Acute cellular rejection after liver transplantation: variability, morbidity, and mortality

Expanding the liver donor pool worldwide with hepatitis C infected livers, is it the time?

Liver transplantation (LT) provides a life-saving option for cirrhotic patients with complications and hepatocellular carcinoma. Despite the increasing number of liver transplants performed each year, the number of LT candidates on the waitlist remains unchanged due to an imbalance between donor organ supply and the demand which increases the waitlist time and mortality. Living donor liver transplant had a great role in increasing the donor pool and shortened waitlist time for LT candidates. Nevertheless, further strategies can be implemented to increase the pool of potential donors in deceased donor LT, such as reducing the rate of organ discards. Utilizing hepatitis C virus (HCV) seropositive liver grafts is one of the expanded donor organ criteria. A yearly increase of hundreds of transplants is anticipated as a result of maximizing the utilization of HCV-positive organs for HCV-negative recipients. Direct-acting antiviral therapy's efficacy has revolutionized the treatment of HCV infection and the use of HCV-seropositive donors in transplantation. The American Society of Transplantation advises against performing transplants from HCV-infected liver donors (D+) into HCV-negative recipient (R-) unless under Institutional Review Board-approved study rules and with full informed consent of the knowledge gaps associated with such transplants. Proper selection of patients to be transplanted with HCV-infected grafts and confirming their access to direct-acting antivirals if needed is important. National and international consensuses are needed to regulate this process to ensure the maximum benefit and the least adverse events.

Precision diagnostics in transplanted organs using microarray-assessed gene expression: concepts and technical methods of the Molecular Microscope® Diagnostic System (MMDx)

There is a major unmet need for improved accuracy and precision in the assessment of transplant rejection and tissue injury. Diagnoses relying on histologic and visual assessments demonstrate significant variation between expert observers (as represented by low kappa values) and have limited ability to assess many biological processes that produce little histologic changes, for example, acute injury. Consensus rules and guidelines for histologic diagnosis are useful but may have errors. Risks of over- or under-treatment can be serious: many therapies for transplant rejection or primary diseases are expensive and carry risk for significant adverse effects. Improved diagnostic methods could alleviate healthcare costs by reducing treatment errors, increase treatment efficacy, and serve as useful endpoints for clinical trials of new agents that can improve outcomes. Molecular diagnostic assessments using microarrays combined with machine learning algorithms for interpretation have shown promise for increasing diagnostic precision via probabilistic assessments, recalibrating standard of care diagnostic methods, clarifying ambiguous cases, and identifying potentially missed cases of rejection. This review describes the development and application of the Molecular Microscope® Diagnostic System (MMDx), and discusses the history and reasoning behind many common methods, statistical practices, and computational decisions employed to ensure that MMDx scores are as accurate and precise as possible. MMDx provides insights on disease processes and highly reproducible results from a comparatively small amount of tissue and constitutes a general approach that is useful in many areas of medicine, including kidney, heart, lung, and liver transplants, with the possibility of extrapolating lessons for understanding native organ disease states.

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.

Evaluation of Vitamin D Levels in Children With Liver Transplant

OBJECTIVES

Vitamin D deficiency is common in pediatric chronic liver disease despite oral replacement. We evaluated vitamin D deficiency before and after liver transplant and the relationship between posttransplant and pretransplant vitamin D deficiency and graft rejection.

MATERIALS AND METHODS

Pediatric recipients with chronic liver disease (N =138) were divided into 4 groups: cholestatic liver diseases, cirrhosis, metabolic disorders, and acute liver failure. Pretransplant and posttransplant vitamin D levels, liver function tests, Pediatric End-Stage Liver Disease scores, rejection activity index scores by graft liver biopsy, and posttransplant patient survival were recorded.

RESULTS

There were 62 (45%) female and 76 (55%) male participants (mean transplant age, 6.1 ± 5.6 years). Pretransplant mean available vitamin D of 90 patients was 25.2 ± 20.9 ng/mL, with 36 (40%) within reference range. Posttransplant level for 109 patients was 27.3 ± 18 ng/mL, with 64 (58.7%) within reference range. Pretransplant and posttransplant levels were available for 61 patients, and mean pretransplant levels were lower than posttransplant levels (23.7 ± 19.3 vs 28.3 ± 16.9 ng/mL; P = .01). Patients with cholestatic liver disease had lower pretransplant vitamin D levels (P = .04), which disappeared after transplant. Pretransplant vitamin D levels were positively correlated with serum albumin levels (r = 0.20) in all patients and negatively correlated with total/direct bilirubin (r = 0.29 and r = -0.30) in those with liver diseases and cirrhosis. No correlations were found between pretransplant vitamin D levels and Pediatric End-Stage Liver Disease scores, rejection activity index scores, and posttransplant mortality.

CONCLUSIONS

Vitamin D deficiency is prevalent in pediatric chronic liver disease before and after transplant, especially for cholestatic liver diseases. However, no association between vitamin D levels and liver graft rejection or patient survival was noted. We recommend close monitoring and individualized vitamin D supplementation before and after liver transplant.

Detrimental impact of early biopsy-proven rejection in liver transplantation

Existing literature offers conflicting conclusions about whether early acute cellular rejection influences long-term outcomes in liver transplantation. We retrospectively collected donor and recipient data on all adult, first-time liver transplants performed at a single center between 2008 and 2020. We divided this population into two cohorts based on the presence of early biopsy-proven acute cellular rejection (EBPR) within the first 90 days post-transplant and compared outcomes between the groups. There were 896 liver transplants that met inclusion criteria with 112 cases (12.5%) of EBPR. Recipients who developed EBPR had higher biochemical Model for End-Stage Liver Disease scores (28 vs. 24, p < .01), but other donor and recipient characteristics were similar. Recipients with EBPR had similar overall survival compared to patients without EBPR (p = .09) but had decreased graft survival (p < .05). EBPR was also associated with decreased time to first episode of late (> 90 days post-transplant) rejection (p < .0001) and increased vulnerability to bacterial and viral infection (p < .05). In subgroup analysis of recipients with autoimmune indications for liver transplantation, EBPR had a more pronounced association with patient death (hazard ratio [HR] 3.9, p < .05) and graft loss (HR 4.0, p < .01). EBPR after liver transplant is associated with inferior graft survival, increased susceptibility to late rejections, and increased vulnerability to infection.

Value of Doppler ultrasonography in predicting clinical outcomes for patients with acute cellular rejection after liver transplantation

PURPOSE

This study investigated the value of Doppler ultrasonography in predicting clinical outcomes after antirejection treatment for patients with acute cellular rejection (ACR) following liver transplantation (LT).

METHODS

This retrospective study included 84 patients who were pathologically diagnosed with ACR and received antirejection treatment within 90 days following LT. Two radiologists searched for abnormal Doppler parameters at ACR diagnosis and within 7 days after antirejection treatment initiation, including portal blood velocity (PBV) <20 cm/s, hepatic artery resistive index <0.5, and a monophasic hepatic vein flow pattern. Interval PBV changes were also evaluated. The frequencies of abnormal Doppler parameters and PBV changes were compared by treatment outcome.

