[Glomerulopathy during Behçet's syndrome. Immunofluorescent and electron microscopy studies (author's transl)]

Full renal investigation were conducted in 11 patients with Behçet's syndrome. Biological tests revealed the presence of mild proteinuria in 5 of them. Needle biopsy showed extra-membranous or mesangial fibrinoid deposits in 6 cases, associated in 1 case with segmental and focal glomerulitis lesions. Immunofluorescence studies demonstrated glomerular deposits of mesangial and extra-membranous C3, sometimes with immunoglobulins (IgA-AgG). Ultrastructural examination was carried out in 7 cases and showed "hump" deposits attached to the external face of the basal membrane and rounded nodules of 7 to 15 mu included in the mesangium. The presence of immune complexes in the renal glomeruli, therefore, is not all unusual in this disease, which is probably auto-immune in nature, and in fact appears to be a quite frequent occurrence. These deposits, which were probably well-tolerated by most of the patients in this series, might be involved in the production of progressive glomerulopathies in chronic cases, as observed in one of the cases studied.