The serological diagnosis of juvenile rheumatoid arthritis (JRA) is difficult, with only 7-10% of patients 19S IgM rheumatoid factor positive. About 60-70% of patients are positive for hidden 19S IgM rheumatoid factor, but this test requires serum separation and is not available in most laboratories. Antiperinuclear factor has been described in both seropositive and seronegative adult patients ...

The antiperinuclear factor, an autoantibody specific for rheumatoid arthritis, was found in 51/63 (81%) patients with rheumatoid arthritis by indirect immunofluorescence on human buccal mucosa cells. The sensitivity of the antiperinuclear factor test was increased by pretreating the buccal mucosa cells with 0.5% Triton-X100. The specificity of the test for rheumatoid arthritis as compared with ...

Sera from 53 Nigerian patients satisfying the American Rheumatism Association criteria for a diagnosis of definite or probable rheumatoid arthritis and sera from sick and healthy Nigerian controls were tested for rheumatoid factor, autoantibodies, and immunoglobulin levels. Rheumatoid factor and autoantibodies were found no more frequently in patients with rheumatoid arthritis than in controls....

The clinical value of enzyme linked immunosorbent assays (ELISA) assays for IgM and IgG rheumatoid factors was assessed in a series of studies using rabbit IgG as antigen. The tests were reproducible with intra-assay coefficients of variation of 6% and could be simply and rapidly performed. Normal ranges were established using 106 sera from healthy controls. In a cross sectional study of 208 rh...

IgA and IgM rheumatoid factors as well as antibodies to Ro and La were measured in 37 patients with the sicca syndrome and 9 patients with Sjögren's syndrome secondary to rheumatoid arthritis. Positive results were found in 84% (IgA rheumatoid factor), 76% (IgM rheumatoid factor), 62% (Ro), and 50% (La) of patients with the sicca syndrome. There was no significant difference in the frequency of...

Rheumatoid arthritis (RA) is a systemic disease affecting mainly joints. Since rheumatoid arthritis is a common and a world wide problem therefore accurate diagnosis of this disease is essential. In the past rheumatoid factor was considered as the only marker for diagnosing this disease; however rheumatoid factor is present in many other disorders and even in up to 15% of healthy population. Fo...