Does Valganciclovir Hydrochloride (Valcyte) Provide Effective Prophylaxis Against Cytomegalovirus Infection in Liver Transplant Recipients?

Incidence and risk factors for the development of cytomegalovirus viremia in a steroid sparing liver transplant center

BACKGROUND

Cytomegalovirus (CMV) is a common opportunistic infection in patients after liver transplant (LT). Guidelines recommend 900mg daily of valganciclovir, however, valganciclovir commonly causes dose-dependent hematologic toxicities. Use of a low-dose valganciclovir (450mg) has been used to prevent these adverse effects, but the data regarding this dosing strategy is not as robust in a steroid sparing LT center.

METHODS

Retrospective chart review of adult LT recipients between January 1, 2008 and June 30, 2019. All patients received low-dose valganciclovir 450 mg PO daily for CMV prophylaxis. Primary outcome was the incidence of CMV viremia in LT recipients at 12 months post-LT. Secondary outcomes include time to CMV viremia, risk factors for the development of CMV viremia, and incidence of breakthrough CMV viremia while on valganciclovir prophylaxis.

RESULTS

A total of 266 patients were included. Overall, the majority were male (63.2%) and Caucasian (45.5%). The most common indication for transplant was decompensated cirrhosis (82%). The incidence of CMV at one year post-transplant was 7.9%. Independent risk factors included high risk status (OR 5.97, 95% CI 2.14-16.61, p = 0.001) as well as having an episode of rejection (OR 5.99, 95% CI 2.16-16.66, p = 0.001).

CONCLUSION

Low-dose valganciclovir can be effective in the prevention of CMV viremia in LT patients and may be a beneficial strategy for CMV prophylaxis in a steroid-sparing transplant center. Further studies may be needed to determine appropriate length of prophylaxis therapy for different risk groups. This article is protected by copyright. All rights reserved.

Comparison of standard versus low-dose valganciclovir regimens for cytomegalovirus prophylaxis in high-risk liver transplant recipients

PURPOSE

The purpose of this study was to compare the safety and efficacy of two valganciclovir (VGCV) institutional dosing protocols for cytomegalovirus (CMV) prophylaxis in liver transplant (LT) recipients with CMV serotype donor +/recipient- (D+/R-).

METHODS

This was a single-center review of CMV D+/R- adult LT recipients who received VGCV 450 mg/day for 90 days (low-dose) or VGCV 900 mg/day for 180 days (standard-dose). The primary outcome was incidence of CMV disease at 1 year. Secondary outcomes included rates of CMV syndrome, end-organ disease, breakthrough infection, and resistance. Neutropenia, early discontinuation of VGCV, growth colony stimulating factors use (G-CSF), biopsy-proven rejection (BPAR), graft loss, and death at 1 year were analyzed.

RESULTS

Ninety-six CMV D+/R- LT recipients were included. Although no difference in CMV disease was observed (low-dose 26% vs. standard-dose 23%, p = 0.71), 75% of CMV infections in the low-dose group presented with end-organ disease. Ganciclovir (GCV) resistance was observed only in the low-dose group (n = 2). Significantly more patients in the standard-dose group developed neutropenia (low-dose 10% vs 60% standard-dose, p < 0.001). In the standard-dose group, 29% required early discontinuation of VGCV (vs. 5% in the low-dose group, p < 0.001), and 20% were treated with G-CSF. Both cohorts had similar rates of BPAR, graft loss, and death at 1 year.

CONCLUSIONS

VGCV 900 mg/day for 180 days had higher rates of hematologic adverse effects resulting in frequent treatment interruptions. However, the occurrence of two cases of GCV-resistant CMV disease raises concerns about routinely using low-dose VGCV prophylaxis.

Risk-guided strategy to prevent cytomegalovirus associated complications after liver transplantation

Aim: We evaluated a risk-guided strategy to prevent cytomegalovirus-associated complications (CMV-ac) after liver transplantation (LT). Patients & methods: Forty liver graft recipients were stratified according to their CMV risk status to prophylactic (high risk, HR and group) or pre-emptive antiviral treatment (intermediate, IR, and low risk, LR and group). A detailed analysis of clinical and virological data was performed. Results: 8/40 patients were classified within the HR, 28/40 within the IR and 4/40 within the LR group. Incidence of CMV viremia was 3/8 (38%) in the HR, 9/28 (32%) in the IR and 0/5 in the LR group. Mortality rate of CMV-ac was 0%. Conclusion: A risk-guided antiviral strategy is effective to prevent severe CMV-ac up to 1 year after LT.

Effect of Low-Dose Vs Standard-Dose Valganciclovir in the Prevention of Cytomegalovirus Disease in Kidney Transplantation Recipients: A Systemic Review and Meta-Analysis

BACKGROUND

Valganciclovir is widely used to prevent post-transplant cytomegalovirus (CMV) infection in kidney transplant patients. However, the currently used dose remains controversial because the continuous use of this drug decreases kidney function and can induce leukopenia.

OBJECTIVE

The purpose of this study was to measure the appropriate dose of valganciclovir required to prevent CMV infection.

METHODS

A systematic review and meta-analysis were performed by using a random effects model. The Cochrane Central Register, MEDLINE, EMBASE, and PubMed databases were searched up to April 15, 2017. We conducted analysis on low-dose (450 mg) and standard-dose (900 mg) valganciclovir groups.

