Thrombin and plasmin activity and platelet activation in the development of venous thrombosis.

This study was designed to determine whether venous thrombosis is associated with a characteristic pattern in the plasma concentrations of fibrinopeptides and platelet alpha granule proteins. Patients undergoing elective craniotomy for tumor or vascular abnormality were studied prospectively for venous thrombosis with the 1251-fibrinogen uptake test and with daily measurement of the plasma concentrations of FPA (fibrinopeptide A). TIFPB (thrombin-increasable fibrinopeptide B reflecting B/9 1-42). and I9TG (j -thrombogIobulin). Eighteen patients developed venous thrombosis and 14 did not. In the 14 patients who did not develop thrombosis. the mean FPA level was highest on the day after surgery and exceeded the TIFPB level so that the ratio of FPA to TIFPB. which is 0.5 in normals. was 1 .2. During the next 14 days. both FPA and TIFPB levels were elevated. but the FPA/TIFPB ratio was not significantly different from the preoperative value. I3TG and PF4 levels showed no clear pattern of change in the postoperative period. In 1 0 of the patients who developed thrombosis. the time of onset of thrombosis was documented by a change in the leg scan from negative to