Prevalence of anti-cyclic citrullinated peptide antibodies in patients classified as rheumatoid and undifferentiated arthritis at Kenyatta National Hospital

Abstract

Background: Rheumatoid Arthritis (RA) is a debilitating condition. Early diagnosis of RA can be difficult as the disease may initially be indistinguishable from Undifferentiated Arthritis (UA). American College of Rheumatology Criteria (ACR) is not suitable for early diagnosis as its characteristics are fulfilled when bone damage has already taken place. Anti-cyclic citrullinated antibodies (Anti-CCP) are highly specific for RA and have been used to confirm early diagnosis. We carried out a study to find the prevalence of these antibodies in patients classified as RA and UA by the ACR criteria at the Kenyatta National Hospital (KNH) in Nairobi, Kenya. Objective:To determine the prevalence and clinical utility of Anti-CCP antibodies in patients with rheumatoid and undifferentiated arthritis at presentation to KNH medical clinics. Design:This was a cross-sectional descriptive study. Setting:KNH Medical Outpatient Clinics (MOPCs) between the month of October 2008 and February 2009. Results: A total of 95 patients were recruited. The mean age of the patients studied in the RA and UA was 44.7 and 41.2(p=0.356) respectively. Sixty four patients satisfied ACR criteria. The overall prevalence of Anti-ccp antibodies in the population studied was 47.4%. The prevalence of Anti-ccp antibodies in patients who satisfied the ACR criteria was 62.5%. The prevalence of RF in patients who satisfied the ACR criteria was 50% compared to 9.7% for those who did not (p=0.000). The male to female ratio of the subjects studied was 1:11 Conclusion: Anti-ccp antibodies are more prevalent in this cohort of patients with rheumatoid and undifferentiated arthritis than RF. It was also concluded that ACR characteristics correlated well with Anti-ccp and RF. A greater percentage of the patients who were RF negative were Anti-ccp positive