Significance of CD55/CD59 deficiency analysis in the diagnosis of paroxysmal nocturnal hemoglobinuria

Objective To establish an efficient way for the diagnosis of paroxysmal nocturnal hemoglobinuria(PNH) through the combination of the hemolytic anemia(HA) associated routine tests with flow cytometry (FCM) of the red cell CD55/CD59 expression. Methods The peripheral erythrocytes and granulocytes were analyzed with flow cytometry for CD55/CD59 expression while the deficient red blood cells were further studied for forward scatter (FS), FS/CD55 and FS/CD59. Other hemolytic anemia associated tests were also employed as routine. Results PNH could be diagnosed based on the results of FCM and routine tests for peripheral erythrocytes and granulocytes, which showed the characteristic defects when the HA broke out. During remission , PNH deficient red blood cells were mainly destroyed and the peripheral blood was negative for Ham's test. FCM analysis revealed those PNH cells with CD55/CD59 deficiency and the changes of FS/CD59, which was helpful in the diagnosis and the differentiation from those PNH patients with aplastic anemia whose PNH cells also exist. Conclusions FCM analysis of the peripheral red blood cells' CD55/CD59 expression in combination with HA-related routine tests was efficient in the diagnosis of PNH.