rheumatoid factor


Summary: Antibodies found in adult RHEUMATOID ARTHRITIS patients that are directed against GAMMA-CHAIN IMMUNOGLOBULINS.

Top Publications

  1. Otani M, Nakata J, Kihara M, Leroy V, Moll S, Wada Y, et al. O-glycosylated IgA rheumatoid factor induces IgA deposits and glomerulonephritis. J Am Soc Nephrol. 2012;23:438-46 pubmed publisher
    ..In this study, mice implanted with hybridoma secreting 6-19 IgA anti-IgG2a rheumatoid factor, but not 46-42 IgA rheumatoid factor bearing the same IgA allotype, developed mesangial deposits consisting ..
  2. Miriovsky B, Michaud K, Thiele G, O Dell J, Cannon G, Kerr G, et al. Anti-CCP antibody and rheumatoid factor concentrations predict greater disease activity in men with rheumatoid arthritis. Ann Rheum Dis. 2010;69:1292-7 pubmed publisher
    To examine associations of anti-cyclic citrullinated peptide (aCCP) antibody and rheumatoid factor (RF) concentrations with future disease activity in men with rheumatoid arthritis (RA)...
  3. Sweet R, Christensen S, Harris M, Shupe J, Sutherland J, Shlomchik M. A new site-directed transgenic rheumatoid factor mouse model demonstrates extrafollicular class switch and plasmablast formation. Autoimmunity. 2010;43:607-18 pubmed publisher
    The AM14 rheumatoid factor (RF) transgenic (Tg) mouse has been valuable for studying how self-reactive B cells are regulated beyond central tolerance, because they remain ignorant in normal mice...
  4. Newkirk M, Zbar A, Baron M, Manges A. Distinct bacterial colonization patterns of Escherichia coli subtypes associate with rheumatoid factor status in early inflammatory arthritis. Rheumatology (Oxford). 2010;49:1311-6 pubmed publisher
  5. Isaacs J, Cohen S, Emery P, Tak P, Wang J, Lei G, et al. Effect of baseline rheumatoid factor and anticitrullinated peptide antibody serotype on rituximab clinical response: a meta-analysis. Ann Rheum Dis. 2013;72:329-36 pubmed publisher
    Studies examining the relationship between serological status (rheumatoid factor and/or anticitrullinated antibody) and rituximab treatment outcome in rheumatoid arthritis (RA) have been hampered by limited numbers of seronegative ..
  6. Ursum J, Bos W, van Dillen N, Dijkmans B, van Schaardenburg D. Levels of anti-citrullinated protein antibodies and IgM rheumatoid factor are not associated with outcome in early arthritis patients: a cohort study. Arthritis Res Ther. 2010;12:R8 pubmed publisher
    To investigate whether baseline levels of anti-citrullinated protein antibody (ACPA) or IgM rheumatoid factor (IgM-RF) and changes in the year thereafter are associated with disease activity, functional and radiographic outcome in early ..
  7. van Baarsen L, Bos W, Rustenburg F, van der Pouw Kraan T, Wolbink G, Dijkmans B, et al. Gene expression profiling in autoantibody-positive patients with arthralgia predicts development of arthritis. Arthritis Rheum. 2010;62:694-704 pubmed publisher
    ..To identify molecular features associated with the development of rheumatoid arthritis (RA), to understand the pathophysiology of preclinical development of RA, and to assign predictive biomarkers...
  8. Hodkinson B, Meyer P, Musenge E, Ally M, Wadee A, Anderson R, et al. The diagnostic utility of the anti-CCP antibody test is no better than rheumatoid factor in South Africans with early rheumatoid arthritis. Clin Rheumatol. 2010;29:615-8 pubmed publisher
    ..A cross-sectional study comparing the rheumatoid factor (RF) and aCCP status in RA patients and a control group consisting of healthy subjects, and patients with ..
