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Absence of Cyclic Citrullinated Peptide Antibody in Nonarthritic Patients with Chronic Hepatitis C Infection
DOUGLAS LIENESCH, ROBERT MORRIS, ALLAN METZGER, PAIGE DEBUYS, and KENNETH SHERMAN
ABSTRACT. Objective. The increased prevalence of rheumatoid factor (RF) in patients with chronic hepatitis C virus (HCV) infection markedly diminishes the diagnostic specificity of serum rheumatoid factor (RF) for rheumatoid arthritis (RA) in patients with HCV. Cyclic citrullinated peptide (CCP) antibody, a highly specific biomarker for RA in the general population, may have better diagnostic utility for RA in the HCV population. To investigate if CCP antibody retains its specificity for RA in HCV infection, we determined the prevalence of CCP antibodies and examined the relationship between RF production and CCP antibody levels in a population of nonarthritic patients with chronic HCV infection. Methods. CCP antibody and IgM, IgG, and IgA RF isotypes were determined by ELISA in serum from nonarthritic patients with chronic HCV infection. Results. In a series of 50 HCV patients, IgG-RF, IgM-RF, and IgA-RF were detectable in 52%, 26%, and 14%, respectively, with a total seropositivity rate of 54%. Marginally elevated CCP antibody was detected in a single patient (2%). By regression analysis, serum levels of CCP antibodies did not correlate with RF levels. Conclusion. In contrast to RF, CCP antibody is not increased in HCV infection. CCP antibody may have improved utility for the diagnosis of RA in this patient population. (J Rheumatol 2005;32:489–93) Key Indexing Terms:
HEPATITIS C VIRUS
From the Department of Medicine, University of Cincinnati College of Medicine, Cincinnati, Ohio; and Department of Medicine, UCLA School of Medicine, Los Angeles, California, USA. Supported in part by NIH grant R01 AI49508 and RDL Reference Laboratory, Los Angeles, California. D.W. Lienesch, MD; P.C. Debuys, MD, Department of Medicine, Division of Immunology, University of Cincinnati College of Medicine; R. Morris, MD; A. Metzger, MD, Department of Medicine, Division of Rheumatology, UCLA School of Medicine, and RDL Laboratories, Los Angeles, California; K.E. Sherman, MD, PhD, Department of Medicine, Division of Gastroenterology, University of Cincinnati College of Medicine. Address reprint requests to Dr. D.W. Lienesch, 231 Albert Sabin Way, Cincinnati, OH 45267-0563. E-mail: lienesd@ucmail.uc.edu Submitted March 23, 2004; revision accepted October 23, 2004. |