Clinical factors affecting rejection rates in liver transplantation

Metabolomics profiling in acute liver transplant rejection in a pediatric population

Pediatric liver transplantation rejection affects 20% of children. Currently, liver biopsy, expensive and invasive, is the best method of diagnosis. Discovery and validation of clinical biomarkers from blood or other biospecimens would improve clinical care. For this study, stored plasma samples were utilized from two cross-sectional cohorts of liver transplant patients at Children's Healthcare of Atlanta. High resolution metabolic profiling was completed using established methods. Children with (n = 18) or without (n = 25) acute cellular rejection were included in the analysis (n = 43 total). The mean age of these racially diverse cohorts ranged from 12.6 years in the rejection group and 13.6 years in the no rejection group. Linear regression provided 510 significantly differentiating metabolites between groups, and OPLS-DA showed 145 metabolites with VIP > 2. A total of 95 overlapping significant metabolites between OPLS-DA and linear regression analyses were detected. Pathway analysis (p < 0.05) showed bile acid biosynthesis and tryptophan metabolism as the top two differentiating pathways. Network analysis also identified tryptophan and clustered with liver enzymes and steroid use. We conclude metabolic profiling of plasma from children with acute liver transplant rejection demonstrates > 500 significant metabolites. This result suggests that development of a non-invasive biomarker-based test is possible for rejection screening.

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.

Pediatric living donor liver transplantation (LDLT): Short- and long-term outcomes during sixteen years period at a single centre- A retrospective cohort study

Background and objectives

Pediatric living donor liver transplantation (LDLT) is an effective tool for managing pediatric patients with end-stage liver disease (ESLD) with good long-term graft and patient survival, especially after improvement in peri-operative care, surgical tools and techniques; however, the morbidity and mortality after such a procedure are still a challenging matter. The study aimed to analyze short-and long-term outcomes after pediatric LDLT in a single centre.

Methods

We retrospectively analyzed 67 pediatric patients who underwent LDLT in the period from April 2003 to July 2018. The overall male/female ratio was 40/27.

Results

Forty-one (61.2%) of patients had ≥1 early and/or late morbidities; the early (less than 3months) and late (≥3months) ones affected 36(53.7%) and 12(17.9%) of them respectively. The 16-year graft and patient survivals were 35(52.2%) while early and late mortalities were 23(34.3%) and 9(13.4%) respectively. Sepsis and chronic rejection were the most frequent causes of early and late mortalities respectively. Moreover, more packed RBCs transfusion units, bacterial infections, and pulmonary complications were independent predictors of poor patient survival.

Conclusions

More packed RBCs transfusion units intra-operatively, and post-liver transplant (LT) bacterial infection, sepsis, chronic rejection, as well as pulmonary complications had a negative insult on our patients' outcomes, so proper management of them is mandatory for improving outcomes after pediatric LDLT.

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More packed RBCs transfusion units intra-operatively had a negative insult on outcomes after paediatric LDLT.

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Bacterial infection and pulmonary complications led to poor outcomes after paediatric LDLT.

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Sepsis and chronic rejection led to post paediatric LDLT poor patient outcomes.

Immunosuppression in liver and intestinal transplantation

Immunosuppression handling plays a key role in the early and long-term results of transplantation. The development of multiple immunosuppressive drugs led to numerous clincial trials searching to reach the ideal regimen. Due to heterogeneity of the studied patient cohorts and flaws in many, even randomized controlled, study designs, the answer still stands out. Nowadays triple-drug immunosuppression containing a calcineurin inhibitor (preferentially tacrolimus), an antimetabolite (using mycophenolate moffettil or Azathioprine) and short-term steroids with or without induction therapy (using anti-IL2 receptor blocker or anti-lymphocytic serum) is the preferred option in both liver and intestinal transplantation. This chapter aims, based on a critical review of the definitions of rejection, corticoresistant rejection and standard immunosuppression to give some reflections on how to reach an optimal immunosuppressive status and to conduct trials allowing to draw solid conclusions. Endpoints of future trials should not anymore focus on biopsy proven, acute and chronic, rejection but also on graft and patient survival. Correlation between early- and long-term biologic, immunologic and histopathologic findings will be fundamental to reach in much more patients the status of operational tolerance.