RESULTS

After completion of the research, the analysis revealed that the glomerular filtration rate, graft loss, tacrolimus level, antibody-mediated rejection, and fungal and Candida infection rates did not differ between the 2 groups. However, the incidence of CMV tended to decrease in the low-dose group (0.584 [95% confidence interval [CI], 0.352-0.967]; P = .036). The biopsy-proven rejection rate decreased by 0.427 times in the low-dose group compared with the standard-dose group (95% CI, 0.274-0.667; P = .002). Furthermore, the incidence of leukopenia decreased by 0.371 times in the low-dose group compared with the standard-dose group (95% CI, 0.264-0.523; P = .001).

CONCLUSIONS

The 450-mg dose of valganciclovir effectively prevented post-transplantation CMV infection and decreased drug-induced side effects such as leukopenia. In the future, the lower dose of valganciclovir should be considered to prevent CMV infection and enhance cost-effectiveness.

Low-dose valganciclovir for cytomegalovirus prophylaxis in intermediate-risk liver transplantation recipients

Liver transplantation recipients (LTRs) who are seropositive for cytomegalovirus (CMV) (recipient seropositive [R+]) are at intermediate risk for CMV disease. A preventative strategy following transplant is considered standard of care. Current guidelines recommend high-dose valganciclovir (VGCV; 900 mg/day adjusted for renal function) for prophylaxis given limited data on the efficacy and safety of low-dose VGCV (450 mg/day adjusted for renal function). We describe our experience using low-dose VGCV prophylaxis for R+ LTRs at our institution. A single-center, retrospective study was conducted using a database of 364 LTRs over a 4-year period (2011-2014). Adult first-time R+ LTRs receiving low-dose VGCV prophylaxis were included. The primary endpoint was CMV disease at 1 year after transplant. Patients were compared with historical controls receiving high-dose VGCV prophylaxis. Secondary endpoints were biopsy-proven rejection and leukopenia on VGCV. With respect to leukopenia, patients receiving low-dose VGCV were compared with a group of D+R- patients from the database receiving high-dose VGCV. Univariate analyses were performed using chi-squared, Fisher's exact, and Wilcoxon rank sum tests. A total of 200 R+ LTRs met inclusion criteria. Median age was 60 years (interquartile range [IQR], 54-66 years), and 129 (65%) LTRs were male. Median Model for End-Stage Liver Disease score was 22 (IQR, 14-31), and 178 (89%) patients received deceased donor transplants. CMV disease occurred in only 9 (5%) patients, similar to rates in previous studies of LTRs receiving high-dose VGCV. Biopsy-proven rejection occurred in 18 (9%) patients. Patients received VGCV prophylaxis for a median of 3.4 (IQR, 3.1-4.3) months; 151 (76%) R+ LTRs receiving low-dose VGCV developed leukopenia. Premature VGCV discontinuation and granulocyte-colony stimulating factor use were infrequent and not significantly different between the 2 groups. In conclusion, low-dose VGCV was safe and effective for prevention of CMV disease in our cohort of 200 R+ LTR and should be considered as an option in future guidelines. Liver Transplantation 24 616-622 2018 AASLD.

High-Dose Acyclovir for Cytomegalovirus Prophylaxis in Seropositive Abdominal Transplant Recipients

Background: Following abdominal solid organ transplant (aSOT), valganciclovir (VGC) is recommended for cytomegalovirus (CMV) prophylaxis. This agent is associated with efficacy concerns, toxicity, and emergence of ganciclovir resistance. Objective: To evaluate the incidence of high-dose acyclovir (HD-A) prophylaxis failure in seropositive aSOT recipients (R+). Methods: This was a retrospective, single-center study of R+ transplanted without lymphocyte-depleting induction between January 1, 2000, and June 30, 2013, discharged with 3 months of HD-A prophylaxis (800 mg 4 times daily). The primary outcome was incidence of prophylaxis failure. Secondary outcomes were incidence of biopsy-proven tissue-invasive disease and prophylaxis failure for each allograft subgroup. Results: A total of 1525 patients met inclusion criteria: 944 renal (RTX), 108 simultaneous pancreas-kidneys (SPK), 462 liver (LTX), and 11 pancreas (PTX) transplant recipients. The composite rate of HD-A prophylaxis failure was 7%; incidence of tissue-invasive disease was 0.4%. Failure rates were 4.5%, 6.1%, 11%, and 20% in the RTX, SPK, LTX, and PTX populations, respectively; tissue-invasive disease rates were 0.2%, 0%, 0.7%, and 10%. Failure occurred more frequently in the LTX and PTX populations ( P < 0.0001, HR = 2.6; P = 0.04 HR = 4.4). Incidence of tissue-invasive disease was minimal and not different in the RTX, LTX and SPK populations ( P = 0.34). When evaluating recipients of seronegative allografts (D−), the composite failure rate was 3.4% with no significant difference between allograft subgroups ( P = 0.45). Conclusion: HD-A may be a reasonable prophylaxis alternative for D−/R+ recipients, in the absence of lymphocyte-depleting induction, if low incidence viremia is tolerable. Future studies are needed to determine the long-term impact of CMV viremia in the setting of this prophylaxis approach.

