Clinical and Serological Differences between Systemic Lupus Erythematosus Patients with Antibodies to Ro Versus Patients with Antibodies to Ro and La

sus patients having antibodies to Ro and/or La, two major groups were distinguished by titration of sera in counterimmunoelectrophoresis. The first group (30 patients) had antibodies to Ro alone. This was asso-ciated with a high incidence of antibodies to DNA (77%) and serious renal disease (53%). The second group (23 patients) had antibodies to Ro and La, and this was associated with a lower incidence of antibodies to DNA (30%) and a very low incidence of nephritis (9%). In this group a phenomenon of linkage of anti-Ro and anti-La titers was observed. Additionally two patients with only anti-La were found. Neither had clinically apparent renal disease. Thus, systemic lupus erythematosus patients with anti-Ro fall into two subgroups that differ considerably in their prevalence of anti-DNA and serious renal disease