title: Platelet transfusions in heparin-induced thrombocytopenia: a report of four cases and review of the literature.
abstract: BACKGROUND
  Heparin-induced thrombocytopenia (HIT) is a complication of heparin therapy associated with thrombocytopenia and thrombosis. The diagnosis of HIT is based on clinical criteria and laboratory tests, including the serotonin release assay (SRA). Because HIT patients are thrombocytopenic, platelet (PLT) transfusions may be contemplated; however, many published reviews have concluded that PLT transfusions are contraindicated in HIT because they may precipitate thrombotic events. This study reports four patients with clinically suspected HIT who received PLT transfusions without complications, and the literature regarding this subject has been reviewed.
  
  
  METHODS
  Patients with a SRA ordered for suspected HIT were retrospectively identified. Charts of patients with positive SRAs who received a PLT transfusion when HIT was clinically suspected were reviewed for evidence of PLT transfusion safety and efficacy. A comprehensive search of the published literature regarding PLT transfusions in patients with HIT was conducted.
  
  
  RESULTS
  A SRA was performed on 189 patients with suspected HIT. Thirteen patients tested positive and 4 of these received a PLT transfusion. No patient developed a thrombotic complication. All 4 patients had adequate posttransfusion PLT increments. Two of the 3 patients with active bleeding had cessation of bleeding after transfusion. Review of the literature revealed no case of a complication clearly attributable to PLT transfusion.
  
  
  CONCLUSIONS
  Four patients with clinically suspected HIT and a positive SRA were transfused PLTs both efficaciously and safely. These outcomes, combined with the results of the literature review, suggest that PLT transfusions should not be withheld when clinically indicated in patients with HIT.
authors.affiliation: Department of Pathology and Laboratory Medicine, Division of Transfusion Medicine, David Geffen School of Medicine at University of California, Los Angeles, California, USA. c.k.hopkins@hotmail.com
authors.forename: Courtney K
authors.initials: CK
authors.lastname: Hopkins
authors.forename: Dennis
authors.initials: D
authors.lastname: Goldfinger
mesh_terms: D000369:Aged, 80 and over; D000925:Anticoagulants / Q000009:adverse effects*; D005260:Female; D006493:Heparin / Q000009:adverse effects*; D006801:Humans; D008297:Male; D008875:Middle Aged; D017713:Platelet Transfusion; D013921:Thrombocytopenia / Q000139:chemically induced* / Q000628:therapy*
chemical_list: D000925:Anticoagulants; D006493:Heparin