The detection of anti-Sm-RNP activity in sera of patients with monoclonal gammopathies

Clin Exp Immunol. 1989 Mar;75(3):349-53.


The sera of 141 patients with monoclonal gammopathies were examined for the presence of anti-RNP and anti-Sm activities. An enzyme-linked immunosorbent assay (ELISA) was employed. Thirty-two sera were found to bind RNP while 16 bound to Sm. The anti-Sm and anti-RNP antibodies were found in sera of patients with IgG, IgM and IgA gammopathies. The activity against RNP and/or Sm was confirmed further by using purified immunoglobulins, employing competition assays and immunoblotting. Anti-Sm antibodies are regarded as being highly specific for SLE, yet none of the patients whose serum was found to contain high titres of anti-Sm/anti-RNP antibodies presented with symptoms related to SLE or other rheumatic diseases. Our results of a high incidence of anti-ribonucleoproteins activity in the serum of patients with monoclonal gammopathies support previous reports of autoantibody properties characteristic of these immunoglobulins.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Antibodies, Antinuclear / analysis*
  • Autoantigens / immunology*
  • Humans
  • Paraproteinemias / immunology*
  • Ribonucleoproteins / immunology*
  • Ribonucleoproteins, Small Nuclear*
  • snRNP Core Proteins


  • Antibodies, Antinuclear
  • Autoantigens
  • Ribonucleoproteins
  • Ribonucleoproteins, Small Nuclear
  • snRNP Core Proteins