Protein C abnormalities in spinal cord injured patients with end-stage renal disease.

Patients with chronic spinal cord injury (SCI) and end-stage renal disease (ESRD) exhibit antithrombin III deficiency and several other coagulation abnormalities. In view of increasing recognition of protein C (PC) as an important, naturally occurring anticoagulant and fibrinolytic factor, we studied plasma PC in this population. PC antigen concentration and its anticoagulant activity were measured in nine SCI men with ESRD maintained on hemodialysis and in a control group of ten normal able-bodied men. The results showed a significant increase in PC anticoagulant activity in the SCI group. Consequently, the ratio of the PC activity to its concentration, which is a measure of the functional integrity of PC molecule, was markedly depressed. These findings are indicative of the presence of inactive or abnormal PC in SCI-ESRD patients and may suggest its in vivo activation. The combination of impaired PC activity shown in this study, with previously demonstrated antithrombin III deficiency and other coagulation abnormalities, is suggestive of a hypercoagulable state.

Antithrombin deficiency in end-stage renal disease associated with paraplegia: effect of hemodialysis.

Plasma antithrombin III activity and concentration were determined in nine men with end-stage renal disease (ESRD) associated with spinal cord injury (SCI). To determine the possible effects of hemodialysis measurements were repeated following dialysis. Values obtained in the SCI-ESRD group were compared with those obtained in a group of healthy volunteers and a group of 10 ambulatory men with ESRD. A normal pooled plasma was used as the internal standard for all assays. While antithrombin deficiency was observed in both uremic groups it was most severe in the group with SCI. Results demonstrated the association of antithrombin deficiency with ESRD and its potentiation in the presence of SCI. The mechanisms by which SCI compounds the uremia-induced antithrombin deficiency were not known. A mild increase in antithrombin level was noted following dialysis and was thought to be in part due to fluid removal by dialysis.