Prevalence And Clinical Utility Of Anti-ccp In Patients With Inflammatory Arthritis At Kenyatta National Hospital

Abstract

Introduction Rheumatoid arthritis(RA) IS a debilitating condition that causes serious morbidity and mortality.Diagnosed early, the condition can be treated with appropriate therapy so as to either stop or slow the progression of the disease. However early diagnosis of RA can be difficult as the disease may initially be indistinguishable from other forms of arthritis. American College of Rheumatology(ACR) criteria for the diagnosis of RA is such that by the time the patient fulfills this criteria the disease has caused serious irreversible morbidity hence the need to get a criteria that might pick the disease early enough.A new serological marker, Anti-cyclic citrullinated peptide antibodies(Anti-ccp) are highly specific for RA and have been used to confirm early diagnosis of RA when the features for the condition are indistinguishable from other arthritis. Objective The objective of this study was to determine the -prevalence and clinical utility of Anti-ccp antibodies in patients with inflammatory arthritis at presentation to KNH medical clinics. Design This was a cross-sectional descriptive study. Setting The study was conducted at KNH MOPCs between the month of October 2008 to February 2009. Results A total of 134 patients with arthritis were screened. 1declined consent. 133 patients were eligible and consented to participate in this study.The entry point for further analysis was a raised erythrocyte sedimentation rate(ESR) and 95 patients fulfilled this criteria and hence had inflammatory arthritis and their samples were further analysed.64 patients had RA as per the ACR criteria.31 patients who did not satisfy the ACR criteria were classified as unspecified arthritis(U A). The mean age of the patients studied in the RA and VA as classified by the revised ACR criteria was 44.7 and 41.2 years(p=0.356) respectively. The overall prevalence of Anti-ccp antibodies in the population was 47.4% in comparison to that of rheumatoid factor(RF) that was prevalent at 36.8%.The prevalence of Anti-ccp antibodies in patients with RA was 62.5% as compared to 16.1% of those who had UA(p=0.000).The prevalence of RF in patients who had RA was 50% as compared to 9.7% for those who had UA(P=0.000).Themale to female ratio of subjects studied was 1:I1.The calculated sensitivity and specifity for Anti-ccp was 62.5% and 83.9% respectively.20% of patients who were RF negative had their sera test positive for Anti-ccp antibodies.5.26% of patients who did not satisfy the ACR criteria were Anti-ccp positive.The number of joints involved positively correlated with the ACR and Anti-ccp levels. Conclusion Anti-ccp antibodies are more prevalent in this cohort of patients with inflammatory arthritis than RF hence its reliability in early diagnosis of RA. It was also concluded that ACR characteristics correlated well with Anti-ccp and RF.Inflammatory arthritis is more prevalent in females than males and affects the middle aged.A greater percentage of patients with inflammatory arthritis were Anti-ccp positive but did not satisfy ACR and were negative for RF.Patients who never satisfied the ACR criteria and were thus classified as VA can still have RA because of positive Anti-ccp.The sensitivity of Anti-ccp was higher than that of RF.About 5.26% of patients who were classified as VA and did not satisfy the ACR criteria were positive for Anti-ccp.