[Distribution of fibronectin in renal pathology (author's transl)]

The distribution of fibronectin (FN), a major glycoproteic component of extracellular matrix, has been detected in the human kidney by an indirect immunofluorescence technique using a rabbit anti-human FN serum on 6 embryonic renal tissues, 5 normal kidneys and 120 renal biopsies. In the metanephros, FN was seen within tubular basement membranes and in embryonic glomeruli. There was a progressive loss of tubular basement membrane staining during the differentiation of renal parenchyma. In the normal kidney and in kidneys with nephritis without endo- and/or extracapillary proliferation, FN was localized only in the mesangium and faintly in capillary walls of glomeruli. In glomerulonephritis with endo- and/or extracapillary proliferation, FN was increased around mesangial cells. FN was also bound to fibrin in epithelial crescents, fibrinoid necrosis and in thrombi of thrombotic microangiography. FN was increased in the mesangium of diabetic glomeruli without endocapillary proliferation. FN has not been found in amyloid deposits and in sclerosed glomeruli. We therefore conclude that FN is a good mesangial marker and is probably involved in the inflammatory process.