Recipient-donor race mismatch for African American liver transplant patients with chronic hepatitis C

Joint testing of donor and recipient genetic matching scores and recipient genotype has robust power for finding genes associated with transplant outcomes

Genetic matching between transplant donor and recipient pairs has traditionally focused on the human leukocyte antigen (HLA) regions of the genome, but recent studies suggest that matching for non-HLA regions may be important as well. We assess four genetic matching scores for use in association analyses of transplant outcomes. These scores describe genetic ancestry distance using identity-by-state, or genetic incompatibility or mismatch of the two genomes and therefore may reflect different underlying biological mechanisms for donor and recipient genes to influence transplant outcomes. Our simulation studies show that jointly testing these scores with the recipient genotype is a powerful method for preliminary screening and discovery of transplant outcome related single nucleotide polymorphisms (SNPs) and gene regions. Following these joint tests with marginal testing of the recipient genotype and matching score separately can lead to further understanding of the biological mechanisms behind transplant outcomes. In addition, we present results of a liver transplant data analysis that shows joint testing can detect SNPs significantly associated with acute rejection in liver transplant.

The Impact of Share 35 Policy on Patient Survival in Patients Undergoing Liver Transplantation With Gender- and Race-Mismatched Donors: An Analysis of the United Network for Organ Sharing Registry

INTRODUCTION

The United Network for Organ Sharing (UNOS) instituted the Share 35 policy in June 2013 in order to reduce death on liver transplant waitlist. The effect of this policy on patient survival among patients with gender- and race-mismatched donors has not been examined.

RESEARCH QUESTION

To assess the impact of Share 35 policy on posttransplantation patient survival among patients with end-stage liver disease (ESLD) transplanted with gender- and race-mismatched donors.

DESIGN

A total of 16 467 adult patients with ESLD who underwent liver transplantation between 2012 and 2015 were identified from UNOS. An overall Cox proportional hazards model adjusting for demographic, clinical, and geographic factors and separate models with a dummy variable of pre- and post-Share 35 periods as well as its interaction with other factors were performed to model the effect of gender and race mismatch on posttransplantation patient survival and to compare the patient survival differences between the first 18 months of Share 35 policy to an equivalent time period before.

RESULTS

Comparison of the pre- and post-Share 35 periods did not show significant changes in the numbers of gender- and race-mismatched transplants, or the risk of death for gender-mismatched recipients. However, black recipients with Hispanic donors (hazard ratio: 0.51, 95% confidence interval, 0.29-0.90) had significantly increased patient survival after Share 35 policy took effect.

CONCLUSION

The Share 35 policy had a moderate impact on posttransplantation patient survival among recipients with racially mismatched donors according to the first 18-month experience. Future research is recommended to explore long-term transplantation.

Impact of Donor Recipient Gender and Race Mismatch on Graft Outcomes in Patients With End-Stage Liver Disease Undergoing Liver Transplantation

CONTEXT

The discrepancy between donor supply and organ demand increased the possibility of gender and race mismatch between the donors and recipients. However, the findings of their impact on graft and patient survival are outdated and mixed.

OBJECTIVE

To estimate the effects of gender and race mismatch on graft survival and patient survival among adult patients (18 years and older) with end-stage liver disease.

DESIGN

A total of 38 768 patients undergoing liver transplant between 2002 and 2011 were identified from United Network for Organ Sharing database. Kaplan-Meier curves, log-rank tests, and Cox proportional hazard regressions with backward elimination adopting a marginal approach with a working independence assumption and stratification on recipient hepatitis C virus status were used.

MAIN OUTCOME MEASURES

Posttransplantation graft survival and patient survival.

RESULTS

Both gender mismatch (hazard ratio [HR]: 1.14, 95% confidence interval [CI]: 1.09-1.12) and race mismatch (HR 1.08, 95%C: 1.04-1.12) had significantly adverse effects on graft survival and patient survival after controlling for other factors, especially among hepatitis C-positive female recipients with male donors (HR 1.13, 95%CI 1.03-1.24), black recipients with white donors (1.39, 1.29-1.49) or Hispanic donors (HR 1.48, 95%CI 1.27-1.72), and these effects were even worse among hepatitis C-positive recipients.

CONCLUSION

Gender and race mismatch between donors and recipients adversely affected graft survival and patient survival among adult patients with end-stage liver disease, both independently and after the adjustment for other factors. Future research is recommended to explore other factors such as new model for end-stage liver disease sharing policy change and disparities in access to waiting-list or transplantation.

