Prophylaxis versus pre-emptive treatment for prevention of cytomegalovirus infection in CMV-seropositive orthotopic liver-transplant recipients

Antiviral prophylaxis or preemptive therapy for cytomegalovirus after liver transplantation?: A systematic review and meta-analysis

BACKGROUND

To conduct a meta-analysis with the aim of comparing the outcomes of antiviral prophylaxis and preemptive therapy for the prevention of cytomegalovirus (CMV) infection in liver transplant (LT) recipients.

METHODS

We searched databases for qualified studies up until March 2022. Finally, a meta-analysis was carried out using a fixed-effect or random-effect model based on the heterogeneity.

RESULTS

With a total of 1834 LT patients, the pooled incidence of CMV infection and CMV disease in the overall LT recipients using antiviral prophylaxis and preemptive therapy were 24.7% vs. 40.4% and 6.4% vs. 9.4%, respectively. Our meta-analysis exhibited a significant reduction in the incidence of CMV infection due to antiviral prophylaxis when compared to preemptive therapy in the high-risk group (OR: 6.67, 95% CI: 1.73, 25.66; p = 0.006). In contrast, there was a significant reduction in the incidence of late-onset of CMV disease in preemptive therapy compared to antiviral prophylaxis in the high-risk group (OR: 0.29, 95% CI: 0.12, 0.74; p = 0.009). However, the incidence of CMV disease, allograft rejection, graft loss, drug related adverse effects, opportunistic infections and mortality did not differ significantly between both the interventions (all p> 0.05).

CONCLUSIONS

We found the use of antiviral prophylaxis, compared with preemptive therapy, is superior in controlling CMV infection and prolonging the time to CMV disease in LT recipients without an increased risk of opportunistic infections, allograft rejection, graft loss, drug related adverse effects, development of drug resistance, and mortality.

What is the optimal antimicrobial prophylaxis to prevent postoperative infectious complications after liver transplantation? A systematic review of the literature and expert panel recommendations

BACKGROUND

Antimicrobial prophylaxis is well-accepted in the liver transplant (LT) setting. Nevertheless, optimal regimens to prevent bacterial, viral, and fungal infections are not defined.

OBJECTIVES

To identify the optimal antimicrobial prophylaxis to prevent post-LT bacterial, fungal, and cytomegalovirus (CMV) infections, to improve short-term outcomes, and to provide international expert panel recommendations.

DATA SOURCES

Ovid MEDLINE, Embase, Scopus, Google Scholar, and Cochrane Central.

METHODS

Systematic review following PRISMA guidelines and recommendations using the GRADE approach derived from an international expert panel.

PROSPERO ID

CRD42021244976.

RESULTS

Of 1853 studies screened, 34 were included for this review. Bacterial, CMV, and fungal antimicrobial prophylaxis were evaluated separately. Pneumocystis jiroveccii pneumonia (PJP) antimicrobial prophylaxis was analyzed separately from other fungal infections. Overall, eight randomized controlled trials, 21 comparative studies, and five observational noncomparative studies were included.

CONCLUSIONS

Antimicrobial prophylaxis is recommended to prevent bacterial, CMV, and fungal infection to improve outcomes after LT. Universal antibiotic prophylaxis is recommended to prevent postoperative bacterial infections. The choice of antibiotics should be individualized and length of therapy should not exceed 24 hours (Quality of Evidence; Low | Grade of Recommendation; Strong). Both universal prophylaxis and preemptive therapy are strongly recommended for CMV prevention following LT. The choice of one or the other strategy will depend on individual program resources and experiences, as well as donor and recipient serostatus. (Quality of Evidence; Low | Grade of Recommendation; Strong). Antifungal prophylaxis is strongly recommended for LT recipients at high risk of developing invasive fungal infections. The drug of choice remains controversial. (Quality of Evidence; High | Grade of Recommendation; Strong). PJP prophylaxis is strongly recommended. Length of prophylaxis remains controversial. (Quality of Evidence; Very Low | Grade of Recommendation; Strong).

Impact of cytomegalovirus reactivation just before liver transplantation: A prospective cohort study

BACKGROUND

Cytomegalovirus (CMV) is the most common viral pathogen after liver transplantation (LT). Although reactivation of CMV infection is generally described in the context of immunosuppression, it has also been described in critically ill immunocompetent patients including cirrhotic patients.

AIM

To determine the incidence of reactivated CMV prior to LT.

