Antibodies to vimentin intermediate filaments in sera from patients with SLE and RA: quantitation by solid phase radioimmunoassay.

A solid phase radioimmunoassay was used to quantify levels of antibodies to vimentin intermediate filaments (VIF) of the cytoskeleton in sera from patients with systemic lupus erythematosus (SLE) and rheumatoid arthritis (RA). Significantly higher levels of these antibodies were found in 52% of the SLE sera studied, compared to 6% in RA sera and 10% of sera from healthy controls. These antibodies include IgG and IgM classes of immunoglobulins. Our results show that high levels of anti-VIF antibodies are more prevalent in SLE sera, whereas no significant differences are found between sera from patients with RA and healthy controls.