Clinical Course and Outcome of Liver Transplantation in Patients with Hepatitis C in Iran

Background: Hepatitis C is one of the most common causes of end-stage liver disease and liver transplant worldwide. In recent years, with the rapid advances in the treatment of hepatitis C by direct-acting antiviral drugs (DAAs), the clinical course of the disease as well as liver transplantation have had significant improvement. Also, DAAs have completely replaced interferon-based regimens in the treatment and prevention of HCV recurrence after liver transplant. Objectives: This is the first study that aimed to investigate the clinical course of liver transplantation in patients with hepatitis C in Iran. Methods: This retrospective study was conducted on patients with HCV liver transplantation within five years (2012 - 2017) with the age range of 18 to 65 years at Shiraz Organ Transplant Center. All demographic and clinical data were recorded. Pre-transplant viral load, disease recurrence, graft rejection, and mortality rate were the most important indices in this study. Results: Among 55 transplant patients, 49% had received hepatitis C treatment before liver transplantation and interferon-based regimens were more prevalent. Besides, HCV genotype 3, followed by genotype 1, was the most prevalent one. A liver biopsy was performed in patients with elevated liver enzyme levels. The numbers of patients with HCV recurrence at 2, 6, 12, and 24-month intervals were three, two, zero, and two patients, respectively. At these time intervals, eight, eight, one, and three cases of acute graft rejection were found, respectively. Eight patients died with a one-year survival rate of 85%. Sepsis and infectious complications were the most leading causes of death. Conclusions: This study is the first study of liver transplant patients with hepatitis C in Iran. In the five-year study period, rapid development was made in the treatment of HCV patients. It led to the introduction of DAAs, which replaced interferon-based therapies. The results of this study indicated the high success rate of liver transplantation in patients with hepatitis C in Iran. The results of this study could be used to compare the efficacy of DAAs in future research.

De Novo Donor Specific Antibody and Long-Term Outcome After Liver Transplantation: A Systematic Review and Meta-Analysis

Background

The impact of de novo anti-HLA donor-specific alloantibodies (DSA) which develop after long-term liver transplantation (LT) remains controversial and unclear. The aim of this study was to investigate the role of de novo DSAs on the outcome in LT.

Methods

We did a systematic review and meta-analysis of observational studies published until Dec 31, 2019, that reported de novo DSA outcome data (≥1 year of follow-up) after liver transplant. A literature search in the MEDLINE/PubMed, EMBASE, Cochrane Library, Scopus and Web of Science Core Collection databases was performed.

Results

Of 5,325 studies identified, 15 fulfilled our inclusion criteria. The studies which reported 2016 liver transplant recipients with de novo DSAs showed an increased complication risk, i.e. graft loss and chronic rejection (OR 3.61; 95% CI 1.94-6.71, P < 0.001; I2 58.19%), and allograft rejection alone (OR 6.43; 95% CI: 3.17-13.04; P < 0.001; I2 49.77%); they were compared to patients without de novo DSAs. The association between de novo DSAs and overall outcome failure was consistent across all subgroups and sensitivity analysis.

Conclusions

Our study suggested that de novo DSAs had a significant deleterious impact on the liver transplant risk of rejection. The routine detection of de novo DSAs may be beneficial as noninvasive biomarker-guided risk stratification.

Recipient risk factors for acute cellular rejection after orthotopic liver transplant - a single-center, retrospective study

The use of model for end-stage liver disease (MELD) score for liver allocation has resulted in transplanting sicker patients. As such, it is unclear whether the risk factors and severity of acute cellular rejection (ACR) have changed. To identify ACR characteristics where average MELD score at transplant is higher than previously published studies. This is a single-center, retrospective study designed to assess risk factors associated with ACR after adult orthotopic liver transplant (OLT) using a steroid sparing regimen. This study included 174 OLT patients transplanted from 2008 to 2013 at a single tertiary care center. Recipient demographics, preoperative clinical, and laboratory data were recorded for each transplant. Univariate and multivariate regression analyses were performed to identify variables that are significant predictors for ACR. The median MELD at transplantation was 29.5. The average time from transplant to ACR diagnosis was 283.9 days and a majority of ACR episodes were mild to moderate. Serum creatinine, primary sclerosing cholangitis etiology, and tacrolimus use were significant predictors for ACR (P < 0.05). This study confirmed a change in timing and severity of ACR in the MELD era. Recipient characteristics may affect the risk for developing ACR and should be considered when managing immunosuppression.

