Curso clínico de la nefropatía membranosa lúpica pura

Background: The long-term outcome of the pure form of WHO type V lupus membranous glomerulonephritis is apparently more benign than that of other forms of lupus glomerulonephritis. However 12% of such patients progress to terminal renal failure. The presence of proteinuria may be an indication of cytotoxic agents. Aim: To study the clinical long-term outcome of WHO type V lupus membranous glomerulonephritis. Material and methods: A retrospective analysis of all kidney biopsies of a University Pathology Department, with the diagnosis of WHO type V lupus membranous glomerulonephritis. Review of medical records of patients with the disease and one clinical assessment of all living patients. Results: Between 1973 and 2000, 703 kidney biopsies were done to patients with systemic lupus erythematosus. Of these, 40 were membranous glomerulonephritis and in 33 patients (28 women, age range 6-71 years), data on the evolution and survival was obtained. Nineteen had type Va and the rest type Vb nephritis. Two presented with renal failure and 11 with proteinuria over 3.5 g/24h. The median follow-up since the renal biopsy was 63 months (range 1-316). At the end of follow-up, four had a creatinine clearance of less then 15 ml/h and four a clearance between 15 and 29 ml/h (one of these received a renal allograft). Eleven (33%) patients had died, mostly due to infections. Life expectancy at five years with a creatinine clearance over 15 ml/h was 75%. Bad prognostic factors were an elevated creatinine clearance over 15 ml/h was 75%. Bad prognostic factors were an elevated creatinine and high blood pressure at the moment of the biopsy. Conclusions: The clinical outcome of these patients was bad. Twelve percent reached a stage of terminal renal failure. This is in contrast with the 3% progression to a similar stage of proliferative glomerulonephritis treated with i.v. cyclophosphamide. New therapies for this condition must be sought.