Influence of donor/recipient HLA-matching on outcome and recurrence of hepatitis C after liver transplantation

Impact of human leukocyte antigen compatibility on outcomes of living donor liver transplantation: Experience from a tertiary care center

INTRODUCTION

The role of HLA compatibility in kidney, heart, and stem cell transplantation is well known, but with regard to living donor liver transplantation (LDLT), there is a different scenario. In the present study, we aim to examine the effects of donor-recipient HLA mismatches at A, B, and DR loci on various outcomes of LDLT-like graft survival, early allograft dysfunction (EAD), acute rejection, length of hospital (LOH) stay, sepsis, and cytomegalovirus (CMV) reactivation.

METHODS

This is a retrospective single center study of a cohort of adult patients who underwent first time ABO-compatible (ABOc) LDLT between January 2010 and December 2018. Transplants with incomplete records or without HLA typing data were excluded. Donor-recipient HLA-A, B, and DR mismatches were assessed in the host versus graft (HVG) direction and were correlated with various post-transplant outcomes.

RESULTS

Among 140 transplants being evaluated, approximately two third had total HLA mismatches between 2 and 3. HLA mismatches at each locus as well as cumulative HLA mismatches did not show any association with overall graft survival, EAD, acute rejection episodes, and LOH stay. However, the presence of minimum one mismatch at HLA-A and DR loci was associated with the development of CMV reactivation (P = .03) and sepsis (P = .02) post-LDLT respectively.

CONCLUSION

HLA mismatch is not associated with acute rejection, early graft dysfunction, and overall survival in LDLT. Its impact on CMV reactivation and sepsis needs further evaluation.

Role of Human Leukocyte Antigen Compatibility in Graft Outcomes After Living Donor Liver Transplantation

PURPOSE

The influence of human leukocyte antigen (HLA) mismatch on liver transplantation has been widely studied, but is still controversial. The aim of this large single-center study was to analyze the role of HLA compatibility between donor and recipient in the graft outcomes of living donor liver transplantation (LDLT).

MATERIALS AND METHODS

A total of 925 recipients who had undergone LDLT between March 2001 and April 2012 were retrospectively analyzed. HLA typing was performed using a standard complement-dependent cytotoxicity technique. The degree and type of HLA-A, HLA-B, and HLA-DR mismatch were assessed. We also investigated the posttransplantation laboratory data, incidence of rejection, recurrence of hepatitis B virus (HBV), and graft survival as outcome parameters.

RESULTS

The type of HLA-A, HLA-B, and HLA-DR mismatch had no effect on rejection episodes, whereas the beneficial effect of a much lower degree (0-2) of HLA mismatch was notable. Recipients with 2 HLA-B mismatches or recipients with a higher degree of mismatch were associated with elevated bilirubin level, a higher recurrence rate of HBV, and inferior graft survival. A complete mismatch of 2 at the DR locus also decreased graft survival in LDLT recipients.

CONCLUSIONS

This study confirmed that the degree of HLA mismatch, as well as the locus-specific type of HLA mismatch, namely B and DR, play a major role in graft outcomes after LDLT. To obtain an improved graft outcome, HLA compatibility should be considered in the setting of LDLT, which provides sufficient time to select a more favorable donor-recipient combination.

Impact of alloimmune T cell responses on hepatitis C virus replication in liver transplant recipients

We investigated the influence of alloimmune T cell responses on hepatitis C virus (HCV) replication in HCV-infected patients after liver transplantation (LT). To monitor the immune-status in 27 HCV-infected LT recipients, we routinely performed mixed lymphocyte reaction (MLR) assays within 4 weeks after LT. HCV RNA titers in most patients fluctuated in inverse proportion to the stimulation index (SI) of anti-donor reactive T cells early after LT. Two weeks after LT, recipients with high HCV RNA titers (>1000 KIU/mL) displayed a significantly lower SI for anti-donor reactive T cells than recipients with low HCV RNA titers did (<1000 KIU/mL). An in vitro transwell assay mimicking the anatomical features of the interaction between HCV-infected hepatocytes and alloreactive T cells in allograft livers demonstrated that interferon (IFN)-γ was necessary to suppress HCV replication. This study proves the significant impact of alloimmune T cell responses on HCV replication in HCV-infected LT recipients.