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

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

Strategies for the prevention of infection after solid organ transplantation

Infection is a frequent complication of organ transplantation and is associated with significant morbidity and mortality. Preventative antimicrobial strategies are a key component of the care received by transplant patients. This review summarizes the evidence supporting anti-infective prophylaxis in this setting. Specific recommendations for the prevention of bacterial, fungal, viral and parasitic infection after transplant are made, with a focus on recent developments in the field of transplant infectious diseases.

Advances in the antiviral therapy of herpes virus infection in children

Herpes viruses are ubiquitous and primary infections, with many of these viruses common during childhood. In general, children tolerate primary infection well, with only mild symptoms, but in the immunocompromised, including the newborn, infection can be associated with serious morbidity and mortality. Drug treatment for many of the herpes infections is available but is often associated with serious side effects. In the pediatric age group, treatment is further hindered by a lack of information on suitable dosing regimes, unavailability of oral solutions and a lack of clinical trials specifically investigating response to treatment in this group of patients. This article will review current evidence regarding the pharmacokinetics and dosing of the most commonly used antiherpetic agents and will look specifically at the treatment of the more common herpes virus infections in children.

Prevention of cytomegalovirus following solid organ transplantation: a literature review

CMV is the most common opportunistic infection affecting SOT recipients. Although current strategies to prevent both CMV infection and disease have been effective, CMV related complications continue to occur, particularly late-onset CMV disease. This literature review article examines the benefits and disadvantages of different prevention modalities, and presents emerging strategies to better prevent CMV in organ transplant recipients.

Risk of cytomegalovirus disease in high-risk liver transplant recipients on valganciclovir prophylaxis: a systematic review and meta-analysis

Valganciclovir (VGC) was approved by the Food and Drug Administration in 2004 as cytomegalovirus (CMV) prophylaxis except for liver transplant recipients because of their high incidence of CMV disease with this drug. However, surveys have shown its common off-label use for CMV prophylaxis in liver transplant recipients. We aimed to evaluate the risk of CMV disease with VGC prophylaxis in liver transplant recipients. All studies that evaluated liver transplant recipients and used VGC (900 or 450 mg daily) for the prevention of CMV disease were included. Five controlled studies (n = 483) were pooled with a random effects model; five single-arm studies (n = 380) were pooled for the prevalence rate of CMV disease. The risk of CMV disease with VGC versus ganciclovir was 1.81 [95% confidence interval (CI) = 1.00-3.29, P = 0.05, I(2) = 0%]. For high-risk (donor-positive/recipient-negative) patients, the risk of CMV disease was 1.96 (95% CI = 1.05-3.67, P = 0.035, I(2) = 0%). The risk of CMV disease remained significant with 900 mg of VGC daily (P = 0.04) but not with 450 mg of VGC daily (P = 0.76). The risk of leukopenia with VGC was 1.87 (95% CI = 1.03-3.37, P = 0.04, I(2) = 0%). In single-arm trials, the overall CMV disease rate was 12% (95% CI = 9%-16%, P < 0.001), and the rate for high-risk patients was 20% (95% CI = 10%-38%, P = 0.002). In conclusion, 900 mg of VGC daily may not be safe as CMV prophylaxis in high-risk liver transplant recipients because of the significant 2-fold increase in the risk of CMV disease and the 1.9-fold increase in the risk of leukopenia. Alternative CMV prophylaxis should be used for liver transplant recipients.

The value of pre-emptive therapy for cytomegalovirus after liver transplantation

BACKGROUND

Cytomegalovirus (CMV) infections are among the most common infections following liver transplantation. The main preventive methods for CMV infections are universal prophylaxis and pre-emptive therapy. In our study, we adopted a pre-emptive strategy in a higth-risk group of donor CMV-positive (D+)/recipient CMV-negative (R-) casses. We investigated whether this strategy was safe and effective to prevent CMV disease.

METHODS

One hundred fifty-nine liver transplantation recipients who underwent over a 15-year period were retrospectively analyzed after follow-up for at least 6 months (mean, 63 months). Weekly quantitative polymerase chain reaction (PCR) measurements were performed to detect viral DNA. No CMV drug prophylaxis was given: antiviral CMV therapy was initiated when the PCR for CMV-DNA was >400 copies/mL.

RESULTS

Fifty-one of 159 liver transplant recipients enrolled in the study received antiviral therapy. High-risk patients (D+/R-) developed CMV infections significantly more often than D-/R- serostatus (P = .005). CMV disease was diagnosed in 12% of CMV-positive patients. Independent of serostatus in 14 cases (27.5%) virological recurrence of CMV infection occurred after primary treatment. Survival analysis showed no significant difference between patients with versus without CMV infection (P = .950). No relationship could be found between transplant rejection and CMV infection (P = .349).

CONCLUSION

Our results showed that a pre-emptive strategy to prevent CMV disease was possible, even among the serological high-risk group. Only 12% of cases with CMV infection went on to manifest CMV disease with organ involvement. Survival curves were similar among patients with versus without CMV infections.

