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Rheumatoid factors antedating clinical rheumatoid arthritis.

The relationship between rheumatoid factors (RF) and rheumatoid arthritis (RA) was studied in the Mini-Finland Health Survey. This covered a representative sample of the Finnish population over 30 years of age, initially comprising 8,000 persons, of whom 7,217 participated in the field survey carried out in 1978-80. The participants were followed using record linkage with the Social Insurance Institution's population register to identify patients entitled to free medication. Until the end of 1988, 21 persons had developed new seropositive RA. In 15 cases, preillness specimens contained elevated levels (greater than or equal to 20 IU/ml) of RF. In the remaining 6 cases with RF negative preillness specimens, the interval from taking the blood specimen to the onset of disease was 4 years or more. RF represent a key element in the rheumatoid inflammatory process. Their occurrence in preillness specimens suggests that they may have a primary role in the pathogenesis of the disease.

Adult↗

Human monoclonal rheumatoid factor derived from rheumatoid synovial cells monospecific for rabbit IgG.

Rheumatoid factors (RF) in rheumatoid arthritis (RA) are polyclonal autoantibodies directed against antigenic epitopes located in the Fc portion of the IgG molecule. Hybridoma technology has overcome the difficulty of their polyclonality, so that monoclonal RF (mRF) can be examined for their individual binding specificities and genetics. We isolated a monoclonal IgM RF secreting hybridoma (designated H4) from the rheumatoid synovial cells (RSC) of a patient with RA. H4 bound specifically with rabbit IgG (RIgG) and had no human IgG (HIgG) reactivity. By direct binding ELISA and absorption experiments, 6% of the RIgG reactive RSC RF in this patient with RA was monospecific for RIgG. H4 was tested against RIgG F(ab')2 and pFc' fragments, and bound only to the pFc' fragment (CH3 domain). Moreover, H4 mRF had high avidity for RIgG in a capture ELISA. Total RNA was extracted and the variable region heavy (VH) and light (VL) chain cDNA were amplified using polymerase chain reaction technology. Sequence analysis of the IgM RF VH and VL chain genes indicated usage of the VH26 germline gene (VhIII gene family) and a new V lambda germline gene. Our results suggest preferential use of restricted germline genes in the formation of autoantibodies in human autoimmune diseases. The pathological significance of RIgG specific RF is still unclear. However, this finding suggests that all RSC RF production may not necessarily be induced by autologous IgG.

Amino Acid Sequence↗

A minor group of rheumatoid factors isolated from a patient with rheumatoid arthritis is derived from somatically mutated Vk1 genes further evidence that rheumatoid factors during autoimmune diseases undergo an antigen driven maturation.

To better understand the structural basis for rheumatoid factor [RF] activity and the origin of autoantibodies in human autoimmune diseases, we isolated the RF producing B cells from the peripheral blood and from the synovial fluid of a patient suffering from rheumatoid arthritis [RA]. We previously demonstrated that a significant fraction of these RF were derived from three V kappa III genes known to encode most of the monoclonal RF light chain variable regions. To get more insight into the actual repertoire of RF-V kappa genes during RA, we analyzed the nucleotide sequences of RF light chain variable regions of other V kappa families. Using two sets of polymerase chain reactions in order to amplify the cDNA derived from RF producing cells from the same patient KRA, we isolated only three different rearranged V kappa-J kappa complexes: slkv5, slkv7 and bkv42, all derived from V kappa I germ-line genes not previously known to be associated with RF activity; this suggests that the repertoire of VL genes coding for RF during RA is more diverse than the one involved in the generation of paraprotein RF during monoclonal lymphoid proliferations, although there remains a possible bias in favor of the V kappa III family. Moreover, each of these genes is somatically mutated with a pattern suggesting a selective pressure of the antigen. Particularly interesting is the additional proline residue at the V kappa-J kappa junction of bkv42, an unorthodox feature that we found previously in more than 50% of RF V kappa III-J kappa gene complexes. Finally, the homogeneity of some non conservative mutations suggests the existence of a restricted set of pathogenic epitopes driving the production of RF during RA.

Amino Acid Sequence↗

Oxygen free radicals denature human IgG and increase its reactivity with rheumatoid factor antibody.

