Plasmapheresis therapy of pemphigus and bullous pemphigoid.

Trials of plasmapheresis or plasma exchange (PE) in pemphigus and pemphigoid have been justified by the well demonstrated role of autoantibodies and the side effects of conventional therapy with high doses of steroids. Most open studies reported effectiveness of PE, mainly in steroid-resistant cases. However, a controlled study showed no benefit from PE in pemphigus when associated with a low steroid dose. This study points to the difficulty of removing pemphigus antibody unless PE is accompanied by strong immunosuppression. Encouraging preliminary results have been obtained by synchronizing PE and bolus high doses of cyclophosphamide. Until confirmation of these results, steroids will remain the principal from of immunosuppressive therapy in pemphigus, and the clinical usefulness of PE in this disease will be restricted to the management of cases resistant to high steroid doses. On the other hand, a controlled study of PE in bullous pemphigoid demonstrated a dramatic steroid-sparing effect, whether patients had serum autoantibodies or not, suggesting that PE may act by mechanisms other than the removal of antibodies from serum.