Abstract
Nuclear ribonucleoprotein (nRNP) was prepared from rabbit thymus extract by the ultracentrifugation and ammonium sulfate precipitation. Immunoglobulin class of anti nRNP antibody was measured by the enzyme linked immunosorbent assay (ELISA). In the measurement of IgA anti nRNP antibody, IgG of serum samples was removed by absorption with Sepharose 4B conjugated with goat anti human IgG antibody. Both IgG and IgA anti nRNP antibody levels were markedly reduced by the massive corticosteroid therapy and gradually recovered in accordance with tapering of corticosteroid dose. Highly elevated levels of IgA anti nRNP antibody were demonstrated in patients with sicca complexes, suggesting IgA anti nRNP antibody might be related with exocrine disturbances presnted in Sjögren's syndrome. IgM anti nRNP antibody was not detected in any case of patients in present study.
