Autoantibodies to ribonucleoproteins.

Presently we recognize at least 12 different autoantibodies that involve ribonucleoproteins as antigens in patients with SLE and other rheumatic diseases. Such autoantibodies have a number of clinically useful diagnostic associations. Moreover, they have proved to be powerful tools for understanding the structure and function of a variety of cellular components that involve RNA molecules. In SLE, autoantibodies that recognize the U1 snRNP (i.e. anti-(U1)RNP and anti-Sm antibodies) and the Ro scRNPs (i.e. anti-Ro and anti-La antibodies) are especially prominent in terms of their high frequency and titre. These particles, along with the nucleosome (which is the principal focus of autoantibodies to chromatin) appear to have active roles in eliciting autoimmune responses in such patients. Future studies aimed at understanding how and when these particular structures interact with the immune system could provide important insights into the aetiology and pathogenesis of this disorder.