associated with a lower peak DNAemia (p = 0.04), fewer recurrences (odds ratio 0.16; 95% confidence interval 0.05-0.55; p = 0.01) and shorter anti-CMV curative treatment (40 vs. 60 days, p < 0.0001). As a corollary, we found that Vδ2(neg) γδ T cell expansion was faster in LOD than in EOD (31 vs. 168 days after the beginning of CMV disease, p < 0.0001). In D+R- KTRs, universal prophylaxis is associated with more LOD, which had better infection management and a faster immune response. These results support the use of universal prophylaxis over a preemptive strategy and reappraise outcomes of LOD.

The effect of cytomegalovirus infection on acute rejection in kidney transplanted patients

Introduction: It is known that cytomegalovirus (CMV) infection is a common problem among kidney transplant patients. This infection can be increased morbidity and decreased graft survival. This problem has been associated with acute rejection too.

Patients and Methods: One hundred and thirty renal transplant patients were included in a prospective, case-control study. The renal transplant patients were divided into two groups; patients group with CMV infection and control group without CMV infection. Serum CMV-IgG in all patients was positive (donor and recipients). None of patients had received anti-thymocyte-globulin and thymoglobulin. CMV infection was diagnosed by quantitative CMV-PCR (polymerase chain reaction) test (more than 500 copies/μg). Rejection episode was defined by kidney isotope scan or biopsy.

Results: In the group of 66 CMV infection patients (41 male [62.1%] and 25 female [37.9%]) the incidence of graft rejection was 36%, however in the group of 64 control patients the incidence of graft rejection was 9.4 % (P < 0.005).

Conclusion: CMV infection is important predisposing factor for acute allograft rejection after kidney transplantation. The results of this study suggests that the control of CMV infection could decrease episodes of acute kidney rejection.

Tubuloreticular Inclusions in Renal Allografts Associate with Viral Infections and Donor-Specific Antibodies

The presence of tubuloreticular inclusions (TRIs) in native glomerular endothelial cells associates with viral infections and lupus nephritis. However, the associations of TRIs in renal transplant biopsy specimens are not known. We analyzed data from 316 patients who had a transplant biopsy with electron microscopy examination; 41 of 316 (13.0%) patients had TRIs. Patients with TRIs had significantly lower allograft survival rates (50.9%) than patients without TRIs (74.3%; P=0.03). Transplant glomerulopathy-free survival was also inferior in the TRI-positive group (57.5%) compared with the TRI-negative group (87.3%; P=0.002). Serologically, hepatitis C associated with the presence of TRIs (P=0.04) along with donor-specific antibodies (P=0.01). Furthermore, patients who were TRI positive were more likely than patients who were TRI negative to have had a previous rejection episode (P=0.02). On multivariate analysis, TRIs associated with prior rejection, viral infections, and class 1 HLA donor-specific antibodies. These results show that the presence of TRIs in renal allograft biopsy specimens associates with poor allograft outcomes and serologic evidence of viral infections and alloimmunity. The association with alloimmunity is a novel finding that warrants additional investigation.

Cytomegalovirus & Epstein Barr Virus serostatus as a predictor of the long-term outcome of kidney transplantation

AIM

Cytomegalovirus (CMV) and Epstein Barr Virus (EBV) disease and asymptomatic infection have been associated with poor outcomes in kidney transplantation. Recipients who acquire primary infection through transplantation from a seropositive donor may be at particular risk of complications. The primary aim of this study was to evaluate the relationship between donor/recipient (D/R) CMV and EBV serostatus pretransplant and allograft and patient survival in a large cohort of kidney transplant recipients.

METHODS

Data were obtained from the Australian and New Zealand Dialysis and Transplant Registry and the Australian and New Zealand Organ Donation Registry on 4516 first deceased donor kidney transplants performed between 1998 and 2010. Graft and patient survival were analysed using the Kaplan-Meier method.

RESULTS

Pretransplant CMV D/R serostatus was available for the whole cohort, with EBV D/R serostatus available for 2566 transplants (56.8%). Serostatus for both viruses was significantly associated with donor and recipient age and recipient smoking status. For both viruses the majority of transplants were in a D+/R+ serostatus setting: 45.3% for CMV and 77.9% for EBV. D/R serostatus for either virus did not have a significant effect on graft or patient survival.