Risk stratification of allograft failure secondary to hepatitis C recurrence after liver transplantation

AIM

Hepatitis C virus (HCV) recurrence after liver transplantation decreases survival rates. Improved understanding of the multiple factors influencing HCV recurrence could aid decision-making for donor-recipient pairing and maximize transplant outcomes. The aim of this study was to create a model based on pretransplant variables to stratify patients at risk of HCV-related allograft failure.

METHODS

This retrospective study enrolled 154 liver transplant recipients with HCV at Cleveland Clinic.

RESULTS

Among the study population, 54 recipients (35.1%) experienced HCV recurrence, histologically defined as moderate to severe hepatitis and/or bridging fibrosis to cirrhosis. The multivariate analysis found donor age (≥60 years, P < 0.002), donor body mass index (≥30 kg/m² , P < 0.05), African American recipient (P < 0.01) and genotype 1 (P < 0.02) as risk factors for HCV-related allograft failure. When these four factors were scored as a combined index (no factor [n = 15], one factor [n = 76], two factors [n = 43] and three or more factors [n = 20]), the HCV recurrence-free survival showed good stratification according to the scores: 93.3% with no factor, 79.3% with one factor, 52.0% with two factors and 24.4% with three or more factors at 3 years after transplant (P < 0.0001). Moreover, this risk index also identified the patient group at high risk of HCV recurrence after acute rejection.

CONCLUSION

While the introduction of direct-acting antiviral agents has been changing the paradigm of HCV treatment, the natural history of recipients with HCV as shown in this study would help estimate the risk of HCV-related allograft failure in those who do not tolerate such new treatment.

Pathological Roles of Interleukin-22 in the Development of Recurrent Hepatitis C after Liver Transplantation

OBJECTIVE

The aim of this study was to longitudinally evaluate and analyze the role of interleukin-22-producing CD4 positive cells (IL-22) in the pathogenesis of Hepatitis C Virus recurrence after Orthotopic Liver Transplantation (HCV-OLT).

METHODS

15 HCV-OLT, 15 age- and gender- matched non-HCV post-OLT (OLT) and 15 hepatitis C virus infected (HCV) patients were enrolled into our study from the liver transplantation and research center at Beijing 302 Hospital. We determined the frequencies of IL-22 using flow cytometry and expression of IL-22 mRNA using PCR in peripheral blood and liver tissue. We also divided HCV-OLT patients into rapid fibrosis progression (RFP) and slow fibrosis progression (SFP), examined IL-22 cells and analyzed the correlations between IL-22 frequencies and liver injury, fibrosis and clinical parameters. Moreover, we investigated the role of IL-22 in Human Hepatic Stellate Cells (HSCs).

RESULTS

The levels of serum IL-22, frequencies of IL-22 producing cells in peripheral blood mononuclear cells, and expression of IL-22 mRNA and protein in the liver in the HCV-OLT group were significantly higher than that in the HCV and OLT groups. Furthermore, eight (53.3%) patients developed RFP after two years; another three patients were diagnosed liver cirrhosis. The frequencies of IL-22 were much higher in RFP compared with SFP, while no significant difference existed between OLT and SFP. Intrahepatic IL-22 positive cells were located in fibrotic areas and significantly correlated with α-smooth muscle actin (α-SMA) and fibrosis staging scores, not with grading scores and HCRVNA. In vitro, IL-22 administration prevented HSCs apoptosis, promoted HSCs proliferation and activation, up-regulated the expression of HSC-sourced growth factors including α-SMA, TGF-β and TIMP-1, and increased the production of liver fibrosis markers including laminin, hyaluronic acid and collagen type IV.

CONCLUSION

Peripheral and intrahepatic IL-22 is up-regulated and plays a pathological role in exacerbating liver fibrosis by activating HSCs in HCV-OLT patients, which may predict RFP and serve as an attractive target for anti-fibrotic therapy.

Hepatitis C virus recurrence after liver transplantation: how to treat and when

Chronic hepatitis C (CHC) is an important cause of cirrhosis and hepatocellular carcinoma and a common indication of liver transplantation (LT). Recurrence of hepatitis C occurs universally after LT with an accelerated course of the natural history of CHC in the graft. Treatment of hepatitis C before transplantation is the most effective strategy because it prevents graft reinfection, but applicability is low with pegylated interferon regimens. Treatment after LT is the strategy more frequently used. A sustained viral response (SVR) is achieved by one-third of those treated with dual therapy and is associated with better outcomes after LT. Triple therapy with protease inhibitors after LT has efficacy to 60%-70% of SVR but is associated with higher rates of secondary effects and drug-drug interactions that require an intensified and frequent monitoring of calcineurin inhibitors during treatment. In the near future, interferon-free regimens with new oral antiviral drugs will likely prevent viral reinfection before or after LT, and shorter treatment regimens and less toxicity are expected.

