View clinical trials related to Hepatitis A.
Filter by:This study will identify and characterize immune factors involved in hepatitis C infection and elimination of the virus. Individual responses to hepatitis C infection vary; some people are able to eliminate the virus, whereas others remain chronically infected. This study may identify factors important in preventing infection that may be of help in developing a vaccine or more effective treatments. People over 18 years old who have been exposed to hepatitis C virus may participate in this study. Subjects will be recruited from the National Institutes of Health, Inova Fairfax Hospital, Occupational Medical Services-IDP P.C., Washington Hospital Center and Holy Cross Hospital, all in the Washington, D.C. metropolitan area. Individual patients from other centers will also be recruited on a case by case basis. Participants will have 40 to 60 cc (1 to 2 ounces) of blood drawn at seven intervals. The first collection will be as soon as possible after exposure to hepatitis C virus and then again at 2, 4, 6, 12, 24, and 48 weeks after exposure. The white blood cells will be studied for their response to the virus, and markers for infection will be followed. If infection develops, additional samples of blood may be requested, and patients will be offered evaluation for treatment. Test results will be kept confidential and will not be entered into any medical records.
The HALT-C Trial is a National Institute of Diabetes and Digestive and Kidney Diseases sponsored, randomized clinical trial of long-term use of Peginterferon alfa-2a (pegylated interferon) in patients who failed to respond to prior interferon treatment. All patients who enter the trial will be treated for 6 months with Peginterferon alfa-2a and Ribavirin. Patients who respond to this 6 month treatment will continue to be treated for an additional 6 months. Patients who do not respond to this treatment will be eligible for the long-term maintenance phase of this study where patients will be randomly selected to be treated with Peginterferon alfa-2a or to discontinue treatment for 3.5 years. Patients in both arms of this study will be followed closely with quarterly study visits. The combination of peginterferon plus ribavirin has recently been approved by the FDA for treatment of chronic hepatitis C. Patients who remain HCV-RNA positive after being treated for at least 6 months with peginterferon and ribavirin outside of this study may be eligible to directly enter the randomized portion of the HALT-C Trial. The HALT-C study is designed to determine if continuing interferon long-term over several years will suppress Hepatitis C virus, prevent progression to cirrhosis, prevent liver cancer and reduce the need for liver transplantation.
The diverse clinical syndromes associated with hepatitis C underscore the multifactorial and polygenic nature of HCV infection. Both viral and host factors likely contribute to variations in infection outcome, disease susceptibility and progression, and treatment response. This protocol will focus on the immunogenetics of HCV infection. Various candidate genes, most of them related to host immune response in microbial infection, have defined genetic polymorphisms that have been associated with variable manifestations of infections including malaria, tuberculosis, leprosy, AIDS and hepatitis B. In this proposal, we plan to collect peripheral blood mononuclear cells as a source of DNA from approximately 1500 patients with HCV infection, analyze genetic polymorphisms of various candidate genes in association with viral clearance, disease progression or treatment response, and characterize the functional consequences of these polymorphisms in patients with well-defined clinical sequelae of HCV infection. We will also collect blood from patients with other forms of liver diseases (approximately 300) or normal volunteers (approximately 200) as controls. By identifying relevant host factors genetically and investigating their molecular interactions with HCV, we may gain additional insights into HCV pathogenesis and uncover new potential targets for vaccine development and treatment intervention.
To elucidate the role of hepatitis delta virus (HDV) in the development of chronic liver disease in patients with hemophilia.
To determine the prevalence of hepatitis delta virus (HDV) in a large cohort of hemophiliacs and to elucidate the role of HDV in the development and progression of liver disease in this population.
