The optimal immunosuppression management to prevent early rejection after liver transplantation: A systematic review of the literature and expert panel recommendations.

BACKGROUND: The optimal immunosuppression protocol to prevent early acute cellular rejection (ACR) after liver transplantation (LT) avoiding prolonged hospitalization and early hospital readmission is undefined. OBJECTIVES: To identify the most suitable immunosuppression regimen for inclusion in ERAS programs in order to minimize early ACR after LT and to provide 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. Studies from January 2000 onward focusing on early ACR were included. Rates of early renal dysfunction and infection were evaluated. CRD42021245586 RESULTS: Thirty-seven studies met inclusion criteria; 23 randomized controlled trials, 14 retrospective or prospective observational comparative or noncomparative studies. Several sources of biases which potentially confound conclusions were identified: heterogeneity in immunosuppression protocols, higher serum tacrolimus levels than currently used in clinical practice, differences in the definition of ACR. CONCLUSIONS: Tacrolimus is the standard immunosuppression after LT and can be used in combination with other drugs such as corticosteroids and MMF, and in association with anti-IL2 receptor antibody (IL2Ra) induction. (Quality of Evidence; Low | Grade of Recommendation; Strong). Low dose or delayed introduction of tacrolimus in association with corticosteroids and MMF and/or anti-IL2Ra induction can be used to reduce acute kidney injury. (Quality of Evidence; Low | Grade of Recommendation; Strong). Use of tacrolimus in association with corticosteroids and MMF and/or anti-IL2Ra induction does not lead to increased infection rates. (Quality of Evidence; Low | Grade of Recommendation; Weak).

Liver transplantation for HCC: validation of prognostic power of the RETREAT score for recurrence in a UK cohort.

BACKGROUND: The Risk Estimation of Tumor Recurrence After Transplant (RETREAT) score as a prognostic index for recurrence has been reported previously and has not been validated outside the USA. Our study has validated the score in a single center UK cohort of patients being transplanted for HCC. METHODS: LT for HCC between 2008 and 2018 at our center were analyzed. Recurrence-free survival (RFS) was compared by the RETREAT score and validated using Net Reclassification Improvement (NRI) by comparing it to Milan criteria. RESULTS: 346 adult HCC patients were transplanted of whom 313 were included. 28 (8.9%) had a recurrence. Summation of largest diameter and total number of viable tumors (HR = 1.19, p < 0.001), micro-/macro-vascular invasion (HR = 3.74, p = 0.002) and AFP>20 ng/ml (HR = 3.03, p = 0.005) were associated with recurrence on multivariate analysis. RFS decreased with increasing RETREAT score (log-rank p = 0.016). RETREAT performed better than Milan with significant NRI at 1- and 2-years post-transplant (0.43 (p = 0.004) and 0.38 (p = 0.03) respectively). CONCLUSION: LT outcomes using the revised UK criteria are equivalent to Milan criteria. Further, RETREAT score was validated as a prognostic index for the first time in a UK cohort and may assist risk stratification, selection for adjuvant therapies and guide surveillance.

A novel microRNA-based prognostic model outperforms standard prognostic models in patients with acetaminophen-induced acute liver failure.

BACKGROUND & AIMS: Acetaminophen (APAP)-induced acute liver failure (ALF) remains the most common cause of ALF in the Western world. Conventional prognostic models, utilising markers of liver injury and organ failure, lack sensitivity for mortality prediction. We previously identified a microRNA signature that is associated with successful regeneration post-auxiliary liver transplant and with recovery from APAP-ALF. Herein, we aimed to use this microRNA signature to develop outcome prediction models for APAP-ALF. METHODS: We undertook a nested, case-control study using serum samples from 194 patients with APAP-ALF enrolled in the US ALF Study Group registry (1998-2014) at early (day 1-2) and late (day 3-5) time-points. A microRNA qPCR panel of 22 microRNAs was utilised to assess microRNA expression at both time-points. Multiple logistic regression was used to develop models which were compared to conventional prognostic models using the DeLong method. RESULTS: Individual microRNAs confer limited prognostic value when utilised in isolation. However, incorporating them within microRNA-based outcome prediction models increases their clinical utility. Our early time-point model (AUC = 0.78, 95% CI 0.71-0.84) contained a microRNA signature associated with liver regeneration and our late time-point model (AUC = 0.83, 95% CI 0.76-0.89) contained a microRNA signature associated with cell-death. Both models were enhanced when combined with model for end-stage liver disease (MELD) score and vasopressor use and both outperformed the King's College criteria. The early time-point model combined with clinical parameters outperformed the ALF Study Group prognostic index and the MELD score. CONCLUSIONS: Our findings demonstrate that a regeneration-linked microRNA signature combined with readily available clinical parameters can outperform existing prognostic models for ALF in identifying patients with poor prognosis who may benefit from transplantation. LAY SUMMARY: While acute liver failure can be reversible, some patients will die without a liver transplant. We show that blood test markers that measure the potential for liver recovery may help improve identification of patients unlikely to survive acute liver failure who may benefit from a liver transplant.