Post-liver transplant hepatitis C virus recurrence: an unresolved thorny problem

Hepatitis C virus (HCV)-related cirrhosis represents the leading cause of liver transplantation in developed, Western and Eastern countries. Unfortunately, liver transplantation does not cure recipient HCV infection: reinfection universally occurs and disease progression is faster after liver transplant. In this review we focus on what happens throughout the peri-transplant phase and in the first 6-12 mo after transplantation: during this crucial period a completely new balance between HCV, liver graft, the recipient's immune response and anti-rejection therapy is achieved that will deeply affect subsequent outcomes. Nearly all patients show an early graft reinfection, with HCV viremia reaching and exceeding pre-transplant levels; in this setting, histological assessment is essential to differentiate recurrent hepatitis C from acute or chronic rejection; however, differentiating the two patterns remains difficult. The host immune response (mainly cellular mediated) appears to be crucial both in the control of HCV infection and in the genesis of rejection, and it is also strongly influenced by immunosuppressive treatment. At present no clear immunosuppressive strategy could be strongly recommended in HCV-positive recipients to prevent HCV recurrence, even immunotherapy appears to be ineffective. Nonetheless it seems reasonable that episodes of rejection and over-immunosuppression are more likely to enhance the risk of HCV recurrence through immunological mechanisms. Both complete prevention of rejection and optimization of immunosuppression should represent the main goals towards reducing the rate of graft HCV reinfection. In conclusion, post-transplant HCV recurrence remains an unresolved, thorny problem because many factors remain obscure and need to be better determined.

Natural history, treatment and prevention of hepatitis C recurrence after liver transplantation: Past, present and future

Hepatitis C virus (HCV)-related liver disease, including cirrhosis and hepatocellular carcinoma is the main indication for liver transplantation (LT) worldwide. Post-transplant HCV re-infection is almost universal and results in accelerated progression from acute hepatitis to chronic hepatitis, and liver cirrhosis. Comprehension and treatment of recurrent HCV infection after LT have been major issues for all transplant hepatologists and transplant surgeons for the last decades. The aim of this paper is to review the evolution of our knowledge on the natural history of HCV recurrence after LT, including risk factors for disease progression, and antiviral therapy. We will focus our attention on possible ways (present and future) to improve the final long-term results of LT for HCV-related liver disease.

Strategies to reduce hepatitis C virus recurrence after liver transplantation

Hepatitis C virus (HCV) is a major health problem that leads to chronic hepatitis, cirrhosis and hepatocellular carcinoma, being the most frequent indication for liver transplantation in several countries. Unfortunately, HCV re-infects the liver graft almost invariably following reperfusion, with an accelerated history of recurrence, leading to 10%-30% of patients progressing to cirrhosis within 5 years of transplantation. In this sense, some groups have even advocated for not re-transplanting this patients, as lower patient and graft outcomes have been reported. However, the management of HCV recurrence is being optimized and several strategies to reduce post-transplant recurrence could improve outcomes, decrease the rate of re-transplantation and optimize the use of available grafts. Three moments may be the focus of potential actions in order to decrease the impact of viral recurrence: the pre-transplant moment, the transplant environment and the post-transplant management. In the pre-transplant setting, it is not well established if reducing the pre transplant viral load affects the risk for HCV progression after transplant. Obviously, antiviral treatment can render the patient HCV RNA negative post transplant but the long-term benefit has not yet been fully established to justify the cost and clinical risk. In the transplant moment, factors as donor age, cold ischemia time, graft steatosis and ischemia/reperfusion injury may lead to a higher and more aggressive viral recurrence. After the transplant, discussion about immunosuppression and the moment to start the treatment (prophylactic, pre-emptive or once-confirmed) together with new antiviral drugs are of interest. This review aims to help clinicians have a global overview of post-transplant HCV recurrence and strategies to reduce its impact on our patients.