  9. Georges A, Charrié A, Raynaud S, Lombard C, Corcuff J. Thyroxin overdose due to rheumatoid factor interferences in thyroid-stimulating hormone assays. Clin Chem Lab Med. 2011;49:873-5 pubmed publisher
    Immunoassays are susceptible to interferences by anti-hormone antibodies, heterophilic antibodies or rheumatoid factor (RF)...

More Information


  1. Barra L, Pope J, Bessette L, Haraoui B, Bykerk V. Lack of seroconversion of rheumatoid factor and anti-cyclic citrullinated peptide in patients with early inflammatory arthritis: a systematic literature review. Rheumatology (Oxford). 2011;50:311-6 pubmed publisher
    ..It is unclear whether antibody-negative patients are more likely to remit and be lost to follow-up in established RA populations. ..
  2. Deane K, O Donnell C, Hueber W, Majka D, Lazar A, Derber L, et al. The number of elevated cytokines and chemokines in preclinical seropositive rheumatoid arthritis predicts time to diagnosis in an age-dependent manner. Arthritis Rheum. 2010;62:3161-72 pubmed publisher
    ..9 samples per case; samples collected a mean of 6.6 years prior to diagnosis) were tested for rheumatoid factor (RF) isotypes, anti-cyclic citrullinated peptide (anti-CCP) antibodies, 14 cytokines and chemokines (by bead-..
  3. Arlestig L, Mullazehi M, Kokkonen H, Rocklöv J, Ronnelid J, Dahlqvist S. Antibodies against cyclic citrullinated peptides of IgG, IgA and IgM isotype and rheumatoid factor of IgM and IgA isotype are increased in unaffected members of multicase rheumatoid arthritis families from northern Sweden. Ann Rheum Dis. 2012;71:825-9 pubmed publisher
    ..All anti-CCP and RF isotypes analysed occurred more commonly in unaffected first-degree relatives from multicase families than in controls, but with different isotype distribution from patients with RA. ..
  4. Horvath D, Kayser C, Silva C, Terreri M, Hilário M, Andrade L. Decreased recent thymus emigrant number in rheumatoid factor-negative polyarticular juvenile idiopathic arthritis. Clin Exp Rheumatol. 2010;28:348-53 pubmed
    ..TCR excision circle (TREC) levels, a marker of recent thymic emigrants, in the peripheral lymphocyte pool of rheumatoid factor-negative (RFØ) polyarticular juvenile idiopathic arthritis (JIA) children...
  5. Tasliyurt T, Kisacik B, Kaya S, Yildirim B, Pehlivan Y, Kutluturk F, et al. The frequency of antibodies against cyclic citrullinated peptides and rheumatoid factor in healthy population: a field study of rheumatoid arthritis from northern Turkey. Rheumatol Int. 2013;33:939-42 pubmed publisher
    ..b>Rheumatoid factor (RF) is a widely used auto antibody in diagnosis of the RA and found positive in 50-80 % of the patients but ..
  6. Barra L, Bykerk V, Pope J, Haraoui B, Hitchon C, Thorne J, et al. Anticitrullinated protein antibodies and rheumatoid factor fluctuate in early inflammatory arthritis and do not predict clinical outcomes. J Rheumatol. 2013;40:1259-67 pubmed publisher
    In inflammatory arthritis, rheumatoid factor (RF) and anticitrullinated protein antibodies (ACPA) are believed to be associated with more severe clinical outcomes...
  7. Moon S, Hong Y, Ju J, Kwok S, Park S, Min J. Increased levels of interleukin 34 in serum and synovial fluid are associated with rheumatoid factor and anticyclic citrullinated peptide antibody titers in patients with rheumatoid arthritis. J Rheumatol. 2013;40:1842-9 pubmed publisher
    ..Rheumatoid arthritis (RA) is characterized by increased osteoclastogenesis. To identify the significance of IL-34 in RA, the IL-34 concentration was measured in serum and synovial fluid (SF)...
  8. Barceló Martín B, Marquet P, Ferrer J, Castanyer Puig B, Barcelo Bennasar A, Riesco Prieto M, et al. Rheumatoid factor interference in a tacrolimus immunoassay. Ther Drug Monit. 2009;31:743-5 pubmed publisher
    ..The role of rheumatoid factor (RF) as a cause of immunoassay interferences is well known...
