Circulating plasmin‐antiplasmin complexes in acute leukaemia

Thirty consecutive patients presenting with acute leukaemia were studied throughout their hospital course to determine if plasma-alpha 2 antiplasmin (P-AP) complexes could be detected during episodes of increased fibrinolytic activity and to correlate this finding with other more conventional laboratory parameters. Increased fibrinolytic activity was a common finding, it was detected in 19 (63%) patients. This was usually present at diagnosis, but occasionally occurred later as a transient phenomenon. Increased fibrinolytic activity could not clearly be associated with either infection or chemotherapy. P-AP complexes were found in 11 (37%) patients and were almost always accompanied by additional laboratory evidence of increased fibrinolysis. These complexes were present in most instances at diagnosis and disappeared following successful chemotherapy. Forty-five per cent of patients with P-AP complexes had low alpha 2-antiplasmin levels and 36% had low plasminogen levels which returned to normal following successful chemotherapy. At diagnosis six of eight patients with P-AP complexes had major haemorrhagic manifestations.