Urinary proteinase activity in patients with multiple traumatic injuries, sepsis, or acute renal failure

Urinary proteinase activity was measured and partly characterized in 29 patients, most of whom had multiple traumatic injuries and 14 of whom had sepsis. Seven of these 29 patients also had acute renal failure. When they were compared with healthy controls, a significant increase of urinary proteinase activity measured with azocasein as a substrate could be found 1 day after admission (15.3 +/- 4.8 vs. 4.8 +/- 1.0 U/ml; P less than 0.05). In urine fractions of patients with sepsis, significantly higher proteolytic activities were measured than in patients without septicemia (20.5 +/- 4.2 vs. 12.3 +/- 2.2 U/ml; P less than 0.05). Patients with sepsis and acute renal failure showed higher urinary proteinase activity than patients with sepsis and normal kidney function (37.7 +/- 4.9 vs. 20.5 +/- 4.2 U/ml; P less than 0.05). During recovery from sepsis urinary proteinase activity decreased to normal values. Phosphorylase kinase was used to characterize the type of urinary proteinase(s). A predominant splitting of the alpha and gamma subunits of the enzyme was observed after trauma and sepsis. However all three subunits, alpha, beta, and gamma, were rapidly digested in the case of posttraumatic acute renal failure and sepsis, indicating the presence of different urinary proteinases. We conclude that proteolytic enzymes are present in urine fractions after traumatic injuries. Sepsis, acute renal failure, or both induce a further increase in urinary proteolytic activity caused by different proteinases.