CONCLUSION

We conclude that in the current era of viral prophylaxis and surveillance, long-term outcome for the kidney transplant population is unaffected by D/R CMV and EBV serostatus.

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.

Rhabdomyolysis associated with cytomegalovirus infection in kidney transplant recipients

Rhabdomyolysis is a pathological syndrome caused by skeletal muscle cell damage that affects the integrity of the cellular membrane and leads to the release of toxic intracellular constituents into the bloodstream. Although cytomegalovirus (CMV) has rarely been reported as a cause of rhabdomyolysis, CMV infection could be considered as a possible cause because of its clinical significance in kidney transplant recipients (KTRs). We report 2 cases of rhabdomyolysis associated with CMV infection in KTRs. A 64-year-old woman (Case 1) and a 65-year-old man (Case 2), who had each received a kidney from a living unrelated donor, were admitted with complaints of weakness in both legs and myalgia. Laboratory findings revealed highly increased creatine phosphokinase and myoglobinuria. In both cases, no recent alterations of medications had occurred, and other causes of rhabdomyolysis--such as trauma, alcohol, drugs, and electrolyte abnormalities - were excluded. CMV pp65 antigen was positive, and patients were diagnosed with rhabdomyolysis associated with CMV infection. Both patients recovered without complications after ganciclovir treatment. In conclusion, CMV infection should be considered as a possible cause of rhabdomyolysis in KTRs.

Decreased incidence of cytomegalovirus infection with sirolimus in a post hoc randomized, multicenter study in lung transplantation

BACKGROUND

Cytomegalovirus (CMV) is the most common opportunistic infection in lung transplantation. A recent multicenter, randomized trial (the AIRSAC study) comparing sirolimus to azathioprine in lung transplant recipients showed a decreased incidence of CMV events in the sirolimus cohort. To better characterize this relationship of decreased incidence of CMV events with sirolimus, we examined known risk factors and characteristics of CMV events from the AIRSAC database.

METHODS

The AIRSAC database included 181 lung transplant patients from 8 U.S.-based lung transplant centers that were randomized to sirolimus or azathioprine at 3 months post-transplantation. CMV incidence, prophylaxis, diagnosis and treatment data were all prospectively collected. Prophylaxis and treatment of CMV were at the discretion of each institution.

RESULTS

The overall incidence of any CMV event was decreased in the sirolimus arm when compared with the azathioprine arm at 1 year after lung transplantation (relative risk [RR] = 0.67, confidence interval [CI] 0.55 to 0.82, p < 0.01). This decreased incidence of CMV events with sirolimus remained significant after adjusting for confounding factors of CMV serostatus and CMV prophylaxis.

CONCLUSIONS

These data support results from other solid-organ transplantation studies and suggest further investigation of this agent in the treatment of lung transplant recipients at high risk for CMV events.

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.

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.

Common infections in kidney transplant recipients

Infections are a major cause of morbidity and mortality in kidney transplant recipients. To some extent, these may be preventable. Careful pretransplant screening, immunization, and post-transplant prophylactic antimicrobials may all reduce the risk for post-transplant infection. However, because transplant recipients may not manifest typical signs and symptoms of infection, diagnoses may be confounded. Furthermore, treatment regimens may be complicated by drug interactions and the need to maintain immunosuppression to avoid allograft rejection. This article reviews common post-transplant infections, including prophylactic, diagnostic, and treatment strategies, providing guidance regarding care of kidney transplant patients with infection.

Advances in cytomegalovirus-preventive strategies in solid organ transplantation: defending pre-emptive therapy

Prevention of cytomegalovirus (CMV) infection is an important part of clinical care provided to patients after solid organ transplantation. While the optimal preventive strategy has not been defined, most centers rely on universal prophylaxis or pre-emptive therapy. This article comments on recent studies designed to identify strategies that effectively reduce the incidence of late-onset CMV disease as the main problem associated with prophylaxis, and on recent data regarding the development of CMV-specific immunity depending on the CMV-preventive regimen used. Despite an apparent trend to prefer prophylaxis in clinical practice, this approach does not seem to be based on robust evidence.

