PP is a safe, expensive, labor-intensive procedure. Its absolute SLE indications include hyperviscosity, cryoglobulinemia, pulmonary hemorrhage and TTP. PP may be useful in cyclophosphamide-resistant, serious, organ-threatening disease. It may be potentially useful in the antiphospholipid syndrome or mothers or children at risk for congenital heart block. Refinements in apheresis technology may expand the indications for PP.