Abstract
Eculizumab was used to treat an 86-year-old male patient with paroxysmal nocturnal hemoglobinuria, the oldest reported case in Japan. As observed in younger patients, this drug rapidly suppressed hemolysis in the present patient, which allowed weaning from blood transfusion. Eculizumab treatment has been continued for 2 years and resulted in the alleviation of renal dysfunction. Despite the patient's advanced age, the inhibition of complement activity caused by this drug did not result in infection, indicating that it is safe to use in elderly patients.