Hepatitis C Virus and the Humoral Immune System
Hepatitis C Virus and the Humoral Immune System
The purpose of this study is to measure specific chemokines, antibodies, and
 antibody-producing B cells in the blood of patients with hepatitis C virus (HCV) infection.
 Our hypothesis is that changes in chemokine levels affect the development of an effective
 immune response against HCV.
The long-term goal of our research is to understand why immune complexes (ICs) are produced
 in patients infected with HCV, and whether these complexes affect virus interaction with
 target cells. We have found that many patients infected with HCV have an increased frequency
 of circulating B cells, but no evidence that the increased B cells are activated of
 proliferating. One possible mechanism for such an increase would be a change in levels of
 chemokines that influence B cell localization and trafficking. Our studies are aimed at
 testing the following hypotheses:

 1. One hypothesis is that HCV infection results in increased levels of specific cytokines
 and chemokines that may affect the motility and localization of immature and mature B
 cells. An alternative model is that HCV infection leads to chronic antigenic stimulation
 of B lymphocytes, and that the abnormalities of B cell function associated with HCV
 infection reflect this chronic antigenic stimulation.

 2. A second hypothesis is that autoantibodies and immune complexes present in HCV patient
 serum contribute to the persistence and spread of viral infection.

 To test these hypotheses, we are measuring levels of chemokines, the frequency of circulating
 B cells (mature resting B cells, mature activated B cells, memory B cells, and immature B
 cells), and the levels and components of ICs in the blood of HCV-infected patients. Controls
 include healthy volunteers and patients with chronic liver disease unrelated to HCV
 infection. No interventions in patient care are planned. When patients elect to undergo
 standard antiviral therapies under the supervision of their hepatologists, we will study the
 outcomes of therapy (no virologic response, partial or transient virologic response,
 sustained virologic response) to determine whether any of the observed alterations in
 chemokine levels, B cell frequency or activation, or immune complex levels correlate with the
 patient's response to antiviral therapy.
Inclusion Criteria:

 -  Healthy volunteers, no liver disease

 -  Chronic infection with hepatitis C virus

 -  Other chronic liver disease unrelated to hepatitis C virus

 -  Subjects in all groups must have sufficiently healthy veins to allow blood collection.

 Exclusion Criteria:

 -  Any medical condition that, in the opinion of the investigators, precludes the
 patient's participation