Assessing the Time-Dependent Impact of Performance Status on Outcomes After Liver Transplantation.

BACKGROUND AND AIMS: Identifying how the prognostic impact of performance status (PS) differs according to indication, era, and time period ("epoch") after liver transplantation (LT) could have implications for selection and treatment of patients on the waitlist. We used national data from the United Kingdom and Ireland to assess impact of PS on mortality separately for HCC and non-HCC recipients. APPROACH AND RESULTS: We assessed pre-LT PS using the 5-point modified Eastern Cooperative Oncology Group scale and used Cox regression methods to estimate hazard ratios (HRs) that compared posttransplantation mortality in different epochs of follow-up (0-90 days and 90 days to 1 year) and in different eras of transplantation (1995-2005 and 2006-2016). 2107 HCC and 10,693 non-HCC patients were included. One-year survival decreased with worsening PS in non-HCC recipients where 1-year survival was 91.9% (95% confidence interval [CI], 88.3-94.4) in those able to carry out normal activity (PS1) compared to 78.7% (95% CI, 76.7-80.5) in those completely reliant on care (PS5). For HCC patients, these estimates were 89.9% (95% CI, 85.4-93.2) and 83.1% (95% CI, 61.0-93.3), respectively. Reduction in survival in non-HCC patients with poorer PS was in the first 90 days after transplant, with no major effect observed between 90 days and 1 year. Adjustment for donor and recipient characteristics did not change the findings. Comparing era, post-LT mortality improved for HCC (adjusted HR, 0.55; 95% CI, 0.40-0.74) and non-HCC recipients (0.48; 95% CI, 0.42-0.55), but this did not differ according to PS score (P = 0.39 and 0.61, respectively). CONCLUSIONS: Impact on mortality of the recipient's pretransplant PS is principally limited to the first 3 months after LT. Over time, mortality has improved for both HCC and non-HCC recipients and across the full range of PS.

Validation of a Capillary Dry Blood Sample MITRA-Based Assay for the Quantitative Determination of Systemic Tacrolimus Concentrations in Transplant Recipients.

BACKGROUND: Tacrolimus is a narrow therapeutic index medication, which requires therapeutic drug monitoring to optimize dosing based on systemic exposure. MITRA microsampling offers a convenient, minimally invasive approach for the collection of capillary blood samples from a finger prick versus conventional venous blood sampling for quantitation of tacrolimus blood concentrations. However, the suitability of MITRA microsampling for the determination of tacrolimus concentrations requires assessment in clinical settings. METHODS: Paired venous (2 mL) and capillary (10 µL) blood samples were collected pre-tacrolimus dose and 1 and 3 hours postdose during routine outpatient visits from stable adult liver or kidney transplant patients receiving prolonged-release tacrolimus. Tacrolimus concentrations were determined by liquid chromatography-tandem mass spectrometry, and the concentrations obtained by the 2 sampling methods were compared by linear regression and Bland-Altman agreement analyses. RESULTS: Samples were available for 82 transplant recipients (kidney, n = 41; liver, n = 41). A high correlation was observed between tacrolimus concentrations in capillary and venous blood samples (Pearson correlation coefficient, 0.97; Lin concordance coefficient, 0.87; slope of the fitted line, >1.0). Tacrolimus concentrations in capillary samples were 22.5% higher on average than in the corresponding venous blood samples (95% limits of agreement, 0.5%-44.6%). Similar results were observed in both transplant subgroups. CONCLUSIONS: MITRA finger prick sampling provides a convenient alternative to venipuncture for therapeutic drug monitoring in transplant recipients maintained on prolonged-release tacrolimus. When using the finger prick MITRA method, the positive bias in tacrolimus concentrations observed with this technique, when compared with venipuncture, needs to be taken into consideration.

