Heparin-induced Thrombocytopenia with Anaphylactoid Reaction during Hemodialysis.

We herein report a 64-year-old man with heparin-induced thrombocytopenia accompanied by anaphylactoid reaction during hemodialysis. The patient was admitted to our hospital with acute myocardial infarction and developed acute kidney injury after percutaneous coronary intervention. When maintenance hemodialysis with heparin was initiated, the patient developed an anaphylactoid reaction with dyspnea, hypotension, nausea, and vomiting. Laboratory tests revealed thrombocytopenia. Immunoglobulin G antibodies to heparin-platelet factor 4 complexes were positive, and a functional assay showed heparin-independent platelet activation. These results provide a definitive diagnosis of heparin-induced thrombocytopenia. The onset timing supported a diagnosis of 'rapid-onset' heparin-induced thrombocytopenia.