Relevance of HLA compatibility in living donor liver transplantation: the double-edged sword associated with the patient outcome

HLA compatibility in living donor liver transplantation (LDLT) seems relevant to the acceptability of graft livers because LDLT recipients often share most or some part of HLAs with the respective donors. This study retrospectively investigated whether HLA compatibility affected the outcome of LDLT. Three hundred ninety LDLTs were performed in this hospital, and 346 pairs of HLAs (HLA-A, B, DR) were retrieved from the medical record between October 1996 and March 2011. The dates of the deaths were censored when a recipient apparently died of or was retransplanted by other causes than graft failure because of host-versus-graft (HVG) response to purely analyze the outcomes of LDLT in view of HVG response. The relationship between HLA compatibility and graft-versus-host disease (GVHD) was also analyzed. No recipients with recipient-against-donor HLA mismatch (R→D MM) 0 experienced graft failure by HVG response. On the other hand, three of five recipients with "R→D MM 0" together with "donor-against-recipient MM 3" died of fatal GVHD. HLA compatibility in LDLT not only affected the long-term acceptance of graft livers but also the risk of fatal GVHD.

Influence of larger graft weight to recipient weight on the post-liver transplantation course

Size matching between recipient and donor livers is an important factor in organ allocation in the context of liver transplantation (LT). The aim of this study was to determine whether a large graft for recipient size influenced the post-transplant course. One hundred and sixty-two successive LT recipients were included and retrospectively divided into two groups: 25 (15%) had a graft-to-recipient weight ratio (GWRW) ≥ 2.5% and 137 (85%) had a GWRW <2.5%. Postoperative complications and outcomes were recorded. In the GWRW >2.5% group, more end-to-end caval replacement (72% vs. 38%, p = 0.003) and veno-venous bypass (48% vs. 23%, p = 0.01) were used. Peak AST/ALT values were higher in the GWRW >2.5% group (AST: 596 [70-5876] vs. 453 [29-5132] IU/l, p = 0.03; ALT: 773 [101-5025] vs. 383 [36-4921] IU/l, p = 0.02). Among postoperative complications, the rate of respiratory failure was higher in the GWRW >2.5% group (32% vs. 14%, p = 0.04). The rates of other complications did not differ between the two groups. Both groups had similar graft and patient survival rates at one yr. Using large grafts for recipient size did not impair liver function and did not modify graft and patient outcomes at one yr. However, a GWRW >2.5% appeared to be a determining factor for respiratory morbidity following LT.

HLA tissue typing has no effect on the outcome of patients undergoing a living-donor liver transplant: a single-center experience in Egypt

OBJECTIVES

To analyze the effect of human leukocyte antigen tissue typing on outcome of live-donor liver transplant.

MATERIALS AND METHODS

Fifty recipients underwent live-donor liver transplant in the Dar Al-Fouad Hospital in Egypt and were retrospectively evaluated. Patients were classified into 2 groups: those with human leukocyte antigen +ve, and those with human leukocyte antigen -ve and donors. Hepatitis C virus-related end-stage liver disease was the main indication for transplant. Demographic data, preoperative laboratory data, results of human leukocyte antigen tissue typing, Child score, model for end-stage liver disease score, graft/recipient weight-ratio, ischemia times, surgical complications, postoperative laboratory data, liver biopsy, immunosuppression, and pulse steroids were collected. Graft and patient survivals were studied using Kaplan-Meier curves.

RESULTS

The mean model end-stage liver disease score was 18 ± 3.61 in group 1 and 17.73 ± 3.72 in group 2, with no significant difference. Graft/recipient weight ratio, ischemia times, and postoperative complications showed P = NS. Cyclosporine and tacrolimus were used in 5/9, 8/41, and 4/9 in group 1, and 32/41 in group 2 (P = NS). Rejection and pulse steroids were reported in 3/9 and 12/41 of group 1, and 3/12 and 11/41 of group 2 (P = NS). Hepatitis C virus-recurrence was diagnosed in 5/9 of patients (55%) and 8/41 of patients (29.5%) in groups 1 and 2 (P < .05). No statistical difference was found regarding mortality; 5-year patient and graft survival was 35/50 (70% in group 1 [human leukocyte antigen +ve]), 7/9 (77.8%), and 28/41 in group 2 (68.3%) (human leukocyte antigen -ve).