  9. Gomez E, Gun S, Somanath S, Chinna K, Radhakrishnan A. Ethnic differences in the prognostic utility of rheumatoid factor isotypes and anticyclic citrullinated peptides in rheumatoid arthritis patients: a cross-sectional study. Mod Rheumatol. 2013;23:716-21 pubmed publisher
    The prognostic significance of rheumatoid factor (RF) and anticyclic citrullinated peptide antibody (anti-CCP) in rheumatoid arthritis (RA) remains contentious due to the conflicting lines of evidence...
  10. LeGatt D, Blakney G, Higgins T, Schnabl K, Shalapay C, Dias V, et al. The effect of paraproteins and rheumatoid factor on four commercial immunoassays for vancomycin: implications for laboratorians and other health care professionals. Ther Drug Monit. 2012;34:306-11 pubmed publisher
    ..b>Rheumatoid factor (RF), a known immunoassay interferant, may cause falsely elevated results...
  11. Gorevic P. Rheumatoid factor, complement, and mixed cryoglobulinemia. Clin Dev Immunol. 2012;2012:439018 pubmed publisher
    ..Potential activators include monoclonal IgM rheumatoid factor (RF), IgG antibodies, and the complexing of the two in the cold, perhaps modulated by the rheology and ..
  12. Goeldner I, Skare T, de Messias Reason I, Nisihara R, Silva M, Utiyama S. Anti-cyclic citrullinated peptide antibodies and rheumatoid factor in rheumatoid arthritis patients and relatives from Brazil. Rheumatology (Oxford). 2010;49:1590-3 pubmed publisher
    ..The results demonstrate a significant positivity of anti-CCP2 in relatives of RA patients from Brazil and reinforce the importance of serological tools to identify undiagnosed RA. ..
  13. Miller A, Mahtani K, Waterfield M, Timms A, Misbah S, Luqmani R. Is rheumatoid factor useful in primary care? A retrospective cross-sectional study. Clin Rheumatol. 2013;32:1089-93 pubmed publisher
    b>Rheumatoid factor (RF) is frequently tested in general practice where its utility as a diagnostic test for rheumatoid arthritis (RA) is not known...
  14. Kolfenbach J, Deane K, Derber L, O Donnell C, Gilliland W, Edison J, et al. Autoimmunity to peptidyl arginine deiminase type 4 precedes clinical onset of rheumatoid arthritis. Arthritis Rheum. 2010;62:2633-9 pubmed publisher
  15. van Baarsen L, de Hair M, Ramwadhdoebe T, Zijlstra I, Maas M, Gerlag D, et al. The cellular composition of lymph nodes in the earliest phase of inflammatory arthritis. Ann Rheum Dis. 2013;72:1420-4 pubmed publisher
    ..Therefore, we investigated the cellular composition of the lymph node in the earliest phases of inflammatory arthritis...
  16. Choi S, Lee H, Song J, Lee S, Park Y. Analysis of rheumatoid factor according to various hepatitis B virus infectious statuses. Clin Exp Rheumatol. 2014;32:168-73 pubmed
    b>Rheumatoid factor (RF) can be seen in hepatitis B virus (HBV) infection. We investigated RF positive rates according to various HBV infectious statuses and vaccination, and the relationship between RF titers and serum HBV DNA levels...
  17. Todd D, Knowlton N, Amato M, Frank M, Schur P, Izmailova E, et al. Erroneous augmentation of multiplex assay measurements in patients with rheumatoid arthritis due to heterophilic binding by serum rheumatoid factor. Arthritis Rheum. 2011;63:894-903 pubmed publisher
    Serum rheumatoid factor (RF) and other heterophilic antibodies potentially interfere with antibody-based immunoassays by nonspecifically binding detection reagents...
