Precursor frequencies for DNA-specific B lymphocytes in patients with systemic lupus erythematosus (SLE)

Abstract

SUMMARY: Precursor frequencies for anti-DNA-secreting B cells were estimated in six healthy donors and 18 SLE patients with active and inactive disease. Precursors for IgG anti-dsDNA-secreting B cells were exclusively detected in SLE patients (73% of active patients and one inactive patient, 0.01 – 0.99% of IgG-producing B cells). These frequencies were in the same order of magnitude as frequencies of precursors for IgG anti-tetanus toxoid, which were detectable in three healthy volunteers after booster vaccination (0.07–0.8% of IgG-producing B cells), but not before (94% of clones secreting IgG anti-DNA were derived from in vivo sIgG + B cells. slgM + B cells were induced to switch in vitro; however, only twice were cultures containing IgM and IgG anti-DNA antibodies observed under clonal conditions, In conclusion, our results indicate that precursor B cells for IgG anti-dsDNA in SLE patients are similarly selected and expanded as are precursor B cells specific for foreign antigens such as tetanus toxoid.