Correlation and clinical utility of pp65 antigenemia and quantitative polymerase chain reaction assays for detection of cytomegalovirus in pediatric renal transplant patients

qPCR and pp65 antigenemia assays are used to monitor CMV infection in renal transplant recipients, but correlation of assays in a pediatric population has not been evaluated. Paired CMV real-time qPCR and pp65 antigenemia tests from 882 blood samples collected from 115 pediatric renal transplant recipients were analyzed in this retrospective cohort study for the strength of association and clinical correlates. The assays correlated well in detecting infection (κ = 0.61). Higher qPCR values were demonstrated with increasing levels of antigenemia (p < 0.01). Discordant test results were associated with antiviral treatment (OR 4.33, p < 0.01) and low-level viremia, with odds of concordance increasing at higher qPCR values (OR 3.67, p < 0.01), and no discordance occurring above 8500 genomic equivalents/mL. Among discordant samples, neither test preceded the other in detecting initial infection or in returning to negative while on treatment. Only two cases of disease occurred during the two-yr study period. With strong agreement in the detection of CMV infection, either qPCR or pp65 antigenemia assays can be used effectively for monitoring pediatric renal transplant patients for both detection and resolution of infection.

Reinfection of cytomegalovirus in renal transplantation

Cytomegalovirus (CMV) is the most important pathogen affecting the outcome of renal transplantation. Reinfection of CMV can occur in CMV-seropositive donors and CMV seropositive recipients (D+/R+) settings because the protection against CMV conferred by preexisting immunity is limited due to its strain-dependent immune responses. To analyze the influence of CMV reinfection in renal transplantation, ELISA using fusion proteins encompassing epitope of glycoprotein H(gH) from both AD169 and Towne strains was employed before transplantation. The CMV-gH seropositive rate increased with increases in age and the rate of samples which contained antibodies against both AD169 and Towne were significantly high in the age of 50 years or over. Antibodies from HLA-DR10 and DR11 were associated with a significantly lower response rate against CMV-gH. In renal transplantation, the high degrees of antigenemia and high incidences of CMV disease are more prevalent in the CMV gH antibody-mismatched group in D+/R+ setting. The nucleotide sequence of the region of the gH epitope in the CMV-DNA extracted from the transplant recipients who showed high degree of antigenemia revealed the CMV reinfection from the donors. As a CMV indirect effect, the incidence of acute rejection in the mismatched gH antibody group was higher than that observed in the matched and D+/R- groups. The adverse events were more likely to occur in cases of D+/R+ renal transplantation with mismatched strain-specific antibodies which would indicates the risk of CMV reinfection after transplantation.

Human cytomegalovirus and kidney transplantation: a clinician's update

Infection with human cytomegalovirus (CMV) is an important cause of morbidity and mortality in kidney transplant recipients. CMV disease is diagnosed based on the detection of viral replication by phosphoprotein 65 antigenemia or CMV DNA polymerase chain reaction in combination with typical signs and symptoms. Risk factors include CMV-seronegative recipients receiving a CMV-seropositive transplant, older donor age, exposure to cyclosporine and/or antilymphocyte antibody, rejection episodes, and impaired transplant function. Current preventive strategies in kidney transplant recipients include pre-emptive therapy with valganciclovir or intravenous ganciclovir and universal prophylaxis with valacyclovir, valganciclovir, or ganciclovir for 3-6 months after kidney transplantation and for 1-3 months after treatment with antilymphocyte antibody. Established disease should be treated using either intravenous ganciclovir or oral valganciclovir until CMV replication can no longer be detected. In addition to direct effects, CMV infection also induces a wide range of indirect effects, such as decreased transplant and recipient survival and susceptibility to rejection and opportunistic infections. In this review, we highlight the most relevant topics on CMV and kidney transplantation based on current evidence and guidelines.

Impact of CMV infection on acute rejection and long-term renal allograft function: a systematic analysis in patients with protocol biopsies and indicated biopsies

BACKGROUND

Higher rates of acute rejection (AR) and reduced graft survival have been reported in patients with cytomegalovirus (CMV) infection, but an association between these factors remains controversial.

METHODS

In this study, serial protocol biopsies (PBs) and clinically indicated biopsies (IBs) from a large cohort of renal allograft recipients (n &frac14; 594) were analyzed to examine the relation between CMV and AR.