Hepatitis C genotype influences post-liver transplant outcomes

BACKGROUND

In nontransplant patients with chronic hepatitis C virus (HCV), HCV genotype has been linked with a differential response to antiviral therapy, risk of steatosis and fibrosis, as well as all-cause mortality, but the role of HCV genotypes in posttransplant disease progression is less clear.

METHODS

Using the multicenter CRUSH-C cohort, genotype-specific rates of advanced fibrosis, HCV-specific graft loss and response of antiviral therapy were examined.

RESULTS

Among 745 recipients (605 [81%] genotype 1, 53 [7%] genotype 2, and 87 [12%] genotype 3), followed for a median of 3.1 years (range, 2.0-8.0), the unadjusted cumulative rate of advanced fibrosis at 3 years was 31%, 19%, and 19% for genotypes 1, 2, and 3 (P = 0.008). After multivariable adjustment, genotype remained a significant predictor, with genotype 2 having a 66% lower risk (P = 0.02) and genotype 3 having a 41% lower risk (P = 0.07) of advanced fibrosis compared to genotype 1 patients. The cumulative 5-year rates of HCV-specific graft survival were 84%, 90%, and 94% for genotypes 1, 2, and 3 (P = 0.10). A total of 37% received antiviral therapy, with higher rates of sustained virologic response in patients with genotype 2 (hazard ratios, 5.10; P = 0.003) and genotype 3 (hazard ratios, 3.27; P = 0.006) compared to patients with genotype 1.

CONCLUSION

Risk of advanced fibrosis and response to therapy are strongly influenced by genotype. Liver transplantation recipients with HCV genotype 1 have the highest risk of advanced fibrosis and lowest sustained virologic response rate. These findings highlight the need for genotype-specific management strategies.

Hepatitis C in African Americans

The care of hepatitis C virus (HCV) in African Americans represents an opportunity to address a major health disparity in medicine. In all facets of HCV infection, African Americans are inexplicably affected, including in the prevalence of the virus, which is higher among them compared with most of the racial and ethnic groups. Ironically, although fibrosis rates may be slow, hepatocellular carcinoma and mortality rates appear to be higher among African Americans. Sustained viral response (SVR) rates have historically significantly trailed behind Caucasians. The reasons for this gap in SVR are related to both viral and host factors. Moreover, low enrollment rates in clinical trials hamper the study of the efficacy of anti-viral therapy. Nevertheless, the gap in SVR between African Americans and Caucasians may be narrowing with the use of direct-acting agents. Gastroenterologists, hepatologists, primary care physicians, and other health-care providers need to address modifiable risk factors that affect the natural history, as well as treatment outcomes, for HCV among African Americans. Efforts need to be made to improve awareness among health-care providers to address the differences in screening and referral patterns for African Americans.

Recurrent hepatitis C after liver transplant

End stage liver disease from hepatitis C is the most common indication for liver transplantation in many parts of the world accounting for up to 40% of liver transplants. Antiviral therapy either before or after liver transplantation is challenging due to side effects and lower efficacy in patients with cirrhosis and liver transplant recipients, as well as from drug interactions with immunosuppressants. Factors that may affect recurrent hepatitis C include donor age, immunosuppression, IL28B genotype, cytomegalovirus infection, and metabolic syndrome. Older donor age has persistently been shown to have the greatest impact on recurrent hepatitis C. After liver transplantation, distinguishing recurrent hepatitis C from acute cellular rejection may be difficult, although the development of molecular markers may help in making the correct diagnosis. The advent of interferon free regimens with direct acting antiviral agents that include NS3/4A protease inhibitors, NS5B polymerase inhibitors and NS5A inhibitors holds great promise in improving outcomes for liver transplant candidates and recipients.

Hepatitis viruses and liver transplantation: evolving trends in antiviral management

Viral hepatitis is both a leading indication for liver transplant (LT) and an important cause of posttransplant graft loss and mortality. Treatment and prevention of hepatitis B virus in LT recipients, with the observed corresponding improvement in post-LT outcomes, is among the great success stories in transplantation. By comparison, treatment of hepatitis C virus with safe and effective regimens is only just becoming a reality. Chronic hepatitis E virus infection in LT recipients represents a newly described phenomenon that can also lead to graft loss; early diagnosis and treatment may be key in the management of these patients.

