text: [The clinical implication of detection of CD59(-) cells in paroxysmal nocturnal hemoglobinuria].
  To evaluate the significance of glycophosphatidylinositol deficient cells in the diagnosis of paroxysmal nocturnal hemoglobinuria (PNH). RBC, and PMN from peripheral blood and mononuclear cells (MNCs) from bone marrow of 29 PNH patients were treated with FITC labelled anti-CD59 monoclonal antibody. Percentages of labelled and unlabelled cells were discriminated by flow cytometry. Normally CD9(-) cells constituted less than 5% in RBCs, PMNs and marrow MNCs, while in each of the patients more than 10% of RBCs were CD59(-) (ranging from 12.8% to 98.0%). More than 10% of PMNs were CD59(-) as well in each of the patients (ranging from 12.0% to 90.1%). Marrow MNCs from the patients contained even more CD59(-) cells (ranging from 17.9% to 73.5%). Ten patients with atypical manifestations were confirmed to be PNH, whereas 7 suspected cases were excluded by this measurement. Determination of CD59(-) cells in RBCs, PMNs and more preferably in marrow MNCs could be considered a direct, specific and reliable method for diagnosis of PNH.