- Patients undergo apheresis (collection of white blood cells) at a number of different time points in the study (maximum 6 times) to look at the differences in the leukemia cells before and during treatment with cyclosporine. For apheresis, blood is withdrawn through a needle in an arm vein and directed through a catheter (plastic tube) into a machine that separates it into its components. The white cells are extracted and the rest of the blood is returned through the same needle or through a second needle in the other arm.