Venous limb gangrene and fatal hemorrhage: adverse consequences of HIT "overdiagnosis" in a patient with antiphospholipid syndrome.

This unfortunate patient case highlights the problems with "overdiagnosis" of HIT. Despite "positive" tests for HIT antibodies, the low pretest probability for HIT and the known propensity of patients with APS to yield false-positive HIT antibody results suggests that the patient did not have a true diagnosis of HIT. Moreover, the early administration of warfarin and the choice of argatroban for parenteral anticoagulation when monitoring was hindered by a prolonged baseline aPTT likely play a key factor in the progression of UE DVT to VLG.