Biomedical subjects
Jay H Hoofnagle
Publications and source records attributed to Jay H Hoofnagle.
Primary sclerosing cholangitis.
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Cellular immune responses to the hepatitis B virus polymerase.
CD4 T cells play an important role in hepatitis B virus (HBV) infection by secretion of Th1 cytokines that down-regulate HBV replication, and by promoting CD8 T cell and B cell responses. We have identified and characterized 10 CD4 T cell epitopes within polymerase and used them to analyze the immunological effects of long-term antiviral therapy as compared with spontaneous recovery from HBV infection. Candidate epitopes were tested for binding to 14 HLA-DR molecules and in IFN-gamma ELISPOT and cytotoxicity assays using peripheral blood lymphocytes from 66 HBV-infected patients and 16 uninfected controls. All 10 epitopes bound with high affinity to the most prevalent HLA-DR Ags, were conserved among HBV genomes, and induced IFN-gamma responses from HBV-specific CD4+ T cells. Several epitopes contained nested MHC class I motifs and stimulated HBV-specific IFN-gamma production and cytotoxicity of CD8+ T cells. HBV polymerase-specific responses were more frequent during acute, self-limited hepatitis and after recovery (12 of 18; 67%) than during chronic hepatitis (16 of 48 (33%); p=0.02). Antiviral therapy of chronic patients restored HBV polymerase and core-specific T cell responses during the first year of treatment, but thereafter, responses decreased and, after 3 years, were no more frequent than in untreated patients. Decreased T cell responsiveness during prolonged therapy was associated with increased prevalence of lamivudine-resistant HBV mutants and increased HBV titers. The data provide a rationale for the combination of antiviral and immunostimulatory therapy. These newly described HBV polymerase epitopes could be a valuable component of a therapeutic vaccine for a large and ethnically diverse patient population.
A pilot study of pioglitazone treatment for nonalcoholic steatohepatitis.
Nonalcoholic steatohepatitis (NASH) is a common chronic liver disease for which there is no known effective therapy. A proportion of patients with NASH progress to advanced fibrosis and cirrhosis. NASH is considered one of the clinical features of the metabolic syndrome in which insulin resistance plays a central role. This prospective study evaluates the role of insulin-sensitizing agent in treatment of NASH. Eighteen nondiabetic patients with biopsy-proven NASH were treated with pioglitazone (30 mg daily) for 48 weeks. Tests of insulin sensitivity and body composition as well as liver biopsies were performed before and at the end of treatment. By 48 weeks, serum alanine aminotransferase values fell to normal in 72% of patients. Hepatic fat content and size as determined by magnetic resonance imaging decreased, and glucose and free fatty acid sensitivity to insulin were uniformly improved. Histological features of steatosis, cellular injury, parenchymal inflammation, Mallory bodies, and fibrosis were significantly improved from baseline (all P < 0.05). Using strict criteria, histological improvement occurred in two-thirds of patients. Pioglitazone was well tolerated; the main side effects were weight gain (averaging 4%) and an increase in total body adiposity. In conclusion, these results indicate that treatment with an insulin-sensitizing agent can lead to improvement in biochemical and histological features of NASH and support the role of insulin resistance in the pathogenesis of this disease. The long-term safety and benefits of pioglitazone require further study.
Liver disease research funding.
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Biliary Atresia Research Consortium (BARC).
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Hepatobiliary pathophysiology study section.
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Drug-induced liver injury network (DILIN).
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Hepatocellular carcinoma: summary and recommendations.
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A survey of liver transplantation from living adult donors in the United States.
BACKGROUND: The transplantation of the right lobe of a liver from a living adult donor into an adult recipient has been performed increasingly frequently in the United States. Although the use of grafts from living donors is standard practice in transplantation in children, their use in adults remains controversial. METHODS: To study the use of liver transplantation from a living donor, we sent a 24-item questionnaire to all liver-transplantation programs in the United States. Data on indications, evaluation, and outcomes were analyzed with the use of univariate and multivariate methods. Data on recent transplantations were gathered from the Scientific Registry of Transplant Recipients and directly from the transplantation programs. RESULTS: Questionnaires were returned by 84 of the 122 programs (69 percent) describing the results of 449 adult-to-adult transplantations of partial livers from living donors that were performed in 42 centers. Fourteen centers had performed more than 10 such transplantations each and together accounted for 80 percent of such transplantations. Centers that performed such transplantations also performed more transplantations of livers from cadaveric donors and more transplantations from living donors in children than centers that did not perform the adult-to-adult procedure (P=0.002 and P=0.001, respectively). A total of 45 percent of potential donors who were evaluated eventually donated a lobe of their liver; 99 percent of these donors were genetically or emotionally related to the recipient. Complications in the donor were more frequent in the centers performing the fewest transplantations from living donors in adults and included biliary complications requiring intervention (in 6.0 percent), reoperation (in 4.5 percent), and death (in one donor [0.2 percent]). Among the recipients, 1.6 percent did not meet criteria for receipt of a cadaveric transplant; cancer, retransplantation, and acute liver failure were uncommon indications for transplantation from a living donor. Biliary complications occurred in 22.0 percent of recipients, and vascular complications occurred in 9.8 percent. CONCLUSIONS: Adult-to-adult liver transplantation from a living donor is increasingly performed in the United States but is concentrated in a few large-volume centers. Mortality among donors is low, but complications in the donor are relatively common.
