Clinical importance of antibodies against double-stranded ribonucleic acid in systemic lupus erythematosus and similar diseases of connective tissue.

Prolonged repeated analyses of sera from 98 patients with systemic lupus erythematosus (SLE) and 76 patients with similar diffuse diseases of connective tissue by a radioisotope membrane binding method for the assessment of antibodies against double-stranded ribonucleic acid (anti-ds-RNA) revealed that these antibodies are most frequently encountered in patients with the evolutive form of SLE (53%), but also in approximately one fifth of patients with non- evolutive SLE and in patients with similar diffuse diseases of connective tissue. Anti-ds-RNA are not linked with stages of clinical activity; their occurrence is on the whole independent on the occurence of antibodies against ds-DNA and nuclear ribonucleoprotein. There is a very close association with the incidence of antibodies against denatured DNA and a substantially small association with antibodies against acid nuclear antigen (Sm). The occurrence of anti-ds-RNA is a favourable prognostic sign, as in the majority of patients who had such antibodies at any time in their serum, later the disease can be suppressed by treatment, while patients who never had anti-ds-RNA in serum remain for a long time in the active stage of the disease.