Autoimmune response to U1 small nuclear ribonucleoprotein (U1 snRNP) associated with cytomegalovirus infection

The induction of autoantibodies to U1 small nuclear ribonucleoprotein (U1 s nRNP) complexes is not well understood. We present evidence that healthy in dividuals with cytomegalovirus (CMV) infection have an increased frequency and quantity of antibodies to ribonucleoprotein, directed primarily against the U1-70k protein. A significant association between the presence of anti bodies to CMV and antibodies to the total RNP targeted by the immune respon se to the spliceosome (to both the Sm and RNP; Sm/RNP) was found for patien ts with systemic lupus erythematosus (SLE) but not those with mixed connect ive-tissue disease. CMV thus may play a role in inducing autoimmune respons es in a subset of patients with systemic lupus erythematosus.