This study will evaluate hepatitis C virus (HCV) infection in blood donors who test positive for antibodies to this virus. Most HCV-infected people do not become ill and are not aware that they have hepatitis or have had it in the past. Some infected people recover completely, whereas others remain chronically infected. The study will try to define infectivity of anti-HCV positive individuals, routes of transmission of the virus, and the number of HCV-infected persons who have evidence of liver disease. Blood donors at the NIH Clinical Center or the Central Maryland Chapter of the American Red Cross who test positive for HCV may be eligible for this study. Participants will have a physical examination and history, including questions about socioeconomic status and current sexual practices. They will have 100 milliliters (ml) (6 tablespoons) of blood drawn at the first visit and 50 ml (3 tablespoons) drawn 3, 6, 9 and 12 months after the initial visit. Some participants may undergo plasmapheresis, a procedure for collecting additional plasma (the liquid portion of the blood). For this procedure, whole blood is collected through a needle placed in an arm vein. The blood circulates through a machine that separates it into its components. The plasma is then removed, and the red and white cells and platelets are returned to the body, either through the same needle used to draw the blood or through a second needle placed in the other arm. In some individuals, other body fluids (saliva, urine or semen) may also be collected. Participants may be asked to bring their household contacts and sexual partners to NIH for interview and blood testing for evidence of HCV infection and liver disease. Although this is not required for participation in the study, it would provide additional valuable information. Participants found to have chronic viral infection will be seen more often and will provide additional blood samples for routine medical care. Further medical evaluation may include X-rays or liver scans and referral to a specialist for additional tests or therapy. Ten people in this study will be recruited to participate in a secondary investigation to analyze changes in the level of HCV and the immune response to it, and to relate these changes to the degree of liver damage. In addition to blood collected for the primary study, participants in this investigation will have an additional 50 ml (3 tablespoons) of blood drawn from an arm vein every week for 10 weeks to measure levels of virus, ALT (a liver enzyme), and immune response.
This protocol represents a continuation of a series of prospective studies to define the incidence and etiology of transfusion-associated hepatitis (TAH) and to examine the impact on TAH of various modifications in the selection of blood donors. The primary goal of the study will be to determine TAH incidence after the institution of a variety of interventive measures to exclude hepatitis and AIDS virus carriers: including surrogate assays (ALT, anti-HBc), a specific assay for the hepatitis C virus (HCV), a specific assay for the human immunodeficiency virus (HIV) and intensified donor questioning for high-risk behavior patterns. There is high probability that the exclusion of donors at high risk for AIDS transmission will also exclude donors at high risk for hepatitis transmission. Incidence data obtained in the study will be enhanced by the simultaneous follow-up of a control population undergoing identical surgical procedures, but receiving no blood or only autologous blood. This control population, made possible by the recent dramatic increase in the amount of autologous blood utilized, will allow for a clear distinction between transfusion-associated hepatitis and that due to nosocomial transmission or other background causes of hepatocellular inflammation in cardiac surgery patients.
OBJECTIVES: I. Determine whether the initial response to interferon alfa (IFN-A) can be increased by starting at a dose of 5 MU three times a week in patients with chronic hepatitis C. II. Determine whether patients who had normalized alanine aminotransferase (ALT) levels can maintain normal ALT during stepwise dose reduction from 5 MU to 3 MU to 1.5 MU.
Hepatitis C is a disease of the liver caused by the Hepatitis C Virus (HCV). Patients with hepatitis C may feel well and show no signs or symptoms of being ill. However, researchers would like to study the long-term effects of this disease. Volunteer blood donors diagnosed with chronic hepatitis C viral (HCV) and various levels of liver enzyme activity will be offered a complete medical evaluation and liver biopsy. The tests will enable researchers to provide the patients with an idea of how severe their liver disease is. The virus and patient will be studied in order to understand why patients with hepatitis C develop different levels of liver damage.
Hepatitis is an inflammation of the liver. Hepatitis can be caused by an infection with a virus, but poisonous (toxic) substances can also cause it. Researchers have identified several of the viruses responsible for hepatitis, however some patients with hepatitis show no evidence of being infected with known hepatitis viruses. Researchers call conditions like this, seronegative hepatitis. It means that a patient has hepatitis but he/she does not have evidence in their blood of a viral infection. Seronegative hepatitis is often complicated by autoimmune disorders and associated severe disorders especially, fulminant hepatitis of childhood and post-hepatitis aplastic anemia. Researchers have attempted to identify the cause of these conditions but have been unsuccessful. Therefore, this study was developed to collect blood and stool samples from patients with seronegative hepatitis in order to help identify the virus responsible.