RESULTS

The frequency of abnormal PBV in the early post-treatment phase (PBVearly post-treatment) was significantly higher among poor responders (50.0% [10/20]) than among good responders (7.8% [5/64]) (P<0.001). The sensitivity, specificity, and accuracy of abnormal PBVearly post-treatment as a predictor of poor response to antirejection treatment were 50.0% (10/20), 92.2% (59/64), and 82.1% (69/84), respectively. A decrease (>10%) from the PBV at event (PBVevent) to PBVearly post-treatment was significantly more common among poor responders (50.0% [10/20]) than among good responders (20.3% [13/64]) (P=0.019). The sensitivity, specificity, and accuracy of this PBV decrease in predicting poor treatment response were 50.0% (10/20), 79.7% (51/64), and 72.6% (61/84), respectively.

CONCLUSION

Abnormal PBVearly post-treatment and a decrease between PBVevent and PBVearly post-treatment were significantly associated with poor treatment response in patients with ACR after LT. Consequently, Doppler ultrasonography may be useful for predicting clinical outcomes in these patients.

Risk factors for acute rejection in liver transplantation and its impact on the outcomes of recipients

OBJECTIVE

To determine the risk factors for acute rejection in liver transplantation and its impact on the outcomes of the recipients.

METHODS

Clinicopathological data of 290 patients who underwent liver transplantation from January 2012 to December 2021 at our center were retrospectively evaluated. Patients were grouped into an acute rejection (AR) group and a normal (NM) group based on the confirmed histopathological diagnosis of acute rejection. Univariate and multivariate logistic regression were used to determine the risk factors for acute rejection.

RESULTS

244 patients were included in the study. Acute rejection occurred in 27 (11.1%) of the patients. Warm ischemia time (P = 0.137), cold ischemia time (P = 0.064) and chronic liver failure (P = 0.001) were potential risk factors for acute rejection. Chronic liver failure (P < 0.001, OR = 8.22, 95% CI = 2.47-27.32) was the independent risk factor. There was no significant difference in overall survival between recipients with acute rejection and those without it (P = 0.985). The 1-, 3- and 5-year overall survival in the NM group was 98.1%, 85.7% and 78.6% respectively vs 88.9%, 82.5% and 82.5% respectively in the AR group.

CONCLUSION

Acute rejection does not appear to affect the long-term survival of the recipients. Only chronic liver failure was an independent risk factor for acute rejection. Our findings further illustrate that contradictions still exist on which factors influence acute rejection in liver transplant recipients.

SUMMARY

Clinicopathological data of 290 liver transplant recipients at our center between January 2012 and December 2021 were retrospectively evaluated to determine the risk factors for acute rejection and its impact on the outcomes of the recipients. 244 patients were included in the analysis. 27 of the 244 experienced acute rejection. Propensity score matching was performed to reduce the confounding effect. Patients were assigned to an acute rejection group (n = 27) and a normal group (n = 54). Chronic liver failure (P < 0.001, OR = 8.22, 95% CI = 2.47-27.32) was the determined to be independent risk factor for acute rejection. Acute rejection did not appear to affect the long-term survival of the recipients and there was no significant difference in overall survival between the patients with acute rejection and those without it.

Immunotolerance in liver transplantation: a primer for the clinician

The use of immunosuppressive medications for solid organ transplantation is associated with cardiovascular, metabolic, and oncologic complications. On the other hand, the development of graft rejection is associated with increased mortality and graft dysfunction. Liver transplant recipients can withdraw from immunosuppression without developing graft injury while preserving an adequate antimicrobial response - a characteristic known as immunotolerance. Immunotolerance can be spontaneously or pharmacologically achieved. Contrary to the classic dogma, clinical studies have elucidated low rates of true spontaneous immunotolerance (no serologic or histological markers of immune injury) among liver transplant recipients. However, clinical, serologic, and tissue biomarkers can aid in selecting patients in whom immunosuppression can be safely withdrawn. For those who failed an immunosuppression withdrawal trial or are at high risk of rejection, pharmacological interventions for immunotolerance induction are under development. In this review, we provide an overview of the mechanisms of immunotolerance, the clinical studies investigating predictors and biomarkers of spontaneous immunotolerance, as well as the potential pharmacological interventions for inducing it.

Low-dose aspirin confers protection against acute cellular allograft rejection after primary liver transplantation

This study investigated the effect of low-dose aspirin in primary adult liver transplantation (LT) on acute cellular rejection (ACR) as well as arterial patency rates. The use of low-dose aspirin after LT is practiced by many transplant centers to minimize the risk of hepatic artery thrombosis (HAT), although solid recommendations do not exist. However, aspirin also possesses potent anti-inflammatory properties and might mitigate inflammatory processes after LT, such as rejection. Therefore, we hypothesized that the use of aspirin after LT has a protective effect against ACR. This is an international, multicenter cohort study of primary adult deceased donor LT. The study included 17 high-volume LT centers and covered the 3-year period from 2013 to 2015 to allow a minimum 5-year follow-up. In this cohort of 2365 patients, prophylactic antiplatelet therapy with low-dose aspirin was administered in 1436 recipients (61%). The 1-year rejection-free survival rate was 89% in the aspirin group versus 82% in the no-aspirin group (hazard ratio [HR], 0.77; 95% confidence interval [CI], 0.63-0.94; p = 0.01). The 1-year primary arterial patency rates were 99% in the aspirin group and 96% in the no-aspirin group with an HR of 0.23 (95% CI, 0.13-0.40; p < 0.001). Low-dose aspirin was associated with a lower risk of ACR and HAT after LT, especially in the first vulnerable year after transplantation. Therefore, low-dose aspirin use after primary LT should be evaluated to protect the liver graft from ACR and to maintain arterial patency.

Evaluating the Incidence and Risk Factors for Acute Cellular Rejection in a Steroid Sparing Liver Transplant Center

BACKGROUND

Corticosteroids has been the mainstay of immunosuppression (IMS) following liver transplant (LT). With the advent of more potent IMS, complete steroid withdrawal has become possible after LT. However, there is limited data regarding the incidence and risk factors for acute cellular rejection (ACR) in LT recipients on steroid sparing regimens.

OBJECTIVE

To identify the incidence and risk factors of ACR in LT recipients at an urban LT center utilizing a steroid-sparing IMS regimen.

METHODS

This was a single center retrospective study evaluating incidence of ACR in adults (>18 years) who received a LT between 01/01/2008 and 6/30/2019 at a steroid-sparing liver transplant center. Data between patients who had ACR and patients who did not were compared and risk factors were identified by multivariate logistic linear regression.

RESULTS

A total of 266 patients were included in this analysis, of which 18.4% experienced ACR within the first year of LT. Median time to first ACR was 134 (interquartile range [IQR]: 34-246) days. Black race (odds ratio [OR]: 4.39, P < 0.001), continued need for prednisone (OR: 2.80, P = 0.015) and cytomegalovirus (CMV) viremia (OR: 6.27, P < 0.001)) were independent risk factors for ACR. Tacrolimus use was associated with less ACR (OR: 0.33, P = 0.013).

CONCLUSION AND RELEVANCE

Steroid sparing regimens for IMS post-LT were not associated with an increased incidence of ACR when compared to reported ACR rates in literature. Potential risk factors for ACR include Black race, the use of prednisone maintenance IMS therapy, and CMV viremia.

