Eculizumab before and after allogeneic hematopoietic stem cell transplantation in a patient with paroxysmal nocturnal hemoglobinuria.

Paroxysmal nocturnal hemoglobinuria (PNH) is characterized by the triad of intravascular hemolysis, venous thrombosis, and cytopenia. Treatment of PNH is generally supportive. Bone marrow transplantation is the only curative therapy for PNH, but is associated with significant morbidity and mortality. Herein, we present a patient with PNH that received eculizumab, a humanized monoclonal antibody that blocks activation of the terminal complement at C5, before and immediately following allogeneic peripheral stem cell transplantation. Prior to hematopoietic stem cell transplantation eculizumab treatment markedly reduced hemolysis and transfusion requirement; however, 1 d post transplantation a hemolytic episode occured, which was successfully stopped with eculizumab re-treatment. Afterwards the patient did not require additional transfusions. The results of this study indicate that early administration of eculizumab may be a safe and effective therapy for hemolytic episodes associated with allogeneic peripheral stem cell transplantation in patients with PNH.