The activities of antithrombin III (ATIII) and α2-plasmin inhibitor (α2-Pl) in bone marrow aspirates from 43 patients with blood disorders including 7 cases of acute promyelocytic leukemia (APL) with DIC were measured functionally and immunologically and compared with those of normal subjects.
The antigen levels of ATIII and α2-Pl in normal controls were both higher than their respective functional activities, the levels of which were the same as those of their peripheral activities.
Both inhibitors were functionally and immunologically normal in patients with AML, AMoL, ALL, CML and hypoplastic anemia, but the levels of their functional activities were significantly low in patients with polycythemia vera.
In patients with APL, both the activity and antigen levels of α2-Pl were lower than in normal controls. On the other hand, in spite of DIC, markedly high levels of ATIII antigen were found in comparison with the normal ATIII activity. The decreased levels of α2-Pl antigen and its activity and the increased level of ATIII antigen returned to normal levels in complete remission without DIC. This discrepancy in the ATIII level between antigen and functional activity in APL might be associated with some material from APL cells themselves cross-reacting with ATIII, rather than compensatory overproduction by DIC.
