A case of heparin-induced thrombocytopenia with multiple thrombosis concomitant with various allergic manifestations

Abstract

We found frequent clot formation in extracorporeal circulation in a 83-year-old man after the start of hemodialysis treatment, and the severe thrombocytopenia progressed from 17.8×10⁴/mm³ before starting hemodialysis to 1.6×10⁴/mm³ after the sixth hemodialysis treatment. We started constant infusion of heparin sodium because this condition was considered due to DIC and there was coexisting thrombotic stenosis in the shunt run-off vein. Thereafter, deep venous thrombosis, shunt obstruction, and pulmonary embolism occurred. As a result of positive findings on platelet aggregation test, we diagnosed heparin-induced thrombocytopenia and stopped heparin. Thereafter, the platelet count soon recovered and anti-PF4/heparin antibody was also determined. Thrombotic condition persisted, even after withdrawal of heparin, but it was improved by administering an anti-thrombin agent, argatroban. In this case, there were various allergic episodes including drug allergy to antibiotics, eosinophilia after starting CAPD, and newly appearing multiple irregular antibodies. Although the mechanism of HIT antibody production remains unclear, some immunological abnormalities, including allergy might be involved. To elucidate HIT risk factors, further accumulation and analysis of many cases appears necessary.