Delayed‐onset HIT caused by low‐molecular‐weight heparin manifesting during fondaparinux prophylaxis

AbstractHeparin‐induced thrombocytopenia (HIT) is a prothrombotic condition caused by platelet‐activating antibodies that react with platelet factor 4 (PF4)/heparin complexes. Delayed‐onset HIT occurs after heparin is stopped. Fondaparinux, a synthetic pentasaccharide, is thought to be a safe alternative anticoagulant in HIT. We describe a patient with delayed‐onset HIT triggered by low‐molecular‐weight heparin (LMWH) which occurred during fondaparinux prophylaxis and which was complicated by microangiopathic hemolytic anemia. Patient serum contained high‐titer anti‐PF4/heparin antibodies demonstrating heparin‐dependent platelet activation with serial dilutions. Confirmed delayed‐onset HIT with LMWH has not been previously reported. Low dose fondaparinux does not necessarily prevent thrombotic complications of HIT. Am. J. Hematol., 2008. © 2008 Wiley‐Liss, Inc.

Delayed‐onset HIT caused by low‐molecular‐weight heparin manifesting during fondaparinux prophylaxis Journal Articles