[Renal biopsy and diagnosis of angiitis. 13 cases]

The renal biopsies of 13 patients presenting with a predominantly renal form of angiitis were reviewed. The principal lesions were glomerular with a segmental and focal extracapillary glomerular nephritis in all cases. Arteriolar lesions with necrosis or granuloma were inconstant (6/13) but necrosis of the tuft reflecting capillary involvement were common (11/13). Interstitial tubular disease and immunofluorescence were not specific. Renal biopsy is a good indication of diagnostic when performed early before the development of sclerosis: arteriolar necrosis and suggestive changes: extracapillary segmental and focal glomerulonephritis. In the latter case, a careful search for extrarenal involvement with guided biopsy studies usually allow a diagnosis to be confirmed. The renal and extrarenal clinical signs, the biochemical changes, treatment and outcome were analysed. Two of the 13 patients had Wegener's disease, one patient had angiitis and linear fixation of IgG along the glomerular and tubular basal membranes.