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be a contributing factor; "make things factor into a companys profitability"
any of the numbers (or symbols) that form a product when multiplied together
an independent variable in statistics
anything that contributes causally to a result; "a number of factors determined the outcome"
consider as relevant when making a decision; "You must factor in the recent developments" (同)factor in, factor out
resolve into factors; "a quantum computer can factor the number 15" (同)factor in, factor out
an event known to have happened or something known to have existed; "your fears have no basis in fact"; "how much of the story is fact and how much fiction is hard to tell"
a concept whose truth can be proved; "scientific hypotheses are not facts"
a piece of information about circumstances that exist or events that have occurred; "first you must collect all the facts of the case"
a statement or assertion of verified information about something that is the case or has happened; "he supported his argument with an impressive array of facts"

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radio frequency無線周波数
(…の)『要因』,(…を生み出す)要素《+『in』+『名』(do『ing』)》 / 囲数,約数 / 代理人,《おもに英》仲買人 / =factorize
〈C〉『事実』,実際にある(あった)事 / 〈U〉真相,真実(truth) / 《the~》(法律用語で)犯行
リューマチ[性]の

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出典(authority):フリー百科事典『ウィキペディア（Wikipedia）』「2015/10/12 16:29:13」(JST)

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Rheumatoid factor (RF) is the autoantibody (antibody directed against an organism's own tissues) that was first found in rheumatoid arthritis. It is defined as an antibody against the Fc portion of IgG (an antibody against an antibody). RF and IgG join to form immune complexes that contribute to the disease process.^[1]

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 type 3 (polyclonal IgM to polyclonal IgG) cryoglobulin.

Although predominantly encountered as IgM, rheumatoid factor can be of any isotype of immunoglobulins, i.e. IgA, IgG, IgM,^[2] IgE,^[3] IgD.^[4]

Testing

RF is often evaluated in patients suspected of having any form of arthritis even though 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 play a role in both diagnosis and disease prognosis. It is part of the usual disease criteria of rheumatoid arthritis.^{[citation needed]}

The presence of rheumatoid factor in serum can also indicate the occurrence of suspected autoimmune activity unrelated to rheumatoid arthritis, such as that associated with tissue or organ rejection. In such instances, RF may serve as one of several serological markers for autoimmunity.^[5] The sensitivity of RF for established rheumatoid arthritis is only 60-70% with a specificity of 78%.^[6]

Many patients with rheumatoid disease are seronegative to begin with but seroconvertion (becoming positive) occurs in 80% of them.^[7]

Interpretation

High levels of rheumatoid factor (in general, above 20 IU/mL, 1:40, or over the 95th percentile; there is some variation among labs) occur in rheumatoid arthritis (present in 80%) and Sjögren's syndrome (present in 70%).^[8] The higher the level of RF the greater the probability of destructive articular disease.^{[citation needed]} It is also found in Epstein-Barr virus or Parvovirus infection and in 5-10% of healthy persons, especially the elderly.

There is an association between rheumatoid factor and more persistently active synovitis, more joint damage, greater eventual disability and Arthritis.^[9]^[10]

Other than in rheumatoid arthritis, rheumatoid factor may also be elevated in:^{[citation needed]}

Systemic lupus erythematosus (SLE)
Sjögren's syndrome
Interstitial pulmonary fibrosis
Hepatitis B, Chronic liver disease and chronic hepatitis
Essential mixed cryoglobulinaemia
Primary biliary cirrhosis
Infectious mononucleosis and any chronic viral infection
Bacterial endocarditis
Leprosy
Sarcoidosis
Tuberculosis
Syphilis
Visceral leishmaniasis
Malaria
Leukemia
Dermatomyositis
Systemic sclerosis
After vaccination/transfusion in normal individuals

History

The test was first described by Norwegian Dr Erik Waaler in 1940 and redescribed by Dr H.M. Rose and colleagues in 1948. Redescription is said to be due to the uncertainties due to World War II. It is still referred to as the Waaler-Rose test.^[11]^[12]