Incidence, risk factors, and outcomes associated with cytomegalovirus disease in small bowel transplant recipients

Despite improved prophylaxis, monitoring, and more efficient immunosuppression, CMV infection remains a common opportunistic infection in transplant recipients. We assessed the incidence of CMV disease in pediatric SBT recipients, the timing of CMV disease after transplantation, and its impact on patient outcome. The medical records of 98 SBT recipients were reviewed. We performed descriptive analysis, regression analysis, and Kaplan-Meier curves to determine the time-to-event after transplantation. Fifty-three percent patients were male and 47% female, with a mean age of 38.3 months. Thirty-five percent of patients received prophylactic VGC, 55% GCV, 10% a combination of GCV/VGC, and 99% CMV immunoglobulins. A total of 24.5% recipients were CMV D+/R- (CMV serostatus donor positive/recipient negative). Seven (c. 7%) patients developed CMV disease. CMV disease was associated with 2.5 times (0.52-12.1; p = 0.25) higher rate of CMV mismatch and 11.1 times (1.3-95.9; p = 0.03) higher risk of death. CMV prophylaxis increased time-to-death (p = 0.074). Time-to-CMV disease was shorter in patients with enteritis (p < 0.0001), and CMV disease was associated with shorter time-to-death after transplantation (p = 0.001). CMV disease in SBT recipients was associated with an 11-fold mortality increase and a fourfold faster time-to-death. Time-to-death was significantly shorter with CMV enteritis.

Retrospective review of the incidence of cytomegalovirus infection and disease after liver transplantation in pediatric patients: comparison of prophylactic oral ganciclovir and oral valganciclovir

Cytomegalovirus (CMV) is the most common viral infection after solid organ transplantation (SOT). Safe and effective prophylactic regimens that decrease its incidence after SOT are essential for long-term graft survival. Although valganciclovir is not Food and Drug Administration-approved for CMV prophylaxis in liver transplant recipients, postmarketing studies have shown valganciclovir to be as effective as ganciclovir in high-risk adult patients undergoing SOT. Currently, data are lacking for pediatric liver transplantation. The purpose of this study was to compare the efficacy and safety of valganciclovir and ganciclovir for CMV infection prophylaxis in pediatric liver transplant recipients. This was a retrospective study of 56 pediatric liver transplant recipients who were prescribed either oral ganciclovir (n = 37) or valganciclovir (n = 19). Patients were followed until 200 days after transplantation or death. The primary outcome measure compared the rates of early-onset CMV infection and CMV disease in the 2 medication groups. Secondary outcome measures identified patient-specific factors that contributed to CMV acquisition and the incidence of late-onset CMV infection or disease. The rates of adverse drug effects and discontinuation were also evaluated. Early-onset CMV disease was documented in 0% of valganciclovir patients and in 5.4% of ganciclovir patients (P = 0.54). There were no statistically significant differences in the secondary outcomes. An increased incidence of late-onset CMV disease was seen in the valganciclovir group versus the ganciclovir group (22.2% versus 8.1%, P = 0.23). No differences in adverse events were reported. In conclusion, no statistically significant differences were found in the incidence of CMV infection or disease between patients receiving oral valganciclovir and patients receiving oral ganciclovir.

Viral factors influencing the outcome of human cytomegalovirus infection in liver transplant recipients

BACKGROUND

Cytomegalovirus (CMV) remains the leading viral cause of disease following orthotopic liver transplantation (OLT) despite the availability of antiviral agents for prophylaxis and therapy.

OBJECTIVE

Examine the viral factors that influence the outcome of CMV infection following valganciclovir prophylaxis or laboratory-guided preemptive therapy in OLT recipients.

STUDY DESIGN

The value of valganciclovir prophylaxis and laboratory-guided preemptive therapy for the prevention of CMV infection and disease was observed in 64 OLT recipients. Prophylaxis was given to all CMV seronegative recipients receiving a liver from a seropositive donor (D+R-; n=15), and all other recipients were randomised to receive either prophylaxis (n=24) or laboratory-guided preemptive therapy (n=25). Recipients were monitored for CMV DNAemia, viral load, emergence of antiviral resistant strains and co-infections.

RESULTS

CMV end-organ disease and antiviral resistant strains only occurred in D+R- recipients despite the use of prophylaxis in these patients. The D+R- recipients commencing prophylaxis immediately following transplantation had better outcomes compared to those for whom prophylaxis was delayed due to renal impairment. Prophylaxis reduced the incidence of CMV DNAemia, persistent infection, and high viral loads for CMV seropositive (D-R+and D+R+) recipients, but laboratory-guided preemptive therapy effectively controlled CMV infection and prevented disease in these OLT recipients.

CONCLUSION

Delaying the commencement of valganciclovir prophylaxis may be associated with worse outcomes for high-risk OLT recipients. Laboratory-guided pre-emptive therapy remains an alternative approach for seropositive recipients at lower risk of CMV disease.

Valganciclovir is an effective prophylaxis for cytomegalovirus disease in liver transplant recipients

OBJECTIVES

Cytomegalovirus (CMV) infection is responsible for significant morbidity and mortality among solid organ transplant recipients. Prophylaxis using valganciclovir (VGCV) in orthotopic liver transplant (OLT) recipients is not approved by the Food and Drug Administration and its use is controversial. This study aimed to evaluate the effectiveness of VGCV in CMV prophylaxis in OLT recipients.

METHODS

We carried out a retrospective, single-centre study including all OLT procedures performed during 2005-2008. Patients with early death (at ≤ 30 days), without CMV serology or prophylaxis, or with follow-up of <1 year were excluded.