Rheumatoid inflammation is characterised by the production of rheumatoid factor antibodies directed against denatured IgG. Oxygen free radicals have the potential to denature all manner of proteins and can be generated by activated phagocytic cells in the inflamed joint. By modifying routine ELISA and nephelometric procedures for measuring rheumatoid factor, (i.e. substituting free radical altered IgG for rabbit and heat aggregated IgG as antigens) we have observed that oxygen radicals, generated by (1) UV light and (2) PMA-activated neutrophils, give rise to monomeric and polymeric forms of IgG which have increased reactivity towards IgM and IgA polyclonal rheumatoid factor antibodies. We conclude that free radical alteration of IgG may be a stimulus to the formation of immune complexes with rheumatoid factor antibody, thereby promoting and amplifying tissue damage during rheumatoid inflammation.

Antibodies↗

Mapping IgG epitopes bound by rheumatoid factors from immunized controls identifies disease-specific rheumatoid factors produced by patients with rheumatoid arthritis.

We have mapped the specificity of 28 monoclonal IgM rheumatoid factors (RFs) produced by heterohybridomas derived from five healthy blood donors immunized with mismatched human red blood cells (HID). The HID-RFs did not differ in their binding specificity for IgG epitopes from RFs that we previously analyzed from patients with Waldenström's macroglobulinemia. However, IgM RFs produced by HID differed in their specificity for IgG compared with RFs expressed by patients with rheumatoid arthritis (RA-RFs). Only 1 of 28 HID-RFs bound all IgG subclasses (pan binding pattern) compared with 7 of 19 RA-RFs (p = 0.006). Three HID-RFs bound IgG3 compared with 9 RA-RFs (p = 0.007). Fine specificity differences were also identified between HID- and RA-RFs. Therefore, some RA-RFs show novel specificities for IgG not found among RFs from HID or individuals with Waldenström's macroglobulinemia who do not have joint disease. These Abs with unique specificities may represent disease-specific autoantibodies in patients with RA. Nine of the HID-RFs from the same individual were clonally related, and several contained somatic mutations. Even when the clonally related HID-RFs were considered as one RF for comparison, the reactivity of the HID-RFs differed significantly from RA-RFs in their inability to recognize all IgG subclasses (p = 0.044) and recognize IgG3 (p = 0.041). Interestingly, among the clonally related RFs, considerable differences in the specificity for IgG were also observed, with the RF containing the most somatic mutations in VH and VL showing the most distinctive specificity changes. Therefore, these studies also demonstrate a correlation between somatic mutation and binding specificity.

Amino Acids↗

Relationship among the HLA-DRB1 shared epitope, smoking, and rheumatoid factor production in rheumatoid arthritis.

OBJECTIVE: Rheumatoid factor (RF) production in rheumatoid arthritis (RA) is generally associated with more severe disease. In some studies, RF production has been associated with carriage of HLA-DRB1 alleles encoding the RA-associated shared epitope (SE). Patients who smoke are also more likely to be RF positive. In this study, we investigated whether the association between RF production and smoking was influenced by carriage of the SE. METHODS: The smoking histories of 371 RA patients attending a hospital clinic were recorded. RF levels and SE status were determined for every patient, and the associations between the SE, smoking, and RF production were examined. HLA-DRB1 typing was performed using polymerase chain reaction. Results were analyzed using chi-square tests and logistic regression analysis. RESULTS: Patients who had ever smoked were significantly more likely to be RF positive than nonsmokers (odds ratio 2.2, P < 0.0001). This remained significant (P = 0.003) after correction for age, sex, and disease duration in a logistic regression model. An association was also found between RF positivity and carriage of the SE (P = 0.03, after correction for age, sex, and disease duration), but significance was reduced or lost after correction for previous or current smoking (P = 0.05 and 0.09, respectively). Examination of the major SE phenotypes in this RA population by multivariate logistic regression analysis revealed that only DRB1*0401 was associated with RF positivity, and that this was independent of the influence of smoking. CONCLUSION: Our data confirm that RF production in RA patients is associated with smoking. This does not appear to depend on an HLA-DR-restricted immune response. The association of the SE with RF positivity is primarily due to HLA-DRB1*0401. This appears to be independent of the association with smoking, although smoking further increases the likelihood of RF production in DRB1*0401 patients.

