Estrogen enhancement of anti-double-stranded DNA antibody and immunoglobulin G production in peripheral blood mononuclear cells from patients with systemic lupus erythematosus.

Objective To study the in vitro effect of estrogen on IgG anti–double-stranded DNA (anti-dsDNA) antibody and total IgG production in peripheral blood mononuclear cells (PBMC) from patients with systemic lupus erythematosus (SLE), in order to elucidate its regulatory role in SLE. Methods PBMC from SLE patients and normal donors were cultured with 17β-estradiol (E2). IgG anti-dsDNA antibodies, total IgG, and cytokine activity in the culture supernatants were measured by enzyme-linked immunosorbent assay. Results E2 enhanced production of IgG anti-dsDNA antibodies as well as total IgG in PBMC from SLE patients. Anti-dsDNA production in patients with inactive disease was less responsive to E2 than that in patients with active disease. E2 also enhanced total IgG, but not anti-dsDNA, production in the PBMC of normal donors. Antibody production was increased by E2 to a lesser extent in patients' B cells than in their PBMC. Anti–interleukin-10 (anti–IL-10) antibodies partially blocked the E2-induced increase in antibody production in patients' PBMC, but anti–IL-10 had no effect on B cells. E2 increased IL-10 production by patients' monocytes. Exogenous IL-10 acted additively with E2 in increasing antibody production in patients' B cells. Conclusion These results suggest that E2 may polyclonally increase the production of IgG, including IgG anti-dsDNA, in SLE patients' PBMC by enhancing B cell activity and by promoting IL-10 production in monocytes. These findings support the involvement of E2 in the pathogenesis of SLE.