A comparison of serologic reactivity among SLE patients with or without anti-Ro (SS-A) antibodies.

The serum from 112 patients with systemic lupus erythematosus (SLE) was examined to compare serologic reactivity among anti-Ro positive and anti-Ro negative patients. While hypergammaglobulinemia, rheumatoid factor (RF) and elevated Clq binding were significantly more frequent among the anti-Ro positive group there was no increase in the frequency of anti-dsDNA antibody measured by the Farr assay or antibodies to ssDNA, dsDNA, poly dG . poly dC, poly (dA-dT) and cardiolipin measured by ELISA. Patients with the highest levels of anti-DNA antibody by the Farr assay did not have any increased frequency of anti-Ro antibodies. We concluded that anti-Ro and anti-DNA antibodies are independently regulated. The frequent occurrence of RF in anti-Ro positive SLE patients may provide a useful screening assay for this autoantibody among pregnant SLE patients.