1558 - Use Of Anti-Cyclic Citrullinated Peptide Antibodies to Distinguish Between Rheumatoid Arthritis and Hepatitis C Virus Infection Associated Polyarthritis

M.Salah Abdel Baky1, Dahlia Abdel-Mohsen1, Howaida Mansour1, Mohamed Abdel-Hafeez2, Gamal Abdel-Ghany2. 1Ain Shams University-Rheumatology Division, Cairo, Egypt; 2Maadi Military Hospital, Cairo, Egypt
Presentation Number: 1558

Background: Hepatitis C is a major health problem in Egypt. Among the different extrahepatic manifestations associated with HCV infection, articular involvement is a frequent complication,and the clinical picture of HCV-related arthropathy varies widely.Differentiating patients with HCV-related polyarthritis from patients with rheumatoid arthritis represents both a diagnostic and a therapeutic challenge.
Purpose: to assess the utility of anti-cyclic citrullinated peptide (anti-CCP) antibodies in distinguishing between patients with rheumatoid arthritis (RA) and patients with chronic hepatitis C virus (HCV) infection associated polyarthritis who are seropositive for rheumatoid factor .
Methods: The study included 66 subjects divided as follows : Group (1) 21 patients with RA fulfilling the ACR criteria, all were seropositive for RF and negative for HCV infection. Group (2) 8 patients with chronic HCV infection and RA fulfilling the ACR criteria ,all were seropositive for RF .Group (3) 11 patients with HCV undifferentiated polyarthralgia or arthritis , all were seropositive for RF. Group (4) 10 patients with HCV infection without articular involvement. Group (5) 16 age and sex matched healthy controls. HCV infection had been diagnosed on the basis of the presence of anti-HCV antibodies as detected by third generation ELISA and confirmed by the detection of viral RNA in serum by PCR technique. Anti-CCP was measured by second-generation (ELISA), the positive cutoff level >20 units. The statistical study was carried out by the chi2, Fisher ,Student's t, and Mann-Whitney tests.
Results: Anti-CCP was detected in 16/21 patients with RA group 1 (76%), 7/8 patients with HCV and RA Group 2 (87.5%), 3/11 patients with HCV undifferentiated arthropathy Group 3 (27%) and 1/10 patients with HCV Group 4 (10%).Anti-CCP was not found in the sera of the healthy controls. Anti-CCP was significantly higher in RA patients group 1 compared to HCV arthropathy patients group 3 and HCV patients group 4 (p<0.05), also it was significantly higher in HCV and RA patients group 2 compared to HCV arthropathy patients group 3 and HCV patients group 4 (p<0.05).The 3 patients with positive Anti-CCP in group 3 with HCV undifferentiated arthropathy, showed significant serum levels (84 units, 126 units and 212 units ) and they are representing most probably early RA cases. Meanwhile the only patient with borderline-positive anti-CCP level (25 units) in HCV Group 4 ,was mostly false-positive result caused by nonspecific binding in the ELISA observed infrequently in patients with mixed cryoglobulinemia.
Conclusion: Anti-CCP antibodies may be a useful marker in distinguishing between patients with rheumatoid arthritis (RA) and patients with chronic hepatitis C virus (HCV) associated polyarthritis who are seropositive for rheumatoid factor .

 M. Abdel Baky, None; D. Abdel-Mohsen, None; H. Mansour, None; M. Abdel-Hafeez, None; G. Abdel-Ghany, None.