[Expression of phosphorylated STAT5 in bone marrow hematopoietic stem cells of patients with paroxysmal nocturnal hemoglobinuria before and after in vitro G-CSF or SCF stimulation]

Abstract

Objective: To study the expressions of phosphorylated STAT5 (P-STAT5) in CD34(+)CD59(-) and CD34(+)CD59(+) bone marrow cells of the patients with paroxysmal nocturnal hemoglobinuria (PNH) before and after in vitro G-CSF or SCF stimulation, then evaluate the functions of G-CSF and SCF receptors in PNH clone cells.

Methods: Bone marrow mononuclear cells (BMMNC) of 26 PNH patients and 14 normal controls were stimulated in vitro with G-CSF (100 ng/ml) or SCF (100 ng/ml) for 10 min. Before and after these stimulations, the mean fluorescence intensity (MFI) of P-STAT5 in CD34(+)CD59(+) BMMNC and CD34(+)CD59(-) BMMNC were measured by flow cytometry.

Results: (1) The P-STAT5 MFI was (24 ± 18) in unstimulated CD34(+)CD59(-) cells. And it was significantly lower than that in unstimulated CD34(+)CD59(+) cells of PNH patients (64 ± 49) and normal controls (61 ± 33) (both P < 0.01). No statistic difference existed between the latter two. (2) The P-STAT5 MFI was (36 ± 35) in G-CSF stimulated CD34(+)CD59(-) cells of PNH patients. And it was significantly lower than that in G-CSF stimulated CD34(+)CD59(+) cells of PNH patients (124 ± 84) and normal controls (116 ± 59) (both P < 0.01). There was no statistic difference between the latter two. (3) The P-STAT5 MFI was (34 ± 27) in SCF stimulated CD34(+)CD59(-) cells of PNH patients. And it was significantly lower than that in SCF stimulated CD34(+)CD59(+) cells of PNH patients (124 ± 97) and normal controls (128 ± 62) (both P < 0.01). And no statistic difference existed between the latter two. (4) The increased P-STAT5 MFI in G-CSF stimulated CD34(+)CD59(-) cells of PNH patients was significantly lower than that in G-CSF stimulated CD34(+)CD59(+) cells of PNH patients and normal controls (both P < 0.01). No statistic difference existed between the latter two. The increase of P-STAT5 MFI in SCF stimulated CD34(+)CD59(-) cells of PNH patients was significantly lower than that in SCF stimulated CD34(+)CD59(+) cells of PNH patients and normal controls (both P < 0.01). No statistic difference existed between the latter two.

Conclusion: There is a lower expression of P-STAT5 expressed in G-CSF or SCF stimulated PNH clone cells compared to that in normal clone cells.