Pseudo-pulmonary embolism as a sign of acute heparin-induced thrombocytopenia in hemodialysis patients: safety of resuming heparin after disappearance of HIT antibodies

Nephron Clin Pract. 2006;104(4):c143-8. doi: 10.1159/000094959. Epub 2006 Aug 10.

Abstract

Heparin-induced thrombocytopenia (HIT) is a syndrome caused by platelet-activating antibodies that recognize complexes of platelet factor 4 (PF4) and heparin. Thrombocytopenia is the most common clinical feature of HIT. HIT can be considered as a hypercoagulable state, with a high risk of thrombosis. Another feature of HIT is an acute systemic reaction that characteristically begins 5-30 min after receiving an intravenous bolus of unfractionated heparin, such as is commonly given for hemodialysis (HD). Here we present 4 patients who developed acute HIT at or near the start of their chronic HD. All patients were anticoagulated with the low-molecular-weight heparin, nadroparin, for HD. Three of our patients underwent surgery approximately 1-2 weeks before developing HIT. All patients presented with an acute systemic reaction during HD. All patients were treated and further dialyzed with lepirudin. Under this treatment we observed a quick recovery of the platelet count, and patients remained symptom-free. Antibodies against the PF4-heparin complex were detected with a combination of a 'quick test' and an enzyme-linked immunosorbent assay test. The likelihood of having HIT previous to the detection of antibodies was estimated with the pre-test probability score criteria. The tests for PF4-heparin antibodies remained positive for an average of 165 days. Three patients underwent a rechallenge with nadroparin after disappearance of the HIT antibodies in their serum. All 3 remained symptomless when they were further hemodialyzed on nadroparin. Our observations indicate that nadroparin can be successfully reintroduced for HD anticoagulation once the patient's HIT antibodies have disappeared.

Publication types

  • Case Reports

MeSH terms

  • Aged
  • Anticoagulants / adverse effects
  • Autoantibodies / immunology*
  • Drug-Related Side Effects and Adverse Reactions / prevention & control
  • Female
  • Heparin / administration & dosage*
  • Humans
  • Male
  • Middle Aged
  • Pulmonary Embolism / chemically induced*
  • Pulmonary Embolism / immunology*
  • Pulmonary Embolism / prevention & control
  • Renal Dialysis / adverse effects
  • Thrombocytopenia / chemically induced*
  • Thrombocytopenia / immunology*
  • Thrombocytopenia / prevention & control
  • Thrombosis / etiology
  • Thrombosis / prevention & control
  • Treatment Outcome

Substances

  • Anticoagulants
  • Autoantibodies
  • Heparin