High Intrapatient Variability in Tacrolimus Exposure Is Not Associated With Immune-mediated Graft Injury After Liver Transplantation

BACKGROUND

A high intrapatient variability (IPV) in tacrolimus exposure is associated with impaired long-term clinical outcome after kidney transplantation. It remains to be determined if this is equally detrimental for liver transplant recipients. The objective of this study was to investigate the association between IPV in tacrolimus exposure and immune-mediated graft injury after liver transplantation.

METHODS

For 326 liver transplant recipients, transplanted between 2000 and 2015, tacrolimus IPV was calculated from at least 5 tacrolimus trough samples obtained between months 6 and 18 after liver transplantation and expressed as the coefficient of variation. Primary composite endpoint consisted of immune-mediated graft injury (chronic rejection, biopsy proven, and suspected late acute rejection) after month 6. Secondary outcomes were the association between tacrolimus IPV on (1) loss of renal function per year of follow-up and (2) cytomegalovirus viremia after month 6.

RESULTS

Of the 326 included liver transplant recipients, 70 patients (21.5%) reached the primary endpoint. Median tacrolimus coefficient of variation was 28%. There was no significant difference in reaching the primary composite endpoint between the low- and high-IPV groups (P = 0.068). Model for End-Stage Liver Disease score pretransplantation and the number of acute rejections were identified as independent predictors for immune-mediated graft injury (P = 0.049 and 0.016). A higher IPV in combination with a low kidney function at baseline (estimated glomerular filtration rate < 40 mL/min) was associated with greater loss of renal function per year of follow-up (P = 0.007). Tacrolimus variability was not associated with late cytomegalovirus viremia.

CONCLUSIONS

High IPV in tacrolimus exposure beyond month 6 postliver transplantation was not associated with immune-mediated graft injury.

Acute Liver Failure Secondary to Drug-Induced Liver Injury

Drug-induced liver injury (DILI) is the most common cause of acute liver failure (ALF) in Western countries. Without liver transplantation, the mortality rate for ALF approaches greater than 80%. Acetaminophen-related ALF may be associated with a rapid progression but fortunately has a high chance for spontaneous survival compared with idiosyncratic DILI-related ALF. Several prognostic scoring systems for severe DILI have been developed to aid clinicians in selecting patients who require urgent liver transplantation. Patients who undergo liver transplantation for ALF are at risk for early graft loss and death and should be closely followed.

Acute cellular rejection in hepatitis C recipients following liver transplantation in the era of direct-acting antivirals: chronological analysis of the United Network for Organ Sharing database

INTRODUCTION

Interferon (IFN) treatment for liver transplant (LT) recipients with hepatitis C virus (HCV) increases acute cellular rejection (ACR) and worsens graft and patient survival. It is unknown if direct-acting antivirals (DAAs) affect rejection rates or post-transplant survival.

METHOD

The United Network for Organ Sharing STAR files of December 2017 (n = 25,916) were analyzed.

RESULTS

Compared with non-HCV-LT, HCV-LT survival was worse in the IFN-era (2007-2008) and IFN+DAA-era (2011), but not in the DAA-era (2014-2015). ACR6m rate has been less frequent in newer eras and was lower in HCV-LT than in non-HCV-LT in both the DAA-era (6.9% vs. 9.3%, P < 0.001) and in the IFN+DAA-era (8.8% vs. 11.8%, P = 0.001), but not in the IFN-era (10.8% vs. 11.0%, P = 0.39). HCV-LT recipients who had ACR6m had worse 2-year survival than those without ACR6m, in the IFN-era (80.0% vs. 88.4%, P < 0.0001) and in the IFN+DAA-era (81.4% vs. 89.2%, P < 0.01) but not in the DAA-era (90.4% vs. 93.2%, P = 0.085). Cox proportional hazard model identified ACR6m as independent risk factor for mortality in HCV-LT in the IFN-era (HR = 1.88, P ≤ 0.001) and in the IFN+DAA-era (HR = 1.84, P = 0.005), but not in the DAA-era (P = n.s.).

