Ribosomal Protein Antigens In

Although ant ibodies against nuclear antigens are considered the hal lmark of systemic lupus e ry thematosus (SLE) 1, antibodies against cytoplasmic consti tuents have also been identified (1, 2). Despite their recogni t ion more than 25 years ago, the prevalence, antigenic specificities, and disease associations of antir ibosomal antibodies (ARA) are all controversial (3-10) . Since these problems may relate to detect ion of di f ferent r ibosomal or r ibosome-associated antigens, we a t t e m p t e d to define m o r e precisely the identity of the r ibosomal prote in antigens. T h e results o f this study indicate that ARA reactive with r ibosomal proteins occur in ~ 5 1 0 % of SLE patients, but are highly specific, b inding to epi topes on 3 out o f a total o f 8 0 proteins.