title: Rapid and durable response to intravenous immunoglobulin in delayed heparin-induced thrombocytopenia: a case report.
abstract: Heparin-induced thrombocytopenia (HIT) results in platelet consumption and a virulent thrombotic state, which generally responds to cessation of heparin and initiation of anticoagulation. Rarely, delayed HIT can occur and/or persist after heparin is discontinued.
  
  
  
  A 47-year-old male developed delayed HIT with severe thrombocytopenia and thrombosis after cardiac surgery. Thrombocytopenia developed and persisted after heparin cessation and did not improve despite sequential use of argatroban followed by bivalirudin. Treatment with intravenous immunoglobulin (IVIg) was well tolerated and resulted in rapid resolution of thrombocytopenia.
  
  
  
  There are few case reports on the management of delayed HIT with severe and prolonged thrombocytopenia. The risk for thrombosis and bleeding in the setting of an undefined time course increases uncertainty in management.
  
  
  
  This case, along with others accumulating in the literature, suggest that IVIg may be effective in treating delayed HIT with persistent thrombocytopenia.
authors.affiliation: Division of Hematology and Medical Oncology, Oregon Health and Science University, Knight Cancer Institute, Portland, Oregon.
authors.forename: Brandon Z
authors.initials: BZ
authors.lastname: Lei
authors.affiliation: Division of Hematology and Medical Oncology, Oregon Health and Science University, Knight Cancer Institute, Portland, Oregon.
authors.forename: Joseph J
authors.initials: JJ
authors.lastname: Shatzel
authors.affiliation: Division of Hematology and Medical Oncology, Oregon Health and Science University, Knight Cancer Institute, Portland, Oregon.
authors.forename: Merav
authors.initials: M
authors.lastname: Sendowski
mesh_terms: D001120:Arginine / Q000031:analogs & derivatives; D006348:Cardiac Surgical Procedures / Q000009:adverse effects*; D006493:Heparin / Q000008:administration & dosage / Q000009:adverse effects*; D006629:Hirudins / Q000008:administration & dosage; D006801:Humans; D016756:Immunoglobulins, Intravenous / Q000008:administration & dosage*; D008297:Male; D008875:Middle Aged; D010446:Peptide Fragments / Q000008:administration & dosage; D010875:Pipecolic Acids / Q000008:administration & dosage; D011183:Postoperative Complications / Q000097:blood / Q000139:chemically induced / Q000188:drug therapy; D011994:Recombinant Proteins / Q000008:administration & dosage; D013449:Sulfonamides; D013921:Thrombocytopenia / Q000097:blood / Q000139:chemically induced / Q000188:drug therapy; D013927:Thrombosis / Q000097:blood / Q000139:chemically induced / Q000188:drug therapy
chemical_list: D006629:Hirudins; D016756:Immunoglobulins, Intravenous; D010446:Peptide Fragments; D010875:Pipecolic Acids; D011994:Recombinant Proteins; D013449:Sulfonamides; D006493:Heparin; D001120:Arginine; C031942:argatroban; C074619:bivalirudin