Fibrinolytic and protease inhibitory systems in spinal cord injured patients with end-stage renal disease.

Earlier studies have revealed a variety of coagulation abnormalities in patients with long-standing spinal cord injury (SCI) and end-stage renal disease (ESRD). The present study was undertaken to examine the fibrinolytic and protease inhibitory systems in this population. Twelve spinal cord injured men with ESRD were studied. All patients had chronic active urinary tract infections, pressure ulcers and were practically bed-bound. The results were compared with those obtained in a group of 32 normal volunteers. Plasma plasminogen and unstimulated tissue-type plasminogen activator (t-PA) concentrations in the SCI-ESRD group were comparable with those found in the control group. No significant difference was found in plasma plasminogen activator inhibitor (PAI) activity in the two groups. In contrast, plasma alpha 2-antiplasmin antigen concentration and antiplasmin activity were significantly reduced in the study population. In addition, plasma alpha 1-antitrypsin activity and antigen concentration were significantly increased while the alpha 2-macroglobulin activity-to-antigen concentration ratio was significantly reduced in the SCI-ESRD group. Although the mechanism of the observed reduction in alpha 2-antiplasmin and total antiplasmin activity is uncertain, its presence could enhance fibrinolysis in this otherwise thrombosis-prone population. Likewise, elevated alpha 1-antitrypsin could attenuate tissue damage by leukocyte-derived proteases in the face of persistent suppurative infections. The reduced alpha 2-macroglobulin activity-to-antigen concentration ratio was thought to reflect the presence of alpha 2-macroglobulin complexes with various proteases generated by the activation of leukocytes, coagulation, fibrinolytic and other proteolytic systems.

Increased levels of protein C activity, protein C concentration, total and free protein S in nephrotic syndrome.

Plasma protein C (PC) antigen concentration has been shown to be normal or increased in patients with proteinuria. However, the available data concerning PC anticoagulant activity in nephrotic syndrome (NS) are limited. We measured plasma PC antigen concentration. PC anticoagulant activity, total and free protein (PS) concentrations, and antithrombin III (AT-III) antigen concentration in 21 adult patients with NS. The results were compared with those obtained in a control group of normal volunteers. PC antigen concentration and its anticoagulant activity were significantly increased in the NS group when compared with the normal control group. Likewise, plasma total and free PS values were significantly higher in the NS patients than the corresponding values found in the control group. In contrast, plasma AT-III antigen concentration was significantly reduced in patients with NS. A negative correlation was found between plasma PC and AT-III levels. These observations suggest that increased plasma PC concentration and anticoagulant activity in NS may afford some protection against the thrombotic diathesis associated with antithrombin deficiency and other coagulation abnormalities in this otherwise hypercoagulable state.