Rapid onset heparin-induced thrombocytopenia (HIT) without history of heparin exposure: A new case of so-called 'spontaneous' HIT

摘要

Heparin-induced thrombocytopenia (HIT) is a life-threatening adverse effect of heparin therapy, resulting from the formation of heparin-dependent and platelet-activating antibodies favouring hy-percoagulability and promoting thrombosis (1). Although the understanding of the pathogenesis of the syndrome has much increased, many unresolved questions remain, more particularly dealing with exceptional situations where the typical delay of occurrence of HIT (5-20 days after starting heparin therapy) is not present, such as delayed-onset HIT described in early 2000. More recently, few cases of another very atypical HIT-related situation have been reported, challenging the conventional understanding of the syndrome, the so-called 'spontaneous HIT', occurring in patients who have never been exposed with heparin (2-4).