References

^ Edkins A and Cushley W. (November 2012) The Jekyll and Hyde nature of antibodies. Biological Sciences Review 25(2):4
^ Hermann, E; Vogt, P; Müller, W (1986). "Rheumatoid factors of immunoglobulin classes IgA, IgG and IgM: Methods of determination and clinical value". Schweizerische medizinische Wochenschrift 116 (38): 1290–7. PMID 3775335.
^ Herrmann, D; Jäger, L; Hein, G; Henzgen, M; Schlenvoigt, G (1991). "IgE rheumatoid factor. Occurrence and diagnostic importance in comparison with IgM rheumatoid factor and circulating immune complexes". Journal of investigational allergology & clinical immunology 1 (5): 302–7. PMID 1669588.
^ Banchuin, N; Janyapoon, K; Sarntivijai, S; Parivisutt, L (1992). "Re-evaluation of ELISA and latex agglutination test for rheumatoid factor detection in the diagnosis of rheumatoid arthritis". Asian Pacific journal of allergy and immunology 10 (1): 47–54. PMID 1418183.
^ Rostaing, Lionel; Modesto, Anne; Cisterne, Jean Marc; Izopet, Jacques; Oksman, Françoise; Duffaut, Michel; Abbal, Michel; Durand, Dominique (1998). "Serological Markers of Autoimmunity in Renal Transplant Patients with Chronic Hepatitis C". American Journal of Nephrology 18 (1): 50–6. doi:10.1159/000013304. PMID 9481439.
^ Nishimura, K; Sugiyama, D; Kogata, Y; Tsuji, G; Nakazawa, T; Kawano, S; Saigo, K; Morinobu, A; Koshiba, M; Kuntz, KM; Kamae, I; Kumagai, S (5 June 2007). "Meta-analysis: diagnostic accuracy of anti-cyclic citrullinated peptide antibody and rheumatoid factor for rheumatoid arthritis.". Annals of internal medicine 146 (11): 797–808. PMID 17548411.
^ Pincus, T (2006). "Advantages and limitations of quantitative measures to assess rheumatoid arthritis: joint counts, radiographs, laboratory tests, and patient questionnaires.". Bulletin of the NYU hospital for joint diseases 64 (1-2): 32–9. PMID 17121487.
^ Rheumatoid Factor - Patient UK
^ http://www.medicinenet.com/rheumatoid_factor/article.htm^{[full citation needed]}
^ The Arthritis Association, Report by MHC 19.2
^ Waaler, Erik (2009). "On the Occurrence of a Factor in Human Serum Activating the Specific Agglutination of Sheep Blood Corpuscles". Acta Pathologica Microbiologica Scandinavica 17 (2): 172. doi:10.1111/j.1699-0463.1940.tb01475.x. reproduced in Waaler, E (2007). "On the Occurrence of a Factor in Human Serum Activating the Specific Agglutintion of Sheep Blood Corpuscles". APMIS 115 (5): 422–38; discussion 439. doi:10.1111/j.1600-0463.2007.apm_682a.x. PMID 17504400.
^ Rose, HM; Ragan, C (1948). "Differential agglutination of normal and sensitized sheep erythrocytes by sera of patients with rheumatoid arthritis". Proceedings of the Society for Experimental Biology and Medicine 68 (1): 1–6. doi:10.3181/00379727-68-16375. PMID 18863659.

External links

RF on MedlinePlus
Rheumatoid Factor on Lab Tests Online
Rheumatoid Factor at eMedicine
Rheumatoid Factor on WebMD

UpToDate Contents

全文を閲覧するには購読必要です。 To read the full text you will need to subscribe.

1. リウマチ因子の発生および測定の有用性 origin and utility of measurement of rheumatoid factors
2. 臨床的に有用な生物学的マーカーによる関節リウマチの診断および転帰評価 clinically useful biologic markers in the diagnosis and assessment of outcome in rheumatoid arthritis
3. リウマチ性血管炎の臨床症状および診断 clinical manifestations and diagnosis of rheumatoid vasculitis
4. Polyarticular juvenile idiopathic arthritis: Clinical manifestations and diagnosis
5. 未分化型炎症性関節炎患者における関節リウマチの発症率の評価 assessing the probability of developing rheumatoid arthritis in patients with undifferentiated inflammatory arthritis

English Journal

Transcriptional and metabolic pre-B cell receptor-mediated checkpoints: Implications for autoimmune diseases.

Zouali M.
Molecular immunology.Mol Immunol.2014 Dec;62(2):315-320. doi: 10.1016/j.molimm.2014.01.009. Epub 2014 Mar 4.
At the pre-B cell stage of lymphocyte development, immunoglobulin light-chains are not yet produced, and heavy-chains are covalently linked to surrogate light-chains composed of VpreB and λ5 to form the pre-B cell receptor (pre-BCR) in a non-covalent association with signal-transducing modules. Eve
PMID 24602812

Clinical evaluation of a novel chemiluminescent immunoassay for the detection of anti-citrullinated peptide antibodies.