RESULTS

Patients with CMV were more likely to receive IB (85 of the 153 patients; 56%) compared to patients without CMV (138 of 441 patients; 32%; P = 0.003). However, this did not translate into a greater number of patients with episodes of acute cellular rejection on histopathology in IBs. Analysis of PBs revealed a significantly higher number of episodes of rejection per patient with CMV infection (P = 0.04), but only in a subgroup of patients with triple immunosuppression. Long-term graft function post-transplantation was analyzed in four different subgroups according to CMV infection and/or AR. Differences in renal function were apparent within the first 6 weeks after transplantation and persisted during follow-up, with the best renal function in patients without AR or CMV, whereas patients with both AR and CMV had the worst (P < 0.012 at 1 year; P < 0.001 at 2 years). On average, the latter group had significantly older donors and more often delayed graft function.

CONCLUSIONS

Our data suggests that the link between CMV and AR is far less significant than previously thought. Outcome in patients with CMV may be more determined by coexisting conditions like high donor age and delayed graft function.

Update and review: state-of-the-art management of cytomegalovirus infection and disease following thoracic organ transplantation

PURPOSE

Cytomegalovirus (CMV) is among the most important viral pathogens affecting solid organ recipients. The direct effects of CMV (eg, infection and its sequela; tissue invasive disease) are responsible for significant morbidity and mortality. In addition, CMV is associated with numerous indirect effects, including immunomodulatory effects, acute and chronic rejection, and opportunistic infections. Due to the potentially devastating effects of CMV, transplant surgeons and physicians have been challenged to fully understand this infectious complication and find the best ways to prevent and treat it to ensure optimal patient outcomes.

SUMMARY

Lung, heart, and heart-lung recipients are at considerably high risk of CMV infection. Both direct and indirect effects of CMV in these populations have potentially lethal consequences. The use of available treatment options depend on the level of risk of each patient population for CMV infection and disease. Those at the highest risk are CMV negative recipients of CMV positive organs (D+/R-), followed by D+/R+, and D-/R+. More than 1 guideline exists delineating prevention and treatment options for CMV, and new guidelines are being developed. It is hoped that new treatment algorithms will provide further guidance to the transplantation community. The first part describes the overall effects of CMV, both direct and indirect; risk factors for CMV infection and disease; methods of diagnosis; and currently available therapies for prevention and treatment. Part 2 similarly addresses antiviral-resistant CMV, summarizing incidence, risk factors, methods of diagnosis, and treatment options. Parts 3 and 4 present cases to illustrate issues surrounding CMV in heart and lung transplantation, respectively. Part 3 discusses the possible mechanisms by which CMV can cause damage to the coronary allograft and potential techniques of avoiding such damage, with emphasis on fostering strong CMV-specific immunity. Part 4 highlights the increased incidence of CMV infection and disease among lung transplant recipients and its detrimental effect on survival. The possible benefits of extended-duration anti-CMV prophylaxis are explored, as are those of combination prophylaxis with valganciclovir and CMVIG.

CONCLUSION

Through improved utilization of information regarding optimized antiviral therapy for heart and lung transplant recipients to prevent and treat CMV infection and disease and through increased understanding of clinical strategies to assess, treat, and monitor patients at high risk for CMV recurrence and resistance, the health care team will be able to provide the coordinated effort needed to improve patient outcomes.

Cytomegalovirus serostatus pairing and deceased donor kidney transplant outcomes in adult recipients with antiviral prophylaxis

BACKGROUND

The objectives of this study are to investigate the impact of cytomegalovirus (CMV) donor (D)/recipient (R) serostatus on kidney transplant outcomes in recipients who received CMV prophylaxis and to investigate the association of individual antiviral agents (acyclovir, ganciclovir, and valganciclovir) with outcomes in high-risk recipients (D+/R-).

METHODS

By using the Organ Procurement and Transplant Network/United Network for Organ Sharing database, 25,058 deceased donor kidney recipients (≥ 18 years, 2004-2008) who received CMV prophylaxis were stratified into four groups: D+/R+ (11,875), D-/R+ (6046), D+/R- (4555), and D-/R- (2582). The impact of CMV D/R serostatus on acute rejection (6 months and 1 year posttransplant) and long-term outcomes of death-censored graft failure and mortality were compared. The impact of the individual antiviral agent on long-term outcome was further evaluated in the high-risk group (D+/R-).