RESULTS

The overall incidence of CMV disease was 6% (n= 9). The ganciclovir (GCV) and VGCV groups had similar incidences of CMV disease (4.6% vs. 7.0%; P= 0.4) and similar distributions of disease presentation (CMV syndrome vs. tissue-invasive CMV; P= 0.4). Incidences of CMV infection, as well as disease presentation, were similar between the high-risk (CMV D+/R-) and non-high-risk groups (P= 0.16). Although acute cellular rejection occurred more frequently in patients who developed CMV disease (P= 0.005), overall survival in these patients did not differ from that in patients who did not develop CMV infection (P= 0.5).

CONCLUSIONS

Valganciclovir is an effective antiviral for the prevention of CMV disease in liver transplant recipients. Our data support its use in high-risk OLT patients.

Current concepts on cytomegalovirus infection after liver transplantation

Cytomegalovirus (CMV) is the most common viral pathogen that negatively impacts on the outcome of liver transplantation. CMV cause febrile illness often accompanied by bone marrow suppression, and in some cases, invades tissues including the transplanted allograft. In addition, CMV has been significantly associated with an increased predisposition to allograft rejection, accelerated hepatitis C recurrence, and other opportunistic infections, as well as reduced overall patient and allograft survival. To negate the adverse effects of CMV on outcome, its prevention, whether through antiviral prophylaxis or preemptive therapy, is regarded as an essential component to the medical management of liver transplant patients. Two recent guidelines have suggested that antiviral prophylaxis or preemptive therapy are similarly effective in preventing CMV disease in modest-risk CMV-seropositive liver transplant recipients, while antiviral prophylaxis is the preferred strategy over preemptive therapy for the prevention of CMV disease in high-risk recipients [CMV-seronegative recipients of liver allografts from CMV-seropositive donors (D+/R-)]. However, antiviral prophylaxis has only delayed the onset of CMV disease in many CMV D+/R- liver transplant recipients, and at least in one study, such occurrence of late-onset primary CMV disease was significantly associated with increased mortality after liver transplantation. Therefore, optimized strategies for prevention are needed, and aggressive treatment of CMV infection and disease should be pursued. The standard treatment of CMV disease consists of intravenous ganciclovir or oral valganciclovir, and if feasible, one should also reduce the degree of immunosuppression. In one recent controlled clinical trial, valganciclovir was found to be as effective and safe as intravenous ganciclovir for the treatment of mild to moderate CMV disease in solid organ (including liver) transplant recipients. In this article, the authors review the current state and the future perspectives of prevention and treatment of CMV disease after liver transplantation.

The efficacy and safety of valganciclovir vs. oral ganciclovir in the prevention of symptomatic CMV infection in children after solid organ transplantation

Routine prophylaxis for CMV with valganciclovir is common in adult recipients but data to support its use in children are scarce. The aim of this study was to compare the efficacy and safety of valganciclovir vs. ganciclovir in a pediatric cohort. We performed a retrospective analysis of 92 children after KTx and/or LTx. All children have received IV ganciclovir for two wk, and then oral ganciclovir (TID; n = 41) before 2004, or valganciclovir (OD; n = 51) thereafter. Treatment was given for three months in R+/D+ or R+/D- recipients and for six months in R-/D+. Patients were followed for one yr post transplant. Both groups were comparable in their demographic and transplant-related history. Symptomatic CMV infection/disease developed in 13.7% vs. 19.5% of valganciclovir and ganciclovir groups, respectively (P-NS). Time-to-onset of CMV infection was comparable in both groups (P-NS); rates of acute allograft rejection were similar in both groups (3.9% vs. 9.8%). Risk factors for CMV infection included young age, serostatus of R-/D+, and allograft from cadaver donor. No significant side effects were noted in both groups. As in adults, valganciclovir appears to be as efficacious and safe as oral ganciclovir. Valganciclovir should be considered as a possible prophylactic treatment for CMV in pediatric recipients of KTx or LTx.

Prophylactic therapy with valgancyclovir in high-risk (cytomegalovirus D+/R-) liver transplant recipients: a single-center experience

A retrospective study was performed in liver transplant patients with high risk to develop cytomegalovirus infection (CMV D+/R-) who were treated with valgancyclovir for 3 months as prophylactic therapy. The aim of this study was to determine the safety and efficacy of prophylactic therapy with valgancyclovir. Weekly CMV antigenemia was routinely assessed during the first 3 months posttransplantation, twice a month to month 6, and monthly until the end of the first year, as well as when clinically indicated. The follow-up period was 1 year. From January 2003 to February 2007, 199 liver transplantations were performed at our institution, including 23 (11%) high-risk patients for CMV infection. Median age was 47 +/- 11.6 years. Nineteen patients (70.4%) were men. Five subjects (21.7%) developed CMV infections. Three patients with positive CMV antigenemia at 3, 4, or 6 months posttransplantation were asymptomatic, while 2 (8.7%) showed gastrointestinal CMV disease at 2 months posttransplantation or CMV hepatitis at 1 month after the end of the prophylactic therapy. Treatment with intravenous gancyclovir followed by oral valgancyclovir was successful in both patients. No opportunistic infections were observed and only 1 patient developed leukopenia as an adverse event related to valgancyclovir.

