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.
Citation
Master of Medicine in Internal Medicine, The University Of Nairobi, 2009Publisher
University of Nairobi. Faculty of Medicine