Rheumatoid factors $$$
Synonym(s)
DefinitionThis section has been translated automatically.
Autoantibodies against the Fc part of complexed or altered IgG. The rheumatoid factors can belong to all immune classes (IgG, IgM, IgA). The classical rheumatoid factor is an autoantibody of the immune class IgM. The IgM isotypes are predominantly determined.
General informationThis section has been translated automatically.
Standard value: The standard value in serum is < 40 IU/ml
Pathologically increased: in rheumatoid arthritis (80%), lupus erythematosus (often), Sjörgen syndrome, systemic sclerosis, Tbc, syphilis, sarcoidosis, primary biliary cirrhosis, Waldenström's disease, healthy persons, subacute bacterial endocarditis, mononucleosis, acute viral hepatitis, rheumatoid arthritis, type II kyroglobulinemia, parasitic, viral and bacterial infections, vasculitis, chronic lung diseases
OccurrenceThis section has been translated automatically.
- Primary chronic polyarthritis (rheumatoid arthritis) (50-90%)
- subacute bacterial endocarditis (50-60%)
- Lupus erythematosus, systemic (15-35%)
- Sjögren's syndrome (75-95%)
- Cryoglobulinemia (40-100%)
- Mixed Connective Tissue Disease (MTCD) (50-60%)
- Scleroderma (20-30%)
- Polyarteritis nodosa,
- Dermatomyositis about 30%.
Negative for arthropathic psoriasis!
Note(s)This section has been translated automatically.
RF should only be assessed in the context of clinical symptoms.
Auto-Ak against citrullinated proteins / peptides(anti-CPA, ACPA) have a higher sensitivity in the diagnosis of RA than the rheumatoid factor!
LiteratureThis section has been translated automatically.
- Böhm BO (2018) Autoantibody diagnostics. In: Neumeier B et al. (Eds) Clinical guide to laboratory diagnostics. Elsevier GmbH S. 412-413