Heparin-induced
thrombocytopenia (HIT) is known to complicate
disseminated intravascular coagulation (
DIC), but rarely to be complicated by
DIC. We measured the titers of anti-PF4/hepatin complex
antibodies by ELISA (HIT-Elisa) and examined 4 parameters of coagulation and fibrinolysis [
D-dimer,
thrombin/antithrombin complex (TAT),
plasmin/alpha2-
plasmin inhibitor complex (PIC), and
antithrombin levels] in 80 patients with
DIC diagnosed by a
DIC scoring system. Fourteen patients were HIT-Elisa-positive, 11 of whom received
heparin. In 3 of these 11 patients, platelet counts were < or =10 x 10(9)/l and/or reduced by more than 50% for 5-10 days after the
heparin (2 patients treated with
renal replacement therapy for chronic
uremia and postoperative
renal failure, and 1 with
DIC from a solid
tumor). The 3 patients had an optical density reading of >1.0 and a high level of
IgG for HIT
antibodies, and were thus considered to have
DIC complicated with HIT (
DIC-HIT). The other 8 patients had optical density readings of 0.4-1.0, and it was unclear whether their
thrombocytopenia was caused by HIT alone or by sustained
DIC. There were no significant differences in platelet counts and the 4 parameters of coagulation and fibrinolysis between the patients with
DIC-HIT and
DIC patients with a weakly positive result (0.4-1.0). No differences were observed in platelet counts, or levels of
D-dimer and
antithrombin between HIT-Elisa-positive and -negative
DIC patients. However, the HIT-Elisa-negative patients showed significantly higher levels of TAT and PIC, presumably reflecting
DIC-related
hypercoagulability. In conclusion,
DIC patients treated with
heparin occasionally showed HIT antibody seroconversion and developed HIT. HIT-Elisa could assist in the diagnosis of HIT.