Rheumatoid factor (RF) is used to be for a long time the most commonly performed serological test in suspected rheumatoid arthritis (RA). These antibodies (predominantly of Class IgM) occur in 60-80% of RA patients. RF is a sensitive but not a very specific test for RA, since they can occur in healthy individual and in patients with various autoimmune diseases (SLE, Sjogren�s syndrome, scleroderma, etc
In recent years, it has been shown that rare amino acid citrulline which is present in filaggrin (a protein in the keratin of the epidermis linking keratin filaments to each other) is a substantial component of the antigenic epitope. Antibodies against cyclic citrullinated peptide (CCP) are a new and highly specific marker for RA
Antibodies against CCP are predominantly of class IgG and have much higher specificity of 97% for RA , compared to 62 % for RF. The sensitivity of 80%, on the other hand is similar to both tests. This test, in addition, can be detected in early stages of the disease in 79% of patients
Conclusion: anti-CCP is a new test with a very high specificity for Rheumatoid arthritis and a high sensitivity. It is now widely replacing �Rheumatoid Factor� as a diagnostic test for �Rheumatoid arthritis
We, in the First Medical Laboratory, are dedicated to bring the best of laboratory medicine to clinical practice to Jordan
Dr. Hussam Abu-Farsakh
American Board of Anatomic & Clinical Pathology, and Cytopathology
Circular: is a periodic circular that distributed to clinician informing them about new and important tests available at First Medical Laboratory. All information listed are supported by recent literature