Webb T1, Lakos G1, Swart A2, Gürtler I2, Favalli EG3, Schioppo T3, Mahler M4.
Clinica chimica acta; international journal of clinical chemistry.Clin Chim Acta.2014 Nov 1;437:161-7. doi: 10.1016/j.cca.2014.07.032. Epub 2014 Jul 30.
BACKGROUND: We evaluated the analytical and clinical performances of a novel, automated chemiluminescent immunoassay in comparison with several anti-citrullinated protein antibody (ACPA) assays (2nd and 3rd generations) based on various platforms and technologies.METHODS: Samples from rheumatoid art
PMID 25086283

Differential co-expression analysis of rheumatoid arthritis with microarray data.

Wang K1, Zhao L2, Liu X1, Hao Z2, Zhou Y1, Yang C1, Li H2.
Molecular medicine reports.Mol Med Rep.2014 Nov;10(5):2421-6. doi: 10.3892/mmr.2014.2491. Epub 2014 Aug 14.
The aim of the present study was to investigate the underlying molecular mechanisms of rheumatoid arthritis (RA) using microarray expression profiles from osteoarthritis and RA patients, to improve diagnosis and treatment strategies for the condition. The gene expression profile of GSE27390 was down
PMID 25118911

Japanese Journal

Immunogenicity and lupus-like autoantibody production can be linked to each other along with type i interferon production in patients with rheumatoid arthritis treated with infliximab: A retrospective study of a single center cohort

PLOS ONE 11(9), 2016-09-19
NAID 120005860037

最新原著レビュー腫瘍壊死因子阻害薬使用中の関節リウマチ患者においてメトトレキサート併用が人工関節置換術の発生に与える影響

整形外科 = Orthopedic surgery 67(6), 591-593, 2016-06
NAID 40020862661

関節リウマチの心血管病変 (特集関節リウマチupdate : 基礎・臨床の最新情報) -- (合併症に関する最新知見)

日本臨床 74(6), 1012-1016, 2016-06
NAID 40020861596

Related Pictures

★リンクテーブル★

リンク元	「リウマチ因子」「RF」「リウマトイド因子」
拡張検索	「rheumatoid factor test」
関連記事	「fact」「factor」「rheumatoid」

「リウマチ因子」

　　[★]

英: rheumatoid factor, RF
同: リウマトイド因子

[show details]

リウマチ因子 : 約 20,800 件
リウマトイド因子 : 約 11,900 件

概念

IgGのFc部分に対する自己抗体(主にIgM)

IgM-RFが最も多く検出される。IgA-RF, IgE-RFもあるが、IgG-RFは関節リウマチ患者の活動性をよりよく反映する (OLM.400)

リウマチ因子と疾患 (OLM.401)

1. 関節リウマチ

関節リウマチ患者の80%で陽性　→　seropositive RA　⇔20%の患者は全経過を通じて陰性。→ seronegative RA

発症1年以内では約50%の患者のみ陽性。

2. RA以外の膠原病

全身性エリテマトーデス、シェーグレン症候群、強皮症、皮膚筋炎、多発性筋炎などでも約20%の頻度で陽性

3. その他の疾患

肝疾患、悪性腫瘍、高γグロブリン血症、亜急性細菌性心内膜炎でも陽性を示すことが少なくない。RFの疾患特異度は高くない。

4. 生理的

高齢になると陽性を示すことがある(日本では0.3-5%)。

医療系の雑誌より(日経カデット11月？)

表5 リウマトイド因子が陽性となる疾患(文献9)

膠原病	Siogren症候群、SLE、混合性結合組織病、強皮症、多発性筋炎.皮膚筋炎、クリオグロブリン血症性血管炎
感染症	感染性心内膜炎、B型肝炎、C型肝炎、ウイルス感染症(パルポウイルスB19、風疹、ムンブス、HIV、インフルエンザ)、結核、梅毒、ハンセン病
肺疾患	間質性肺炎、珪肺症
肝疾患	原発性胆汁性肝硬変、肝硬変
その他	回帰性リウマチ、サルコイドーシス、一部の悪性腫痩、ワクチン接種後、　　注意:健常若年者の最大4%、高齢者では最大25%で陽性