2024 Volume 73 Issue 1 Pages 33-38
A 60‑year‑old man was noted to have pancytopenia w ith hemolysis. The presence of paroxysmal nocturnal hemoglobinuria（ PNH）‑type erythrocytes, dysplasia of blood cells in the bone marrow, and cytogenetic abnormalities of del（ 13q） led to the diagnosis of PNH with myelodysplastic syndrome. We initiated eculizumab 2 years after the diagnosis of PNH and switched to ravulizumab. Although good inhibition of hemolysis was obtained for some time, extravascular hemolysis worsened and transfusion dependence increased. Seven years after the diagnosis of PNH, a splenic infarction occurred and the patient was treated with unfractionated heparin（ UFH）， followed by apixaban. One month later, he was retreated with UFH because the splenic infarction had worsened. Two days after the initiation of UFH, acute myocardial infarction and renal infarction occurred sequentially. Considering heparin‑induced thrombocytopenia（ HIT）， we changed UFH to argatroban； however, further cerebral infarction occurred and the patient died. Since the platelet count decreased during the initial administration of UFH, thrombosis occurred after the re administration of UFH, and the HIT antibody was positive, it was possible that HIT was the cause of multiple thromboses. UFH is often used as anticoagulant therapy for thrombosis in PNH patients； however, HIT should be considered as a complication if thrombocytopenia or thrombosis occurs during the clinical course.
