Relevance of the problem of rheumatoid arthritis
Rheumatoid arthritis (RA) is an autoimmune disease when the immune system attacks its own body, resulting in damage to various organ systems. Structural damage to the joints occurs more frequently, resulting in stiffness, soreness, swelling or redness, usually of symmetrical distribution (e.g., both hands or both feet).
WHO estimates that as of 2019, about 18 million people worldwide suffered from rheumatoid arthritis (RA), and the number of patients with the disease is only increasing each year.
Why should early diagnosis of RA be done?
The main feature of RA is that the prognosis of the disease largely depends on the time of diagnosis.
In case of untimely diagnosis in the course of time from the onset of the disease, the majority of patients suffering from RA, lose the ability to work, have a pronounced pain syndrome and a tendency to chronicity.
RA is a vivid example of a disease in which the long-term prognosis is largely determined by the timeliness of diagnosis and the start of treatment. Early detection allows slowing the progression of joint lesions, preventing structural changes and preserving the patient's functional activity for a long time.
What methods are used for early diagnosis of rheumatoid arthritis?
In addition to joint inflammation, RA results in the production of specific markers such as rheumatoid factor (RF) and antibodies to cyclic citrullinated peptide (ACCP), which are important diagnostic tools.
Today, different isotypes to rheumatoid factor (RF), IgM, IgG and IgA are distinguished. But for a long time, clinical laboratories have been measuring classical rheumatoid factor as IgM antibodies. It has been shown that the sensitivity of RF IgM to RA varies from 55% to 90%, with the prognostic value of a positive result being about 30%, which is certainly not optimal.
Further study of RF immunoassays to IgG and IgA has significantly improved the diagnostic specificity (accuracy) of the test. Moreover, it has been reported that co-determination of RF IgA together with RF IgM precedes the development of RA several years earlier. RF IgG has also been shown to have a higher specificity for RA. And, during routine diagnosis, the presence of all three RF isotypes provided a specificity of up to 96%.
Of course, the main diagnostic criterion for RA remains the determination of antibodies to cyclic citrullinated peptide (ACCP). And according to recent studies of RA diagnosis, it has been suggested that the combination of RF IgM, IgA, IgG and ACCP has a specificity for RA close to 100%.
This combination of tests for ACCP and RF IgM, IgA, IgG can lead to early diagnosis of RA, even before clinical symptoms appear. For those who are very likely to have or develop RA, early diagnosis can change the outcome, as early treatment of RA has significant benefits for the overall result.
Finally, it should be emphasized that patients who have early diagnosis of RA have a higher "quality of life" and functional status throughout the whole period
