- Lymphocytopheresis: Lymphocytes are collected three times - once during the last month of baseline before starting treatment, once during the fifth month of treatment, and once during the last month of treatment - for immunologic study. Blood is collected through a needle in an arm vein in a similar way to donating blood. The blood flows from the vein through a catheter (plastic tube) into a machine that separates it into its components by centrifugation (spinning). The lymphocytes are removed and the rest of the blood (red cells, plasma and platelets) is returned to the body, either through the same needle or through another needle in the other arm.