Challenges in therapy of chronic hepatitis B.
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Hepatitis C and renal disease: an update.
Hepatitis C is both a cause and a complication of chronic renal disease. Chronic infection with hepatitis C virus (HCV) can lead to the immune complex syndromes of cryoglobulinemia and membranoproliferative glomerulonephritis (MPGN). The pathogenetic mechanisms for these conditions have not been defined, although they are clearly caused by the chronic viral infection. Management of HCV-related cryoglobulinemia and MPGN is difficult; antiviral therapy is effective in clearing HCV infection in a proportion of patients, but these conditions can be severe and resistant to antiviral therapy. Hepatitis C also is a complicating factor among patients with end-stage renal disease and renal transplants. The source of HCV infection in these patients can be nosocomial. Screening and careful attention to infection control precautions are mandatory for dialysis units to prevent the spread of hepatitis C. Prevention of spread is particularly important in these patients because HCV infection is associated with significant worsening of survival on dialysis therapy, as well as after kidney transplantation. Furthermore, therapy for hepatitis C is problematic, only partially effective, and associated with significant side effects in this population. There are significant needs in both basic and clinical research in the pathogenesis, natural history, prevention, and therapy for hepatitis C in patients with renal disease.
Appendix: The National Institutes of Health Consensus Development Conference Management of Hepatitis C 2002.
The incidence of newly acquired hepatitis C infection has diminished in the United States. This decline is largely because of a decrease in cases among IDUs for reasons that are unclear and, to a lesser extent, to testing of blood donors for HCV. The virus is transmitted by blood, and such transmission now occurs primarily through injection drug use, sex with an infected partner or multiple partners, and occupational exposure. Most infections become chronic, and therefore the prevalence of HCV infections is high, with about 3 million Americans estimated, to be chronically infected. HCV is a leading cause of cirrhosis, a common cause of HCC and the leading cause of liter transplantation in the United States. The disease spectrum associated with HCV infection varies greatly. Various studies have suggested that 3% to 10% of chronically infected patients will develop cirrhosis over a 20-year period, and these patients are at risk for HCC. Persons who are older at the time of infection, patients with continuous exposure to alcohol, and those coinfected with HIV or HBV demonstrate accelerated progression to more advanced liver disease. Conversely, individuals infected at a younger age have little or no disease progression over several decades. The diagnosis of chronic hepatitis C infection often is suggested by abnormalities in ALT levels and is established by EIA followed by confirmatory determination of HCV RNA. Several sensitive and specific assays are automated partly for the purposes of detecting HCV RNA and quantifying the viral level. Although there is little correlation between viral level and disease manifestations, these assays have proven useful in identifying those patients who are more likely to benefit from treatment and, particularly, in demonstrating successful response to treatment as defined by an SVR. Liver biopsy is useful in defining baseline abnormalities of liver disease and in enabling patients and healthcare providers to reach a decision regarding antiviral therapy. Noninvasive tests do not provide the information that can be obtained through liver biopsy. Information on the genotype of the virus is important to guide treatment decisions. Genotype 1, most commonly found in the United States, is less amenable to treatment than genotypes 2 or 3. Therefore, clinical trials of antiviral therapies require genotyping information for appropriate stratification of subjects. Recent therapeutic trials in defined, selected populations have shown clearly that combinations of interferons and ribavirin are more effective than monotherapy. Moreover, trials using pegylated interferons have yielded improved SVR rates with similar toxicity profiles. Results continue to show, however, that the SVR rate is less common in patients with genotype 1 infections, higher HCV RNA levels, or more advanced stages of fibrosis. Genotype 1 infections require therapy for 48 weeks, whereas shorter treatment is feasible in genotype 2 and 3 infections. In genotype 1, the lack of an early virologic response (< 2 log decrease in HCV RNA) is associated with failure to achieve an SVR. The SVR is lower in patients with advanced liver disease than in patients without cirrhosis. Ongoing trials are exploring the usefulness of combination therapy in various populations. Preliminary experience in IDUs, individuals coinfected with HIV, children, and other special groups suggests similar responses are achievable in these populations. Patients with acute hepatitis C may be treated, but specific recommendations for antiviral treatment must await further evaluation of the rate of spontaneous clearance of the virus and determination of the optimal time to initiate treatment. Preventive measures beyond blood-banking practices include prompt identification of infected individuals, awareness of the potential for perinatal transmission, implementation of safe injection practices, linkage of drug users to drug treatment programs. and implementation of community-based education and support programs to modify risk behavior. Some of these measures have been implemented successfully in the control of HIV infections, and it stands to reason that they would be valuable for reducing HCV transmission. Future advances in the diagnosis and management of hepatitis C require continued vigilance concerning the transmission of this infection, extending treatment to populations not evaluated previously in treatment trials, and the introduction of more effective therapies.
