Relationship Between Immunologic Abnormalities And Paroxysmal Nocturnal Hemogloblnuria-Associated Clones In Myelodysplastic Syndromes

Blood cells representing a paroxysmal nocturnal hemoglobinuria (PNH)-associated clone have been reported in patients with myelodysplastic syndromes (MDS). Since immunologic abnormalities are frequent in MDS, we investigated relationships between immune dysfunction and PNH clones. Erythrocyte and granulocyte fractions from 38 MDS patients were examined by flow cytometry to detect PNH clone cells, which lack CD55 and CD59 antigens. Six patients, all among is showing immunologic abnormaliteis, had PNH clones constituting 1 to 5% of blood cells; one also had rheumatoid arthritis. As a significant association was found between PNH clones and immunologic abnormalities (p=.0009), PNH clones may reflect immune disturbance in MDS.