Safety of Tacrolimus Monotherapy within 12 Months after Liver Transplantation in the Era of Reduced Tacrolimus and Mycophenolate Mofetil: National Registry Study

Tacrolimus monotherapy is accepted as a feasible option during early post-liver transplantation as per current international consensus guidelines. However, its effects in the recent era of reduced tacrolimus (TAC) and mycophenolate mofetil (MMF) remain unclear. Liver recipients who either received TAC monotherapy from the treatment onset or switched from TAC/MMF to TAC-mono within 12 months (TAC-mono group; n = 991) were chronologically matched to patients who continued to receive TAC/MMF (TAC/MMF group; n = 991) at the corresponding time points on time-conditional propensity scores. Outcomes within 12 months after matched time points were compared. Biopsy-proven rejection (TAC/MMF: 3.5% vs. TAC-mono: 2.6%; p = 0.381) and graft failure (0.2% vs. 0.7%; p = 0.082) were similar in both groups. However, the decline in eGFR was 3.1 mL/min/1.73 m² (95% CI: 0.8–5.3) greater at six months (p = 0.008) and 2.4 mL/min/1.73 m² (95% CI: −0.05–4.9) greater at 12 months (p = 0.048) after the matched time points in TAC-mono group than that in TAC/MMF group. TAC trough levels were also higher in the TAC-mono group throughout the study period. TAC-mono within 12 months after liver transplantation is immunologically safe. However, it can increase the required TAC dose and the decline in renal function than that in TAC/MMF combination therapy.

The Use of Hepatitis C Virus-Positive Organs in Hepatitis C Virus-Negative Recipients

The use of hepatitis C virus (HCV) -positive organs in HCV-negative recipients with posttransplant antiviral treatment has increasingly been studied since the introduction of new direct-acting antivirals. This article reviews existing experience in liver and kidney transplant. Fifteen studies with 218 HCV D+/R- liver transplants, with 182 from viremic donors, show a sustained viral response for 12 weeks (SVR12) rate of 99.5%. Nine studies involving 204 HCV donor-positive recipient-negative kidney transplant recipients had an SVR12 rate of 99.5%. Complications are infrequent. Preemptive treatment in kidney transplant of for only 4 weeks or even 4 days showed surprising success rates.

Recipient gender and body mass index are associated with early acute rejection in donation after cardiac death liver transplantation

BACKGROUND

Early acute rejection (EAR) is a common complication after liver transplantation (LT).

AIM

The aim of this study was to evaluate the incidence and risk factors of EAR in donation after cardiac death (DCD) liver transplantation recipients.

METHOD

We retrospectively analysed the data of 461 DCD liver transplants performed during the period from January 2010 to June 2016 to study the relationship between EAR and various clinical factors. EAR was defined as histologically proven acute cellular rejection occurring less than 90 days after transplantation.

RESULT

The median follow-up time for this study was 33.1 months (range: 0.03-92.8 months). Thirty-two (6.9%) patients developed EAR with a median period of 20.5 days (5-88 days) after transplantation. A multivariate analysis revealed that female recipient (hazard ratio: 2.801; P=0.024) and high recipient body mass index (BMI) (hazard ratio: 1.005; P=0.049) were two independent risk factors for early acute rejection.

CONCLUSIONS

In DCD liver transplantation, recipient female gender and high BMI were associated with a higher incidence of EAR, while the use of CD25-Ab and/or MMF had a protective effect.

Identification of High-Mobility Group Box 1 (HMGB1) Expression as a Potential Predictor of Rejection and Poor Prognosis After Liver Transplantation

BACKGROUND Acute cellular rejection (ACR) frequently occurs after liver transplantation (LT) and can result in permanent damage of the liver allograft. Specific and sensitive biomarkers for predicting and monitoring ACR are vital for guiding post-transplantation care. In the present study, we aimed to investigate the function of high-mobility group box 1 (HMGB1) in predicting ACR and prognosis after LT. MATERIAL AND METHODS A total of 113 LT recipients were enrolled in the study, including 62 patients in an ACR group and 51 patients in a non-rejection group. Using tissues from the 113 patients, HMGB1 expression was examined by immunohistochemistry, and the total score for HMGB1 expression was calculated by multiplying the percentage of immunoreactive cells score and the staining intensity score. We then analyzed the association between HMGB1 expression and clinical features. Finally, the function of HMGB1 in predicting the prognosis of LT was determined using Kaplan-Meier (K-M) survival and Cox multivariate analyses. RESULTS Immunohistochemical staining results demonstrated that the expression of HMGB1 was significantly increased in the ACR group, compared with that in the non-rejection group (P<0.05). Clinical characteristic analysis revealed that high HMGB1 levels were related to ACR (P<0.05). Moreover, K-M survival analysis showed that patients with high HMGB1 expression displayed poorer prognosis (P<0.05). Cox multivariate analysis demonstrated that HMGB1 was an independent prognostic predictor for post-LT survival (odds ratio, 3.283; P=0.008). CONCLUSIONS LT recipients' HMGB1 levels may be a useful and noninvasive biomarker for the prediction of ACR and prognosis after LT.

Outcomes following liver transplantation from HCV-seropositive donors to HCV-seronegative recipients

BACKGROUND & AIMS

Grafts from HCV-seropositive donors can now be considered for liver transplantation (LT) owing to the advent of direct-acting antivirals (DAAs). We report on our multicenter experience of transplanting liver grafts from HCV-seropositive donors into HCV-seronegative recipients.

METHODS

This is a prospective multicenter observational study evaluating outcomes in adult HCV-seronegative LT recipients who received grafts from HCV-seropositive donors in 3 US centers.

RESULTS

From 01/18 to 09/19, 34 HCV-seronegative LT recipients received grafts from HCV-seropositive donors (20 HCV-viremic and 14 non-viremic). Seven grafts were from cardiac-dead donors. The median MELD-Na score at allocation was 20. Six recipients underwent simultaneous liver-kidney transplant and 4 repeat LT. No recipient of an HCV-non-viremic graft developed HCV viremia. All 20 patients who received HCV-viremic grafts had HCV viremia confirmed within 3 days after LT. DAA treatment was started at a median of 27.5 days after LT. Median pre-treatment viral load was 723,000 IU/ml. All (20/20) patients completed treatment and achieved SVR12. Treatment was well tolerated with minimal adverse events. One patient developed HCV-related acute membranous nephropathy that resulted in end-stage kidney disease, despite achieving viral clearance. This patient died due to presumed infectious complications. A recipient of an HCV-non-viremic graft died with acute myocardial infarction 610 days post LT.

CONCLUSIONS

Transplantation of liver grafts from HCV-seropositive donors into HCV-seronegative recipients resulted in excellent short-term outcomes. Antiviral therapy was effective and well tolerated. Careful ongoing assessment and prompt initiation of antiviral therapy are recommended. Longer term follow-up in carefully conducted clinical trials is still required to confirm these results.

LAY SUMMARY

This study shows that livers from donors exposed to HCV expand the donor pool and can be used safely in patients who are seronegative for hepatitis C infection. Treatment, initiated early post transplantation, is effective and resulted in cure in all patients.

