Recurrent Hepatitis C in Liver Allografts: Prospective Assessment of Diagnostic Accuracy, Identification of Pitfalls, and Observations about Pathogenesis

Rationale and Design: The accuracy of a prospective histopathologic diagnosis of rejection and recurrent hepatitis C (HCV) was determined in 48 HCV RNA-positive liver allograft recipients enrolled in an "immunosuppression minimization protocol" between July 29, 2001 and January 24, 2003. Prospective entry of all pertinent treatment, laboratory, and histopathology results into an electronic data-base enabled a retrospective analysis of the accuracy of histopathologic diagnoses and the pathophysiologic relationship between recurrent HCV and rejection. Results: Time to first onset of acute rejection (AR) (mean, 107 days; median, 83 days; range, 7-329 days) overlapped with the time to first onset of recurrent HCV (mean, 115 days; median, 123 days; range, 22-315 days), making distinction between the two difficult. AR and chronic rejection (CR) with and without co-existent HCV showed overlapping but significantly different liver injury test profiles. One major and two minor errors occurred (positive predictive values for AR = 91%; recurrent HCV = 100%) ; all involved an overdiagnosis of AR in the context of recurrent HCV. Retrospective analysis of the mistakes showed that major errors can be avoided altogether and the impact of unavoidable minor errors can be minimized by strict adherence to specific histopathologic criteria, close clinicopathologic correlation including examination of HCV RNA levels, and a conservative approach to the use of additional immunosuppression. In addition, histopathologic diagnoses of moderate and severe AR and CR were associated with relatively low HCV RNA levels, whereas relatively high HCV RNA levels were associated with a histopathologic diagnosis of hepatitis alone, particularly the cholestatic variant of HCV. Conclusions: Liver allograft biopsy interpretation can rapidly and accurately distinguish between recurrent HCV and AR/CR. In addition, the histopathologic observations suggest that the immune mechanism responsible for HCV clearance overlap with those leading to significant rejection

DCs Pulsed with Novel HLA-A2-Restricted CTL Epitopes against Hepatitis C Virus Induced a Broadly Reactive Anti-HCV-Specific T Lymphocyte Response

OBJECTIVE: To determine the capacity of dendritic cells (DCs) loaded with single or multiple-peptide mixtures of novel hepatitis C virus (HCV) epitopes to stimulate HCV-specific cytotoxic T lymphocyte (CTL) effector functions. METHODS: A bioinformatics approach was used to predict HLA-A2-restricted HCV-specific CTL epitopes, and the predicted peptides identified from this screen were synthesized. Subsequent IFN-γ ELISPOT analysis detected the stimulating function of these peptides in peripheral blood mononuclear cells (PBMCs) from both chronic and self-limited HCV infected subjects (subjects exhibiting spontaneous HCV clearance). Mature DCs, derived in vitro from CD14(+) monocytes harvested from the study subjects by incubation with appropriate cytokine cocktails, were loaded with novel peptide or epitope peptide mixtures and co-cultured with autologous T lymphocytes. Granzyme B (GrB) and IFN-γ ELISPOT analysis was used to test for epitope-specific CTL responses. T-cell-derived cytokines contained in the co-cultured supernatant were detected by flow cytometry. RESULTS: We identified 7 novel HLA-A2-restricted HCV-specific CTL epitopes that increased the frequency of IFN-γ-producing T cells compared to other epitopes, as assayed by measuring spot forming cells (SFCs). Two epitopes had the strongest stimulating capability in the self-limited subjects, one found in the E2 and one in the NS2 region of HCV; five epitopes had a strong stimulating capacity in both chronic and self-limited HCV infection, but were stronger in the self-limited subjects. They were distributed in E2, NS2, NS3, NS4, and NS5 regions of HCV, respectively. We also found that mDCs loaded with novel peptide mixtures could significantly increase GrB and IFN-γ SFCs as compared to single peptides, especially in chronic HCV infection subjects. Additionally, we found that DCs pulsed with multiple epitope peptide mixtures induced a Th1-biased immune response. CONCLUSIONS: Seven novel and strongly stimulating HLA-A2-restricted HCV-specific CTL epitopes were identified. Furthermore, DCs loaded with multiple-epitope peptide mixtures induced epitope-specific CTLs responses

Aplicação do escore MELD em pacientes submetidos a transplante de fígado: análise retrospectiva da sobrevida e dos fatores preditivos a curto e longo prazo The application of MELD score in patients submitted to liver transplantation: a retrospective analysis of survival and the predictive factors in the short and long term

