Rheumatoid Factor (RF) Screen ELISA

Rheumatoid factor screening ELISA is a solid-phase enzyme immunoassay with high-purity human immunoglobulin (IgG) Fc fragments for the combined quantitative detection of IgG, IgM and IgA rheumatoid factors (RF) in human serum. This assay is helpful in the diagnosis of rheumatoid arthritis (RA). Although the presence of IgM RF in serum has been regarded as the most important serological indicator of RA, and therefore has been included in the standard list of ACR to diagnose the disease, the RF and IgA subclasses of IgG are also important for diagnosis. Compared with traditional techniques, the determination of these isotypes provides other information about the diagnosis, differential diagnosis and follow-up of RA. Although the RF of the IgM subtype is the most sensitive to the diagnosis of RA and is therefore the most suitable for screening, the RF of the IgG subtype is the most specific to RA, and like the IgA subtype is related to clinical parameters and disease activity. The coexistence of these three subtypes is 100% specificity of RA. RF in SLE is associated with Sjögren’s syndrome, hyperglobulinemia, high titers of antinuclear antibodies, anemia, and the usual appearance of SS-A and SS-B antibodies. All three subcategories can be found in SLE. In particular, the IgA subclass defines a subgroup of SLE patients, which is characterized by unique autoimmune phenomena and high disease activity in the absence of nephritis