Anti-DNA antibodies secreted by peripheral B cells of lupus patients have both normal and lupus-specific features

Autoantibodies present in sera of patients with systemic lupus erythematosus (SLE) are found in low titer in sera of healthy individuals. Hence, it is possible that B cell populations in SLE patients and in normal individuals are homologous and in the absence of regulatory forces would secrete similar antibodies. We therefore studied antibody secretion of Epstein-Barr virus-transformed B cells of 20 SLE patients and 20 healthy subjects. Normal and lupus antibody repertoires did not differ significantly with respect to antigenic specificities, isotype, avidity, and titer. However, anti-DNA antibodies bearing the anti-DNA-associated idiotype 8.12 were found only in SLE. These findings suggest that the B cell repertoire of SLE and normal individuals is more similar than the serum antibody profile. However, part of the anti-DNA response in SLE probably reflects affinity (antigen driven) maturation as it differs in idiotype profile from anti-DNA response of normal individuals.