Autoantibodies in hepatitis C: red flag or bystander effect?
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ABSTRACT: Antinuclear antibodies (ANA) frequently arise in the sera of children with connective tissue disease and is used in the diagnosis of these diseases. Therefore it is also important to know the prevalence of ANA in normal children. The main objective of the present study was to determine the prevalence of antinuclear antibody (ANA) in healthy children. Ninety-nine serum samples from a serum bank and 108 samples from patients who had attended elective surgery and whose blood had been withdrawn for other investigations, were tested for ANA by indirect immunofluorescence method using HEp-2 cells as substrate. Sera from 52 children with SLE were also tested during the same period. It was found that antinuclear antibodies were present in 32 (15%) of the 207 sera of healthy children at a dilution of 1:40 or higher. ANA were positive in 9% at a serum dilution of 1:40, in 3% at 1:80 and in 3% at 1:160. The patterns of immunofluorescence staining were as follows: homogeneous in 46.7%, speckled in 20%, and nucleolar in 10%. In SLE patients, ANA were positive in 91%; 13% at a serum dilution of 1:40, 7% at 1:80, 20% at 1:160, 15% at 1:320, 9% at 1:640, 20% at 1:1,280 and 9% at > or = 1:2,560. It was concluded that the prevalence of positive ANA using the HEp-2 cells as substrate was 15% in healthy children at dilutions of 1:40 or higher. Using the cutoff serum dilution of 1:40, the sensitivity of this test was 91%, the specificity was 85%, the positive predictive value was 57% and the negative predictive value was 97%.Asian Pacific journal of allergy and immunology / launched by the Allergy and Immunology Society of Thailand 11/2004; 23(2-3):153-7. · 1.26 Impact Factor
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ABSTRACT: Interferon alpha (IFN alpha) is the cornerstone therapeutic agent for chronic hepatitis C virus (HCV) infection. Prospective studies have shown that up to 15% of HCV patients receiving IFN alpha develop clinical thyroid disease, and up to 40% become thyroid antibody positive. In some cases IFN-induced thyroiditis (IIT) may result in discontinuation of interferon therapy; thus, IIT represents a major clinical problem for hepatitis C patients receiving IFN alpha therapy. Recently, the mechanisms leading to the development of IIT have begun to be unraveled. It is now clear that HCV itself plays a role in the disease. Moreover, recent data suggest the IFN alpha precipitates thyroiditis by both immune modulatory mechanisms and direct thyroid toxic effects. Genetic factors also play a major role in the etiology of IIT. IIT can manifest both as clinical autoimmune thyroiditis (ie, Hashimoto's thyroiditis and Graves' disease) and as nonautoimmune thyroiditis (ie, destructive thyroiditis). Early detection and therapy of these conditions are important to avoid complications of thyroid disease such as cardiac arrhythmias. This article reviews the epidemiology and clinical manifestations of IIT and the mechanisms causing IIT, focusing on the role of HCV.Endocrinology & Metabolism Clinics of North America 01/2008; 36(4):1051-66; x-xi. DOI:10.1016/j.ecl.2007.07.001 · 2.86 Impact Factor
Article: HCV and autoimmunity[Show abstract] [Hide abstract]
ABSTRACT: Hepatitis C virus (HCV) infection is characterized by a number of autoreactive manifestations, such as autoantibody production, cryoglobulinemia and thyroid disorders. We will analyse critically the mechanisms invoked, and partially documented, to explain such manifestations arising in genetically predisposed individuals exposed to HCV. In particular we will examine the available evidence implicating the virus in lowering the B cell activation threshold, in directly infecting lymphocytes and in inducing self-reactivity through a mechanism of molecular mimicry. We will then move to the HCV related clinical immunopathological manifestations, with a specific attention to the effects of antiviral treatment.Current pharmaceutical design 02/2008; 14(17):1678-85. DOI:10.2174/138161208784746824 · 3.29 Impact Factor