Care for the organ transplant recipient on the intensive care unit

All transplant recipients receive tacrolimus, mycophenolate and glucocorticoids and these drugs have many side-effects and drug-drug interactions. Common complications include surgical complications, infections, rejection and acute kidney injury. Infections as CMV and PJP can be prevented with prophylactic treatment. Given the complexity of organ transplant recipients a multi-disciplinary team of intensivists, surgeons, pharmacists and transplant specialists is essential. After heart transplantation a temporary pacemaker is required until the conduction system recovers. Stiffening of the heart and increased cardiac markers indicate rejection. An endomyocardial biopsy is performed via the right jugular vein, necessitating its preservation. For lung transplant patients, early intervention for aspiration is warranted to prevent chronic rejection. Risk of any infection is high, requiring active surveillance and intensive treatment, mainly of fungal infections. The liver is immunotolerant requiring lower immunosuppression. Transplantation surgery is often accompanied by massive blood loss and coagulopathy. Other complications include portal vein or hepatic artery thrombosis and biliary leakage or stenosis. Kidney transplant recipients have a high risk of cardiovascular disease and posttransplant anemia should be treated liberally. After postmortal transplantation, delayed graft function is common and dialysis is continued. Ureteral anastomosis complications can be diagnosed with ultrasound.

The molecular diagnosis of rejection in liver transplant biopsies: First results of the INTERLIVER study

Molecular diagnosis of rejection is emerging in kidney, heart, and lung transplant biopsies and could offer insights for liver transplant biopsies. We measured gene expression by microarrays in 235 liver transplant biopsies from 10 centers. Unsupervised archetypal analysis based on expression of previously annotated rejection-related transcripts identified 4 groups: normal "R1_normal " (N = 129), T cell-mediated rejection (TCMR) "R2_TCMR " (N = 37), early injury "R3_injury " (N = 61), and fibrosis "R4_late " (N = 8). Groups differed in median time posttransplant, for example, R3_injury 99 days vs R4_late 3117 days. R2_TCMR biopsies expressed typical TCMR-related transcripts, for example, intense IFNG-induced effects. R3_injury displayed increased expression of parenchymal injury transcripts (eg, hypoxia-inducible factor EGLN1). R4_late biopsies showed immunoglobulin transcripts and injury-related transcripts. R2_TCMR correlated with histologic rejection although with many discrepancies, and R4_late with fibrosis. R2_TCMR , R3_injury , and R4_late correlated with liver function abnormalities. Supervised classifiers trained on histologic rejection showed less agreement with histology than unsupervised R2_TCMR scores. No confirmed cases of clinical antibody-mediated rejection (ABMR) were present in the population, and strategies that previously revealed ABMR in kidney and heart transplants failed to reveal a liver ABMR phenotype. In conclusion, molecular analysis of liver transplant biopsies detects rejection, has the potential to resolve ambiguities, and could assist with immunosuppressive management.

The immunoregulation of mesenchymal stem cells plays a critical role in improving the prognosis of liver transplantation

The liver is supplied by a dual blood supply, including the portal venous system and the hepatic arterial system; thus, the liver organ is exposed to multiple gut microbial products, metabolic products, and toxins; is sensitive to extraneous pathogens; and can develop liver failure, liver cirrhosis and hepatocellular carcinoma (HCC) after short-term or long-term injury. Although liver transplantation (LT) serves as the only effective treatment for patients with end-stage liver diseases, it is not very popular because of the complications and low survival rates. Although the liver is generally termed an immune and tolerogenic organ with adaptive systems consisting of humoral immunity and cell-mediated immunity, a high rejection rate is still the main complication in patients with LT. Growing evidence has shown that mesenchymal stromal cell (MSC) transplantation could serve as an effective immunomodulatory strategy to induce tolerance in various immune-related disorders. MSCs are reported to inhibit the immune response from innate immune cells, including macrophages, dendritic cells (DCs), natural killer cells (NK cells), and natural killer T (NKT) cells, and that from adaptive immune cells, including T cells, B cells and other liver-specific immune cells, for the generation of a tolerogenic microenvironment. In this review, we summarized the relationship between LT and immunoregulation, and we focused on how to improve the effects of MSC transplantation to improve the prognosis of LT. Only after exhaustive clarification of the potential immunoregulatory mechanisms of MSCs in vitro and in vivo can we implement MSC protocols in routine clinical practice to improve LT outcome.

Pre-treatments enhance the therapeutic effects of mesenchymal stem cells in liver diseases

Liver diseases caused by viral infection, alcohol abuse and metabolic disorders can progress to end‐stage liver failure, liver cirrhosis and liver cancer, which are a growing cause of death worldwide. Although liver transplantation and hepatocyte transplantation are useful strategies to promote liver regeneration, they are limited by scarce sources of organs and hepatocytes. Mesenchymal stem cells (MSCs) restore liver injury after hepatogenic differentiation and exert immunomodulatory, anti‐inflammatory, antifibrotic, antioxidative stress and antiapoptotic effects on liver cells in vivo. After isolation and culture in vitro, MSCs are faced with nutrient and oxygen deprivation, and external growth factors maintain MSC capacities for further applications. In addition, MSCs are placed in a harsh microenvironment, and anoikis and inflammation after transplantation in vivo significantly decrease their regenerative capacity. Pre‐treatment with chemical agents, hypoxia, an inflammatory microenvironment and gene modification can protect MSCs against injury, and pre‐treated MSCs show improved hepatogenic differentiation, homing capacity, survival and paracrine effects in vitro and in vivo in regard to attenuating liver injury. In this review, we mainly focus on pre‐treatments and the underlying mechanisms for improving the therapeutic effects of MSCs in various liver diseases. Thus, we provide evidence for the development of MSC‐based cell therapy to prevent acute or chronic liver injury. Mesenchymal stem cells have potential as a therapeutic to prolong the survival of patients with end‐stage liver diseases in the near future.

Effects of IL-10- and FasL-overexpressing dendritic cells on liver transplantation tolerance in a heterotopic liver transplantation rat model

Acute rejection is the major determinant for the long-term survival of donor liver after liver transplantation (LT). The aim of this study was to examine the therapeutic potential of interleukin (IL)-10-FasL-overexpressing immature dendritic cells (imDCs) to induce local immunosuppression in liver grafts. imDCs derived from donors were transduced by lentiviral vectors expressing human IL-10 and/or Fas ligand (FasL) gene(s), and the expression of surface molecules and the ability to induce T-cell proliferation were measured. imDCs were intraperitoneally injected into recipient rats as a model of LT to examine the rejection grade [Banff rejection activity index (RAI)], liver functions [Alanine aminotransferase, Aspartate aminotransferase (AST) and total bilirubin (TBIL)] and post-transplant survival. IL-10 and FasL co-transduction of imDCs induced a greater reduction in CD80, CD86 and major histocompatibility complex class II (MHC II) expression, as well as T-cell proliferation, but increased levels of IL-10 and FasL in culture supernatants compared with mono-transduced or untransduced imDCs (P < 0.05). The infusion of co-transduced imDCs in LT recipients reduced RAI scores, decreased plasma AST and TBIL, and prolonged survival compared with mono-transduced or untransduced imDC-treated liver allografts. These findings demonstrated that the transfusion of IL-10-FasL/imDCs enhanced immune tolerance and prolonged the survival of liver allografts after LT. The immunomodulatory activity of IL-10- and FasL-modified imDCs might be a new therapeutic approach to prevent organ rejection in clinical transplantation.

CT of acute rejection after liver transplantation: a matched case-control study

PURPOSE

This study was conducted in order to investigate computed tomography (CT) findings associated with acute cellular rejection (ACR) following liver transplantation (LT) and their relevance to clinical outcomes.

