Rheumatoid factor, IgA antibodies (RF IgA) – testing at Dr. Rødrega Laboratory0774
Rheumatoid factor IgA (RF IgA) are autoantibodies directed against the Fc fragment of IgG. Determining RF IgA in blood serum helps predict erosive damage to joint cartilage in rheumatoid arthritis (RA). Combined with antibodies to cyclic citrullinated peptide (anti-CCP), this test allows detection of the disease at early preclinical stages and is used for screening individuals at risk.
FEIA (Fluorescence Enzyme Immunoassay) – quantitative determination of IgA antibodies to rheumatoid factor.
- Diagnosis of rheumatoid arthritis (RA).
- Monitoring the effectiveness of rheumatoid arthritis treatment.
- Detection of autoimmune processes in systemic connective tissue diseases.
- Blood collection in the morning on an empty stomach between 8 and 11 a.m. or 4-5 hours after the last meal.
- Avoid consuming fatty foods 24 hours before the test.
- For children under 1 year – do not feed 30-40 minutes before the test.
- For children aged 1-5 years – do not feed 2-3 hours before the test.
- Do not smoke 30 minutes before the test.
- Drink 1-2 glasses of clean still water before blood collection.
- Blood should be drawn before taking medications; indicate medication intake on the referral form.
- Avoid physical and emotional stress on the day of the test.
Rheumatoid factors (RF) are autoantibodies that can be present in various autoimmune diseases, including rheumatoid arthritis, Sjögren's syndrome, systemic lupus erythematosus, and others. The IgA subclass of RF is an important diagnostic marker that complements information about disease activity and severity. The presence of RF IgA combined with other RF subclasses and anti-CCP antibodies is 100% specific for rheumatoid arthritis, improving diagnosis, differential diagnosis, and treatment monitoring.