Increased incidence of cytomegalovirus infection in high-risk liver transplant recipients receiving valganciclovir prophylaxis versus ganciclovir prophylaxis

Optimal measures for the prevention of cytomegalovirus (CMV) in high-risk orthotopic liver transplant (OLT) patients are unknown. The charts of high-risk OLT recipients with 12 months of follow-up who were transplanted over a 44-month period were reviewed. The incidence of CMV disease in CMV-seropositive donor/CMV-seronegative recipient patients receiving valganciclovir or ganciclovir prophylaxis was compared. Sixty-six patients met the inclusion criteria and were treated with 1 of 3 prophylactic regimens: valganciclovir (900 mg daily; 27 patients), oral ganciclovir (1000 mg every 8 hours; 17 patients), or intravenous ganciclovir (6 mg/kg daily; 22 patients). Eight CMV cases occurred, all after completion of the prophylaxis. The combined incidence of CMV disease with intravenous and oral ganciclovir was lower than the incidence in valganciclovir recipients (P = 0.056; relative risk, 4.33; 95% confidence interval, 0.94-19.87). CMV disease occurred in 22.2% of valganciclovir recipients, 4.5% of intravenous ganciclovir recipients, and 5.9% of oral ganciclovir recipients. In conclusion, late-onset CMV disease occurred more frequently among high-risk liver transplant recipients treated with valganciclovir prophylaxis. The 4-fold higher incidence of CMV disease in our study supports the avoidance of valganciclovir for prophylaxis in high-risk OLT patients. Liver Transpl 15:963-967, 2009. (c) 2009 AASLD.

CMV infection, diagnosis and antiviral strategies after liver transplantation

Cytomegalovirus (CMV) is a significant pathogen complicating the post-transplant course of organ recipients. In liver transplant patients, the febrile clinical illness caused by CMV may be associated with end-organ disease, such as hepatitis or infection of the gastrointestinal tract. In addition to direct effects, CMV may have indirect effects including the risk of other infections or graft rejection. Recently, major advances in the management of CMV infection have been achieved through the development of new diagnostic techniques and antiviral strategies to prevent CMV disease. Quantitative nucleic acid testing to monitor viral load is now commonly used to diagnose and guide the treatment of CMV infections. The standardization of the testing, however, needs to be improved. There are two main strategies to prevent CMV disease after liver transplantation: prophylaxis and pre-emptive therapy. Both strategies are effective, but also have disadvantages. The disadvantages of prophylaxis include prolonged drug exposure, the development of resistance and, most of all, the development of delayed and late-onset CMV disease. On the other hand, the pre-emptive strategy is based on frequent laboratory monitoring of viral loads, and some patients may develop symptomatic infection before the diagnosis of CMV. This overview summarizes the current status of CMV in liver transplantation.

Valganciclovir for cytomegalovirus prevention in solid organ transplant patients: an evidence-based reassessment of safety and efficacy

BACKGROUND

Several anti-viral drugs have demonstrated efficacy in preventing Cytomegalovirus (CMV) infections in solid organ transplant (SOT) patients. The recently approved valganciclovir is the most commonly used and most expensive drug for CMV prevention. The safety and efficacy data have been drawn from a single trial. We hypothesized that valganciclovir may not be as safe as nor more effective than other therapies for CMV prevention.

METHODS

All experimental and analytical studies that compared valganciclovir with other therapies for prevention of CMV infection after SOT were selected. Based on meta-analytic and multivariate regression methodologies we critically analyzed all available evidence.

FINDINGS

Nine studies were included (N = 1,831). In trials comparing valganciclovir with ganciclovir, the risk for CMV disease is 0.98 (95% Confidence Interval (95%CI) 0.67 to 1.43; P = 0.92; I(2) = 0%). Valganciclovir was significantly associated with the risk of absolute neutropenia (<1,500/mm(3)) compared with all therapies (Odds Ratio (OR) 3.63 95%CI 1.75 to 7.53; P = 0.001; I(2) = 0%); with ganciclovir only (OR 2.88, 95%CI 1.27 to 6.53; P = 0.01; I(2) = 0%); or with non-ganciclovir therapies (OR 8.30, 95%CI 1.51 to 45.58; P = 0.01; I(2) = 10%). For a neutropenia cut-off of <1,000/mm(3), the risk remained elevated (OR 1.97, 95%CI 1.03 to 3.67; P = 0.04; I(2) = 0%). For every 24 patients who receive valganciclovir prophylaxis, one more will develop neutropenia compared to other therapies. The risk of late-onset CMV disease with valganciclovir was similar to ganciclovir and higher than those with non-ganciclovir therapies (OR 8.95, 95%CI 1.07 to 74.83; P = 0.04; I(2) = 0%]. One more patient will develop late-onset CMV disease for every 25 who receive valganciclovir compared to treatment with non-ganciclovir therapies. The risk of CMV tissue-invasive disease in liver recipients receiving valganciclovir was 4.5 times the risk seen with ganciclovir [95%CI 1.00 to 20.14] (p = 0.04). All results remained consistent across different study designs, valganciclovir doses, and CMV serostatus.