  18. van de Sande M, de Hair M, van der Leij C, Klarenbeek P, Bos W, Smith M, et al. Different stages of rheumatoid arthritis: features of the synovium in the preclinical phase. Ann Rheum Dis. 2011;70:772-7 pubmed publisher
    ..It is currently unknown whether the disease process starts in the synovium, the primary target of RA, or at other sites in the body...
  19. Churchman S, Geiler J, Parmar R, Horner E, Church L, Emery P, et al. Multiplexing immunoassays for cytokine detection in the serum of patients with rheumatoid arthritis: lack of sensitivity and interference by rheumatoid factor. Clin Exp Rheumatol. 2012;30:534-42 pubmed
    ..were raised regarding their use in rheumatology due to interference by heterophilic antibodies, notably rheumatoid factor (RF)...
  20. Klaasen R, Cantaert T, Wijbrandts C, Teitsma C, Gerlag D, Out T, et al. The value of rheumatoid factor and anti-citrullinated protein antibodies as predictors of response to infliximab in rheumatoid arthritis: an exploratory study. Rheumatology (Oxford). 2011;50:1487-93 pubmed publisher
    ..However, this correlation is not strong enough to allow a reliable prediction in individual patients. Trial Registration. ISRCTN Register, http://www.controlled-trials.com/isrctn/, ISRCTN36847425. ..
  21. Ibn Yacoub Y, Amine B, Laatiris A, Hajjaj Hassouni N. Rheumatoid factor and antibodies against citrullinated peptides in Moroccan patients with rheumatoid arthritis: association with disease parameters and quality of life. Clin Rheumatol. 2012;31:329-34 pubmed publisher
    ..Immunological status (rheumatoid factor rate, RF) and antibodies against citrullinated peptides rate (ACPAs) by the Elisa method were examined...
  22. Aletaha D, Alasti F, Smolen J. Rheumatoid factor determines structural progression of rheumatoid arthritis dependent and independent of disease activity. Ann Rheum Dis. 2013;72:875-80 pubmed publisher
    b>Rheumatoid factor (RF) is prototypic for rheumatoid arthritis (RA) and serves diagnostic and prognostic purposes...
  23. Laskov R, Yahud V, Hamo R, Steinitz M. Preferential targeting of somatic hypermutation to hotspot motifs and hypermutable sites and generation of mutational clusters in the IgVH alleles of a rheumatoid factor producing lymphoblastoid cell line. Mol Immunol. 2011;48:733-45 pubmed publisher
    ..Our previous studies showed that a monoclonal LCL that secretes a rheumatoid factor expressed activation-induced cytidine deaminase (AID) and displayed an ongoing process of somatic ..
  24. Le Loet X, Brazier M, Mejjad O, Boumier P, Daragon A, Gayet A, et al. Serum IgA rheumatoid factor and pyridinoline in very early arthritis as predictors of erosion(s) at two years: a simple model of prediction from a conservatively treated community-based inception cohort. Arthritis Care Res (Hoboken). 2010;62:1739-47 pubmed publisher
    ..Logistic regression analysis at that time showed erosion(s) strongly associated with serum IgA rheumatoid factor (IgA-RF) and pyridinoline levels for the 190 patients with no baseline erosions, with the corresponding ..
  25. Balsa A, Cabezón A, Orozco G, Cobo T, Miranda Carus E, Lopez Nevot M, et al. Influence of HLA DRB1 alleles in the susceptibility of rheumatoid arthritis and the regulation of antibodies against citrullinated proteins and rheumatoid factor. Arthritis Res Ther. 2010;12:R62 pubmed publisher
    ..to rheumatoid arthritis (RA) and production of antibodies against citrullinated proteins (ACPA) and rheumatoid factor (RF). We studied 408 patients (235 with RA, 173 non-RA) and 269 controls...
  26. Frisell T, Holmqvist M, Kallberg H, Klareskog L, Alfredsson L, Askling J. Familial risks and heritability of rheumatoid arthritis: role of rheumatoid factor/anti-citrullinated protein antibody status, number and type of affected relatives, sex, and age. Arthritis Rheum. 2013;65:2773-82 pubmed publisher
    ..RA) in 3 large population-representative samples and to test if familial aggregation is affected by rheumatoid factor (RF)/anti-citrullinated protein antibody (ACPA) status, type of relative, sex, and age at onset of RA...
