This is one of two grant applications being submitted for this clinical trial of plasmapheresis in severe lupus nephritis. This application provides support for the Biostatistical Coordinating Center while the other application (Dr. Edmund J. Lewis, Principal Investigator) is for the clinical study. Plasmapheresis (plasma exchange) is a costly but unproven therapy in this disease. A clinical trial of 200 patients followed for up to 5 years is proposed, the primary endpoint being mortality or renal failure. The Biostatistical Coordinating Center will provide support for this collaborative trial in the study design (procedures, forms, randomization), execution (data processing support, editing, updating corrections, monitoring performance of clinics, patient safety data monitoring) and final statistical analysis and publications.