Adult↗

HLA susceptibility genes in rheumatoid factor positive juvenile rheumatoid arthritis.

Rheumatoid factor positive (seropositive) juvenile rheumatoid arthritis (JRA) is a relatively uncommon but severe form of JRA which shares clinical features with classical adult onset rheumatoid arthritis. Immunogenetic analysis of these patients supports the concept that this likely represents childhood onset of the same disease process. In this report, we review the clinical features as well as previous HLA studies of this disease. We report complete DNA based HLA typing of a small group of these patients, and discuss mechanistic implications of the results.

Adolescent↗

Enzyme linked (ELISA) immunoabsorbent assay for the detection of hidden 19S IgM rheumatoid factors in juvenile rheumatoid arthritis.

Determination of hidden IgM rheumatoid factors (RF) in juvenile rheumatoid arthritis (JRA) offers advantages for diagnosis and in following disease activity. Sera from 30 patients with JRA were assayed for RF by latex fixation test (LFT), sensitized sheep cell agglutination test (SCAT), nephelometry, and by ELISA. IgM containing fractions were prepared by chromatography and assayed for hidden RF by the hemolytic method and ELISA. Ten patients were seropositive by LFT. All of them gave positive tests on the serum for RF with the SCAT, nephelometry, and ELISA, and on the IgM containing fractions by the hemolytic assay and ELISA. Seventeen patients seronegative by LFT were positive for hidden RF by the hemolytic test and ELISA on the IgM containing fraction. When unfractionated serum was used, 15 were positive by ELISA. Three patients were seronegative and also negative for hidden RF by the hemolytic assay and ELISA. Thus, only 2 of 30 patients had discordant results between the hemolytic assay on the IgM containing fraction and the ELISA on the serum. Our results indicate the ELISA on the serum in conjunction with the LFT offers a simple, rapid, alternative test for hidden 19S IgM RF in JRA patients.

Agglutination Tests↗

Evaluation of a charcoal particle test for rheumatoid factor.

A rheumatoid factor charcoal card test was compared with a rheumatoid factor latex slide and tube agglutination test. Qualitative findings with 280 of 290 selected sera were the same. Quantitative results converted to standard rheumatoid factor units were similar.

Agglutination Tests↗

Rheumatoid factors specific for active rheumatoid arthritis.

To measure rheumatoid factors specific for patients with rheumatoid arthritis an enzyme linked immunosorbent assay (ELISA) was developed to measure rheumatoid factors in human serum that bind a cross-reactive determinant shared on human and other mammalian IgG. Rheumatoid factors that cross link human IgG and sheep IgG in a double binding ELISA were almost completely specific (greater than 99%) for rheumatoid arthritis in assays of 108 sera from patients with rheumatoid arthritis compared with 231 sera from patients with other connective tissue diseases and 365 sera from healthy subjects and patients without these diseases. Moreover, positive tests occurred primarily in patients with active arthritis (r = 0.68). In contrast, these rheumatoid factor autoantibodies were not detected in sera from most of the patients with other autoimmune diseases, including patients with systemic lupus erythematosus. These results show that rheumatoid factors identified in human sera by the double binding test are specific for active rheumatoid arthritis.

Adult↗

Complement activation induced by rabbit rheumatoid factor.

Rabbit rheumatoid factor produced in animals by hyperimmunized with group C streptococcal vaccine activated guinea pig complement. Anti-streptococcal serum was fractionated by Sephacryl S-200 chromatography into excluded (19S) and included (7S) material and examined for hemolytic activity in a sensitive homologous hemolytic assay system. In the presence of complement, both 19S and 7S antistreptococcal serum fractions induced lysis of bovine (ox) erythrocytes coated with mildly reduced and carboxymethylated rabbit anti-erythrocyte immunoglobulin G. That rabbit rheumatoid factor was responsible for the observed hemolytic activity was substantiated by hemolytic inhibition assays. Significant inhibition of hemolysis was effected when antistreptococcal serum fractions were incubated in the presence of human immunoglobulin G, rabbit immunoglobulin G, and Fc, whereas, no inhibition was detected when the same fractions were tested in the presence of rabbit Fab or F(ab')2 fragments. Deaggregation of inhibitor preparations revealed a preferential reactivity of rheumatoid factor for rabbit immunoglobulin G. In addition to the rheumatoid factor-dependent hemolytic activity observed in humoral preparations, immunoglobulin G-specific antibody-forming cells in spleen and peripheral blood lymphocyte isolates were enumerated by plaque-forming cell assay.

