The rarity with which therapy-free remission is achieved in patients with severe SLE demand the continued search for improved treatment strategies. Possibly, therapeutic results can be improved by means of a "synchronized" combination of plasmaphereses followed by pulse cyclophosphamide (Ctx). If the hypothesis is correct, that plasmapheresis induces a compensatory "rebound" proliferation of pathogenic clones, then pulse Ctx applied immediately after plasmapheresis should attack these activated clones when they are most vulnerable and, ideally, eliminate them. Employing a strict variant of this strategy in a pilot study, treatment-free remission lasting now for up to 7 years were achievable in 8 of 14 SLE patients. The Lupus Plasmapheresis Study Group (LPSG) is currently conducting a randomized international multicenter trial comparing a synchronized procedure with the administration of pulse Ctx alone. The present paper explains the rationale of synchronization and reports on the interim status of the LPSG Study.