CONCLUSIONS

Valganciclovir shows no superior efficacy and significantly higher risk of absolute neutropenia, CMV late-onset disease, and CMV tissue-invasive disease compared to other standard therapies. Due to the availability of efficacious, safer, and lower cost drugs (high-dose acyclovir, valacyclovir, ganciclovir), our results do not favor the use of valganciclovir as a first-line agent for CMV preemptive or universal prophylaxis in SOT patients.

Prevention of posttransplant cytomegalovirus disease and related outcomes with valganciclovir: a systematic review

The precise impact of valganciclovir as preventive therapy for cytomegalovirus (CMV) in solid organ transplant (SOT) recipients is not fully defined. Data from studies using valganciclovir as preemptive therapy or prophylaxis for CMV in SOT recipients were synthesized for descriptive analysis. CMV disease occurred in 2.6% and 9.9% of the patients receiving valganciclovir as preemptive therapy and prophylaxis, respectively. Although the incidence of early-onset (<or=90 days posttransplant) CMV disease was only 0.8% and 1.2% in all patients and R-/D+ patients receiving valganciclovir prophylaxis, the incidence of late-onset (>90 days posttransplant) CMV disease rose up to 8.9% and 17.7% in the prophylactic group, respectively. On the contrary, no patients developed late-onset CMV disease in preemptive group. Both approaches with valganciclovir have successfully decreased CMV disease in SOT recipients. Late-onset CMV disease is a complication observed uniquely with valganciclovir prophylaxis, particularly in R-/D+ patients, but not with preemptive therapy.

Iron overload and unique susceptibility of liver transplant recipients to disseminated disease due to opportunistic pathogens

The propensity of liver transplant recipients to develop more fulminant disease presentation and a higher risk of disseminated disease due to a number of opportunistic infections, including invasive aspergillosis, cryptococcosis, zygomycosis, may be related to iron overload. Abnormalities in iron homeostasis may also be a contributor to severe manifestations due to other pathogens such as cytomegalovirus and Staphylococcus aureus in liver transplant recipients. Iron is essential not only for microbial pathogenesis, but directly impairs pivotal pathogen specific host defenses. Studies to assess iron homeostasis and the mechanisms by which iron overload contributes to the pathogenesis of opportunistic infections in liver transplant recipients are warranted.

Maribavir: a new oral anti-cytomegalovirus drug

Prophylactic drug therapy for cytomegalovirus (CMV) disease in stem cell and solid organ transplant recipients is effective and simple to implement, with oral ganciclovir and oral valganciclovir as the primary agents. The main problems with the ganciclovir derivatives are myelotoxicity and development of resistance. The new antiviral drug, maribavir, in Phase III clinical trials of CMV prophylaxis after stem cell and liver transplantation, works through a mechanism distinct from that of ganciclovir and shows no myelotoxicity or cross-resistance. The primary toxicity is headache and taste disturbance. If the clinical trials are effective, it is expected that maribavir will be available in 2009. The availability of a new antiviral agent will help in the control of the persistent bane of transplant care.

Cytomegalovirus infection after liver transplantation: Current concepts and challenges

Cytomegalovirus (CMV) is a common viral pathogen that influences the outcome of liver transplantation. In addition to the direct effects of CMV syndrome and tissue-invasive diseases, CMV is associated with an increased predisposition to acute and chronic allograft rejection, accelerated hepatitis C recurrence, and other opportunistic infections, as well as reduced overall patient and allograft survival. Risk factors for CMV disease are often interrelated, and include CMV D+/R- serostatus, acute rejection, female gender, age, use of high-dose mycophenolate mofetil and prednisone, and the overall state of immunity. In addition to the role of CMV-specific CD4+ and CD8+ T lymphocytes, there are data to suggest that functionality of the innate immune system contributes to CMV disease pathogenesis. In one study, liver transplant recipients with a specific polymorphism in innate immune molecules known as Toll-like receptors were more likely to develop higher levels of CMV replication and clinical disease. Because of the direct and indirect adverse effects of CMV disease, its prevention, whether through antiviral prophylaxis or preemptive therapy, is an essential component in improving the outcome of liver transplantation. In the majority of transplant centers, antiviral prophylaxis is the preferred strategy over preemptive therapy for the prevention of CMV disease in CMV-seronegative recipients of liver allografts from CMV-seropositive donors (D+/R-). However, the major drawback of antiviral prophylaxis is the occurrence of delayed-onset primary CMV disease. In several prospective and retrospective studies, the incidence of delayed-onset primary CMV disease ranged from 16% to 47% of CMV D+/R- liver transplant recipients. Current data suggests that delayed-onset CMV disease is associated with increased mortality after liver transplantation. Therefore, optimized strategies for prevention and novel drugs with unique modes of action are needed. Currently, a randomized controlled clinical trial is being performed comparing the efficacy and safety of maribavir, a novel benzimidazole riboside, and oral ganciclovir as prophylaxis against primary CMV disease in liver transplant recipients. The treatment of CMV disease consists mainly of intravenous (IV) ganciclovir, and if feasible, a reduction in the degree of immunosuppression. A recent controlled clinical trial demonstrated that valganciclovir is as effective and safe as IV ganciclovir for the treatment of CMV disease in solid organ (including liver) transplant recipients. In this article, the author reviews the current state and the future perspectives of prevention and treatment of CMV disease after liver transplantation.

