Extrinsic coagulation factors and tissue factor pathway inhibitor in end-stage chronic renal failure

The relationship between extrinsic coagulation factors, tissue factor pathway inhibitor (TFPI) and activated factor XII (FXIIa) was examined in 71 patients with end-stage chronic renal failure. They had chronic stable uremia due to regular hemodialysis. The patients were divided into two age- and sex-matched groups with and without diabetes mellitus. As extrinsic coagulation parameters, FVIIa and FVII antigen (FVIIag), tissue factor antigen and TFPI (the activity and antigen) were measured. FXIIa was measured as a marker of contact activation, and thrombin generation was evaluated using the two markers thrombin-antithrombin III complex and prothrom-bin fragment 1 + 2. In both hemodialysis groups with and without diabetes, significant elevations of FXIIa, FVIIa and tissue factor, with high levels of TFPI, were found. Thus, hyperactivation of the coagulation system was in part compensated by TFPI, and a significant increase in FXIIa could not directly affect FVIIa hyperactivation. No differences of these parameters, except for FVIIag and fragment 1+2, were found between the groups with and without diabetes. It is suggested that the long-term hemodialysis might have masked any differences due to the underlying disease in these two subgroups.