CONCLUSIONS

Two-year survival of HCV-LT recipients were significantly better in the DAA-era; these were associated with reduced rate and impact of ACR6m.

Metabolomic Characterization of Human Model of Liver Rejection Identifies Aberrancies Linked to Cyclooxygenase (COX) and Nitric Oxide Synthase (NOS)

BACKGROUND Acute liver rejection (ALR), a significant complication of liver transplantation, burdens patients, healthcare payers, and the healthcare providers due to an increase in morbidity, cost, and resources. Despite clinical resolution, ALR is associated with an increased risk of graft loss. A unique protocol of delayed immunosuppression used in our institute provided a model to characterize metabolomic profiles in human ALR. MATERIAL AND METHODS Twenty liver allograft biopsies obtained 48 hours after liver transplantation in the absence of immunosuppression were studied. Hepatic metabolites were quantitated in these biopsies by liquid chromatography and mass spectroscopy (LC/MS). Metabolite profiles were compared among: 1) biopsies with reperfusion injury but no histological evidence of rejection (n=7), 2) biopsies with histological evidence of moderate or severe rejection (n=5), and 3) biopsies with histological evidence of mild rejection (n=8). RESULTS There were 133 metabolites consistently detected by LC/MS and these were prioritized using variable importance to projection (VIP) analysis, comparing moderate or severe rejection vs. no rejection or mild rejection using partial least squares discriminant statistical analysis (PLS-DA). Twenty metabolites were identified as progressively different. Further PLS-DA using these metabolites identified 3 metabolites (linoleic acid, γ-linolenic acid, and citrulline) which are associated with either cyclooxygenase or nitric oxide synthase functionality. CONCLUSIONS Hepatic metabolic aberrancies associated with cyclooxygenase and nitric oxide synthase function occur contemporaneous with ALR. Additional studies are required to better characterize the role of these metabolic pathways to enhance utility of the metabolomics approach in diagnosis and outcomes of ALR.

Harnessing immunotherapy for liver recipients with hepatocellular carcinoma: a review from a transplant oncology perspective

Without stringent criteria, liver transplantation for hepatocellular carcinoma (HCC) can lead to high cancer recurrence and poor prognosis in the current treatment context. Checkpoint inhibitors can lead to long survival by targeting coinhibitory pathways and promoting T-cell activity; thus, they have great potential for cancer immunotherapy. Therapeutic modulation of cosignaling pathways may shift paradigms from surgical prevention of recurrence to oncological intervention. Herein, we review the available evidence from a therapeutic perspective and focus on immune microenvironment perturbation by immunosuppressants and checkpoint inhibitors. Partial and reversible interleukin-2 signaling blockade is the mainstream strategy of immunosuppression for graft protection. Programmed cell death protein 1 (PD-1) is abundantly expressed on human liver allograft-infiltrating T-cells, which proliferate considerably after programmed death-ligand 1 (PD-L1) blockade. Clinically, checkpoint inhibitors are used in heart, liver, and kidney recipients with various cancers. Rejection can occur after checkpoint inhibitor administration through acute T-cell-mediated, antibody-mediated, or chronic allograft rejection mechanisms. Nevertheless, liver recipients may demonstrate favorable responses to treatment for HCC recurrence without rejection. Pharmacodynamically, substantial degrees of receptor occupancy can be achieved with lower doses, with favorable clinical outcomes. Manipulation of the immune microenvironment is a therapeutic niche that balances seemingly conflicting anticancer and graft protection needs. Additional translational and clinical studies emphasizing the comparative effectiveness of signaling networks within the immune microenvironment and conducting overall assessment of the immune microenvironment may aid in creating a therapeutic window and benefiting future liver recipients with HCC recurrence.