Animals↗

IgG rheumatoid factor in subacute bacterial endocarditis: relationship to IgM rheumatoid factor and circulating immune complexes.

With recently developed radioimmunoassays, we have been able to study the levels and properties of IgG rheumatoid factor (IgG RF) and IgM rheumatoid factor (IgM RF) in patients with subacute bacterial endocarditis (SBE), as well as the relationship of these autoantibodies to circulating immune complexes. We found significantly elevated amounts of IgG RF and IgM RF in SBE sera. The IgG RF chromatographed on Sepharose 6B as an intermediate complex, indistinguishable from the pattern seen in rheumatoid arthritis. RF levels peaked later in the course of SBE than did levels of circulating immune complexes. With antibiotic treatment RF levels declined, although not as fast nor as completely as circulating immune complexes. These results suggest that both IgG RF and IgM RF in SBE may be part of a polyvalent antibody response to elevated levels of circulating immune complexes which do not themselves contain RF.

Antigen-Antibody Complex↗

A study of rheumatoid factors in juvenile rheumatoid arthritis (chronic polyarthritis) by the photometric latex test.

The photometric latex test (PLT) for the detection of rheumatoid factors (RF), developed and clinically evaluated in adult rheumatoid arthritis, was applied in a study of juvenile rheumatoid arthritis (JRA). A total of 40 individuals with JRA, 27 with other collagen diseases and 24 in a control group were examined. The incidence of seropositives by PLT was 50% in JRA, 33% in collagen diseases and 17% in controls. The percentage of JRA was significantly higher than in the controls, and also higher than values in the literature claiming that only about 20% of JRA patients are seropositive. These findings were discussed concerning the diagnostic capability of PLT as compared with other serologic tests for RF. The increase in PLT titer values was found to indicate an aggravation of the inflammatory process and could help estimate the clinical stage of the disease. A follow-up of patient titer values could be of great diagnostic value. The data on serum immunoglobulins and complement fractions levels could not confirm the findings on a significant increase in JRA patients, but following of "level profiles" of each patient could add to the estimation of patient's clinical status. In cases of seropositives when other laboratory parameters did not indicate a clear transition from the chronic active to acute stage of disease, the only parameter which often showed such a transition is the RF titer determined by PLT testing, which could be of importance for a timely change of the therapy.

Adolescent↗

[Psychodynamic factors in some rheumatoid factor negative arthritic diseases (author's transl)].

A total of 32 patients with rheumatoid factor negative diseases were investigated by depth psychology: patients with palindromic rheumatism, Reiter's disease and psoriatic arthritis. In each case a typical psychosyndrome could be found correlative with the somatic syndrome, in which the specific form of working out of aggression was at the focal point. An association of psychic factors in the etiopathogenesis of these arthritic diseases is consequently very probable.

Adult↗

Clinical significance of rheumatoid factors in early rheumatoid arthritis: results of a follow up study.

Serum rheumatoid factors (RF) were measured yearly in 135 women with rheumatoid arthritis by the Waaler-Rose and latex fixation tests and IgM, IgA, and IgG RF were measured by enzyme linked immunosorbent assays (ELISAs). The patients were followed up from an early phase of the disease for a mean duration of six years. Patients with a persistently positive RF test, irrespective of the type of test used, had more radiological abnormalities, more disease activity, worse functional ability, more extra-articular manifestations, and needed more treatment with second line drugs than patients with persistently negative or variably positive and negative test results during the follow up. Increased RF levels, especially a high level of IgA RF within three years of the onset of symptoms, was prognostic for a more severe disease outcome six years after the onset of symptoms.

Adult↗