Determination of rheumatoid factors by ELISA

Abstract

IgM and IgA autoantibodies binding to IgG are called rheumatoid factors (RFs) and occur with high frequency in rheumatoid arthritis (RA) and with lower frequency in other autoimmune diseases. RFs have diagnostic and prognostic value in RA, but they also have a high potential to cause false positive reactions in other immunoassays, especially sandwich assays. For these reasons it is imperative to be able to measure RFs in serum samples from patients suspected of RA or other autoimmune diseases and in serum samples to be analyzed by sandwich immunoassay for various clinical parameters. Here, a simple ELISA for IgM and IgA RFs is described.