Plasma levels of
heparin cofactor II (HCII),
thrombin-HCII complex (
THC),
antithrombin (AT), and
thrombin-AT complex (TAT) were evaluated in patients with
disseminated intravascular coagulation (
DIC) associated with several underlying diseases. Plasma levels of AT were significantly reduced in almost all underlying diseases associated with
DIC, but the plasma levels of HCII and HCII/AT ratio were significantly reduced only in patients with
infections. While the plasma level of TAT was significantly increased in patients with all underlying diseases associated with
DIC, the increase of
THC was not significant. Plasma levels of AT were significantly reduced in
DIC and pre-
DIC associated with almost all underlying diseases, but those of HCII were significantly reduced only in
DIC and pre-
DIC patients with inflammatory diseases. The plasma levels of TAT were significantly increased in
DIC, pre-
DIC, and non-
DIC patients with all underlying diseases, and those of
THC were significantly increased in
DIC and pre-
DIC patients with inflammatory diseases. The plasma levels of
THC were not significantly increased in non-
DIC patients of any disease group. The decrease of AT may be caused by
thrombin generation or inflammatory reaction that occurs in
DIC associated with underlying diseases, while the decrease of HCII might be caused by both
thrombin generation and inflammatory reaction. Finally, AT inhibits
thrombin more strongly than HCII in several underlying diseases associated with
DIC except for inflammatory diseases. In inflammatory diseases, HCII might play an important role in preventing the onset of
DIC.