Lupus Flares and Histological Renal Activity at the End of the Treatment (LuFla)

At this moment, the duration of the treatment in Proliferative Lupus Nephritis has not been determined. Almost 30 percent of patients in total remission during or after a treatment, will relapse in the first 5 years. The factors associated to Renal relapses are not completly known. The investigators think that an histological control study performed to patient with complete remission for a year at the end of a 3 years treatment could help us to know which patients are going to relapse.