[Immunopathology of nephropathy secondary to anaphylactoid purpura]

With the purpose of contributing to the study of the pathogenesis of the nephropathy of anaphylactoid purpura (NPA), investigation was made of the presence and extension of immunoglobuline deposits, complement factors and fibrinogen in renal biopsies of 15 patients with NPA, correlating the findings with glomerular lesions seen at the light microscope. Fibrin and IgA deposits were found in all biopsies in mesangium, while C3 was detected only in 5 cases with potentially progressive lesions: 3 with PEEF, one with PEED and one with MP, being negative in PSF and PE cases, which are potentially reversible. The extension of deposits was diffuse or segmentary, without the existence of a precise correlation with the different morphological types. It is concluded that the immunopathologic pattern found in NPA is quite characteristics, different from that of postinfectious acute glomerulonephritis and that there seems to exist relation between findings of C3 with progression of the glomerular lesion.