MATERIALS AND METHODS

We analyzed 120 patients with newly diagnosed ACR following LT for various liver diseases and 119 controls matched for age, sex, type of liver graft, and date of CT exam following LT. Two radiologists analyzed the images for morphological characteristics of the graft, morphological change in the major draining vein, graft enhancement in the portal venous phase, graft attenuation on noncontrast CT, and periportal halo. Univariate analysis was used to determine the association between radiological findings and ACR. Clinical outcomes, including treatment response and graft survival, were compared between patients with and without associated radiological findings.

RESULTS

Morphological characteristics of the graft (i.e., globular swelling), morphological change in the major draining vein (i.e., nonanastomotic luminal narrowing), and heterogeneous enhancement were significantly associated with ACR (all p < 0.001). On univariate analysis, the severity of morphological characteristics of the grafts (mild/severe: odds ratio [OR], 19.98/32.24) and morphological change in the major draining vein (without/with prestenotic dilatation: OR, 4.17/22.5) were significantly associated with the increased possibility of an ACR diagnosis. Clinical outcomes for treatment response and graft survival were not significantly different between patients with and without associated radiological findings.

CONCLUSIONS

Globular swelling, nonanastomotic stenosis with or without prestenotic dilatation of the major draining vein, and heterogeneous enhancement of the graft on portal venous-phase CT were significantly associated with ACR.

KEY POINTS

• Globular swelling of the graft, nonanastomotic narrowing in the major vein, and heterogeneous graft enhancement on CT were significantly associated with acute cellular rejection (ACR). • Associated CT findings were highly specific but not sensitive for differentiating ACRs from matched controls.

Acute allograft rejection in liver transplant recipients: Incidence, risk factors, treatment success, and impact on graft failure

Objective This study was performed to identify risk factors for acute cellular rejection after liver transplantation (LT). Methods Consecutive LT recipients who underwent surgery in our institution from 2002 to 2015 were retrospectively evaluated. Results In total, 176 patients were eligible for statistical analysis. During a mean observation period of 61.1 ± 36.3 months, 43 episodes of acute rejection were evident. Of these, 34 (79.0%) were responsive to methylprednisolone, 3 (7.0%) were treated by adjusting the dosage of immunosuppressive agents, and 6 (14.0%) were methylprednisolone-resistant and treated using anti-thymocyte globulin. Biliary complications (odds ratio [OR] = 4.89, 95% confidence interval [CI] = 2.00-11.98); donor-negative, recipient-positive CMV mismatch (OR = 9.88, 95% CI = 1.18-82.36); sex mismatch (OR = 3.16, 95% CI = 1.31-8.10); and sex mismatch with a female donor (OR = 3.00, 95% CI = 1.10-7.58) were identified as significant risk factors for acute graft rejection after LT. Conclusion In patients who develop acute cellular rejection after LT, biliary complications should be evaluated as a potential cause. Most acute rejections after LT respond to bolus corticosteroid therapy.

Acute and Chronic Rejection After Liver Transplantation: What A Clinician Needs to Know

While antibody mediated hyper-acute vasculitic rejection is rare in liver transplant recipients, acute and chronic rejection have clinical significance. The liver allograft behaves differently to other solid organ transplants as acute rejection generally does not impair graft survival and chronic rejection (CR) is uncommon. The incidence of acute and chronic rejection has declined in current era due to improved immunosuppressive regimens. Acute rejection generally improves with steroid boluses and steroid resistant rejection is uncommon. CR may improve with escalation of immunosuppression or may result in irreversible loss of graft function leading to retransplantation or death. The current review discusses diagnosis and management of acute and chronic liver allograft rejection.

Differences in Phenotypes and Liver Transplantation Outcomes by Age Group in Patients with Primary Sclerosing Cholangitis

BACKGROUND

There is increasing evidence for a heterogeneity of phenotypes in primary sclerosing cholangitis (PSC), but differences across the age spectrum in adults with PSC have not been well characterized.

AIMS

To characterize phenotypic variations and liver transplantation outcomes by age group in adults with PSC.

METHODS

The United Network for Organ Sharing database was used to identify waitlist registrations for primary liver transplantation in adults with PSC. Patients were split into three age groups: 18-39 (young), 40-59 (middle-aged), and ≥60 (older). Their clinical characteristics and outcomes on the waitlist and post-transplant were compared.

RESULTS

Overall, 8272 adults with PSC were listed for liver transplantation during the study period, of which 28.9% were young, 52.0% were middle-aged, and 19.1% were older. The young age group had the greatest male predominance (70.0 vs. 66.2 vs. 65.1%, p = 0.001), the highest proportion of black individuals (20.0 vs. 11.0 vs. 5.5%, p < 0.001), and the most patients listed with concomitant autoimmune hepatitis (2.2 vs. 1.0 vs. 0.8%, p < 0.001). Older patients experienced the greatest waitlist and post-transplant mortality. Graft survival was greatest in the middle-aged group. Young patients were most likely to experience acute rejection (31 vs. 22.8 vs. 18.0%, p < 0.001) and have graft failure due to chronic rejection or PSC recurrence (47.8 vs. 42.3 vs. 17.9%, p < 0.001).

CONCLUSIONS

Age-related differences exist among adults with PSC and are associated with outcomes pre- and post-transplant. Young patients may have a more robust immune-related phenotype that is associated with poorer graft survival. Future studies are needed to further investigate these findings.

Management of Immunosuppression in Liver Transplantation

Liver transplantation outcomes have significantly improved over the past few decades owing largely to the introduction of effective immunosuppression medications. Further comprehension of the unique immune microenvironment of the liver has led to the development of newer molecular targeted therapeutics. Understanding the mechanism of action and adverse effect profiles of these medications is crucial for appropriate management of posttransplant patients. In this review, the author describes the immunologic response elicited by liver transplantation, chronicles the various immunosuppressant drug classes, discusses the evidence behind their use, and evaluates the management of special subpopulations of posttransplantation patients.

Acute Rejection Increases Risk of Graft Failure and Death in Recent Liver Transplant Recipients

BACKGROUND & AIMS

Acute rejection is detrimental to most transplanted solid organs, but is considered to be less of a consequence for transplanted livers. We evaluated risk factors for and outcomes after biopsy-proven acute rejection (BPAR) based on an analysis of a more recent national sample of recipients of liver transplants from living and deceased donors.

METHODS

We analyzed data from the Adult-to-Adult Living Donor Liver Transplantation Cohort Study (A2ALL) from 2003 through 2014 as the exploratory cohort and the Scientific Registry of Transplant Recipients (SRTR) from 2005 through 2013 as the validation cohort. We examined factors associated with time to first BPAR using multivariable Cox regression or discrete-survival analysis. Competing risks methods were used to compare causes of death and graft failure between recipients of living and deceased donors.