Serum MicroRNA Signatures in Recovery From Acute and Chronic Liver Injury and Selection for Liver Transplantation.

We previously demonstrated a distinct hepatic microRNA (miRNA) signature (down-regulation of miRNA-23a, -150, - 200b, -503, and -663 and up-regulation of miRNA-20a) is associated with successful regeneration in auxiliary liver transplantation (ALT). This study aimed to evaluate whether the serum expression of this regeneration-linked miRNA signature is associated with clinical outcomes in acute and chronic liver disease. These were represented by patients with acetaminophen-induced acute liver failure (ALF; n = 18) and patients with hepatitis C virus (HCV) undergoing treatment with direct-acting antivirals (n = 56), respectively. Patients were grouped depending on their clinical outcome. Global serum miRNA expression was analyzed using polymerase chain reaction (PCR) arrays and selected miRNA expression using targeted PCR. We demonstrate that specific regeneration-linked miRNAs discriminate outcomes in both clinical scenarios. We further show that miRNA-20a, -23a, -150, -200b, -503, and -663 undergo concordant changes in expression in 3 distinct clinical settings: liver regeneration accompanying successful ALT, clinical recovery after ALF, and clinical recompensation after cure of HCV. This miRNA signature represents a potentially novel biomarker to predict outcome and optimize patient selection for liver transplantation in both acute and chronic liver disease.

Performance of modified-release tacrolimus after conversion in liver transplant patients indicates potentially favorable outcomes in selected cohorts.

Clinical outcomes, dose changes, and dose-equalized tacrolimus concentrations were examined sequentially in 129 liver transplantation (LT) recipients after successful conversion to once daily modified-release tacrolimus either early (within 1 month) or late (>1 month) after LT. The data were compared with data for a group of 60 patients maintained on twice daily conventional-release tacrolimus. Formulation- and time-dependent changes in dose requirements for once and twice daily tacrolimus differed after transplantation. A 1.7-fold initial increase in the median daily dose was required to achieve target tacrolimus concentrations in the early-conversion cohort (P = 0.006), whereas a 1.25-fold increase was required for those converted later (P = 0.013 and P < 0.001 for the difference). In the subsequent 2 months, the median daily dose fell by 20% in the early-conversion cohort, remained stable for the late-conversion cohort, but rose by 33% with conventional therapy. Lower median dose-equalized concentrations persisted for up to 3 months after the conversion to modified-release therapy. Sex, ethnicity, and the underlying liver disease did not significantly affect these variables. The frequency of treated biopsy-proven acute rejection episodes fell approximately 4-fold after the conversion to modified-release tacrolimus, most notably in the late-conversion cohort, which experienced a high incidence of rejection before conversion. Posttransplant increases in serum creatinine concentrations were smaller after the introduction of modified-release tacrolimus in the late-conversion group (0.7 versus 4 mg/mL for twice daily tacrolimus over 6 months). Reduced interpatient variability in tacrolimus concentrations was evident in the early-conversion cohort versus the twice daily cohort. A decline in intrapatient variability accompanied the reduction in acute rejection in the late-conversion cohort. Our data highlight potential benefits for the rejection rate and renal function on conversion to once daily modified-release tacrolimus late after LT.

Outcomes of pregnancy following liver transplantation: The King's College Hospital experience.