  27. Bartels E, Ribel Madsen S. Cytokine measurements and possible interference from heterophilic antibodies--problems and solutions experienced with rheumatoid factor. Methods. 2013;61:18-22 pubmed publisher
    ..Another type, rheumatoid factor (RF) is a composite of different autoimmune antibodies which can be present in both blood and synovial fluid...
  28. Maneiro R, Salgado E, Carmona L, Gomez Reino J. Rheumatoid factor as predictor of response to abatacept, rituximab and tocilizumab in rheumatoid arthritis: Systematic review and meta-analysis. Semin Arthritis Rheum. 2013;43:9-17 pubmed publisher
    To identify if rheumatoid factor (RF) is predictor of response to rituximab (RTX), abatacept (ABT), and tocilizumab (TCZ) in rheumatoid arthritis (RA)...
  29. Renger F, Bang H, Feist E, Fredenhagen G, Natusch A, Backhaus M, et al. Immediate determination of ACPA and rheumatoid factor--a novel point of care test for detection of anti-MCV antibodies and rheumatoid factor using a lateral-flow immunoassay. Arthritis Res Ther. 2010;12:R120 pubmed publisher
    ..A lateral-flow immunoassay was developed for simultaneous detection of anti-MCV antibodies and rheumatoid factor (RF-IgG) and evaluated in a prospective setting...
  30. Shi J, van de Stadt L, Levarht E, Huizinga T, Toes R, Trouw L, et al. Anti-carbamylated protein antibodies are present in arthralgia patients and predict the development of rheumatoid arthritis. Arthritis Rheum. 2013;65:911-5 pubmed publisher
    ..Therefore, we studied whether anti-CarP antibodies are present in patients with arthralgia and whether their presence is associated with the development of RA...
  31. Olivieri A, Iafusco D, Mellos A, Zanfardino A, Mauro A, Granato C, et al. Refractory rheumatoid factor positive polyarthritis in a female adolescent already suffering from type 1 diabetes mellitus and Hashimoto's thyroiditis successfully treated with etanercept. Ital J Pediatr. 2013;39:64 pubmed publisher
  32. Song Y, Kang E. Autoantibodies in rheumatoid arthritis: rheumatoid factors and anticitrullinated protein antibodies. QJM. 2010;103:139-46 pubmed publisher
    ..Since rheumatoid factor (RF) was first described, a number of other autoantibodies have been discovered in RA patients...
  33. Newkirk M, Mitchell S, Procino M, Li Z, Cosio M, Mazur W, et al. Chronic smoke exposure induces rheumatoid factor and anti-heat shock protein 70 autoantibodies in susceptible mice and humans with lung disease. Eur J Immunol. 2012;42:1051-61 pubmed publisher
    ..b>Rheumatoid factor (RF), anti-cyclic citrullinated peptides (CCPs), and anti-HSP70 autoantibodies were measured in several ..
  34. Kolfenbach J, Deane K, Derber L, O Donnell C, Weisman M, Buckner J, et al. A prospective approach to investigating the natural history of preclinical rheumatoid arthritis (RA) using first-degree relatives of probands with RA. Arthritis Rheum. 2009;61:1735-42 pubmed publisher
    ..shared epitope, 20% had > or =1 copy of the PTPN22 polymorphism, and approximately 16% were positive for rheumatoid factor (RF; including isotypes) and/or anti-cyclic citrullinated peptide antibody...
  35. Tatarewicz S, Miller J, Swanson S, Moxness M. Rheumatoid factor interference in immunogenicity assays for human monoclonal antibody therapeutics. J Immunol Methods. 2010;357:10-6 pubmed publisher
    ..Through careful SE-HPLC monitoring we were able to choose appropriate storage and buffer conditions which led to a reduction in the false reactivity rate in therapeutic-naïve serum from a rheumatoid arthritis population. ..