METHODS

This was a prospective cohort study evaluating adult patients who underwent LT between 2014 and 2016. A plasma sample was obtained from all patients for CMV quantitative real-time PCR testing right before transplantation. Patients were followed for at least 1 year to assess the following outcomes: Incidence of CMV infection, organ rejection and overall mortality.

RESULTS

A total of 72 patients were enrolled. Four patients died before transplantation, thus 68 patients were followed up for a median of 44 mo (20-50 mo). In 23/72 patients (31.9%) CMV was reactivated before transplantation. Post-transplantation, 16/68 (23.5%) patients had CMV infection and that was significantly associated with the recipient being CMV negative and a CMV-positive donor. Pre-transplant CMV reactivation was not associated with overall mortality (log rank: 0.9).

CONCLUSION

This study shows that CMV infection is common in patients with chronic liver disease just before LT, but the clinical impact of this infection seems to be negligible.

Use of Viral Load as a Surrogate Marker in Clinical Studies of Cytomegalovirus in Solid Organ Transplantation: A Systematic Review and Meta-analysis

Symptomatic cytomegalovirus (CMV) disease has been the standard endpoint for clinical trials in organ transplant recipients. Viral load may be a more relevant endpoint due to low frequency of disease. We performed a meta-analysis and systematic review of the literature. We found several lines of evidence to support the validity of viral load as an appropriate surrogate end-point, including the following: (1) viral loads in CMV disease are significantly greater than in asymptomatic viremia (odds ratio, 9.3 95% confidence interval, 4.6-19.3); (2) kinetics of viral replication are strongly associated with progression to disease; (3) pooled incidence of CMV viremia and disease is significantly lower during prophylaxis compared with the full patient follow-up period (viremia incidence: 3.2% vs 34.3%; P < .001) (disease incidence: 1.1% vs 13.0%; P < .001); (4) treatment of viremia prevented disease; and (5) viral load decline correlated with symptom resolution. Based on the analysis, we conclude that CMV load is an appropriate surrogate endpoint for CMV trials in organ transplant recipients.

Comparison of Preemptive Therapy and Antiviral Prophylaxis for Prevention of Cytomegalovirus in Seropositive Liver Transplant Recipients

BACKGROUND

Few studies have directly compared preemptive therapy (PET) and antiviral prophylaxis (AP) for prevention of cytomegalovirus (CMV) disease in CMV seropositive (R+) orthotopic liver transplant (OLT) recipients.

METHODS

We prospectively assessed CMV disease and clinical outcomes among 160 consecutive R+ OLT recipients who received PET (weekly plasma CMV PCR for 3 months, oral valganciclovir 900 mg twice daily for CMV viremia >250 IU/mL, until 2 consecutive negative weekly PCR results) and compared them with a historical cohort of 156 R+ recipients who received AP (valganciclovir, 900 mg daily for 3 months).

RESULTS

Patient characteristics were similar between PET and AP cohorts (P > 0.05 all comparisons). In the PET group, 24% (39/160) developed CMV viremia greater than 250 IU/mL at a median of 42 (range, 7-93) days post-OLT. CMV monitoring adherence in the PET cohort was 85% (1488/1760 required tests) and 86% (30/36) initiated PET within 3 days of the CMV result. By 12 months post-OLT, the incidence of CMV disease, acute allograft rejection, major infection, or death in the PET and AP cohorts was not significantly different: 2% versus 2%, 19% versus 16%, 10.5% versus 10.8%, and 5% versus 8%, respectively (P > 0.05 all comparisons). The estimated proportion of drug-exposed patients and average antiviral drug exposure were significantly lower with PET versus AP: 24% versus 100%, P < 0.001, and 15.8 versus 81 g per patient, P < 0.001, respectively.

CONCLUSIONS

PET is feasible in a nonresearch setting and is associated with similar CMV disease rates and other clinically relevant outcomes to AP in CMV seropositive liver transplant recipients.

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.

Late cytomegalovirus infection in children: High incidence of allograft rejection and hepatitis in donor negative and seropositive liver transplant recipients

The complications and outcome associated with late CMV infection and disease on the graft are poorly characterized in PLT recipients. We studied the overall incidence, risk factors, and outcome of late CMV infection and disease (infection 6 months after transplant) in 180 PLT recipients admitted between 2008 and 2011 at the King's College Hospital. Antiviral prophylaxis of intravenous ganciclovir was given only to the D+R- group starting at day 7 post-transplant. The remaining groups (D-R+, D+R+, and D-R-) received pre-emptive therapy when they have CMV viremia above cut-off value and treatment for symptomatic CMV infection. The overall incidence of late CMV infection and disease was 9.4% (19/180) and 14.5% (19/130) in D+R-, D-R+, D+R- groups. The D-R+ group had the highest incidence of hepatitis (37.5%) and significantly increased incidence of CMV disease, and single and multiple acute rejection episodes when compared to the D+R- group, which received prophylaxis. The late CMV infection and disease in pediatric LT recipients was comparable to adult LT recipients despite variable duration of antiviral prophylaxis. Our results show that D-R+ group had highest rate of hepatitis and rejection episodes, associated with high morbidity, and should be considered for antiviral prophylaxis.

