Cytomegalovirus Infection After Liver Transplantation Incidence, Risks, and Benefits of Prophylaxis

Detrimental impact of immunosuppressive burden on clinical course in patients with Cytomegalovirus infection after liver transplantation

INTRODUCTION

Cytomegalovirus (CMV)-infection and reactivation remain a relevant complication after liver transplantation (LT). The recipient and donor serum CMV-IgG-status has been established for risk stratification when choosing various pharmaceutical regimens for CMV-prophylaxis in the last two decades. However, factors influencing course of CMV-infection in LT remain largely unknown. In this study, the impact of immunosuppressive regimen was examined in a large cohort of patients.

METHODS

All patients that underwent primary LT between 2006 and 2018 at the Charité-Universitaetsmedizin, Berlin, were included. Clinical course as well as histological and laboratory findings of patients were analyzed our prospectively maintained database. Univariate and multivariate regression analysis for impact of variables on CMV-occurrence was conducted, and survival was examined using Kaplan-Meier analysis.

RESULTS

Overall, 867 patients were included in the final analysis. CMV-infection was diagnosed in 325 (37.5%) patients after transplantation. Significantly improved overall survival was observed in these patients (Log rank = 0.03). As shown by correlation and regression tree classification and regression tree analysis, the recipient/donor CMV-IgG-status with either positivity had the largest influence on CMV-occurrence. Analysis of immunosuppressive burden did not reveal statistical impact on CMV-infection, but statistically significant inverse correlation of cumulative tacrolimus trough levels and survival was found (Log rank < .001). Multivariate analysis confirmed these findings (p = .02).

DISCUSSION

CMV-infection remains of clinical importance after LT. Undergone CMV-infection of either recipient or donor requires prophylactic treatment. Additionally, we found a highly significant, dosage-dependent impact of immunosuppression (IS) on long-term outcomes for these patients, underlying the importance of minimization of IS in liver transplant recipients.

Post-Liver Transplant Cytomegalovirus (CMV) Reactivation, Graft, and Patient Survival Rates in Iranian Population

Background: Human cytomegalovirus (CMV) is the major complication of viral infection in immunocompromised patients. This opportunistic infection is associated with high morbidity and mortality in transplanted recipients. Objectives: The present study aimed to determine CMV burden and assess the clinical outcome in the liver recipients with CMV reactivated infection at Nemazi Hospital, Shiraz, Iran. Methods: This retrospective study examined 657 patients who underwent liver transplantation during 2014 - 2017 to identify the CMV infection, morbidity, and mortality rates. To this end, the medical records of such patients were reviewed, and their rejection/survival rates were analyzed. Accordingly, the CMV infection was diagnosed by Taq-Man real-time PCR assays. Results: In this study, 151 (23%) had CMV reactivation at least one year after liver transplantation. Viremic patients had a viral burden between 300 - 738790 copies/mL. In this study, 41 persons (6.2%) died, and 58 liver transplant patients (8.8%) had rejection experience up to one year after their operation. Among the 41 dead patients, 21 and 20 cases were with and without CMV-reactivation, respectively. The results demonstrated that the mortality rate was significantly higher in the CMV-infected patients than the non-CMV-infected counterparts. In contrast, the graft survival rate was not significantly different between the two groups (P ≤ 0.05). Conclusions: In the present study, CMV infection can serve as a significant mortality predictor in LT patients.

Cytomegalovirus Hepatitis in Immunocompetent and Immunocompromised Hosts

Human cytomegalovirus (HCMV) infection is common and affects between 40-100% of the worldwide population. However, the majority of cases are asymptomatic and when severe disease occurs, it is usually restricted to immunocompromised patients. Liver involvement by HCMV differs significantly, accordingly to the immune status of the host. In immunocompromised patients, particularly liver transplant patients, it often causes clinically significant hepatitis. On the other hand, in immunocompetent patients, HCMV hepatitis requiring hospitalization is extremely rare. This review aims to appraise studies regarding the pathophysiology of HCMV hepatitis, including mechanisms of latency and reactivation and its contribution to disease development, clinical presentation, diagnostic modalities and treatment, with a focus on comparing different aspects between immunocompromised and immunocompetent hosts.