Progression of fibrosis in chronic hepatitis C.
BACKGROUND & AIMS: Fibrosis is the hallmark of hepatic cirrhosis, worsening of which is probably the best surrogate marker for progression of chronic liver disease. We evaluated a large cohort of patients with chronic hepatitis C (CHC) using liver histology to assess the rate and predictors of progression of fibrosis. METHODS: The cohort consisted of 123 patients with CHC who underwent 2 liver biopsies 4-212 months (mean, 44 months) apart without intervening treatment. Liver histology was graded using the histology activity index (score, 0-18) and fibrosis staged using a scoring system of 0 (no fibrosis) to 6 (cirrhosis). RESULTS: Among 123 patients, 48 (39%) showed progression in fibrosis scores, 46 (37%) showed no change, and 29 (24%) showed improvement. Of those with worsening fibrosis, 75% had a 1-point increase and 25% a 2-point or greater increase in scores, and 9% showed progression to cirrhosis. The overall rate of progression was 0.12 fibrosis units per year, a rate that predicts progression to cirrhosis in 50 years if progression was linear. The rate of fibrosis progression was variable, and it was higher among older patients, those with higher serum alanine and aspartate aminotransferase levels, and those with the most extensive periportal necrosis on initial liver biopsy. CONCLUSIONS: The best predictors of fibrosis progression in CHC are the extent of serum aminotransferase elevations and the degree of hepatocellular necrosis and inflammation on liver biopsy. These findings support the recommendation that patients with normal aminotransferase levels and mild liver histology can safely defer treatment.
Associations of chemokine system polymorphisms with clinical outcomes and treatment responses of chronic hepatitis C.
BACKGROUND & AIMS: CCR5Delta32, a 32-base pair deletion of the CC chemokine receptor (CCR) 5 gene, is associated with slowed human immunodeficiency virus disease progression in heterozygotes and protection against infection in homozygotes. A recent study found a higher than expected frequency of CCR5Delta32/Delta32 in patients with hepatitis C virus infection. The roles of other disease-associated chemokine system polymorphisms have not been evaluated in hepatitis C virus infection. METHODS: Six chemokine system polymorphisms (CCR5Delta32, CCR5 promoter 59029-G/A, CCR2 -64I, RANTES [regulated upon activation, normal T cells expressed and secreted] -403 -G/A, and -28 -C/G and stromal derived factor 1 -3'A) were studied in 417 patients with liver diseases (339 with hepatitis C) and 2380 blood donors. The clinical parameters of hepatitis C virus infection were compared between carriers and noncarriers of each genetic variant. RESULTS: The frequency of CCR5Delta32 homozygosity was 0.8% in whites with hepatitis C virus and 1.1% in controls (P = 0.75). The CCR5Delta32 allele was not associated with any of the clinical parameters of hepatitis C virus infection. Hepatitis C virus-seropositive whites with the RANTES -403-A allele were less likely to have severe hepatic inflammation compared with those without (odds ratio, 0.34; P = 0.03). In multivariate analysis, the CCR5 promoter 59029 -A allele was marginally associated with a sustained response to interferon therapy (odds ratio, 3.07; P = 0.048). CONCLUSIONS: In this cohort, the frequency of CCR5Delta32 homozygosity in patients with hepatitis C was similar to controls. The high prevalence of CCR5Delta32 homozygosity in the hepatitis C virus patients of the earlier study likely reflects resistance to human immunodeficiency virus infection in hemophiliacs rather than a susceptibility to hepatitis C virus infection. Expression of CCR5 and RANTES may be important in the modulation of hepatic inflammation and response to interferon therapy in chronic hepatitis C.
Mortality rate during interferon alfa-ribavirin combination therapy of chronic hepatitis C.
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Viral kinetics in hepatitis C.
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