The clinical importance of anti-CCP in early diagnosis of Sudanese patients with rheumatoid arthritis

Abstract

Background: Rheumatoid Arthritis (RA) is a systemic inflammatory autoimmune disorder; it is the most common inflammatory arthritis in the world. The early diagnosis and effective treatment of rheumatoid arthritis (RA) can improve the clinical outcome of the disease. Recently, anti-Cyclic-Citrullinated protein antibodies (Anti-CCP) are found to be more specific to RA arthritis although in the early stages when the arthritis is undifferentiated. The objective of this study was to determine the clinical importance and the prevalence of anti-CCP in early diagnosis of Sudanese patients with RA. Methodology This work was a cross-sectional study conducted at Al Ribat teaching hospital (from June 2012 to ? 2014). The study sample included 56 Sudanese patients, known patients of RA who fulfilled the ACR criteria. Demographic and clinical data were collected by questionnaires. All patients and controls sera were investigated for anti-CPP by enzyme linked immunosorbent assay (ELISA). Results The mean age of RA patients in this study was 46.0 (±11.7) years. The control group consisted of 56 Sudanese apparently healthy subjects, 27 (48%) of them were female with mean age of 37 ±17.2years. The anti-CCP antibodies were detected in 60.7% of cases, and in two (3.6%) of the control group. The sensitivity of anti-CCP was 60.7% and specificity of 96.4%. Anti-CCP test has a maximum proportionate reduction in uncertainty (PRU) of 94% for a positive result and 59% for a negative result. Conclusions Anti-CCP antibody has a higher diagnostic specificity and positive predictive value than rheumatoid factor; however its sensitivity was low.