[Immunohistological findings in diffuse mesangial sclerosis associated with the nephrotic syndrome of infancy (author's transl)].

A 10-month-old infant developed a steroid resistant nephrotic syndrome. The renal biopsy revealed diffuse mesangial sclerosis of the glomerula. The child died from interstitial pneumonia 3 months after onset of the renal symptoms. Post mortem, the glomerular changes were diffuse but prominent in certain segments of the glomeruli. The immunohistological examination showed granular deposits of IgM and C3 in the mesangium and in the subendothelial region of the basement membrane. These findings are compatible with the hypothesis that diffuseal sclerosis is caused by glomerular deposition of immune complexes.