Clinical significance of anti-cyclic citrullinated peptide antibodies in Egyptian patients with chronic hepatitis C virus genotype IV infection

Background: Symmetric polyarthritis associated with hepatitis C virus (HCV) infection frequently displays a clinical picture like rheumatoid arthritis (RA). Antibodies to cyclic citrullinated peptide (CCP) have high specificity for the diagnosis of RA. This study examined the frequency and clinical significance of anti-CCP antibodies in patients with chronic HCV infection, with and without manifestations of joint involvement, compared to RA patients. Methods: Serum anti-CCP antibodies and rheumatoid factor (RF) were evaluated in 30 patients with RA and 47 patients with chronic HCV infection. Of those with HCV infection, 20 patients had chronic HCV infection associated with articular involvement and 27 patients had chronic HCV infection without any articular involvement. Results: Anti-CCP antibody level was positive in 70% of RA patients, 8.5% of HCV-infected patients, and in 20% of HCV patients with articular manifestations. RF was positive in 76% of RA patients and in 60% of HCV patients with articular involvement. Cryoglobulins were found in 29% of HCV-infected patients and in 16% of RA patients. Cryoglobulins were more frequent among HCV patients with articular affection (35%) compared to HCV patients without articular affection (26%). Conclusions: Although anti-CCP antibodies remain a useful diagnostic tool for RA, their interpretation in HCV-infected patients with arthritis should be applied with caution. The possibility that those patients could be prone to develop RA cannot be ruled out. Those patients need careful clinical and radiological follow-up. Further large-scale studies are warranted. Clin Chem Lab Med 2009;47:842–7.