RESULTS

At least 1 BPAR episode occurred in 239 of 890 recipients in A2ALL (26.9%) and 7066 of 45,423 recipients in SRTR (15.6%). In each database, risk of rejection was significantly lower when livers came from biologically related living donors (A2ALL hazard ratio [HR], 0.57; 95% confidence interval [CI], 0.43-0.76; and SRTR HR, 0.78; 95% CI, 0.66-0.91) and higher in liver transplant recipients with primary biliary cirrhosis, of younger age, or with hepatitis C. In each database, BPAR was associated with significantly higher risks of graft failure and death. The risks were highest in the 12 month post-BPAR period in patients whose first episode occurred more than 1 year after liver transplantation: HRs for graft failure were 6.79 in A2ALL (95% CI, 2.64-17.45) and 4.41 in SRTR (95% CI, 3.71-5.23); HRs for death were 8.81 in A2ALL (95% CI, 3.37-23.04) and 3.94 in SRTR (95% CI, 3.22-4.83). In analyses of cause-specific mortality, associations were observed for liver-related (graft failure) causes of death but not for other causes.

CONCLUSIONS

Contrary to previous data, acute rejection after liver transplant is associated with significantly increased risk of graft failure, all-cause mortality, and graft failure-related death, regardless of primary liver disease etiology. Living donor liver transplantation from a biologically related donor is associated with decreased risk of rejection.

Profiling immunologic risk for acute rejection in liver transplantation: Recipient age is an important risk factor

BACKGROUND

Careful management of induction and maintenance of immunosuppression is paramount to prevent acute rejection in liver transplantation. A methodical analysis of risk factors for acute cellular rejection may provide a more comprehensive method to profile the immunologic risk of candidates.

METHODS

Using registry data from the Organ Procurement and Transplantation Network (OPTN), we identified 42,508 adult recipients who underwent orthotopic liver transplant (OLT) between 2002 and 2013. We excluded recipients with a blank entry for treated rejection. We analyzed this all inclusive cohort in addition to a subset of 27,493 patients with just tacrolimus immunosuppression. Multivariate logistic regression was used on both cohorts and identified independent risk factors for treated acute rejection at one year.

RESULTS

Recipient age (reference group was 40 to 60years) was a dominant risk factor for rejection in both cohorts and had a dose response relationship. The strongest risk factors in the inclusive cohort were: age 18-25 (OR 2.20), age 26-29 (OR 2.03), and primary biliary cholangitis (OR 1.55). The most protective factors were age 70 and older (OR 0.68), and age 65-69 (OR 0.70). The rates of rejection had a similar pattern.

CONCLUSIONS

Although prior studies have suggested age as a risk factor for rejection in liver transplantation, this is the first study of national-level data to demonstrate a robust dose dependent relationship between age and risk for rejection at one year. Clinicians should place significant weight on recipient age when they assess their recipients for the immunologic risk of rejection.

Management of immunosuppressant agents following liver transplantation: Less is more

Immunosuppression in organ transplantation was revolutionary for its time, but technological and population changes cast new light on its use. First, metabolic syndrome (MS) is increasing as a public health issue, concomitantly increasing as an issue for post-orthotopic liver transplantation patients; yet the medications regularly used for immunosuppression contribute to dysfunctional metabolism. Current mainstay immunosuppression involves the use of calcineurin inhibitors; these are potent, but nonspecifically disrupt intracellular signaling in such a way as to exacerbate the impact of MS on the liver. Second, the impacts of acute cellular rejection and malignancy are reviewed in terms of their severity and possible interactions with immunosuppressive medications. Finally, immunosuppressive agents must be considered in terms of new developments in hepatitis C virus treatment, which undercut what used to be inevitable viral recurrence. Overall, while traditional immunosuppressive agents remain the most used, the specific side-effect profiles of all immunosuppressants must be weighed in light of the individual patient.

Histological and Clinicopathological Evaluation of Liver Allograft Biopsy: An Initial Experience of Fifty Six Biopsies

INTRODUCTION

Liver biopsy is gold standard for diagnosis of allograft dysfunction.

AIM

The aim of study was to evaluate liver allograft biopsies performed for graft dysfunction, study the pattern of injury and intensity, and timeline of occurrence of graft dysfunction.

MATERIALS AND METHODS

Retrospective study was carried out of 56 liver allograft biopsies and their histological findings with clinical presentation were correlated. Totally 56 needle liver allograft biopsies from January 1210 to July 2014, obtained from 35 patients were studied for histological and clinicopathological evaluation.

RESULTS

The mean age was 53.2±5.48 years. The most common original disease was alcoholic cirrhosis. The most common histological lesion was acute cellular rejection (ACR) in 31 (55.36%) biopsies followed by preservation-reperfusion injury (PRI) in 10 (17.86%) biopsies and drug toxicity in 8 (14.29%) biopsies. Chronic rejection was reported in 2 (3.57%) and recurrence of HCV in 3 (5.36%). Ischemic coagulative necrosis and acute cholangitis were seen in 1 (1.79 %) case each.

CONCLUSION

Alcoholic cirrhosis was the most common etiology for end stage liver disease. ACR and PRI were the major complications in liver allograft biopsies at our centre.

Clinical factors affecting rejection rates in liver transplantation

BACKGROUND

With improvements in survival, liver transplant recipients now suffer more morbidity from long-term immunosuppression. Considerations were given to develop individualized immunosuppression based on their risk of rejection.

METHOD

We retrospectively analyzed the data of 788 liver transplants performed during the period from October 1991 to December 2011 to study the relationship between acute cellular rejection (ACR) and various clinical factors.

RESULTS

Multivariate analysis showed that older age (P=0.04, OR=0.982), chronic hepatitis B virus infection (P=0.005, OR= 0.574), living donor liver transplantation (P=0.02, OR=0.648) and use of interleukin-2 receptor antagonist on induction (P<0.001, OR=0.401) were associated with fewer ACRs. Patients with fulminant liver failure (P=0.004, OR=4.05) were more likely to develop moderate to severe grade ACR.

CONCLUSIONS

Liver transplant recipients with older age, chronic hepatitis B virus infection, living donor liver transplantation and use of interleukin-2 receptor antagonist on induction have fewer ACR. Patients transplanted for fulminant liver failure are at higher risk of moderate to severe grade ACR. These results provide theoretical framework for developing individualized immunosuppression.

Efficacy of ursodeoxycholic acid as an adjuvant treatment to prevent acute cellular rejection after liver transplantation: a meta-analysis of randomized controlled trials

BACKGROUND

Acute cellular rejection (ACR) after liver transplantation (LT) is one of the most common problems faced by transplant recipients in spite of advances in immunosuppressive therapy. Recently, clinical trials reported that ursodeoxycholic acid (UDCA) reduced the incidence of ACR significantly. However, others have shown contradictory conclusion. Therefore, we performed a meta-analysis of rigorous randomized controlled trials (RCTs) to determine the efficacy of UDCA in reducing ACR after LT.

DATA SOURCES

All RCTs that evaluated efficacy of UDCA as an adjuvant treatment to prevent ACR after LT were searched from PubMed/MEDLINE, EMBASE, Cochrane Central Register of Controlled Trials, ScienceDirect databases and Web of Science (from January 1981 to March 2012). There was no language limitation in these searches. Relevant abstracts of international meetings were also searched. References of each included study were searched manually.

RESULTS

A total of 234 patients from four high-quality RCTs (Jadad score 4 to 5) were included in this meta-analysis. Prophylactic use of UDCA did not decrease the incidence of ACR (RR: 0.94, 95% CI: 0.77-1.16, P>0.05), steroid-resistant rejection (RR: 0.77, 95% CI: 0.47-1.27, P>0.05) and the number of patients with the multiple episodes of ACR (RR: 0.60, 95% CI: 0.28-1.30, P>0.05). Different intervention programs (high-dose vs low-dose UDCA; early vs delayed UDCA treatment) also did not alter the outcomes.

