Response of lupus nephritis to plasmapheresis without demonstration of circulating immune complexes

A case of post-partum SLE in a 25-year-old Mexican-American woman is presented. The disease was associated with systemic vasculitis and diffuse proliferative glomerulonephritis. Abundant evidence for the deposition of complement activating immune complexes was found in skin and kidney biopsies, but no circulating immune complexes could be measured. Therapeutic modalities including corticosteroids administered both orally and intravenously, azathioprine, antihypertensives, and hemodialysis failed to effectuate lasting benefit. Large volume plasmapheresis led to immediate improvement and a dramatic return of renal function. A mechanism of action for the resulting effect is considered.