Reports of pregnancy in liver transplantation (LT) patients have largely favorable outcomes. Concerns remain with regards to maternal and graft risk, optimal immunosuppression (IS), and fetal outcomes. We review all post-LT pregnancies at our center with regard to the outcomes and safety for the patient, graft, and fetus. A total of 117 conceptions occurred in 79 patients. Median age at conception was 29 years. Maternal complications included graft loss (2%), acute cellular rejection (ACR; 15%), pre-eclampsia/eclampsia (15%), gestational diabetes (7%), and bacterial sepsis (5%). ACR was significantly more common in those women who conceived within 12 months of LT (P = 0.001). The live birth rate was 73%. Prematurity occurred in 26 (31%) neonates, and 24 (29%) neonates were of low or very low birth weight. IS choice (cyclosporine versus tacrolimus) had no significant effect on pregnancy outcomes and complications. No congenital abnormalities occurred, and only 1 child born at 24 weeks had delayed developmental milestones. In conclusion, pregnancy following LT has a favorable outcome in the majority, but severe maternal risks remain. Patients should be counseled with regard to the above information so informed decisions can be made, and pregnancy must be considered high risk with regular monitoring by transplant clinicians and specialist obstetricians.

CXCL10 levels identify individuals with rapid fibrosis at 12 months post-transplant for hepatitis C virus and predict treatment response.

BACKGROUNDS: Recurrent hepatitis C virus (HCV) infection is universal post-transplantation. Fibrosis (F) stage ≥2 at 12 months identifies patients with rapid fibrosis progression. Antiviral therapy (AVT) remains the only option to attenuate fibrosis progression. We hypothesized that CXCL10 levels can distinguish between slow and fast fibrosis progression at 12 months, development of F ≥ 4 post-transplantation, and help predict treatment response in patients undergoing AVT. METHODS: All patients that had undergone primary liver transplantation at King's College Hospital, London, between 2000 and 2011 were identified. Quantification of CXCL10 was performed using an ELISA-based assay on stored plasma at six months post-transplant and pre-treatment. Comparison was made with liver biopsies performed at 12 months and in the post-transplant period where available. RESULTS: One hundred and thirty-three patients were included. CXCL10 levels were lower in the slow fibrosis group compared to the rapid fibrosis group (p < 0.0001). CXCL10 correlated with F stage, necro-inflammatory score, and serum transaminases (<0.0001). CXCL10 was an independent predictor of F ≥ 2 at 12 months and F ≥ 4 (p < 0.05). Pre-treatment CXCL10 levels were an independent predictor of sustained virologic response (p = 0.04). CONCLUSIONS: CXCL10 levels help identify patients with rapid fibrosis progression in patients with recurrent HCV and those that are likely to respond to AVT.

The challenges and potential in developing microRNA associated with regeneration as biomarkers to improve prognostication for liver failure syndromes and hepatocellular carcinoma.

INTRODUCTION: Determining the need for liver transplantation remains critical in the management of hepatocellular carcinoma (HCC) and liver failure syndromes (including acute liver failure and decompensated cirrhosis states). Conventional prognostic models utilize biomarkers of liver and non-liver failure and have limitations in their application. Novel biomarkers which predict regeneration may fulfil this niche. microRNA are implicated in health and disease and are present in abundance in the circulation. Despite this, they have not translated into mainstream clinical biomarkers. AREAS COVERED: We will discuss current challenges in the prognostication of patients with liver failure syndromes as well as for patients with HCC. We will discuss biomarkers implicated with liver regeneration. We then provide an overview of the challenges in developing microRNA into clinically tractable biomarkers. Finally, we will provide a scoping review of microRNA which may have potential as prognostic biomarkers in liver failure syndromes and HCC. EXPERT OPINION: Novel biomarkers are needed to improve prognostic models in liver failure syndromes and HCC. Biomarkers associated with liver regeneration are currently lacking and may fulfil this niche. microRNA have the potential to be developed into clinically tractable biomarkers but a consensus on standardizing methodology and reporting is required prior to large-scale studies.

The challenges and potential of microRNA-based therapy for patients with liver failure syndromes and hepatocellular carcinoma.