CONCLUSIONS

Positive human leukocyte antigen typing before live-donor liver transplant has no effect on the incidence of postoperative complications, rejection episodes, and patient or graft survival. Recipients with positive human leukocyte antigen typing may have increased risk of hepatitis C virus-recurrence after live-donor liver transplant.

A 7-gene signature of the recipient predicts the progression of fibrosis after liver transplantation for hepatitis C virus infection

Fibrosis recurrence after liver transplantation (LT) for hepatitis C virus (HCV) is a universal event and strongly determines a patient's prognosis. The recipient risk factors for fibrosis recurrence are still poorly defined. Here we assess a genetic risk score as a predictor of fibrosis after LT. The cirrhosis risk score (CRS), which comprises allele variants in 7 genes (adaptor-related protein complex 3 S2, aquaporin 2, antizyme inhibitor 1, degenerative spermatocyte homolog 1 lipid desaturase, syntaxin binding protein 5-like, toll-like receptor 4, and transient receptor potential cation channel M5), was calculated for 137 patients who underwent LT for HCV infection and experienced HCV reinfection of the graft. The patients were stratified into 3 CRS categories: <0.5, 0.5 to 0.7, and >0.7. All patients underwent protocol biopsy after LT (median follow-up = 5 years), and liver fibrosis was assessed according to the Desmet and Scheuer score. The data were analyzed with univariate and multivariate analyses. The results showed that the highest CRS category was strongly associated with the presence of F2 or F3 fibrosis in protocol biopsy samples 1, 3, and 5 years after LT (P = 0.006, P = 0.001, and P = 0.02, respectively). Overall, 75.0% of the patients with a CRS > 0.7 developed at least F2 fibrosis, whereas 51.5% developed F3 fibrosis during follow-up. The predictive value of the CRS for fibrosis progression was independent of known clinical risk factors, including the age of the donor, the sex of the recipient, and the occurrence of acute rejection. A Kaplan-Meier analysis confirmed the prognostic value of the CRS with respect to the recurrence of severe liver fibrosis in HCV-infected patients after LT (log rank = 6.23, P = 0.03). In conclusion, the genetic signature of the recipient predicts the likelihood of severe liver fibrosis in the graft after HCV recurrence. The CRS might help with early clinical decision making (eg, the selection of patients for antiviral therapy after LT).

Hepatitis C recurrence after liver transplantation: has the human leukocyte antigen mismatching at individual loci a role?

BACKGROUND AND AIM

The objective of this 11-year cohort retrospective study conducted in adult patients with chronic hepatitis C virus (HCV) who underwent liver transplantation (LT) was to identify whether human leukocyte antigen (HLA) mismatching is associated with the recurrence of HCV and with the time to recurrence of HCV.

METHODS

Among the 181 patients (74% men; mean age: 54 years, range 25-71) who underwent a LT between 1995 and 2006 in the study center, 163 had relevant data in their medical chart documenting HCV recurrence, and 107 (65.64%) reported a histological evidence of HCV recurrence.

RESULTS

Survival was 78% at 5 years. There was no significant relationship between the total score of HLA-mismatches and the recurrence of HCV. Similarly, there was no significant relationship between the total score of HLA mismatches and the time to recurrence of HCV. For the analyses at each individual locus, a significant relationship between the individual scores of HLA-mismatches and the recurrence of HCV were observed. Out of the 40 patients who experienced a rejection, the rate of recurrence was not different according to the severity of the rejection (75% mild, 64% moderate and 64% for severe rejection).

CONCLUSIONS

In conclusion, this large study did not demonstrate any relationship between the total score of HLA mismatches and HCV-recurrence. Contrarily a significant relationship between the individual scores of HLA mismatches (HLA-A3, HLA-B35, HLA-DR3, HLA-DR7, HLA-DQ2, HLA-DQ2-0) and the recurrence of HCV were observed.