Association between CXCL9/10 polymorphisms and acute rejection of liver allograft

While increased serum concentrations of CXCL9/10 are associated with acute cellular rejection (ACR) occurrence, the association between CXCL9/10 single nucleotide polymorphisms (SNPs) and ACR after liver transplantation (LT) remains unknown.In the present case-control study, polymorphisms of CXCL9 (rs10336) and CXCL10 (rs3921) were determined by polymerase chain reaction in 215 liver transplant recipients. ACR was defined as biopsy proven within 6 months after LT. As selected SNPs were in 3'-UTR region, their possible association with protein synthesis was assessed by measuring the plasma concentration of CXCL9/10 in a cohort of 40 new transplant patients using ELISA.There was no association between CXCL9/10 genotypes and overall incidence of ACR. However, patients with CXCL9 genotype AA developed ACR earlier than patients with GG genotype (P = .003), with similar results for CXCL10 gene (CC vs GG; P = .005). There was no statistically significant difference in plasma concentrations of CXCL9/10 between the rejectors and the non-rejectors. Of note, patients with AA CXCL9 genotype had significantly higher CXCL9 plasma concentrations than patients with AG (P = .01) or GG genotype (P = .045).In conclusion, the SNPs of CXCL9 (rs10336) and CXCL10 (rs3921) are not associated with the incidence of ACR. However, patients with CXCL9 genotype AA developed ACR earlier and the same genotype was associated with greater plasma concentrations suggesting the involvement of CXCL9 mediated processes in ACR development.

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

INTRODUCTION

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

PATIENTS AND METHODS

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

CONCLUSION

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

Recurrence of Hepatitis B Infection in Liver Transplant Patients Receiving Long-Term Hepatitis B Immunoglobulin Prophylaxis

BACKGROUND Long-term real-world data are relatively sparse regarding recurrence of chronic hepatitis B virus (HBV) infection after liver transplantation using hepatitis B immunoglobulin (HBIg) and nucleos(t)ide analogue (NUC) prophylaxis. MATERIAL AND METHODS Data from 371 adults transplanted for HBV-related disease at 20 European centers and given HBIg for ³12 months ± NUC therapy were analyzed retrospectively. RESULTS HBIg comprised Hepatect® (iv HBIgB; n=299), subcutaneous Zutectra® (sc HBIg, n=236), and other HBIg preparations (n=130); 93.5% received NUC therapy. Mean follow-up was 6.8±3.5 years. The primary efficacy variable, freedom from HBV recurrence, occurred in 95.7% of patients (95% CI [93.1%, 97.5%]). The observed incidence of recurrence was 16/371 (4.3%) (annual rate 0.65%); 5/16 patients with recurrence had discontinued HBIg and 7/16 had anti-HBs <100 IU/l. Excluding these 7 patients, the HBV recurrence rate was 2.4%. The recurrence rate while on HBIg therapy was 1 per 2069 months. In patients who discontinued HBIg, risk of HBV recurrence versus sc HBIg users was increased by 5.2-fold (1 per 1 603 versus 1 per 8379 treatment months). The annual rate of HBV-related hepatocellular carcinoma (HCC) recurrence was 1.7%. CONCLUSIONS These results support the long-term use of HBIg with NUC therapy as an effective management strategy to minimize risk of HBV recurrence and virus-related complications after liver transplantation.

Clinical use of an immune monitoring panel in liver transplant recipients: A prospective, observational study

