Diagnostic value and clinical significance of anti-CCP in patients with advanced rheumatoid arthritis.

Objectives: To investigate the prevalence of anticyclic citrullinated peptide (anti-CCP) in patients with advanced rheumatoid arthritis (RA) and to compare it with those in control subjects. Further, to study the relation between the anti-CCP and the disease activity parameters in these patients.
Patients and Methods: Seventy-six RA patients who had a mean disease duration of 9.8 years were included. Eighty-three age-matched non-RA volunteers were enrolled as the control group. Disease duration, duration of morning stiffness, swollen and tender joint counts, hand deformity, patient's assessment of pain, anti-CCP, rheumatoid factor (RF) and acute phase proteins were evaluated. The functional disability was also assessed with the Modified Health Assessment Questionnaire (HAQ).
Results: Thirty-seven sera (48.7%) in the patient group and one serum (1.2%) in the control group were positive for anti-CCP. RF was positive in 45% of the RA cases and in 5% of controls. Sensitivity and specificity of anti-CCP reactivity for RA were 49.0% and 99.0%, respectively. HAQ score and duration of morning stiffness were found to be significantly associated with anti-CCP positivity. Disease duration, swollen joint count and anti-CCP positivity were the most important variables predicting hand deformity.
Conclusion: The prevalence, sensitivity and specificity of anti-CCP in patients with advanced RA were found to be similar to those reported in patients with early disease. Anti-CCP was significantly associated with some parameters of both disease activity and severity. Anti-CCP might be a useful parameter in clinical evaluation of patients with advanced RA.