Ribosomal antibodies detected by immunofluorescence in systemic lupus erythematosus and other collagenoses.

A new ribosomal antibody is described in patients with systemic lupus erythematosus which reacts with all tissues from varied species, giving a distinctive immunofluorescence pattern. This can best be distinguished from other known autoantibodies on stomach where it reacts with chief cells and pancreas where exocrine cells are brightly stained. The ribosomal nature of the antigen was demonstrated by absorption of immunofluorescence and complement fixation studies using purified subcellular fractions. The antigen was unaffected by ribonuclease and was destroyed by trypsin, suggesting that it is one of the ribosomal proteins, while previously reported antibodies were mainly directed against ribosomal RNA, RNA–protein complexes, or polynucleotides and hybrids. The present ribosomal antibody is uncommon and occurs in less than 1% of SLE patients; its clinical significance is similar to that of ribosomal precipitins as the patients had renal involvement and several have died.