CONCLUSIONS

UDCA, as an adjuvant treatment, was not able to prevent ACR and steroid-resistant rejection after LT. Further trials should be done to determine whether higher dose of UDCA will be beneficial.

Recipient interleukin-28B Rs12979860 C/T polymorphism and acute cellular rejection after liver transplantation: role of the calcineurin inhibitor used

BACKGROUND

Interleukin-28 (IL-28B) rs12979860 C/T polymorphism is known to predict the outcome of antiviral therapy in hepatitis C. In addition to its interferon-like and antiviral functions, IL-28B possesses the ability to modulate CD8 T cells function. This study aimed to investigate whether recipient IL-28B polymorphism may have a role in predicting the occurrence of acute cellular rejection (ACR) after liver transplantation (LT).

METHODS

Two hundred fifty-one consecutive LT recipients were enrolled. All the patients underwent per protocol liver biopsies at 1, 3, and 12 months after LT. ACR episodes in the first post-LT year were recorded and graded according to the Banff score.

RESULTS

At least one moderate to severe (Banff score ≥ 5) ACR episode was reported in 75 patients (29.9%). ACR was associated with IL-28B polymorphism: C/C=21/102 (20.6%), C/T=43/126 (34.1%), and T/T=11/23 (47.8%) (P=0.003). At logistic regression analysis, IL-28B polymorphism was found to be a predictor of ACR (P=0.012) together with cytomegalovirus reactivation (P=0.023). The association between IL-28B polymorphism and ACR occurrence was evident in tacrolimus but not in cyclosporine-treated patients. ACR episodes occurred more frequently from hepatitis C virus (HCV) negatives carrying the IL-28B C/C genotype (17.8%) to HCV negatives carrying at least one T allele or HCV positives carrying at least one C allele (33.3%) to HCV positives carrying the T/T genotype (50.0%, P=0.002).

CONCLUSIONS

HCV etiology in association with the carriage of IL-28B T/T genotype predicted the highest frequency of ACR. Recipient's IL-28B genotyping could be a useful tool in individualizing immunosuppressive therapy according to the risk of ACR occurrence.

Primary care of the liver transplant recipient

Chronic rejection of liver graft is an insidious process. Major immunosuppression medications such as tacrolimus, cyclosporin, and sirolimus have dose-related toxicity and narrow therapeutic windows. Certain drugs can affect metabolism of calcineurin inhibitors. Primary care physicians should be vigilant for any unusual opportunistic infection in liver transplant recipients. The quality of life of liver transplant recipients is an important aspect of care by primary care physicians. Alcohol relapse and possibility of depression in liver transplant recipients should be a continuous concern for primary care physicians. This article provides a guideline for the care of liver transplant recipients.

Critical care issues in patients after liver transplantation

The majority of patients who undergo liver transplantation (LT) spend some time in the intensive care unit during the postoperative period. For some, this is an expected part of the immediate posttransplant recovery period, whereas for others, the stay is more prolonged because of preexisting conditions, intraoperative events, or postoperative complications. In this review, 4 topics that are particularly relevant to the postoperative intensive care of LT recipients are discussed, with an emphasis on current knowledge specific to this patient group. Infectious complications are the most common causes of early posttransplant morbidity and mortality. The common patterns of infection seen in patients after LT and their management are discussed. Acute kidney injury and renal failure are common in post-LT patients. Kidney injury identification, etiologies, and risk factors and approaches to management are reviewed. The majority of patients will require weaning from mechanical ventilation in the immediate postoperative period; the approach to this is discussed along with the approach for those patients who require a prolonged period of mechanical ventilation. A poorly functioning graft requires prompt identification and appropriate management if the outcomes are to be optimized. The causes of poor graft function are systematically reviewed, and the management of these grafts is discussed.

Anti-thymocyte globulin for the treatment of acute cellular rejection following liver transplantation

INTRODUCTION

Acute cellular rejection (ACR) post-liver transplantation (LT) can usually be reversed with pulse dose steroids. Anti-thymocyte globulin (ATG) is used to treat steroid-resistant rejection (SRR).

PATIENTS AND METHODS

We report 15 male and five female LT recipients with a median age of 48.3 (range 14.3-71.7) years, who received ATG for biopsy-proven steroid-resistant rejection (n =13), severe rejection (6), and severe rejection/recurrent autoimmune hepatitis (n = 1) median 42 (range 6-2,456) days following LT.

RESULTS

Underlying liver diseases included HCV (n = 7), alcoholic cirrhosis (n = 3), NASH (n = 2), HBV (n = 2), autoimmune hepatitis (n =1), PSC (n = 1), miscellaneous (n = 4) including three re LTs. All patients responded to treatment (median AST declined from 172 to 34U/l, median total bilirubin from 9.1 to 1.3 mg/dl; p < 0.001). Three patients developed recurrent ACR, and none chronic rejection. All HCV patients developed recurrence with significant rises in HCV RNA levels. Infections included pneumonia, sepsis, intraabdominal infection, chronic diarrhea, wound infection, EBV, and CMV disease. After a median follow-up of 65.5 (range 4.3-101.7) months post-ATG and median 67.7 (range 9.3-306.3) months post-LT, 17 patients are alive, two died from sepsis/multi-organ failure and one from HCV recurrence.

CONCLUSION

ATG effectively reversed severe and SSR; HCV recurrence and infections remain significant complications.

Chronic rejection of the liver: the role of immunosuppression

Liver transplantation is now widely recognised as an effective treatment option for patients with advanced liver disease. Many units now achieve greater than 85% survival at 1 year, with the majority of patients having a high quality of life. The maintenance of a high quality of life requires careful clinical management to ensure that the continued maintenance of excellent liver graft function is not achieved at the expense of immunosuppressive drug complications or morbidity. Acute liver rejection will occur in between 30 to 45% of patients, although with modern immunosuppressive protocols, usually combining one of the calcineurin agents, either cyclosporin or tacrolimus, with both azathioprine and corticosteroids (prednisolone) ensures that relatively few grafts are lost from severe acute rejection. While the incidence and severity of acute rejection may be one factor in raising the risk of chronic rejection, it may not be the principal one in many patients. It is important to recognise that the frequency of rejection also varies with the primary underlying liver disease, with patients with hepatitis B or alcoholic liver disease having relatively low rejection rates, compared with patients with primary biliary cirrhosis (PBC) or primary sclerosing cholangitis (PSC), which range between 20 to 70%. Chronic rejection will account for some 5% of grafts lost in the first 3 to 5 years. Indeed, there is some evidence that the incidence of chronic rejection is actually declining over the past few years. While the reason for this apparent decline is uncertain, and it could relate to better immunosuppression management, or more likely to the growing recognition that chronic graft dysfunction may be due to recurrent liver disease, such as autoimmune hepatitis, PBC, PSC, or recurrent hepatitis C. The differentiation of recurrent primary liver disease from chronic rejection can prove to be very difficult in clinical practice. Thus, the clinician must carefully monitor liver and graft function, evaluate any biochemical changes, and try to reach a clear diagnosis before considering any modification of immunosuppressive schedules.

