Kidney involvement in Beh�et's syndrome

The finding of a focal and segmental glomerulonephritis (GN) in a patient with a Behcet's syndrome led us to perform systematic renal biopsies in ten other patients with the disease. Renal biopsy specimens of 11 patients with Behcet's syndrome (followed for 6 months to 15 years) have been studied by light, electron and immunofluorescence microscopy. In all cases, blood pressure and renal function were normal. Proteinuria was present in five patients. By light and electron microscopy, amyloidosis could not be demonstrated in any case. In one patient, the focal and segmental GN was associated with fibrinoid, electron dense, mesangial and irregular subepithelial deposits. These deposits were also detected in seven other patients but to a lesser degree. Arteriolosclerosis was present in all cases. By immuno fluorescence, small scattered granules of C3 were observed in 10 patients in the mesangium and along the capillary basement membrane. They were diffuse in six cases and focal in four. Small focal deposits containing IgA and/or IgG, Clq were also observed in four cases. Circulating immune complexes found in six out of seven patients in whom they were sought. Rare cases of focal and segmental GN and amyloidosis have been reported in Behcet's syndrome. To our knowledge, glomerular C3 deposits have not been yet reported. These findings with the presence of circulating immune complexes suggest that renal symptoms occasionnally observed in Behcet's syndrome could be related to immune complex deposition.