Immune heparin‐induced thrombocytopenia resulting from preceding exposure to heparin catheter flushes

Immune heparin‐induced thrombocytopenia (HIT) is a life‐threatening adverse effect of heparin. It can result from any type of heparin exposure and by any route of administration; however only a few cases are reported after exposures to small quantities of heparin from catheter flushes. The major clinical problem associated with HIT is thrombosis. Early detection and institution of alternative, non‐heparin anticoagulation are important. We report a patient with HIT associated with use of therapeutic‐dose unfractionated heparin in whom immune sensitization to heparin was triggered by two 500‐unit exposure to UFH associated with intravascular catheter flushing for antineoplastic chemotherapy in a patient with colon adenocarcinoma. Am. J. Hematol. 82: 2007. © 2006 Wiley‐Liss, Inc.