  36. Barcelos F, Abreu I, Patto J, Trindade H, Teixeira A. Anti-cyclic citrullinated peptide antibodies and rheumatoid factor in Sjögren's syndrome. Acta Reumatol Port. 2009;34:608-12 pubmed
    ..These results suggest that anti-CCP-Abs could be useful in the distinction between pSS and RA with sSS. Although not useful for the differential diagnosis between RA and pSS, RFs may have a prognostic role in pSS. ..
  37. Mjaavatten M, van der Heijde D, Uhlig T, Haugen A, Nygaard H, Sidenvall G, et al. The likelihood of persistent arthritis increases with the level of anti-citrullinated peptide antibody and immunoglobulin M rheumatoid factor: a longitudinal study of 376 patients with very early undifferentiated arthritis. Arthritis Res Ther. 2010;12:R76 pubmed publisher
    ..the importance of the levels of anti-citrullinated peptide antibody (anti-CCP) and immunoglobulin M (IgM) rheumatoid factor (RF) in predicting development of persistent arthritis from undifferentiated arthritis (UA), and to ..
  38. Saevarsdottir S, Ding B, Steinsson K, Grondal G, Valdimarsson H, Alfredsson L, et al. Mannan Binding Lectin (MBL) genotypes coding for high MBL serum levels are associated with rheumatoid factor negative rheumatoid arthritis in never smokers. Arthritis Res Ther. 2011;13:R65 pubmed publisher
    ..and genetic risk factors (smoking, HLA-DRB1 'shared epitope' (SE), PTPN22*620W), which predispose to rheumatoid factor (RF) and/or anti-citrullinated-protein antibody (ACPA)-positive RA...
  39. van de Stadt L, van der Horst A, de Koning M, Bos W, Wolbink G, van de Stadt R, et al. The extent of the anti-citrullinated protein antibody repertoire is associated with arthritis development in patients with seropositive arthralgia. Ann Rheum Dis. 2011;70:128-33 pubmed publisher
    ..To determine the fine specificity of anti-citrullinated protein antibodies (ACPA) in the early phase of arthritis development, the ACPA repertoire in arthralgia patients and the association with arthritis development were studied...
  40. Bang S, Lee K, Cho S, Lee H, Lee K, Bae S. Smoking increases rheumatoid arthritis susceptibility in individuals carrying the HLA-DRB1 shared epitope, regardless of rheumatoid factor or anti-cyclic citrullinated peptide antibody status. Arthritis Rheum. 2010;62:369-77 pubmed publisher
    ..The patients with RA were tested for anti-CCP antibodies and rheumatoid factor (RF). The SE alleles had significant effects on anti-CCP antibody and RF formation...
  41. Shim C, Hwang J, Lee J, Koh E, Cha H, Ahn J. Prevalence of rheumatoid factor and parameters associated with rheumatoid factor positivity in Korean health screening subjects and subjects with hepatitis B surface antigen. Mod Rheumatol. 2012;22:885-91 pubmed publisher
    The purpose of this study is to assess the prevalence and titer of rheumatoid factor (RF) in Korean health screening subjects and consecutive subjects with hepatitis B surface antigen (HBsAg) and to examine the factors influencing RF ..
  42. Nielsen S, Bojesen S, Schnohr P, Nordestgaard B. Elevated rheumatoid factor and long term risk of rheumatoid arthritis: a prospective cohort study. BMJ. 2012;345:e5244 pubmed publisher
    To test whether elevated concentration of rheumatoid factor is associated with long term development of rheumatoid arthritis. A prospective cohort study, the Copenhagen City Heart Study...
  43. da Mota L, dos Santos Neto L, de Carvalho J, Pereira I, Burlingame R, Menard H, et al. The presence of anti-citrullinated protein antibodies (ACPA) and rheumatoid factor on patients with rheumatoid arthritis (RA) does not interfere with the chance of clinical remission in a follow-up of 3 years. Rheumatol Int. 2012;32:3807-12 pubmed publisher
    ..arthritis (<12 months of symptoms) in order to determine the association between serological markers (rheumatoid factor (RF), anti-citrullinated protein antibodies) such as anti-cyclic citrullinated peptide antibodies (anti-CCP) ..
