How should we treat recurrent hepatitis C after liver transplantation?

HLA and autoimmune digestive disease: a clinically oriented review for gastroenterologists

OBJECTIVES

The human leukocyte antigen (HLA) system includes genes involved in graft-vs-host rejection and in immune response. The discovery that HLAs are associated with several diseases led to appealing developments both in basic biomedical research and in clinical medicine, and offered the opportunity to improve the understanding of pathogenesis and classification of diseases, as well as to provide diagnostic and prognostic indicators. The aim of this article is to review the association between HLA alleles and autoimmune digestive disease and its current relationship with modern HLA nomenclature and clinical practice.

METHODS

Articles dealing with the association between HLAs and autoimmune digestive disease (including celiac disease, inflammatory bowel disease, autoimmune hepatitis, sclerosing cholangitis and primary biliary cirrhosis) were searched for using Pubmed and SCOPUS databases from earliest records to January 2008.

RESULTS

The review has provided two sections. In the first, we explain the basic principles of HLA structure, function, and nomenclature, as an introduction to the second section, which describes current associations between HLA alleles and digestive diseases. The clinical implications of each HLA association are critically discussed. Actually, a clinical role for HLA typing is suggested for only a few conditions, e.g., celiac disease.

CONCLUSIONS

The knowledge of current HLA nomenclature and of its association with some digestive diseases such as celiac disease can be useful in clinical practice for diagnostic and prognostic purposes. This can avoid improper HLA typing as well as stressing the need for further studies on other possible clinical applications.

Sustained virological response to antiviral therapy reduces mortality in HCV reinfection after liver transplantation

BACKGROUND/AIMS

HCV infection recurs almost in all HCV-positive patients receiving liver transplantation and carries a poor prognosis. Aim of this study was to analyze efficacy and effect on survival of antiviral therapy in this clinical setting.

METHODS

Pegylated-interferon alpha-2b and ribavirin were administered at a dose of 1 microg/kg of bwt weekly and 600-800 mg/day. Planned duration of treatment was 24 or 48 weeks according to HCV genotype. Patients who failed to respond at week 24 were considered as non-responders.

RESULTS

61 patients were enrolled. According to intention-to-treat analysis, 44 (72%) patients were considered as treatment failure (31 non-responders, 4 relapsers, 9 dropout). Sustained virological response was achieved in 17 cases (28%). Genotype 2, higher doses of antivirals and absence of histological cirrhosis were predictors of sustained virological response. In the follow up, patients with sustained virological response had a significantly lower mortality compared to patients with treatment failure (chi2=6.9; P<0.01).

CONCLUSIONS

Response rate to antiviral therapy in HCV reinfection after liver transplantation is higher if a full dose of antiviral drugs is administered and if treatment starts before histological cirrhosis has developed. Sustained virological response improves patient survival.

HLA class II alleles, genotypes, haplotypes, and amino acids in primary biliary cirrhosis: a large-scale study

Twin and family studies suggest there is a significant genetic component to primary biliary cirrhosis (PBC). However, the inability to replicate reported associations has been a recurring problem, with the only consistently reported genetic association that between PBC and HLA-DRB1*0801. However, recently even this has been questioned, and a number of novel associations have also been reported. We reinvestigated HLA class II DRB1, DQA1, and DQB1 alleles and haplotypes in a total of 492 well-characterized PBC patients, 412 from the United Kingdom and an additional 80 patients from northern Italy. There was a clear and significant association with HLA-DRB1*0801 in both groups of patients compared to population-specific healthy controls (12% versus 4% in the UK patients, P=.00087, OR=3.05; and 18% versus 6% in the Italian patients, P=.021, OR=3.15). There were also significant protective associations with DRB1*11 in the Italian patients (28% versus 47%, P=.0071, OR=0.42), but not in the UK patients (8% versus 8%) and a protective association with DRB1*13 in both series (14% versus 20%, P=.042, OR=0.65 in the UK patients; and 10% versus 31%, P=.00092, OR=0.25 in the Italian patients). In conclusion, a complex relationship exists between HLA and PBC, and some genetic associations may be population specific.

Monoclonal antibody HCV-AbXTL68 in patients undergoing liver transplantation for HCV: results of a phase 2 randomized study

A randomized, double-blind, dose-escalation study evaluated the safety and efficacy of hepatitis C virus (HCV)-Ab(XTL)68, a neutralizing, high-affinity, fully human, anti-E2 monoclonal antibody, in 24 HCV-positive patients undergoing liver transplantation. HCV-Ab(XTL)68 or placebo was administered at doses from 20-240 mg as 2-4 infusions during the first 24 hours after transplantation, followed by daily infusions for 6 days, weekly infusions for 3 weeks, and either 2 or 4 weekly infusions for 8 weeks. Serum concentrations of total anti-E2 obtained during daily infusions of 120-240 mg HCV-Ab(XTL)68 were 50-200 microg/mL above concentrations in the placebo group. Median serum concentration of HCV RNA dropped below baseline in all groups immediately after transplantation. On day 2, median change from baseline in HCV RNA was -1.8 and -2.4 log in the 120-mg and 240-mg groups, respectively, compared with -1.5 log with placebo. The difference was lost after day 7 when the dosing frequency was reduced. The coincidence of increases in anti-E2 with decreases in HCV RNA concentration indicate that the dose-related changes in HCV RNA concentration were a result of HCV-Ab(XTL)68 administration in the 120- and 240-mg groups. The overall incidence of nonfatal serious adverse events was higher with placebo (60%) vs. all active treatments combined (42%). In conclusion, HCV-Ab(XTL)68 may decrease serum concentrations of HCV RNA in patients after liver transplantation. Studies evaluating more frequent daily dosing at doses >120 mg are necessary to investigate sustained viral suppression in this population.

Sensitivity to antiviral therapy may change after liver transplantation in patients with chronic hepatitis C virus infection

In hepatitis C virus (HCV)-infected patients, it is generally assumed that the pattern of response to antiviral therapy remains unaltered after liver transplantation (LT). However, changes in the circulating HCV quasispecies and in the gene expression profiles of the graft might influence response to treatment after LT. We evaluated 22 HCV-infected patients who received antiviral treatment while awaiting LT and in whom HCV infection recurred. Eleven of these patients underwent a new antiviral treatment course. Our study analyses the early virological response to both treatment courses to assess the influence of the changes in HCV on the response to therapy. Patients were considered early virological responders (EVR) if viral load declined > or = 2 log10 during the first 12 weeks of therapy. The remaining individuals were considered nonresponders (NR). HCV sequences from hypervariable region 1 and nonstructural 5A (NS5A) region before both treatment regimens were compared. Of 11 patients, 8 (73%) showed identical early response to both courses of therapy (group A: five EVR-EVR, three NR-NR). Interestingly, the response changed in three patients (27%) (group B): two NR became EVR after transplantation, whereas one EVR became NR. Fixation of mutations within the NS5A occurred preferentially in group B (100%) compared with group A (37%)(P = 0.12). However, the number of fixed mutations was not significantly different between groups, suggesting that the changes in sensitivity to therapy after LT are not exclusively dependent on variations in HCV strains. In conclusion, in HCV-infected patients undergoing LT, the pattern of response to antiviral treatment may change after transplantation, and this possibility needs to be incorporated in clinical practice.