Long term management of liver transplant rejection in children

The current management of hepatic allograft rejection after liver transplantation in children requires effective baseline immunosuppression to prevent rejection and rapid diagnosis and treatment to manage acute rejection episodes. The subsequent impact on chronic rejection is dependent on the combination of adequate prevention and the treatment of acute rejection. Tacrolimus is a macrolide lactone that inhibits the signal transduction of interleukin-2 (IL-2) via calcineurin inhibition. Introduced in 1989, tacrolimus was first used in the salvage of refractory acute or chronic rejection under cyclosporin or to rescue patients with significant cyclosporin-related complications. The majority of paediatric transplant centres use a combination of steroids with tacrolimus as a basic immunosuppressant regimen following paediatric liver transplantation. This combination has allowed the acute cellular rejection-free rate to increase to between 30 and 60%, while lowering the rate of refractory rejection to less than 5%. Corticosteroid-resistant rejection is commonly treated with monoclonal (muromonab CD3) or polyclonal preparations. Although most episodes of acute cellular rejection occur during the first 6 weeks after liver transplant, the appearance of late acute liver allograft rejection must raise the question of noncompliance, especially in the adolescent population. Chronic rejection is becoming increasingly rare under tacrolimus-based immunosuppression. Tacrolimus is effective in reversing refractory acute cellular rejection or early chronic rejection in patients initially treated with cyclosporin-based regimens. Patients with a history of noncompliance as well as children with autoimmune liver disease are at risk of chronic rejection. Retransplantation therapy for chronic rejection has, fortunately, become more rare in the tacrolimus era with only 3% of retransplants being performed for this indication. Newer immunosuppressive agents are further modifying the long term management of liver allograft rejection. These include mycophenolate mofetil, rapamycin and IL-2 antibodies such as daclizumab. The development of these agents is allowing patient-specific immunosuppressive management to minimise rejection as well as the complications related to immunosuppression.

Vitamin D and the risk of acute allograft rejection following human liver transplantation

BACKGROUND

Vitamin D may act as an immune modulator in experimental and human organ transplantation, but these data are yet to be confirmed in human liver transplantation (LT).

AIM

This study aimed to assess the relationship between acute liver allograft cellular rejection (ACR) and pretransplant serum vitamin D concentration or post-transplant vitamin D supplementation.

METHOD

We studied 133 LT recipients who underwent two per protocol allograft biopsies in the early post-operative period, plus on-demand biopsies as clinically indicated. ACR estimate was given according to the Banff scheme in biopsies obtained along two follow-up periods: (a) from the transplant operation to the end of the second month (0-2 months); (b) and from the third month to the end of the eighth month (3-8 months) post-LT.

RESULTS

The median pretransplant serum 25-hydroxyvitamin D concentration was 12.5 ng/ml; 40 patients had concentrations < or =12.5 ng/ml, of whom six had < or =5.0 ng/ml. Seventy-nine recipients received oral vitamin D(3) supplementation to treat post-transplant osteoporosis. In the 0-2 months period, moderate-to-severe rejection episodes were independently associated with cytomegalovirus reactivation (P<0.005) and progressively lower pretransplant serum 25-hydroxyvitamin D concentrations (P<0.02). Early vitamin D(3) supplementation was independently associated with a lack of ACR (P<0.05).

CONCLUSIONS

These results suggest that vitamin D may favour immune tolerance towards the liver allograft.

Serial measurement of Doppler hepatic hemodynamic parameters for the diagnosis of acute rejection after live donor liver transplantation

To elucidate the role of Doppler hepatic hemodynamic parameters as surrogate markers of acute rejection (AR) after live donor liver transplantation (LDLT), serial Doppler measurements were prospectively performed during the first 2 weeks after LDLT to compare the longitudinal hepatic hemodynamic changes between patients with histologically proven AR and patients without histologically proven AR. Forty-six patients that had undergone adult-to-adult LDLT using a right lobe graft were enrolled in this study. The portal venous maximum velocity (PVV; cm/second), portal venous flow volume, hepatic arterial peak systolic velocity, hepatic arterial pulsatility index, hepatic venous maximum velocity, hepatic venous pulsatility index, and splenic arterial pulsatility index were measured. Fourteen patients were diagnosed by biopsy to have clinically relevant AR. Markedly increased PVV was seen soon after surgery and gradually decreased in both patients with clinically relevant AR and patients without clinically relevant AR. This serial change of decreasing PVV was significantly greater in patients with clinically relevant AR (P < 0.0001). After postoperative day 6, the PVV in patients with clinically relevant AR was significantly lower than that in patients without clinically relevant AR (PVV on postoperative day 6: 35.6 +/- 21.3 versus 58.3 +/- 27.1 cm/second, respectively, P = 0.0080). A PVV cutoff value of 20.2 cm/second demonstrated the best accuracy for predicting clinically relevant AR. The sensitivity and specificity for predicting clinically relevant AR were 92.9% and 87.1%, respectively. The area under the curve was 0.94. In conclusion, serial Doppler measurement of hepatic parameters in LDLT is useful for the diagnosis of clinically relevant AR. Clinically relevant AR should therefore be suspected when a marked unexpected decrease in the PVV is observed.

Sirolimus monotherapy effectiveness in liver transplant recipients with renal dysfunction due to calcineurin inhibitors

INTRODUCTION

Among the adverse effects of different calcineurin inhibitors (CIs), nephrotoxicity is the most common (incidence: 18.1% at 13 y from liver transplantation) and depends on a variable degree of tubular-interstitial injury accompanied by focal glomerular sclerosis. A new immunosuppressive drug was introduced in solid organ transplant management, Sirolimus (SRL). It is a nonnephrotoxic immunosuppressor.

METHODS

Twenty-six patients who developed nephrotoxicity owing to CIs, showing an increment of serum creatinine levels (>1.8 mg/dL) were switched to SRL monotherapy, initially at a dosage between 3 and 5 mg/d, and subsequently adapted to achieve trough level between 8 to 10 ng/mL.

RESULTS

Patients were followed-up for a mean period of 40.3 months (range, 8.4 to 76.7) from liver transplantation. Mean follow-up after switch was 27.5 months (range, 2 to 71.2). Immunosuppression therapy was converted after a mean period of 12.8 months (range, 0.2 to 43.4). Serum creatinine, urea, and estimated glomerular filtration rate were significantly improved.

DISCUSSION

Patients developing renal dysfunction after liver transplantation may be successfully treated by conversion from CI to SRL. Hypertriglyceridemia and hypercholesterolemia represent the principal side effects from SRL, but are treatable. Furthermore, SRL can significantly improve glucose tolerance.

Liver transplantation()

Orthotopic liver transplantation (OLT) involves the substitution of a diseased native liver with a normal liver (or part of one) taken from a deceased or living donor. Considered an experimental procedure through the 1980s, OLT is now regarded as the treatment of choice for a number of otherwise irreversible forms of acute and chronic liver disease.The first human liver transplantation was performed in the United States in 1963 by Prof. T.E. Starzl of the University of Colorado. The first OLT to be performed in Italy was done in 1982 by Prof. R. Cortesini. The procedure was successfully performed at the Policlinico Umberto I of the University of Rome (La Sapienza).The paper reports the indications for liver transplantation, donor selection and organ allocation in our experience, surgical technique, immunosuppression, complications and results of liver transplantation in our center.