INTRODUCTION: Morbidity and mortality from liver disease continues to rise worldwide. There are currently limited curative treatments for patients with liver failure syndromes, encompassing acute liver failure and decompensated cirrhosis states, outside of transplantation. Whilst there have been improvements in therapeutic options for patients with hepatocellular carcinoma (HCC), there remain challenges necessitating novel therapeutic agents. microRNA have long been seen as potential therapeutic targets but there has been limited clinical translation. AREAS COVERED: We will discuss the limitations of conventional non-transplant management of patients with liver failure syndromes and HCC. We will provide an overview of microRNA and the challenges in developing and delivering microRNA-based therapeutic agents. We will finally provide an overview of microRNA-based therapeutic agents which have progressed to clinical trials. EXPERT OPINION: microRNA have great potential to be developed into therapeutic agents due to their association with critical biological processes which govern health and disease. Utilizing microRNA sponges to target multiple microRNA associated with specific biological processes may improve their therapeutic efficacy. However, there needs to be significant improvements in delivery systems to ensure the safe delivery of microRNA to target sites and minimize systemic distribution. This currently significantly impacts the clinical translation of microRNA-based therapeutic agents.

Distinct microRNA profiles are associated with the severity of hepatitis C virus recurrence and acute cellular rejection after liver transplantation.

Recurrent hepatitis C virus (HCV) infection is associated with accelerated fibrosis rates after liver transplantation (LT) and is the leading cause of graft failure. Furthermore, distinguishing recurrent HCV from acute cellular rejection (ACR) can be problematic, and this can lead to inappropriate treatments and adverse outcomes. We hypothesized that intragraft microRNA (miRNA) expression profiles could distinguish the severity of recurrent HCV and differentiate recurrent HCV from ACR. We established meticulously matched post-LT patient cohorts in order to derive robust global miRNA expression profiles and minimize the impact of variables known to influence HCV recurrence. These cohorts consisted of patients with slow HCV fibrosis progression (Ishak stage < F2), fast HCV fibrosis progression (Ishak stage ≥ F2), ACR, and nonviral etiologies. We found increased intragraft expression of miRNA-146a, miRNA-19a, miRNA-20a, and miRNA-let7e in slow progressors versus fast progressors, and we validated these findings with quantitative PCR. This miRNA network regulates the expression of cardinal genes implicated in promoting antifibrogenic, antiangiogenic, and anti-inflammatory pathways. miRNA-19a and miRNA-20a were also specifically detected in the serum of slow progressors. Furthermore, intragraft miRNA expression distinguished fast HCV progression from ACR. Here, changes in the expression of key miRNAs regulating fibrogenic and angiogenic pathways were associated with fast HCV progression. We demonstrate specific miRNA expression signatures that discriminate the rates of fibrosis progression in patients with recurrent HCV, and we distinguish recurrent HCV from ACR after LT. A pathway analysis indicates that specific miRNAs may play a regulatory role in these processes. Selected miRNAs may serve as intragraft and serum biomarkers for recurrent HCV after LT and help to distinguish between ACR and recurrent HCV.

The impact of inflammatory bowel disease post-liver transplantation for primary sclerosing cholangitis.

BACKGROUND: An association between primary sclerosing cholangitis (PSC) and inflammatory bowel disease (IBD) is well recognized. However, the disease course of IBD following liver transplantation (LT) for PSC remains ill-defined. AIMS AND METHODS: We aimed to assess the impact of IBD in patients that had undergone LT for PSC to help identify risk factors for flare and to assess the impact of IBD on graft survival. RESULTS: 110 patients underwent LT for PSC (Oct 1990-Aug 2009) at King's College Hospital. 74 (67%) patients had concurrent IBD and 36 had PSC alone prior to transplant. 39 patients developed IBD (flare of IBD and de-novo) post transplant. Cumulative risk for IBD at 1-, 2-, 5- and 10-years was 16%, 24%, 38% and 72% respectively. Flare of IBD occurred in 33 patients with a mean time to flare of 30 ± 28 months. De-novo IBD occurred in 6 patients (all UC). Mean time to diagnosis was 29 ± 25 months. Multivariate cox-regression analysis identified active IBD at time of LT as a significant predictor of graft failure post LT (HR 10, CI 3-39, P = 0.001) and smoking at time of transplantation and subsequent cessation predictive of recurrent IBD post transplantation (HR 17, 2-180, P = 0.02). CONCLUSION: In conclusion, smoking at time of LT was predictive of flare of IBD and active IBD at time of transplantation had a significant effect on graft survival. Medical therapy needs to be maximised in the pre-LT period. Patients with poorly controlled IBD refractory to medical therapy should be considered for colectomy at time of transplantation.

