Urinary procoagulant and fibrinolytic activity in human glomerulonephritis. Relationship with renal function.

Fibrin deposition in kidney is a common event in some forms of human and experimental glomerulonephritis, and is thought to result from local activation of blood coagulation and/or impaired removal by the fibrinolytic system. We studied the urinary procoagulant and fibrinolytic activities in 46 patients with renal disease (26 with IgA nephritis, 13 with other forms of glomerulonephritis and 7 with non-inflammatory kidney disease) and in 15 matched healthy subjects, as possible indicators of the coagulation-fibrinolysis balance in kidney. Procoagulant activity was slightly but not significantly increased in patients with serum creatinine levels higher than 1.5 mg/dl (group II) as compared with patients with normal creatinine (group I) and controls. It was identified as tissue factor by biological criteria (dependence on factor VII). Fibrinolysis studies showed that both plasminogen activator activity and urokinase antigen were significantly lower in group II than in group I patients and controls (P less than 0.0005). Reduced fibrinolytic activity in patients' urine was due to decreased excretion of urokinase since no inhibitor was detected by both fibrin autography and functional assay. No differences were found between patients and controls in plasma fibrinolytic activity, plasminogen activator inhibitor, and procoagulant activity of blood monocytes. The urinary changes in severe renal disease may reflect an unbalance of the coagulation-fibrinolysis equilibrium in kidney and might be of pathogenetic and clinical relevance.