PTH regulation of the human cytomegalovirus immediate-early gene promoter

Secondary hyperparathyroidism and human cytomegalovirus (hCMV) seropositivity are highly prevalent in patients undergoing renal transplantation, and both are linked to the development of chronic allograft nephropathy (CAN). We investigated the hypothesis that parathyroid hormone (PTH) 1-84 regulates hCMV immediate-early gene (IEG) promoter activation in proximal renal tubular cells. PTH 1-84 enhanced hCMV IEG promoter (-548 to +92) activity in opossum kidney cells. Deletion analysis from the 5' end of the promoter localized the PTH 1-84 associated activity to the DNA sequence between -123 and -45. Mutation of an imperfect ATF/AP-1 DNA element within this region abrogated the PTH 1-84 effect and also strongly attenuated basal gene expression. Mobility shift analyses using this DNA element revealed that a member of the ATF-1 family was in the binding complex. In summary, we present evidence for a novel pathogenic role of PTH 1-84 in promoting hCMV immediate-early gene transcription.

Valganciclovir as preemptive therapy for cytomegalovirus in cytomegalovirus-seronegative liver transplant recipients of cytomegalovirus-seropositive donor allografts

The efficacy of valganciclovir as preemptive therapy for the prevention of cytomegalovirus (CMV) disease and its impact on indirect sequelae of CMV were assessed in recipient-negative/donor-positive (R-/D+) liver transplant recipients. Of 187 consecutive liver transplant recipients at our institution since July 2001, 36 (19.2%) belonged to the R-/D+ group. Surveillance tests for CMV were performed on all patients at weeks 2, 4, 6, 8, 10,12, and 16. In all, 27 patients with asymptomatic viremia received preemptive therapy with valganciclovir. At a total follow-up of 62.8 patient years (median: 19 months, range: 3 months to 5.6 years), no episodes of CMV disease were documented in these patients. The incidence of rejection, retransplantation, and bacterial or fungal infections and the probability of survival did not differ for R-/D+ patients and all non-R-/D+ patients treated preemptively with valganciclovir (P > 0.20 for all variables). Thus, preemptive therapy with valganciclovir in R-/D+ patients was not associated with CMV disease during the period of surveillance monitoring or at anytime thereafter (late-onset CMV disease). The indirect outcomes with the use of valganciclovir in R-/D+ patients were comparable to the outcomes of other subgroups of liver transplant recipients receiving preemptive therapy.

Delayed-onset primary cytomegalovirus disease after liver transplantation

Clinical practice guidelines recommend antiviral prophylaxis to cytomegalovirus (CMV) donor-positive/recipient-negative (D+/R-) liver transplant recipients. We assessed the outcome of this strategy by determining the incidence, clinical features, and risk factors of CMV disease among CMV D+/R- liver transplant recipients who received antiviral prophylaxis. Sixty-seven CMV D+/R- liver transplant recipients (mean age+/-standard deviation: 49.5+/-11.4 years; 75% male) received oral ganciclovir [n=9 (13%)] or valganciclovir [n=58 (87%)] prophylaxis for a median duration of 92 days (interquartile range: 91-100). No breakthrough CMV disease was observed during antiviral prophylaxis. However, primary CMV disease was observed in 2%, 25%, 27%, 27%, and 29% of patients at 1, 3, 6, 12, and 24 months, respectively, after antiviral prophylaxis was stopped. The incidence of delayed-onset primary CMV disease was similar between those who received oral ganciclovir and valganciclovir. Nine (47%) patients had CMV syndrome, 8 (42%) had gastrointestinal CMV disease, and 2 (11%) had CMV hepatitis. Female patients (P=0.01) and younger age at transplant (P=0.03) were associated with an increased risk, whereas diabetes mellitus (P<0.001) was significantly associated with a lower risk of delayed-onset primary CMV disease. Allograft loss or mortality occurred in 8 (12%) patients during the median follow-up period of 3.31 (range: 0.8-5.9) years. No significant association was observed between CMV disease and patient and allograft survival. In conclusion, CMV disease remains a common complication in CMV D+/R- liver transplant patients during the contemporary era of antiviral prophylaxis. Female patients and younger patients are at increased risk of delayed-onset primary CMV disease.

Update in infectious diseases in liver transplant recipients

The prevention and management of bacterial, fungal, and viral infections are important components in the care of the liver transplant recipient. Although much progress has been made, challenges still remain. This article provides updates on the management of bilomas and peritonitis, the prevention and management of invasive Candida and Aspergillus infections, the prevention and management of cytomegalovirus disease, and the current status of liver transplantation in HIV-infected patients.

Valganciclovir: what is the status in solid organ transplantation?

Prophylactic drug therapy for cytomegalovirus disease in solid organ transplant recipients is effective and simple to implement, but it is associated with patient nonadherence and viral resistance. Recent data show that the efficacy and safety of oral ganciclovir and oral valganciclovir are similar. However, three large daily doses of oral ganciclovir are required, which is inconvenient, and viral resistance can develop to the drug. The single daily dose and lack of viral resistance are advantages of valganciclovir. This has become the primary agent for the prevention of cytomegalovirus disease. Current trials are underway to determine its effectiveness for treatment of cytomegalovirus disease, the optimal length of prophylaxis, and the safety and efficacy of a syrup formulation in children.