Quantitative analysis of apoptosis in CD41a⁺ cells from TAR syndrome patients.

Blood CD34⁺ cells were grown in liquid culture in the presence of PEG-rHuMGDF (A), SCF plus PEG-rHuMGDF (B), or a combination of 3 cytokines (SCF, IL-3, and IL-6) (C). At day 9, cells were stained by annexin V-FITC, R-PE anti-CD41a MoAb, and 7AAD. Dead cells were excluded on the basis of 7-AAD staining (FL3). Viable cells were studied for CD41a and annexin V staining. The horizontal axis shows cells stained by annexin V and the vertical axis cells stained by the anti-CD41a MoAb. This figure illustrates a typical experiment from 1 patient. Similar results were obtained in 3 other patients.