Paroxysmal nocturnal hemoglobinuria and the age of therapeutic complement inhibition | Aplastic Anemia and MDS International Foundation

Paroxysmal nocturnal hemoglobinuria and the age of therapeutic complement inhibition

Journal Title: 
Expert Rev Clin Immunol
Author(s): 
Varela JC, Brodsky RA.
Primary Author: 
Varela JC
Original Publication Date: 
Saturday, November 9, 2013

Paroxysmal nocturnal hemoglobinuria (PNH) is a rare disease of hematopoietic stem cells due to a mutation in the PIG-A gene leading to a deficiency of GPI-anchored proteins. Lack of two specific GPI-anchored proteins, CD55 and CD59, leads to uncontrolled complement activation that result in both intravascular and extravascular hemolysis. Free hemoglobin leads to nitric oxide depletion that mediates the pathophysiology of some of the common clinical signs of PNH. Clinical symptoms of PNH include evidence of hemolytic anemia, bone marrow failure, smooth muscle dystonias and thromboses. Treatment options for patients with PNH include bone marrow transplantation, a therapy associated with high morbidity and mortality, or treatment with the complement inhibitor eculizumab. Eculizumab is a first-in-class anti-complement drug that in PNH has been shown to block complement-mediated hemolysis, reduce transfusion dependency, reduce thromboembolic complications and improve the quality of life (QoL) of patients.