IgM rheumatoid factor (RF) was measured in the sera of 48 rheumatoid patients and of 48 age and sex-matched normal controls by the Rose-Waaler and latex agglutination tests, a rate nephelometer, and an enzyme-linked immunosorbent assay (ELISA). Good correlation was obtained between all assays. The rate nephelometer assay was the easiest and quickest to perform and gave results in international ...

High-affinity pathologic rheumatoid factor (RF) B cells occur in autoimmune diseases such as rheumatoid arthritis, but are deleted in healthy individuals. The reasons for the survival and differentiation of these autoreactive B cells in rheumatoid arthritis are not known. Previous studies in mice transgenic for a human IgM RF have shown that peripheral encounter with soluble human IgG leads to ...

OBJECTIVES To evaluate the diagnostic and pathogenetic significance of IgA rheumatoid factor (RF) subclasses in rheumatoid arthritis (RA). METHODS Rheumatoid factors of the IgA class and IgA1 and IgA2 subclasses were measured by enzyme linked immunosorbent assay in 58 patients with RA, 31 patients with other rheumatic diseases, 30 non-rheumatic individuals with increased concentrations of IgA...

Objective To evaluate in juvenile idiopathic arthritis (JIA) patients a biomarker panel of anti-cyclic citrullinated peptide (anti-CCP) antibodies, cartilage oligomeric matrix protein (COMP), C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), IgM rheumatoid factor (RF), IgG RF, and IgA RF and compare to the presence of joint erosions (JE), joint space narrowing (JSN), and synovitis...

Four different rapid diagnostic tests (RDTs) for malaria were evaluated by testing 82 healthy control patients, 89 Plasmodium vivax-infected patients, and 92 rheumatoid factor (RF)-positive nonmalaria patients. The false-positive rate ranged from 2.2% to 13% in RF-positive patients. High RF levels are associated with malaria RDT false positivity.

To test the hypothesis that rheumatoid factor (RF) protects against (immune complex mediated) renal disease, patients with rheumatoid arthritis (RA; 48 with nephropathy of various types, 35 without renal disease) and systemic lupus erythematosus (SLE; 35 with and 17 without nephritis) were evaluated for the presence and titre of RF. There was no correlation between RF and nephropathy in RA, whe...

Standardisation of quantitative data obtained by several types of rheumatoid factor test was achieved by the use of a reference serum preparation. Interlaboratory comparability improved for the latex fixation test, the Waaler-Rose test, the IgM RF test by an enzyme linked immunosorbent assay (ELISA), and for the antiperinuclear factor test. Use of a common method and latex preparation was not s...

OBJECTIVE To evaluate the changes in anti-cyclic citrullinated peptide antibodies (anti-CCP) and rheumatoid factor (RF) following etanercept treatment in patients with rheumatoid arthritis. METHODS The study included 90 patients with rheumatoid arthritis who failed treatment with disease modifying antirheumatic drugs (DMARDs). All patients were allowed to continue treatment with DMARDs; 52 of...

The influence of viral infections on the incidence of rheumatoid factor in a normal population was noted by Dresner and Trombly (1959). Five per cent. of 140 normal subjects gave positive latexfixation tests for rheumatoid factor, and all seven individuals had or developed mild acute viral infections of the upper respiratory tract. In all seven subjects, tests for rheumatoid factor (RF) became ...