Abnormal plasma fibronectin levels in patients with proteinuria

We measured plasma fibronectin levels in 21 patients with severe proteinuria secondary to primary renal disorders and compared those results with values obtained in 77 healthy volunteers and 15 patients with chronic renal disease but minimal proteinuria. Seventeen of the 21 patients with proteinuria (81%) demonstrated plasma fibronectin concentrations >2 SDs above control values. Fibronectin levels in the group with chronic renal disease did not differ from normal values. In the group with proteinuria, plasma fibronectin levels were inversely correlated with total serum protein and serum albumin concentrations but were not correlated with the degree of proteinuria, serum creatinine level, or histologic diagnosis of kidney disease. The possible relevance of these findings to the hypercoagulable state of the nephrotic syndrome is discussed.