OBJECTIVETo investigate the expressions of three kinds of glycosyl-phosphatidylinositol anchor proteins (GPI-AP), the CD(55), CD(59) and CD(87) on the peripheral granulocytes and the soluble u-PAR (su-PAR) level in serum from patients with paroxysmal nocturnal hemoglobinuria (PNH), aplastic anemia (AA), and myelodysplastic syndromes (MDS), and to analyse their clinical implications.

METHODSTwenty-two PNH patients, including 4 complicated with thrombotic diseases and 5 with AA-PNH syndrome, 30 AA patients, including 9 being severe AA (SAA) and 11 chronic AA (CAA), 27 MDS-RA patients, and 20 healthy individuals were tested. The expressions of CD(55), CD(59) and CD(87) on peripheral granulocytes were analyzed with flow cytometry. Serum su-PAR was assayed by ELISA.

RESULTSThe CD(55)(+), CD(59)(+) and CD(87)(+) granulocytes in peripheral blood of 20 normal controls were all more than 90%. The expressions of three kinds of GPI-APs in 22 PNH patients were significantly decreased as compared with that in normal controls, AA patients and MDS-RA patients. The serum level of su-PAR in PNH group was higher than that of the other three groups. The expression of CD(87) was significantly decreased in thrombotic PNH patients as compared with that in non-thrombotic PNH patients. The expression of CD(87) was significantly decreased in AA patients than in normal controls. The expressions of three kinds of GPI-APs in 5 AA-PNH syndrome patients were remarkably reduced as compared with AA patients, but no significant difference was found for these indexes between AA-PNH syndrome and PNH patients and between 27 MDS-RA patients and 20 normal controls.

CONCLUSIONMeasurement of CD(55), CD(59) and CD(87) expressions levels on the peripheral granulocytes and su-PAR in serum would be alternative approaches for diagnosis and differential diagnosis of PNH. Serum level of su-PAR may be helpful to monitor thrombosis in PNH patients.