Association of genetic variants with rapid fibrosis: progression after liver transplantation for hepatitis C

BACKGROUND

Recurrence of hepatitis C, the main indication for liver transplantation in the United States, leads to rapid fibrosis progression and worse outcomes compared to other indications. While clinical variables play a role, they are insufficient to explain all inter-patient variability in posttransplant fibrosis progression. Genetic factors associated with hepatitis C virus (HCV) outcomes have been identified, but limited studies have been conducted in the context of HCV-related liver transplantation. Therefore, the purpose of this study was to examine candidate genes related to the immune response and rate of fibrosis in subjects undergoing liver transplantation for HCV.

METHODS

One hundred twelve recipients with detailed posttransplant fibrosis and clinical information were genotyped using 25 single nucleotide variants (SNVs), including five SNVs within the IL28B gene region. Associations between SNVs and rapid fibrosis progression were performed controlling for pertinent clinical variables and haplotype analyses for the IL28B gene were completed.

RESULTS

Significant multivariable associations were found for rs8099917 (IL28B), rs1991401 (DDX5), rs4969168 (SOC3), and rs7976497 (MLEC). The minor allele was protective against rapid fibrosis progression for the IL28B SNV (G allele), MLEC SNV (T allele), and DDX5 SNV (G allele). For the SOC3 SNV, the minor allele (A) increased the risk for rapid fibrosis progression. Additionally, two recipient haplotype structures for IL28B were significantly associated with rapid fibrosis progression.

CONCLUSIONS

These findings indicate that recipient genetic factors play a role in posttransplant HCV-related fibrosis progression. Molecular studies of these pathways may elucidate the pathogenesis of posttransplant fibrosis progression and provide risk prediction markers.

Donor Risk Index for African American liver transplant recipients with hepatitis C virus

African American (AA) liver transplant (LT) recipients with hepatitis C virus (HCV) have higher rates of graft loss than other racial/ethnic groups. The Donor Risk Index (DRI) predicts graft loss but is neither race- nor disease-specific and may not be optimal for assessing donor risk for AA HCV-positive LT recipients. We developed a DRI for AA with HCV with the goal of enhancing graft loss predictions. All U.S. HCV-positive adult AA first deceased donor LTs surviving ≥30 days from March 2002 to December 2009 were included. A total of 1,766 AA LT recipients were followed for median 2.8 (interquartile range [IQR] 1.3-4.9) years. Independent predictors of graft loss were donor age (40-49 years: hazard ratio [HR] 1.54; 50-59 years: HR 1.80; 60+ years: HR 2.34, P < 0.001), non-AA donor (HR 1.66, P < 0.001), and cold ischemia time (CIT) (HR 1.03 per hour >8 hours, P = 0.03). Importantly, the negative effect of increasing donor age on graft and patient survival among AAs was attenuated by receipt of an AA donor. A new donor risk model for AA (AADRI-C) consisting of donor age, race, and CIT yielded 1-year, 3-year, and 5-year predicted graft survival rates of 91%, 77%, and 68% for AADRI <1.60; 86%, 67%, and 55% for AADRI 1.60-2.44; and 78%, 53%, and 39% for AADRI >2.44. In the validation dataset, AADRI-C correctly reclassified 27% of patients (net reclassification improvement P = 0.04) compared to the original DRI.

CONCLUSION

AADRI-C identifies grafts at higher risk of failure and this information is useful for risk-benefit discussions with recipients. Use of AA donors allows consideration of older donors.

Differential effects of donor and recipient IL28B and DDX58 SNPs on severity of HCV after liver transplantation

BACKGROUND & AIMS

IL28B single nucleotide polymorphisms are strongly associated with spontaneous HCV clearance and treatment response in non-transplant populations. A DDX58 single nucleotide polymorphism is associated with the antiviral response of innate lymphocytes. We aimed at evaluating the associations of donor and recipient IL28B (rs12979860 and rs8099917) and DDX58 (rs10813831) genotypes with severity of HCV recurrence after liver transplantation.

METHODS

In a case-control study of 523 liver transplantation recipients with HCV, we matched severe with mild recurrent HCV based on 2-year clinical and histologic follow-up. A total of 440 liver transplantation recipients (severe, n=235; mild, n=205) with recipient DNA and 225 (severe, n=123; mild, n=102) with both recipient and donor DNA were analyzed.

