Paroxysmal nocturnal hemoglobinuria: pathogenesis, testing, and diagnosis.

Paroxysmal nocturnal hemoglobinuria (PNH) is an acquired clonal hematopoietic stem cell disorder with far-reaching multisystem effects that can lead to life-threatening consequences. The clinical features of this disease arise as a result of complement-mediated hemolysis in unprotected red cells, leukocytes, and platelets as well as the release of free hemoglobin that occurs with erythrocyte destruction. Patients may present with a variety of clinical manifestations, such as anemia, thrombosis, kidney disease, smooth muscle dystonias, abdominal pain, dyspnea, and extreme fatigue. There are 3 broad patient categories in whom the incidence of PNH is significantly greater as compared with the general population: patients with hemolysis or hemoglobinuria, patients with bone marrow failure syndromes, and patients with unexplained or unusual thrombosis. The gold standard test for PNH diagnosis consists of high-sensitivity flow cytometry performed on a peripheral blood sample. Recent advances in treatment have emphasized the importance of early diagnosis. Disclaimer Funding for this supplement has been provided by Alexion Pharmaceuticals, Inc. Support of this supplement does not imply the supporter’s agreement with the views expressed herein. Every effort has been made to ensure that drug usage and other information are presented accurately; however, the ultimate responsibility rests with the prescribing physician. Millennium Medical Publishing, Inc, and the participants shall not be held responsible for errors or for any consequences arising from the use of information contained herein. Readers are strongly urged to consult any relevant primary literature. No claims or endorsements are made for any drug or compound at present under clinical investigation. ©2013 Millennium Medical Publishing, Inc., 611 Broadway, Suite 310, New York, NY 10012. Printed in the USA. All rights reserved, including the right of reproduction, in whole or in part, in any form.