Determination of anti-CCP antibodies is used in the evaluation of patients with suspected rheumatoid arthritis and to differentiate rheumatoid arthritis from other connective tissue diseases that may have arthritis.
Anti-CCP (Cyclic Citrullinated Peptide) antibodies are known as antibodies against the cyclic citrated peptide. The citrulent peptide antigen is formed as an intermediate in the conversion of the ornithine amino acid to arginine. Anti-CCP antibodies appear early in the course of rheumatoid arthritis. When anti-CCP antibodies are detected in a patient's blood, there is a high probability that the patient is suffering from rheumatoid arthritis. The measurement of anti-CCP is therefore useful in the diagnosis of patients with unexplained inflammation of the joints, especially when the classical blood test, the rheumatoid factor (RF), is negative.
Many patients with early rheumatoid arthritis may not have high levels of RF, making the diagnosis difficult in the early stages of the disease. Rheumatoid arthritis can be diagnosed, even if RF is negative if anti-CCP antibodies are elevated. This is especially important because treatment in the early stages of rheumatoid arthritis prevents the development of articular injury. The appearance of anti-CCP can occur years before any clinical manifestation of arthritis. The sensitivity and specificity of anti-CCP antibodies for rheumatoid arthritis are 67.5% and 99.3%, respectively. Rheumatoid factor (RF) has a sensitivity of 66.3% and a lower specificity (82.1%) than anti-CCP. When used in both tests, the specificity for diagnosing rheumatoid arthritis reaches 99.1%.
The presence of anti-CCP in rheumatoid arthritis indicates a more aggressive and destructive form of the disease. They are also an indicator of the progression of the disease. Some believe that rheumatoid arthritis with anti-CCP positive and rheumatoid arthritis with anti-CCP negative are clinically two different entities, with the former being a much worse prognosis.
Possible Interpretations of Pathological Values
- Increase: Rheumatoid arthritis, rarely in other autoimmune diseases
Laboratory test results are the most important parameter for the diagnosis and monitoring of all pathological conditions. 70%-80% of diagnostic decisions are based on laboratory tests. Correct interpretation of laboratory results allows a doctor to distinguish "healthy" from "diseased".
Laboratory test results should not be interpreted from the numerical result of a single analysis. Test results should be interpreted in relation to each individual case and family history, clinical findings and the results of other laboratory tests and information. Your personal physician should explain the importance of your test results.
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