Serum chemokine CXC ligand 10 (CXCL10) predicts fibrosis progression after liver transplantation for hepatitis C infection

The recurrence of liver fibrosis after liver transplantation (LT) for hepatitis C virus (HCV) infection is responsible for graft loss and patient mortality. Although the contribution of the immune system to fibrosis recurrence is anticipated, systematic studies evaluating immune parameters as predictive markers of allograft fibrosis are lacking. The infiltration of immune cells into the graft is governed by chemokines. Here we assessed the predictive value of serum levels of chemokines [chemokine (C-X-C motif) ligand 9 (CXCL9), CXCL10, CXCL11, and chemokine (C-C motif) ligand 2 (CCL2)] with respect to fibrosis recurrence after LT in 90 HCV-infected organ recipients. Chemokines were determined within the first and third years after LT and were correlated with histological fibrosis progression in protocol biopsy samples at 1, 3, 5, and 7 years (median follow-up = 3 years). The association of chemokines with fibrosis progression was assessed by univariate and multivariate analyses and by Cox regression analysis. The results for the analyzed chemokines showed that CXCL10 levels in the first year after LT were strongly associated with early fibrosis recurrence (P = 0.005) independently of risk confounders (including the donor age, HCV viral load, HCV genotype, acute rejection, and inflammatory activity). As assessed by Cox regression analysis, a CXCL10 serum level ≤ 140 pg/mL was significantly predictive of the absence of F2 fibrosis (P = 0.001), whereas a level ≤ 220 pg/mL early after LT predicted the absence of F3 fibrosis during follow-up (P = 0.035).

CONCLUSION

CXCL10 is an independent biomarker of the recurrence of significant fibrosis after LT for HCV infection. These results might guide patients' care after transplantation and help us to select optimal candidates for antiviral therapy post-LT.

Impact of human leukocyte antigen mismatching on outcomes of liver transplantation: A meta-analysis

AIM: To assess the effect of human leukocyte antigen (HLA) mismatching on liver graft outcome and acute rejection from a meta-analysis of available cohort studies.

METHODS: Articles in PubMed/MEDLINE, EMBASE and the Cochrane database from January 1970 to June 2009, including non-English literature identified in these databases, were searched. Only studies comparing HLA or sub-phenotype matching with mismatching were extracted. The percentage of graft survival was extracted by “Engauge Digitizer” from survival curves if the raw data were not displayed. A meta-analysis was performed when at least 3 studies provided data.

RESULTS: Sixteen studies met the inclusion criteria. A lower number of HLA mismatches (0-2 vs 3-6) did reduce the incidence of acute rejection (relative risk: 0.77, P = 0.03). The degree of HLA mismatching (0-2 vs 3-6) had no significant effect on 1-year [hazard ratio (HR): 1.04, P = 0.68] and 5-year (HR: 1.09, P = 0.38) graft survival. In sub-phenotype analysis, the degree of HLA-A, B and DR mismatching (0 vs 1-2) had no significant effect on 1-year and 5-year graft survival, either. The HRs and P-values were 0.95, 0.71 (HLA-A, 1-year); 1.06, 0.60 (HLA-A, 5-year); 0.77, 0.16 (HLA-B, 1-year); 1.07, 0.56 (HLA-DR, 1-year); 1.18, 0.23 (HLA-DR, 5-year), respectively.

CONCLUSION: The results of this systematic review imply that good HLA compatibility can reduce the incidence of acute rejection in spite of having no influence on graft outcomes. To obtain a short recovery time and minimize rejection post transplantation, HLA matching studies should be considered before the operation.

Liver transplantation in the ethnic minority population: challenges and prospects

In the USA, end-stage liver disease (ESLD) is a major cause of morbidity and mortality among ethnic minorities. Ethnic populations vary with respect to chronic liver disease prevalence, access to transplantation, and therapeutic outcomes post liver transplantation. These ethnic differences present unique challenges to healthcare professionals involved in the care of patients with chronic liver disease prior and post transplantation. This review will discuss the variations and challenges of liver transplantation in the ethnic minority population.

