Prevalence of anti-neutrophil cytoplasmic antibodies in patients with chronic hepatitis C infection associated mixed cryoglobulinemia.
Chronic hepatitis C virus (HCV) has been linked to extrahepatic autoimmune phenomena. In addition, a variety of autoantibodies are found in patients with HCV. Anti-neutrophil cytoplasmic antibodies (ANCA) have been considered to be highly specific for systemic small vessel vasculitides with renal involvement. The prevalence, nature, a clinical significance of anti-neutrophil cytoplasmic antibodies (ANCA) in serum samples of patients with HCV were therefore investigated. A prospective study of 67 consecutive patients with chronic HCV with no evidence of previous hepatitis B virus (HBV) infection or any other autoimmune disorder. Twenty-seven patients with HBV and 35 healthy volunteers matched for age and sex served as control groups. Anti-neutrophil cytoplasmic antibodies in the serum samples were measured by indirect immunofluorescence assay. The group of patients with HCV and ANCA in their serum showed significantly higher total IgG levels, a higher incidence of antinuclear antibodies, and viraemia (HCV RNA) than the ANCA negative patients. None of the patients with HCV and ANCA showed any clinical manifestations related to those autoantibodies. This study clearly shows a high prevalence of ANCA in the serum of patients with HCV. The role of these autoantibodies on the course of HCV infection and their clinical significance has not been determined yet. In conclusion, ANCA are not only markers of small vessel vasculitides, but can also be (false?) positive in patients with HCV infection. A hepatitis C associated vasculitis should be considered in the differential diagnosis. Determination of target antigens for ANCA is indispensable. Interpretation and therapeutic decisions concerning ANCA associated HCV should only be performed within the clinical context.
Cojocaru
M
M
Colentina Clinical Hospital, Clinical Immunology Department, Bucharest, Romania. mcojocar@cmb.ro
Cojocaru
Inimioara Mihaela
IM
Iacob
Simona Alexandra
SA
D019268:Antibodies, Antineutrophil Cytoplasmic / Q000097:blood*; D016022:Case-Control Studies; D015331:Cohort Studies; D003449:Cryoglobulinemia / Q000097:blood* / Q000821:virology*; D019084:Fluorescent Antibody Technique, Indirect; D019698:Hepatitis C, Chronic / Q000097:blood* / Q000150:complications*; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood; D009504:Neutrophils; D019562:Viral Load
D019268:Antibodies, Antineutrophil Cytoplasmic; D007074:Immunoglobulin G