Prevalence of Anti-cyclic Citrullinated Peptide Antibodies in Patients Classified as Rheumatoid and Undifferentiated Arthritis at Kenyatta National Hospital.

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. 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: A cross-sectional descriptive study. SETTING Kenyatta National Hospital Medical Outpatient Clinics (MOPCs) between the month of October 2008 to 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(64) 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 Rheumatoid Factor (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 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 patients who were RF negative were Anti-ccp positive.