RACIONAL: Utiliza-se o escore MELD (Model End-Stage Liver Disease) para o prognóstico da mortalidade em lista de espera para transplante de fígado e, em alguns estudos, para predição da sobrevida pós-operatória a longo prazo. OBJETIVO: Verificar a aplicação do escore MELD como predição da sobrevida após o transplante. MÉTODOS: Por intermédio de dados coletados prospectivamente efetuou-se um estudo de coorte longitudinal retrospectivo em 232 pacientes. Excluíram-se os retransplantes, insuficiência hepática aguda, crianças e enxertos duplos ou reduzidos. Avaliaram-se os dados dos doadores: idade, sexo, peso, creatinina, bilirrubina, sódio, aspartato aminotransferase, antecedentes pessoais, causa da morte, presença de esteatose, número de critérios expandidos do doador e índice de risco do doador. Em relação aos receptores, analisaram-se as variáveis: sexo, idade, peso, doença hepática, pontos de Child-Turcotte-Pugh, escore MELD, depuração de creatinina, sódio, tempos de isquemia e de hospitalização, quantidade de hemoderivados transfundidos, presença e grau de disfunção do enxerto. A análise estatística foi efetuada usando-se a análise de regressão univariada e/ou múltipla, estatística 'c', teste exato de Fisher, método de Kaplan-Meier (teste log-rank) para sobrevida, e análise de regressão de Cox para risco de óbito ajustado para as condições clínicas. RESULTADOS: O ponto de corte MELD para sobrevida foi 20 e de Child-Turcotte-Pugh foi 11,5. Para escore MELD maior ou igual a 20, os fatores preditivos de sobrevida foram: volume de sangue transfundido, disfunção do enxerto e o sódio do doador. Para os hiponatrêmicos os fatores preditivos de sobrevida foram: volume de sangue transfundido, disfunção do enxerto e sódio do doador. A sobrevida estimada para pacientes com escore MELD >25 foi menor ao final de 12 meses (68,86% vs 39,13%). A sobrevida estimada para os pacientes sem hiponatremia foi maior (65,16% vs 44,44%). A sobrevida aos 5 e 10 anos também seguiu o mesmo padrão. O uso de doadores limítrofes não alterou a sobrevida, mas quando se utilizou o índice de risco do doador observou-se que a sobrevida foi maior para pacientes com índice de risco do doador menor que 1,7 (63,62% vs 53,70%). A associação deste índice com o escore MELD não mostrou diferença estatística em relação à sobrevida. Observou-se que a falência e disfunção do enxerto foram associadas ao número crescente de critérios expandidos do doador. Os receptores de doadores maiores de 50 anos tiveram menor sobrevida (65,58% vs 38,40%) e o escore delta-MELD não discriminou a sobrevida. CONCLUSÃO: A sobrevida dos receptores a curto e longo prazo é associada a escores MELD acima de 25, ao volume de sangue transfundido, à disfunção do enxerto, à hiponatremia, à idade do doador acima de 50 anos e àqueles doadores com índice de risco do doador acima de 1,7.<br>BACKGROUND: The model for end-stage liver disease (MELD) was developed to predict short-term mortality in patients with cirrhosis. There are few reports studying the correlation between MELD and long-term posttransplantation survival. AIM: To assess the value of pretransplant MELD in the prediction of posttransplant survival. METHODS: The adult patients (age >18 years) who underwent liver transplantation were examined in a retrospective longitudinal cohort of patients, through the prospective data base. We excluded acute liver failure, retransplantation and reduced or split-livers. The liver donors were evaluated according to: age, sex, weight, creatinine, bilirubin, sodium, aspartate aminotransferase, personal antecedents, brain death cause, steatosis, expanded criteria donor number and index donor risk. The recipients' data were: sex, age, weight, chronic hepatic disease, Child-Turcotte-Pugh points, pretransplant and initial MELD score, pretransplant creatinine clearance, sodium, cold and warm ischemia times, hospital length of stay, blood requirements, and alanine aminotransferase (ALT >1,000 UI/L = liver dysfunction). The Kaplan-Meier method with the log-rank test was used for the univariable analyses of posttransplant patient survival. For the multivariable analyses the Cox proportional hazard regression method with the stepwise procedure was used with stratifying sodium and MELD as variables. ROC curve was used to define area under the curve for MELD and Child-Turcotte-Pugh. RESULTS: A total of 232 patients with 10 years follow up were available. The MELD cutoff was 20 and Child-Turcotte-Pugh cutoff was 11.5. For MELD score > 20, the risk factors for death were: red cell requirements, liver dysfunction and donor's sodium. For the patients with hyponatremia the risk factors were: negative delta-MELD score, red cell requirements, liver dysfunction and donor's sodium. The regression univariated analyses came up with the following risk factors for death: score MELD > 25, blood requirements, recipient creatinine clearance pretransplant and age donor >50. After stepwise analyses, only red cell requirement was predictive. Patients with MELD score < 25 had a 68.86%, 50,44% and 41,50% chance for 1, 5 and 10-year survival and > 25 were 39.13%, 29.81% and 22.36% respectively. Patients without hyponatremia were 65.16%, 50.28% and 41,98% and with hyponatremia 44.44%, 34.28% and 28.57% respectively. Patients with IDR > 1.7 showed 53.7%, 27.71% and 13.85% and index donor risk <1.7 was 63.62%, 51.4% and 44.08%, respectively. Age donor > 50 years showed 38.4%, 26.21% and 13.1% and age donor <50 years showed 65.58%, 26.21% and 13.1%. Association with delta-MELD score did not show any significant difference. Expanded criteria donors were associated with primary non-function and severe liver dysfunction. Predictive factors for death were blood requirements, hyponatremia, liver dysfunction and donor's sodium. CONCLUSION: In conclusion MELD over 25, recipient's hyponatremia, blood requirements, donor's sodium were associated with poor survival