Monitoring peripheral blood CD4+ adenosine triphosphate activity in recurrent hepatitis C and its correlation to fibrosis progression

The recurrence of hepatitis C virus (HCV) after orthotopic liver transplantation (OLT) is often associated with rapid fibrosis progression attributed to the state of impaired cellular immunity. At present, there are no means to predict those at risk for progression. Peripheral blood CD4+ adenosine triphosphate (ATP) release (the ImmuKnow assay) correlates with immunoreactivity and has been used to monitor global cellular immune function in transplant recipients. The aim of this study was to assess the relationship between cellular immune function measured by the ImmuKnow assay and fibrosis progression in patients with HCV recurrence after OLT. The ImmuKnow assay was prospectively performed in adult HCV patients at 4 and 12 months post-OLT. Protocol liver biopsies were performed (on day 7, in month 4, and yearly) after OLT. The first biopsy that showed fibrosis post-OLT was used to determine the time interval for developing fibrosis. Sixty-two patients met the inclusion criteria. The median follow-up time was 12 (6.5-12.1) months. Fibrosis progression was observed in 61.3% of the patients. ATP levels were lower in patients with fibrosis progression in comparison with patients without progression at 4 months (145 versus 259 ng/mL, P < 0.001) and at 12 months (152 versus 264 ng/mL, P = 0.008). ATP levels at 4 and 12 months post-OLT were found to be significantly associated with a higher hazard of progression. For each 25-unit increase in ATP levels at 4 and 12 months after transplantation, the hazard of fibrosis progression decreased by 22% (P = 0.001) and 12% (P = 0.015), respectively. In conclusion, greater suppression of cellular immunity, as measured by the ImmuKnow assay, is associated with more rapid progression of fibrosis in patients with recurrent HCV post-OLT. Post-OLT monitoring of CD4+ ATP activity may identify a subset of patients at greatest risk for early fibrosis progression.

Molecular and cellular aspects of hepatitis C virus reinfection after liver transplantation: how the early phase impacts on outcomes

Hepatitis C virus (HCV)-related liver disease postliver transplantation is associated with an accelerated course in comparison with that observed in the nonimmunosuppressed individual. Outcomes in transplantation for this indication have, therefore, been a major area of clinical interest in the field of liver transplantation. The factors underlying the rapid progression of HCV-related liver disease posttransplantation are complex and multifactorial. Nevertheless, recent data indicate a range of parameters assessable early posttransplantation that may be useful in the prediction of outcome of transplantation for this condition. This overview, therefore, concentrates on the early events occurring postliver transplantation in the HCV-infected patient, and the implications of these recent observations for the pathogenesis of the various forms of HCV-related allograft injury.

The natural history of recurrent hepatitis C and what influences this

1. Liver failure and liver cancer from chronic hepatitis C are the most common indications for liver transplantation and numbers of both are projected to double over the next 20 years. 2. Recurrent hepatitis C infection of the allograft is universal and immediate following liver transplantation and associated with accelerated progression to cirrhosis, graft loss and death. 3. Graft and patient survival is reduced in liver transplant recipients with recurrent HCV infection compared to HCV-negative recipients. 4. The natural history of chronic hepatitis C is accelerated following liver transplantation compared C, with 20% progressing to cirrhosis by 5 years. However, the rate of fibrosis progression is not uniform and may increase over time. 5. The rates of progression from cirrhosis to decompensation and from decompensation to death are also accelerated following liver transplantation. 6. Multiple host, donor and viral factors are associated with rapid fibrosis progression and HCV-related graft failure. 7. Over the last decade, graft and patient survival rates have improved following liver transplantation for non-HCV disease but not for HCV-cirrhosis. This may reflect worsening donor quality and changes in immunosuppression strategies over recent years. 8. Viral eradication by antiviral therapy prevents disease progression and improves survival. 9. The severity of recurrent hepatitis C at one year post-transplant predicts subsequent progression to cirrhosis. Annual protocol biopsies are recommended to help determine need for antiviral therapy. 10. The projected impact of recurrent hepatitis C on graft and patient survival can only be avoided by the development of safe and effective antiviral strategies which can both prevent initial graft infection and eradicate established hepatitis C recurrence.