Earlier and higher rates of cytomegalovirus infection in pediatric liver transplant recipients as compared to adults: An observational study

AIM:

To study and compare the incidence and time of occurrence of cytomegalovirus (CMV) infection in the posttransplant period in adult and pediatric liver transplant recipients.

MATERIALS AND METHODS:

Consecutive live donor liver transplant recipients not on CMV prophylaxis, were prospectively enrolled from March 2012 to September 2015 and followed up for 1 year post transplant to look for CMV infection. For analysis, patients were divided into pediatric (up to 18 years) and adult (>18 years) age groups.

RESULTS:

The study population of 146 patients consisted of 132 adult and 14 pediatric patients. Overall CMV infection posttransplant was seen in 54/146 (36.98%) patients, and 16/54 (29.6%) patients developed CMV disease. Post-transplant CMV infection rate was significantly higher in pediatric patients(10/14 [71.4%]) as compared to adults (44/132 [33.4%]) (P = 0.004). Among adults, CMV infection was seen in 22 (50%) patients in the 1^st month, 13 (29.5%) patients in the 2^nd month, 5 (11.4%) patients in the 3^rd month, 2 (4.5%) patients in the 4^th month, and 1 (2.3%) patient each in the 5^th and 6^th month. However, in pediatric patients, all the patients having CMV infection had it in the 1^st-month posttransplant (P = 0.003). The median time of occurrence of CMV infection was 11.5 (7.75–19.00) days in pediatric patients versus 30 (18.5–54.5) days in adult patients (P = 0.001).

CONCLUSIONS:

The results of this study show a clear difference in the incidence and timeline of posttransplant CMV infection in pediatric patients as compared to adults.

Prevalence and Impact of Reformed and De Novo Anti-HLA Donor-Specific Antibodies in Liver Transplantation

INTRODUCTION

The prevalence and impact of pre-existing and de novo anti-HLA donor-specific antibodies (DSAs) after orthotopic liver transplantation (OLT) is still controversial. We investigated the prevalence of DSAs and their implication in the development of allograft dysfunction after OLT.

PATIENTS AND METHODS

A total of 65 liver transplant patients were tested for anti-HLA antibodies, with single antigen bead technology, before, 1, 3, 6, and 12 months after transplantation, and thereafter annually, along with other risk factors. Sixteen out of 65 patients (24.6%) had circulating pre-existing anti-HLA antibodies, and 4 of them (25%) had DSAs. All patients positive for anti-HLA antibodies (100%) presented allograft dysfunction. Fourteen out of 65 patients (21.5%) had circulating de novo DSAs, and 12 out of 14 (85.7%) presented allograft dysfunction. The investigated risk factors for allograft dysfunction were: recipient and donor age, time on the waiting list, cold ischemia time, cytomegalovirus infection, immunosuppression regimen, de novo DSAs, Model for End-Stage Liver Disease, aspartate aminotransferase, alanine aminotransferase, gamma-glutamyl transpeptidase (GGT), direct bilirubin and total bilirubin peak post-transplant, and alkaline phosphatase. The multivariate analysis showed that de novo DSAs and time on the waiting list were independent risk factors for allograft dysfunction.

CONCLUSION

Our results show that de novo DSAs are an independent risk factor for allograft dysfunction, along with time on the waiting list.

