This MedLibrary.org supplementary page on Rheumatoid factor is provided directly from the open source Wikipedia as a service to our readers. Please see the note below on authorship of this content, as well as the Wikipedia usage guidelines. To search for other content from our encyclopedia supplement, please use the form below:
Related Sponsors
Rheumatoid factor (RF or RhF) is an autoantibody (antibody directed against an organism's own tissues) most relevant in rheumatoid arthritis. It is an antibody against the Fc portion of IgG, which is itself an antibody. RF and IgG join to form immune complexes which contribute to the disease process. Not all people with rheumatoid arthritis have detectable rheumatoid factor. Those who do not are said to be "seronegative".
Rheumatoid factor can also be a cryoglobulin (antibody that precipitates on cooling of a blood sample); it can be either type 2 (monoclonal IgM to polyclonal IgG) or 3 (polyclonal IgM to polyclonal IgG) cryoglobulin.
Contents |
Indications
RF is often determined in patients suspected in any form of arthritis. It has relatively little use there, as positive results can be due to other causes, and negative results do not rule out disease. But, in combination with signs and symptoms, it can be diagnostic and prognostic. It is part of the disease criteria of RA.
Interpretation
High levels RF (generally above 20 IU/mL, 1:40 or over the 95th percentile there is some variation among labs) are indicative of rheumatoid arthritis (present in 80%) and Sjögren's syndrome (present in almost 100%).1 The higher the levels of RF the higher the possibility of a more destructive articular disease.citation needed
There is a high rate of false positives due to other causes, or when other autoimmune diseases may be present. These include: chronic hepatitis, any chronic viral infection, leukemia, dermatomyositis, infectious mononucleosis, scleroderma and systemic lupus erythematosus (SLE).citation needed
History
The test was first developed by Dr Eric Waaler in 1940 and developed by Dr H.M. Rose and colleagues. It is therefore still occasionally referred to as the Rose-Waaler or Waaler-Rose test.23
References
- ^ Rheumatoid Factor - Patient UK
- ^ Waaler E (1940). "On the occurrence of a factor in human serum activating the specific agglutination of sheep red corpuscles". Acta Pathol Microbiol Scand 17: 172–88. reproduced in Waaler E (May 2007). "On the occurrence of a factor in human serum activating the specific agglutintion of sheep blood corpuscles. 1939". APMIS 115 (5): 422–38; discussion 439. doi:. PMID 17504400.
- ^ Rose HM, Ragan E, Pearce E, Lipman MO (1948). "Differential agglutination of normal and sensitized sheep erythrocytes by sera of patients with rheumatoid arthritis". Proc Soc Exp Biol Med 68: 1–11.
External links
- MedlinePlus on RF
- Labtestsonline page on RF
|
|||||||||||
Wikipedia content modification information:
- This page was last modified on 28 October 2008, at 03:37.
Wikipedia Authorship and Review
Wikipedia content provided here is not reviewed directly by MedLibrary.org. Wikipedia content is authored by an open community of volunteers and is not produced by or in any way affiliated with MedLibrary.org.
Wikipedia Usage Guidelines
This article is licensed under the GNU Free Documentation License. It uses material from the Wikipedia article on "Rheumatoid factor".
The URL for this specific entry is:
All Wikipedia text is available under the terms of the GNU Free Documentation License. (See Copyrights for details). Wikipedia® is a registered trademark of the Wikimedia Foundation, Inc.