Objective: To study the in vitro effect of testosterone on anti-DNA antibody 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 were cultured with testosterone. IgG anti-double-stranded DNA (anti-dsDNA) antibody, total IgG, and cytokine activity in the supernatants were measured by enzyme-linked immunosorbent assay.
Results: Testosterone suppressed both IgG anti-dsDNA antibody and total IgG production in PBMC from SLE patients. Antibody production in B cells was also suppressed by testosterone, although the magnitude of its effect on B cells was lower than that on PBMC. Interleukin-6 (IL-6) partially restored the testosterone-induced decrease in antibody levels in PBMC. Testosterone reduced IL-6 production in monocytes.
Conclusion: These results suggest that testosterone may directly suppress anti-DNA antibody production in PBMC from SLE patients by inhibiting B cell hyperactivity and, indirectly, by down-regulating IL-6 production in monocytes. These results support the therapeutic effects of testosterone on SLE.