A Case of Paroxysmal Nocturnal Hemoglobinuria Following Idiopathic Aplastic Anemia

Abstract

A man aged 52, was first investigated in February 1975, when he was given a two-months history of exertional dyspnea and pallor. He had pancytopenia, and a diagnosis of aplastic anemia was made by aspirated bone marrow; this was assumed to be idiopathic in the absence of any history of exposure to toxic drugs or chemicals. He had a negative Ham's test. Six months later, Ham's test became positive, but the urine contained neither hemosiderin nor hemoglobin; in this stage paroxysmal nocturnal hemoglobinuria was only a laboratory phenomenon. In February 1977, he passed dark urine containing hemosiderin and hemoglobin, and the diagnosis of paroxysmal nocturnal hemoglobinuria was established. The change in neutrophil alkaline phosphatase score was from high values in the stage of aplastic anemia to low ones in the PNH stage.