The gastroenterologist's guide to management of the post-liver transplant patient

The management of the post-liver transplant patient is complex and involves a large interdisciplinary team. After referral to a transplant center, evaluation and listing, and eventual transplantation, the patient is cared for closely by the transplant center. Once deemed ready for discharge, the patient returns to the primary care provider for ongoing management of the various issues that increase in incidence post transplant such as osteoporosis, cardiovascular, and renal diseases, as well as metabolic syndrome. The role of the gastroenterologist is not well defined, but certainly, he or she may be called upon for the initial evaluation and ongoing management of gastrointestinal as well as hepatobiliary issues. This includes but is not limited to the investigation of abnormal liver tests, non-specific gastrointestinal complaints such as nausea, vomiting, or diarrhea, biliary complications, and even recurrent hepatic disease. Having familiarity with post-transplant immunosuppressive agents, drug interactions, and potential infectious and malignancy-related complications of transplant is essential, as the primary gastroenterologist may be expected in some situations to field the initial work-up, if patient access to the transplant center is limited. The aim of this review is to summarize the gastroenterologist's role in the management of the post-liver transplant patient.

CMV-specific T-cell immunity in solid organ transplant recipients at low risk of CMV infection. Chronology and applicability in preemptive therapy

OBJECTIVES

To characterize whether the CMV-specific cellular immune response can be used as a predictor of the control of CMV infection and disease and determine thresholds in solid organ transplant (SOT) recipients seropositive for CMV (R+).

METHODS

The CMV-specific T-cell response was characterized using intracellular cytokine staining and the evolution of clinical and virological parameters were recorded during the first year after transplantation.

RESULTS

Besides having positive CMV serology, only 28.4% patients had positive immunity (CD8⁺CD69⁺IFN-γ⁺ ≥0.25%) at 2 weeks after transplantation. These patients had less indication of preemptive treatment (p = 0.025) and developed less high grade (≥2000 IU/ml) CMV replication episodes (p = 0.006) than patients with no immunity. Of the 49 patients with a pretransplant sample, only 22.4% had positive immunity, and had a detectable immune response early after transplantation (median of 3.7 weeks). However, only 50% of patients with negative pretransplant immunity acquired a positive immune response and it was significantly later, at a median of 11 weeks (p < 0.001). Patients that developed CMV disease had no CMV-specific immunity.

CONCLUSIONS

Having CMV-specific CD8⁺IFN-γ⁺ cells ≥0.25% before transplant; 0.15% at two weeks or 0.25% at four weeks after transplantation, identifies patients that may spontaneously control CMV infection and may require less monitoring.

A cost-utility analysis of prolonged-release tacrolimus relative to immediate-release tacrolimus and ciclosporin in liver transplant recipients in the UK

BACKGROUND

Calcineurin inhibitors (CNIs) represent the cornerstone of immunosuppressive therapy after liver transplantation. A recent network meta-analysis (NMA) evaluated the relative efficacy of CNIs ciclosporin, prolonged-release (PR) tacrolimus, and immediate-release (IR) tacrolimus in adult liver transplant recipients based on randomized and large observational trials published since 2000. Based on the NMA findings, the present study evaluated the cost-utility of PR tacrolimus relative to ciclosporin or IR tacrolimus in liver transplant recipients in the UK.

METHODS

A Markov model was developed to evaluate the cost-utility of immunosuppressive regimens in liver transplant recipients, capturing costs associated with immunosuppression, retransplantation, acute rejection (AR), and cytomegalovirus infection. Mortality, graft loss, and AR odds ratios were derived from the NMA. Costs were taken from the British National Formulary and the NHS National Tariff and expressed in 2016 pounds sterling. Future costs and effects were discounted at 3.5% annually.

RESULTS

Over 25 years, PR tacrolimus resulted in increased life expectancy and quality-adjusted life expectancy (QALE) relative to IR tacrolimus and ciclosporin. Relative to ciclosporin, QALE increased by 1.17 quality-adjusted life years (QALYs) with PR tacrolimus while costs increased by GBP £4645, yielding an incremental cost-effectiveness ratio (ICER) of £3962 per QALY gained. Relative to IR tacrolimus, QALE increased by 0.78 QALYs and costs by £1474, resulting in an ICER of £1889 per QALY gained. Sensitivity analysis showed the analysis to be most sensitive to dosing assumptions.

