Paroxysmal nocturnal hemoglobinuria (PNH) is an acquired hemolytic anemia in which a defect of glycophosphatidylinositol (GPI)-anchored proteins in the cell membrane of bone marrow stem cells leads to increased sensitivity of the red cells to complement, causing intravascular hemolysis and hemoglobinuria. Other clinical features of this disease are cytopenia and an increased frequency of thromb...

Pathophysiology of Paroxysmal Nocturnal Hemoglobinuria Paroxysmal nocturnal hemoglobinuria (PNH) is a non-malignant clonal disorder of hematopoiesis. The genetic basis is acquired somatic mutations of the X-chromosomal gene PIG-A in one or few hematopoietic stem/progenitor cells. The protein encoded by PIG-A is essential for the synthesis of the glycosylphosphatidylinositol (GPI) anchor. The GP...

Ten consecutive patients with myeloysis. One patient had a positive sucrose fibrosis were examined for the following hemolysis test and low red cell ACHE. signs of PNH: Ham’s test, the sucrose The remaining patients had no signs of hemolysis test, low red cell acetylcholinPNH. In two of the patients, the PNH esterase (ACHE) activity and intrasigns disappeared after splenectomy. The vascular hem...

Paroxysmal nocturnal hemoglobinuria is an acquired hemolytic anemia associated with somatic mutations in the X-linked gene PIG-A, which encodes a protein involved in the biosynthesis of glycosyl phosphatidylinositol anchors. To further elucidate the molecular basis of paroxysmal nocturnal hemoglobinuria, we have worked out a systematic and relatively rapid methodology to scan for mutations in t...

T HE OCCURENCE of impaired marrow function in paroxysmal nocturnal hemoglobinuria (PNH) has long been recognized. A smaller group of patients, with an initial diagnosis of aplastic anemia, have been noted to develop signs of PNH during the course of their illness.1 Such persons have been said to have “the aplastic anemia-paroxysmal nocturnal hemoglobinuria syndrome.”2 Also evident, in some case...