Rheumatoid arthritis was once known as an undead cancer, indicating that it is a disease that seriously damages the body and mind of patients, and its harm is no less than that of cancer.
Because the early symptoms of rheumatoid arthritis are relatively hidden, some patients believe that this is joint pain caused by strain, degeneration, colds and other reasons, and do not consider the possibility of rheumatoid arthritis, so they do not go to the rheumatology department.
Clinical diagnosis of rheumatoid arthritis requires a combination of symptoms and signs and hematological tests, of which hematological indicators are the most important. Today, let's talk about the four kings of rheumatoid arthritis.
One. Rheumatoid factor, or RF for short, was the first in history to be found to diagnose rheumatoid arthritis. It is produced by human B cells and appears in the serum of 60% to 80% of patients with rheumatoid arthritis.
Multiple studies have confirmed that rheumatoid factors have higher rates of seroprevalence in patients with rheumatoid arthritis, compared with lower rates of positivity in other types of arthritis, non-rheumatic diseases, and healthy populations.
Therefore, rheumatoid factors are of great significance in the diagnosis and differentiation of rheumatoid arthritis. For some time, rheumatoid factor has been considered the gold standard for diagnosing rheumatoid arthritis.
Since 20% to 40% of patients with rheumatoid arthritis still have negative serum rheumatoid factor, and a few normal people can also be positive for rheumatoid factor, rheumatologists have been looking for other antibodies that are more specific and sensitive to diagnosing rheumatoid arthritis.
Two. Anti-CCP antibody.
Anti-cyclic citrullinated peptide antibody, referred to as anti-CCP antibody, is a polypeptide fragment of cyclic polyfilament protein, which can be seen in the serum of more than 80% of patients with rheumatoid arthritis, and the specificity of anti-CCP antibodies for the diagnosis of rheumatoid arthritis is as high as about 95%.
Because anti-CCP antibodies are important for the early diagnosis of rheumatoid arthritis, they are considered the gold standard for diagnosing rheumatoid arthritis.
As early as 2010, the American Rheumatological Society and the European Anti-Rheumatic Union included anti-CCP antibodies in the classification criteria for rheumatoid arthritis.
Three. Anti-MCV antibody.
Anti-waveform protein antibodies, referred to as anti-MCV antibodies, are autoantibodies that target mutant citrulline waveform proteins.
Waveform protein is an important cytoskeletal protein, mainly manifested in fibroblasts, endothelial cells and white blood cells, etc., and is also found in the synovial fluid of rheumatoid arthritis patients.
Studies have shown that the diagnosis of rheumatoid arthritis by anti-MCV antibodies is comparable to that of anti-CCP antibodies, but its sensitivity is higher than that of anti-CCP antibodies, and bone erosion has better predictive value.
Therefore, anti-MCV antibody can be used as one of the serological indicators for clinical diagnosis of rheumatoid arthritis, and the combination detection with anti-CCP antibody and rheumatoid factor can improve the specificity of rheumatoid arthritis diagnosis.
IV. AKA
In 1979, foreign scholars first discovered anti-keratin antibodies, or AKA, in the serum of rheumatoid arthritis patients. Because AKA can react with antigen antibodies in the stratum corneum of the esophagus of rats, it is named antikeralin antibody.
Existing studies have found that AKA can be detected in patient serum years before the onset of rheumatoid arthritis and is therefore considered to have early diagnostic value.
AKA has a diagnostic specificity of up to 94% for rheumatoid arthritis, but has a low sensitivity of only 40%. Therefore, it is mainly used as a supplementary diagnostic indicator of rheumatoid arthritis.
Rheumatoid factor, anti-CCP antibody, anti-MCV antibody, AKA, although there are differences in the specificity and sensitivity of the diagnosis of rheumatoid arthritis, can form an effective complement to improve the accuracy of early diagnosis of rheumatoid arthritis.