Immunosuppressive therapy greatly contributed to making liver transplantation the standard treatment for end-stage liver diseases. However, it remains difficult to predict and measure the efficacy of pharmacological immunosuppression. Therefore, we used a panel of standardized, commonly available, biomarkers with the aim to describe their changes in the first 3 weeks after the transplant procedure and assess if they may help therapeutic drug monitoring in better tailoring the dose of the immunosuppressive drugs. We prospectively studied 72 consecutive patients from the day of liver transplant (post-operative day #0) until the post-operative day #21. Leukocytes, neutrophils, lymphocytes (CD4+, CD8+), natural killer cells, monocytes, immunoglobulins and tacrolimus serum levels were measured on peripheral blood (at day 0, 3, 7, 14, 21 after surgery). Patients who developed infections showed significantly higher CD64+ monocytes on post operative day #7. IgG levels were lower on post operative day #3 among patients who later developed infections. We also found that a sharp decrease in IgA from post operative day #0 to 3 (-226 mg/dL in the ROC curve analysis) strongly correlates with the onset of infections among HCV- patients. No specific markers of rejection emerged from the tested panel of markers. Our results show that some early changes in peripheral blood white cells and immunoglobulins may predict the onset of infections and may be useful in modulating the immunosuppressive therapy. However, a panel of commonly available, standardized biomarkers do not support in improving therapeutic drug monitoring ability to individualize immunosuppressive drugs dosing.

Deleterious impact of C3d-binding donor-specific anti-HLA antibodies after pediatric liver transplantation

BACKGROUND

The prevalence and clinical impact of anti-HLA donor-specific antibodies (DSA) after liver transplantation (LT) have not been extensively studied, especially in pediatric population.

METHODS

The present cross-sectional study included 100 patients who underwent a first LT in childhood. Anti HLA immunization study was performed at a single time point during routine follow-up using Luminex® single antigen tests with classical anti-IgG conjugate and anti-C3d conjugate.

RESULTS

The main indication for LT was biliary atresia (52%) and median age at LT was 4.6years. The median time between LT and DSA assessment was 7.8years (range 1-21years). DSA was identified in twenty-four patients (24%) after LT, with a prevalence of 8%, 28%, 33%, 50%, respectively 0-5years, 5-10years, 10-15years and >15years after LT. DSA were mainly class II (23/24) with a mean MFI of 9.731±5.489 and 18 (79.3%) were C3d-binding DSA. Multivariate analysis disclosed that time elapsed since LT (p<0.01) and history of fulminant hepatitis (p=0.04) were significantly associated with a higher rate of DSA. Liver function tests (at time of DSA assessment) were not different according to the presence or not of DSA (or C3d-binding DSA). Regarding histology, the DSA group had a higher rate of chronic rejection, cirrhosis and centrilobular fibrosis or cirrhosis. In addition, patients with C3d-binding DSA and high MFI (>10,000) had a significant poorer long-term graft survival (p=0.03).

CONCLUSION

In our pediatric cohort of LT, prevalence of DSA was high and increased regularly with time. Presence of C3d positive-DSA with high MFI was associated with a higher rate of graft loss.

Impact of donor-recipient genetic relationship on outcome of living donor liver transplantation

Living donor liver transplantation (LDLT) is a valuable option for expanding the donor pool, especially in localities where deceased organ harvesting is not allowed. In addition, rejection rates were found to be lower in LDLT, which is attributed to the fact that LDLT is usually performed between relatives. However, the impact of genetic relation on the outcome of LDLT has not been studied. In this study, we examined the difference in rejection rates between LDLT from genetically related (GR) donors and genetically unrelated (GUR) donors. All cases that underwent LDLT during the period from May 2004 until May 2014 were included in the study. The study group was divided into 2 groups: LDLT from GR donors and LDLT from GUR donors. A total of 308 patients were included in the study: 212 from GR donors and 96 from GUR donors. Human leukocyte antigen (HLA) typing was not included in the workup for matching donors and recipients. GUR donors were wives (36; 11.7%), sons-in-law (7; 2.3%), brothers-in-law (12; 3.9%), sisters-in-law (1; 0.3%), and unrelated (38; 12.3%). The incidence of acute rejection in the GR group was 17.4% and 26.3% in the GUR group (P value = 0.07). However, there was a significant difference in the incidence of chronic rejection (CR) between the 2 groups: 7% in GR group and 14.7% in the GUR group (P value = 0.03). In terms of overall survival, there was no significant difference between both groups. LDLT from the GUR donors is not associated with a higher incidence of acute cellular rejection. However, CR was significantly lower when grafts were procured from GR donors. HLA matching may be recommended before LDLT from GUR donors. Liver Transplantation 23:43-49 2017 AASLD.