CONCLUSIONS

Based on a UK-specific analysis of the projected cost-utility of PR tacrolimus relative to IR tacrolimus and ciclosporin, PR tacrolimus was cost-effective, improving life expectancy and QALE relative to both IR tacrolimus and ciclosporin, yielding ICERs below £20 000 per QALY gained. The main limitations of the study were data source heterogeneity and omitting the economic and clinical effects of treating aspects of recurrent liver disease.

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

This study compared the pre-emptive and the prophylactic strategies used to prevent cytomegalovirus (CMV) infection and disease in CMV-seropositive orthotopic liver-transplant recipients and searched for associated predictive factors. Seventy-three orthotopic liver-transplant recipients who had received a transplant before November 2005 were given ganciclovir IV pre-emptively (group I) and 56 recipients who had received a transplant after November 2005 were given prophylactic valganciclovir for 3 months (group II). Demographic and biochemical parameters did not statistically vary between the groups at baseline. Monitoring of CMV DNAemia was similar in both groups. Forty-two (57.5%) patients presented with CMV infection in group I and 18 (32.1%) in group II (P < 0.004). CMV DNAemia was first detected at a median of 33 days post-transplant in group I and at 98.5 days in group II (P < 0.003), but viral loads were not significantly different. The overall incidence of CMV disease was 9.6% in group I versus 7.1% in group II (ns). Thirty-five (47.9%) patients presented with biopsy-proven acute rejection in group I and 13 (23.2%) in group II (P = 0.004). Forty (55%) patients in group I and 25 (44.6%) in group II presented with de novo post-transplant diabetes (P = 0.057). At 1-year post-transplant, global survival curves were not significantly different. Independent factors associated with CMV reactivation were an absence of CMV prophylaxis, CMV serological status of the donor, cold ischemia time, and HLA A + B + DR compatibility. CMV prophylaxis is efficacious and can prevent safely the direct and indirect effects of CMV infection in CMV-seropositive orthotopic liver-transplant recipients.

Determination, validation and standardization of a CMV DNA cut-off value in plasma for preemptive treatment of CMV infection in solid organ transplant recipients at lower risk for CMV infection

BACKGROUND

Valganciclovir preemptive therapy guided by the viral load is the current strategy recommended for preventing CMV disease in CMV-seropositive Solid Organ Transplant Recipients (SOTR) at lower risk for developing CMV infection. However, universal viral load cut-off has not been established for initiating therapy.

OBJECTIVES

Our goal was to define and validate a standardized cut-off determined in plasma by real-time PCR assay for initiating preemptive therapy in this population.

STUDY DESIGN

A prospective cohort study of consecutive cases of CMV-seropositive SOTR was carried out. The cut-off value was determined in a derivation cohort and was validated in the validation cohort. Viral loads were determined using the Quant CMV LightCycler 2.0 real-time PCR System (Roche Applied Science) and results were standardized using the WHO International Standard for human CMV.

RESULTS

A viral load of 3983 IU/ml (2600 copies/ml) was established as the optimal cut-off for initiating preemptive therapy in a cohort of 141 patients with 982 tests and validated in a cohort of 252 recipients with a total of 2022 test. This cut-off had a 99.6% NPV indicating that the great majority of patients at lower risk will not develop CMV disease without specific antiviral therapy. The high sensitivity and specificity (89.9% and 88.9%, respectively) and the relatively small numbers of patients with CMV disease confirm that real-time PCR was optimal.

CONCLUSIONS

We have established a cut-off viral load for starting preemptive therapy for CMV-seropositive SOT recipients. Our results emphasized the importance of a mandatory follow-up protocol for CMV-seropositive patients receiving preemptive treatment.