RESULTS

In multivariate analysis, CMV D/R status was not associated with acute rejection. Compared with D-/R-, D+/R- was associated with an increased risk for death-censored graft failure (hazard ratio=1.28, P=0.01), all-cause mortality(hazard ratio=1.36, P=0.003), and mortality because of viral infection (hazard ratio=8.36, P=0.04). In the D+/R- group, valganciclovir usage was associated with a decreased risk for death-censored graft failure (hazard ratio=0.65, P=0.007) and mortality because of viral infection (hazard ratio=0.22, P=0.03) compared with ganciclovir usage.

CONCLUSIONS

CMV mismatch (D+/R-) was no longer a risk factor for acute rejection in kidney recipients who received antiviral prophylaxis but was still an independent risk factor for death-censored graft failure, all-cause mortality, and viral infection-related mortality.

Cytomegalovirus risk factors in renal transplantation with modern immunosuppression

BACKGROUND

Immunosuppressive regimens have lowered the rate of kidney rejection, but with increasing immunodeficiency-related complications. New cytomegalovirus (CMV) prophylaxis also has become available. The impact of these 2 developments on CMV diseases has not been well evaluated. We conducted a randomized trial comparing a drug regimen common in the 1980s, cyclosporin A (CsA) with azathioprine (Aza), with a drug combination used most today, tacrolimus (Tac) with mycophenolate mofetil (MMF), and we analyzed CMV risk factors in kidney transplant patients.

METHODS

The 300 patients included in the trial underwent the same universal prophylaxis and preemptive therapy. CMV events and risk factors were prospectively recorded.

RESULTS

With preventive and preemptive strategies combined for 3 months, CMV replication was detected in 32.6% and CMV disease in 18.1% of patients. Multivariate analysis on risk factors for CMV disease were CMV donor (D)/recipient (R) matching and first month renal function (risk ratio [95% confidence interval]: 1.02 [1.01; 1.04]; P=0.011), but not the immunosuppressive regimen (P=0.35). The D+/R- combination increased the risk of CMV disease by a factor of 9 (P<0.0001) when compared with D-/R- status, and a factor of 3.5 (P<0.0001) when compared with all CMV-positive recipients. Despite the 50% rate of CMV disease in the D+/R- group, no asymptomatic CMV replication was detected with the preemptive strategy.

CONCLUSIONS

With modern immunosuppression, a sequential quadritherapy with Tac/MMF, and a 3-month CMV prevention strategy, the risk for CMV disease remains close to that with CsA/Aza. A CMV-negative recipient transplanted from a CMV-positive donor (D+/R-) remains a major risk factor, calling for better CMV prophylaxis or matching in negative recipients. Preemptive strategy thus appeared inefficient for this high-risk group. Transplant recipients with altered renal function should also be considered at risk.

The effect of cytomegalovirus antigenemia titer on the efficacy of preemptive therapy for the prevention of cytomegalovirus disease after kidney transplantation

There is some controversy regarding the exact cytomegalovirus (CMV) antigenemia titer that should be used as a guideline for preemptive anti-CMV therapy. We performed 634 consecutive kidney transplantations between January 2000 and June 2007. Preemptive therapy employed intravenous gancyclovir treatment when the CMV antigenemia titer was >or=50/4x10(5) leukocytes after kidney transplantation. The 634 recipients were allocated into 2 groups according to the peak CMV antegenemia: group A, CMV antigenemia titer<50/4x10(5) (n=550); and group B, >or=50/40x10(5) (n=84). Among the 634 recipients, 264 were positive for CMV antigenemia, and 61 developed symptomatic CMV infections. The incidence of symptomatic CMV infections in group B was significantly higher than in group A. Two cases in both groups developed tissue-proven CMV disease: group A CMV colitis and CMV nephritis, and group B, 2 cases of CMV colitis. Graft and patient survival rates in groups A and B at 5 years posttransplantation were not different. The authors concluded that a CMV antigenemia titer of >or=50/4x10(5) leukocytes can be considered an appropriate guideline for preemptive anti-CMV therapy.