  44. Scott D, Wolfe F, Huizinga T. Rheumatoid arthritis. Lancet. 2010;376:1094-108 pubmed publisher
    ..is characterised by persistent synovitis, systemic inflammation, and autoantibodies (particularly to rheumatoid factor and citrullinated peptide)...
  45. Szekanecz Z, Szabo Z, Zeher M, Soos L, Danko K, Horvath I, et al. Superior performance of the CCP3.1 test compared to CCP2 and MCV in the rheumatoid factor-negative RA population. Immunol Res. 2013;56:439-43 pubmed publisher
    ..1 assay, but with special focus on the rheumatoid factor (RF)-negative RA population...
  46. Bobbio Pallavicini F, Caporali R, Alpini C, Avalle S, Epis O, Klersy C, et al. High IgA rheumatoid factor levels are associated with poor clinical response to tumour necrosis factor alpha inhibitors in rheumatoid arthritis. Ann Rheum Dis. 2007;66:302-7 pubmed
    To investigate whether rheumatoid factor isotypes and anti-cyclic citrullinated peptide (anti-CCP) antibodies are related to clinical response in patients with rheumatoid arthritis treated with tumour necrosis factor alpha (TNFalpha) ..
  47. Symmons D. Classification criteria for rheumatoid arthritis--time to abandon rheumatoid factor?. Rheumatology (Oxford). 2007;46:725-6 pubmed
  48. Duquerroy S, Stura E, Bressanelli S, Fabiane S, Vaney M, Beale D, et al. Crystal structure of a human autoimmune complex between IgM rheumatoid factor RF61 and IgG1 Fc reveals a novel epitope and evidence for affinity maturation. J Mol Biol. 2007;368:1321-31 pubmed
    ..The antibody contacts also involve two somatically mutated V(H) residues, reinforcing the suggestion of a process of antigen-driven maturation and selection for IgG Fc during the generation of this RF autoantibody. ..
  49. Güler Yüksel M, Bijsterbosch J, Goekoop Ruiterman Y, de Vries Bouwstra J, Ronday H, Peeters A, et al. Bone mineral density in patients with recently diagnosed, active rheumatoid arthritis. Ann Rheum Dis. 2007;66:1508-12 pubmed
    ..Longer symptom duration and presence of rheumatoid factor (RF) were the only RA-specific markers for osteoporosis and reduced BMD...
  50. Narvaez J, Sirvent E, Narváez J, Bas J, Gomez Vaquero C, Reina D, et al. Usefulness of magnetic resonance imaging of the hand versus anticyclic citrullinated peptide antibody testing to confirm the diagnosis of clinically suspected early rheumatoid arthritis in the absence of rheumatoid factor and radiographic erosions. Semin Arthritis Rheum. 2008;38:101-9 pubmed publisher
    ..peptide (anti-CCP) antibody testing to confirm the diagnosis of clinically suspected RA in the absence of rheumatoid factor (RF) and radiographic erosions...
  51. Gonzalez A, Icen M, Kremers H, Crowson C, Davis J, Therneau T, et al. Mortality trends in rheumatoid arthritis: the role of rheumatoid factor. J Rheumatol. 2008;35:1009-14 pubmed
    ..We examined the contribution of rheumatoid factor (RF) positivity on overall mortality trends and cause-specific mortality...
  52. Mathsson L, Lampa J, Mullazehi M, Ronnelid J. Immune complexes from rheumatoid arthritis synovial fluid induce FcgammaRIIa dependent and rheumatoid factor correlated production of tumour necrosis factor-alpha by peripheral blood mononuclear cells. Arthritis Res Ther. 2006;8:R64 pubmed
    ..b>Rheumatoid factor (RF) develop in response to ICs in many clinical and experimental settings...