Measuring rheumatoid factor in nonrheumatoid subjects: immunoturbidimetric assay, latex slide test, and enzyme-linked immunosorbent assay compared.

摘要: Previous studies of patients with rheumatoid arthritis (RA) have shown a good correlation between results from immunoturbidimetric assays factor (RF) and latex fixation tests. To extend the research to non-RA subjects, we tested sera 1000 pregnant women, half each in first third trimesters. By turbidimetry, 24 were regarded as positive for RF (greater than or equal 20 int. units/mL) 18 borderline (15-19 units/mL). test, 28 gave clear reaction (positive) 17 weak (borderline). The association tests was statistically highly significant (P less 0.001). All reactions by enzyme-linked immunosorbent assay isotypes, together random subsample about one-sixth original serum samples. Positive immunoturbidimetry predominantly due presence IgM-RF. In contrast some earlier findings, saw no difference prevalence