Primary Cytomegalovirus Infection in Seronegative Kidney Transplant Patients Is Associated with Protracted Cold Ischemic Time of Seropositive Donor Organs

Human Cytomegalovirus (CMV) can lead to primary infection or reactivation in CMV-seronegative or -seropositive kidney transplant recipients, respectively. Complications comprise severe end-organ diseases and acute or chronic transplant rejection. Risk for CMV manifestation is stratified according to the CMV-IgG-serostatus, with donor+/recipient- (D+/R-) patients carrying the highest risk for CMV-replication. However, risk factors predisposing for primary infection in CMV-seronegative recipients are still not fully elucidated. Therefore, we monitored D+/R- high-risk patients undergoing kidney transplantation in combination with antiviral prophylaxis for the incidence of CMV-viremia for a median follow-up time of 784 days (156–1155 days). In this period, we analyzed the functional CMV-specific T cell response by intracellular cytokine staining and CMV-serology by ELISA. Only four of eight D+/R- patients developed clinically relevant CMV-viremia followed by seroconversion. Viremia triggered expansion of functional CMV-specific T cells correlating with protection against secondary CMV-reactivations. In contrast, all other patients remained permanently aviremic and showed no immunological correlate of infection after discontinuation of antiviral prophylaxis for up to three years. Comparing cold ischemic times (CIT) of viremic (median = 1020 min; 720–1080 min) and aviremic patients (median = 335 min; 120–660 min) revealed significantly (p = 0.0286) protracted CIT in patients with primary CMV-infection. Taken together, primary CMV-infection affects only a subgroup of D+/R- patients correlating with length of CIT. Therefore, patients with extended CIT should be thoroughly monitored for CMV-replication well beyond discontinuation of antiviral prophylaxis. In contrast, patients with short CIT remained permanently uninfected and might benefit from shorter prophylactic treatment.

Treatment of alpha and beta herpesvirus infections in solid organ transplant recipients

INTRODUCTION

Human herpesviruses frequently cause infections in solid organ transplant (SOT) recipients. Areas covered: We provide an overview of the clinical impact of alpha and beta herpesviruses and highlight the mechanisms of action, pharmacokinetics, clinical indications, and adverse effects of antiviral drugs for the management of herpes simplex virus, varicella zoster virus and cytomegalovirus. We comprehensively evaluated key clinical trials that led to drug approval, and served as the foundation for management guidelines. We further provide an update on investigational antiviral agents for alpha and beta herpesvirus infections after SOT. Expert commentary: The therapeutic armamentarium for herpes infections is limited by the emergence of drug resistance. There have been major efforts for discovery of new drugs against these viruses, but the results of early-phase clinical trials have been less than encouraging. We believe, however, that more antiviral drug options are needed given the adverse side effects associated with current antiviral agents, and the emergence of drug-resistant virus populations in SOT recipients. Likewise, optimized use and strategies are needed for existing and novel antiviral drugs against alpha and beta-herpesviruses in SOT recipients.

Late liver function test abnormalities post-adult liver transplantation: a review of the etiology, investigation, and management

Approximately 24,000 liver transplants are performed annually worldwide, almost 7000 of which are performed in the USA. Survival is excellent and continues to improve, with 1-year survival currently exceeding 85 %, but effective management of patients after liver transplantation is critical to achieve optimal results. A plethora of diseases can affect the transplanted allograft, ranging from recurrence of the original disease to de novo liver pathology, and diagnosis can be complicated by nonclassical presentation, de novo disease, or inconclusive histology. Patients can remain asymptomatic despite significant damage to the transplanted liver, so prompt identification and treatment of liver disease after transplantation is crucial to preserve allograft function. Liver function tests are routinely taken throughout the postoperative period to monitor the graft. Although nonspecific, they are inexpensive, noninvasive, and sensitive for allograft disease and can quickly alert physicians to the presence of asymptomatic pathology. This review will outline possible causes of liver function test abnormalities in the late posttransplant period and provide guidance for investigation, diagnosis, and management.