ABSTRACT
Background: Rheumatoid factor (RF) is commonly used for diagnosis of rheumatoid arthritis (RA). RF positivity is nonspecific for diagnosis of RA because it can be detected in 3-5of normal individuals. Recent studies indicated that anti-Cyclic-Citrullinated protein (Anti-CCP) antibodies are more specific to diagnose rheumatoid arthritis and have the capacity to diagnose RA in early stages of the disease; or even before the onset of the disease when the arthritis is undifferentiated. Objectives: This study has been conducted to assess the reliability and specificity of anti- CCP in the Sudanese as an indicator of RA. Patients and methods: In this study; patients were diagnosed as RA patients according to the American College of Rheumatology (ACR) criteria. To get further insight on the sensitivity and specificity of Anti-CCP test as compared to that of RF test in the diagnosis of RA; analysis of samples obtained was perform negative rate reached 21.2. Although anti-CCP test is more accurate compared with RF; it may sometimes fail to diagnose some patients with rheumatoid antibodies were scarce