[Medical nephropathies: what has changed in 20 years]

The authors analyse the series of patients with medical nephropathy undergoing renal biopsy between 1973 and 1993 in order to make a diagnostic and prognostic comparison between the first (ID) and second (IID) decade. Clinical indications for biopsy, which became more precise during the second decade, led to the diagnosis of fewer patients with normal histology; the introduction of ME and IF allowed non-significant histological conditions to be reduced during IID; echo-guided biopsy has led to a reduced number of post-biopsy complications in IID compared to ID. Epidemiological analysis reveals the reduction of focal glomerulosclerosis in IID in favour of glomerulonephritis with IgA deposits in correlation with the use of IF; the increase in mebranous glomerulonephritis secondary to increased antigenic stimuli; reduced acute post-infective glomerulonephritis and membrane-proliferative glomerulonephritis owing to an improved prophylaxis of sources of infection. Among the patients undergoing renal biopsy and commencing dialysis an increase was observed in IID in the number of cases of membranous glomerulonephritis or caused by IgA deposits. There was an increased interval between biopsy and the start of dialysis in IID compared to ID, in spite of fewer patients receiving immunosuppressive therapy. This was probably due to the increased number of pathologies with a slower evolution, thus justifying the postponement of the start of dialysis.