Satellite liver transplant centres significantly improve transplant assessment outcomes for patients with chronic liver disease but not hepatocellular carcinoma: a retrospective cohort study.

Introduction: Liver transplantation (LT) remains integral to the management of end-stage chronic liver disease (CLD). However, referral thresholds and assessment pathways remain poorly defined. Distance from LT centre has been demonstrated to impact negatively on patient outcomes resulting in the development of satellite LT centres (SLTCs). We aimed to evaluate the impact of SLTCs on LT assessment in patients with CLD and hepatocellular carcinoma (HCC). Methods: A retrospective cohort study was undertaken including all patients with CLD or HCC assessed for LT at King's College Hospital (KCH) between October 2014 and October 2019. Referral location, social, demographic, clinical and laboratory data were collected. Univariable and multivariable analyses (MVA) were performed to assess the impact of SLTCs on patients being accepted as LT candidates and contraindications being identified. Results: 1102 and 240 LT assessments were included for patients with CLD and HCC, respectively. MVA demonstrated significant associations with; patients living greater than 60 min from KCH/SLTCs and LT candidacy acceptance in CLD, and less deprived patients and LT candidacy acceptance in HCC. However, neither variable was associated with identification of LT contraindications. MVA demonstrated that referrals from SLTCs were more likely to result in acceptance of LT candidacy and less likely to result in a contraindication being identified in CLD. However, such associations were not demonstrated in HCC. Conclusion: SLTCs improve LT assessment outcomes in CLD but not HCC reflecting the standardised HCC referral pathway. Developing a formal regional LT assessment pathway across the UK would improve equity of access to transplantation.

The positive impact of the COVID 19 pandemic on organ utilisation in liver transplantation.

Background: As the world recovers from the aftermath of devastating waves of an outbreak, the ongoing Coronavirus disease 2019 pandemic has presented a unique perspective to the transplantation community of ''organ utilisation'' in liver transplantation, a poorly defined term and ongoing hurdle in this field. To this end, we report the key metrics of transplantation activity from a high-volume liver transplantation centre in the United Kingdom over the past two years. Methods: Between March 2019 and February 2021, details of donor liver offers received by our centre from National Health Service Blood & Transplant, and of transplantation were reviewed. Differences in the activity before and after the outbreak of the pandemic, including short term post-transplant survival, have been reported. Results: The pandemic year at our centre witnessed a higher utilisation of Donation after Cardiac Death livers (80.4% vs. 58.3%, p = 0.016) with preserved United Kingdom donor liver indices and median donor age (2.12 vs. 2.02, p = 0.638; 55 vs. 57 years, p = 0.541) when compared to the pre-pandemic year. The 1- year patient survival rates for recipients in both the periods were comparable. The pandemic year, that was associated with increased utilisation of Donation after Cardiac Death livers, had an ischaemic cholangiopathy rate of 6%. Conclusions: The pressures imposed by the pandemic led to increased utilisation of specific donor livers to meet patient needs and minimise the risk of death on the waiting list, with apparently preserved early post-transplant survival. Optimum organ utilisation is a balancing act between risk and benefit for the potential recipient, and technologies like machine perfusion may allow surgeons to increase utilisation without compromising patient outcomes.

Regeneration linked miRNA modify tumor phenotype and can enforce multi-lineage growth arrest in vivo.

Regulated cell proliferation is an effector mechanism of regeneration, whilst dysregulated cell proliferation is a feature of cancer. We have previously identified microRNA (miRNA) that regulate successful and failed human liver regeneration. We hypothesized that these regulators may directly modify tumor behavior. Here we show that inhibition of miRNAs -503 and -23a, alone or in combination, enhances tumor proliferation in hepatocyte and non-hepatocyte derived cancers in vitro, driving more aggressive tumor behavior in vivo. Inhibition of miRNA-152 caused induction of DNMT1, site-specific methylation with associated changes in gene expression and in vitro and in vivo growth inhibition. Enforced changes in expression of two miRNA recapitulating changes observed in failed regeneration led to complete growth inhibition of multi-lineage cancers in vivo. Our results indicate that regulation of regeneration and tumor aggressiveness are concordant and that miRNA-based inhibitors of regeneration may constitute a novel treatment strategy for human cancers.