RESULTS

IL28B [rs12979860, non-CC (vs. CC) and rs8099917, non-TT (vs. TT)] in the recipient-only analysis had higher risk of severe recurrent HCV [OR 1.57 and 1.58, p<0.05]. However, for the 225 with donor and recipient DNA, IL28B rs12979860 CC (vs. non-CC) and rs8099917 TT (vs. non-TT) and DDX58 rs10813831 non-GG (vs. GG) were associated with more (not less) severe recurrent HCV. The greatest risk of severe recurrent HCV was for rs12979860 CC donors in non-CC recipients (OR 7.02, p <0.001, vs. non-CC donor/recipient) and for rs8099917 TT donors in non-TT recipients (OR 5.78, p=0.001, vs. non-TT donor/recipient). These associations persisted after controlling for donor age, donor race, and donor risk index.

CONCLUSIONS

IL28B and DDX58 single nucleotide polymorphisms that are favorable when present in the non-transplant setting or in the recipient are unfavorable when present in a donor liver graft.

Living-donor liver transplantation and hepatitis C

Hepatitis-C-virus- (HCV-) related end-stage cirrhosis is the primary indication for liver transplantation in many countries. Unfortunately, however, HCV is not eliminated by transplantation and graft reinfection is universal, resulting in fibrosis, cirrhosis, and finally graft decompression. In areas with low deceased-donor organ availability like Japan, living-donor liver transplantation (LDLT) is similarly indicated for HCV cirrhosis as deceased-donor liver transplantation (DDLT) in Western countries and accepted as an established treatment for HCV-cirrhosis, and the results are equivalent to those of DDLT. To prevent graft failure due to recurrent hepatitis C, antiviral treatment with pegylated-interferon and ribavirin is currently considered the most promising regimen with a sustained viral response rate of around 30% to 35%, although the survival benefit of this regimen remains to be investigated. In contrast to DDLT, many Japanese LDLT centers have reported modified treatment regimens as best efforts to secure first graft, such as aggressive preemptive antiviral treatment, escalation of dosages, and elongation of treatment duration.

Liver transplantation in the setting of chronic HCV

Recurrent HCV disease is the most common cause of graft loss and patient mortality in HCV-infected liver transplant (LT) recipients. Risk factors for more severe recurrence that are potentially modifiable are older donor age, prolonged cold ischaemia time, prior treated acute rejection, CMV hepatitis, IL28B donor genotype, and post-LT insulin resistance. The most effective means of preventing HCV recurrence is eradicating HCV prior to LT. Select wait-list candidates with compensated or mildly decompensated disease can be considered for antiviral treatment with peginterferon, ribavirin (and protease inhibitor if genotype 1). For the majority of LT patients, HCV treatment must be delayed until post-transplant. Treatment is generally undertaken if histologic severity reaches grade 3 or 4 necroinflammation or stage ≥2 fibrosis, or if cholestatic hepatitis. Achievement of sustained viral response (SVR) post-LT is associated with stabilization of fibrosis and improved graft survival. SVR is attained in ~30% of patients treated with peginterferon and ribavirin. Poor tolerability of therapy is a limitation. Combination therapy with telaprevir or boceprevir added to peginterferon and ribavirin is anticipated to increase efficacy but with higher rates of adverse effects and challenges in managing drug-drug interactions between the protease inhibitors and calcineurin inhibitors/sirolimus.

Liver transplantation and hepatitis C

Hepatitis-C-virus- (HCV-) related end-stage cirrhosis is the primary indication for liver transplantation in many countries. Unfortunately, however, HCV is not eliminated by transplantation and graft reinfection is universal, resulting in fibrosis, cirrhosis, and finally graft decompensation. The use of poor quality organs, particularly from older donors, has a highly negative impact on the severity of recurrence and patient/graft survival. Although immunosuppressive regimens have a considerable impact on the outcome, the optimal regimen after liver transplantation for HCV-infected patients remains unclear. Disease progression monitoring with protocol biopsy and new noninvasive methods is essential for predicting patient/graft outcome and starting antiviral treatment with the appropriate timing. Antiviral treatment with pegylated interferon and ribavirin is currently considered the most promising regimen with a sustained viral response rate of around 30% to 35%, although the survival benefit of this regimen remains to be investigated. Living-donor liver transplantation is now widely accepted as an established treatment for HCV cirrhosis and the results are equivalent to those of deceased donor liver transplantation.