Long-term outcome of human leukocyte antigen mismatching in liver transplantation: results of the National Institute of Diabetes and Digestive and Kidney Diseases Liver Transplantation Database

A perfect or nearly perfect human leukocyte antigen (HLA) match has been associated with better immediate and long-term survival of diseased donor kidney transplants. However, the effect of HLA matching for hepatic allografts remains poorly defined. Using data from the National Institutes of Diabetes and Digestive and Kidney Diseases Liver Transplantation Database, we investigated the association between HLA mismatches and hepatic allograft survival, disease recurrence, and immunosuppression interactions. A, B, and DR loci were used to calculate total mismatch scores of 0 (no mismatches in any loci) to 6 (mismatches in all loci). Seven hundred ninety-nine adults (male, 55%; female, 45%) underwent 883 liver transplants. The 10-year graft survival according to total mismatch score was as follows: 0-2, 60%; 3-4, 54%; and 5-6, 57%. There was a negative effect of mismatching at the A locus on patient survival, with shorter survival for patients with 1 or 2 mismatches compared with 0 mismatches [P = 0.05, hazard ratio (HR) = 1.6]. Patients on tacrolimus with 1 or 2 mismatches at B or DR loci appeared to have increased rates of patient and graft survival compared to patients with 0 mismatches, with the appearance of a protective effect of tacrolimus (HR = 0.67). The effect of HLA mismatching was more pronounced on certain disease recurrences. DR-locus mismatch increased recurrence of autoimmune hepatitis (P = 0.01, HR = 4.2) and primary biliary cirrhosis (P = 0.04, HR = 2). Mismatch in the A locus was associated with more recurrence of hepatitis C virus (P = 0.01, HR = 1.6) and primary sclerosing cholangitis (P = 0.03, HR = 2.9).

CONCLUSION

Mismatching at the A locus decreases patient survival in liver transplant recipients, and mismatching at the DR and A loci affects recurrence of autoimmune liver diseases and hepatitis C, respectively.

Preformed antibodies detected by cytotoxic assay or multibead array decrease liver allograft survival: role of human leukocyte antigen compatibility

The significance of human leukocyte antigen (HLA) compatibility and preformed antibodies in liver transplantation remains unclear. The objectives of this study were to evaluate, in a single-center cohort comprising 896 liver transplants, whether the degree of donor-recipient compatibility and preformed antibodies modified graft survival. Univariate Kaplan-Meier analysis demonstrated that donor-recipient HLA compatibility had a marginal impact on allograft survival. As for compatibility at individual antigen loci, 2 mismatches at HLA-A conferred a survival advantage in retransplanted allografts (P = 0.011). HLA-B and HLA-DR loci did not play a significant role in outcome in any pathology. The concordance of results on preformed antibodies detected by complement-dependent cytotoxicity (CDC) and a multiple bead assay (Luminex xMAP) showed a strong correlation between both techniques (P < 0.0001). Both CDC-detected and Luminex-detected antibodies were associated with shorter graft survival within the first year post-transplant (P = 0.01 and P = 0.016, respectively). Positive CDC T crossmatches and Luminex-detected HLA class II antibodies played a significant role in decreasing graft survival (P = 0.043 and P = 0.0019 at 1 year, respectively, and P = 0.005 and P = 0.038 at 5 years, respectively). A correlation was also observed between the presence of preformed Luminex-detected class II or Luminex I and II antibodies and allograft rejection (P = 0.001 and P = 0.042, respectively). In conclusion, although HLA typing is not a prerequisite for transplantation, screening of HLA antibodies with Luminex techniques and CDC crossmatch may be useful in the detection of at-risk patients that could benefit from increased surveillance and tailored therapy following transplantation.

Récurrence de l'infection par le virus de l'hépatite C (VHC) après transplantation du foie pour hépatopathie due au VHC : facteurs liés à l'hôte et facteurs viraux impliqués dans la survenue et la gravité de la récurrence de l'hépatite virale C

Cirrhosis due to chronic infection by hepatitis C virus (HCV), associated or not to a primary hepatocarcinoma, has become the first indication of liver transplantation. Graft reinfection by HCV is considered to be systematic while its prognosis is variable from one patient to another. A better knowledge of factors implicated in the occurrence and severity of hepatitis C recurrence is crucial in order to make optimal patients' monitoring. This article aims to present available data in this field, clarifying the role of viral factors (viral load, genotype, evolution of viral quasispecies) and host-related factors (immune response) which could take part in the development of hepatitis C recurrence.