Thromboembolic complications in a patient with heparin-induced thrombocytopenia (HIT) showing cross-reactivity to a low molecular weight heparin-treatment with Org 10172 (Lomoparan).

Heparin-induced thrombocytopenia is an immuno-mediated life-threatening side effect of heparin therapy which poses difficulties in diagnosis and major therapeutic problems. Heparin must be instantly discontinued. We describe the case of a 60-year-old male patient with type II heparin-induced thrombocytopenia, complicated by progressive deep venous thrombosis and pulmonary embolism. He failed to improve when therapy was continued with a low molecular weight heparin (Fragmin) and high doses of intravenous immunoglobulins were administered. The test for heparin-dependent platelet aggregation was positive for unfractionated heparin and low molecular weight heparin, but negative for the heparinoid Org 10172. During subsequent anticoagulant therapy with Org 10172 for seven days the number of platelets increased rapidly and the patient recovered. Nine months later Org 10172 was used again in this patient for thrombosis prophylaxis without any adverse effects. In patients with heparin-induced thrombocytopenia requiring immediately acting anticoagulant therapy, Org 10172 can be considered as an effective alternative drug to unfractionated and low molecular weight heparins.