TREATMENT OF NORMAL DONORS WITH RHG-CSF 16 MU-G KG FOR MOBILIZATION OF PERIPHERAL-BLOOD STEM-CELLS AND THEIR APHERETIC COLLECTION FOR ALLOGENEIC TRANSPLANTATION/

Background. Utilization of peripheral blood stem cells (PBSC) in allog eneic transplantation requires a method for their mobilization and col lection that is not inconvenient for the donor. Methods. We administer ed rhG-CSF (filgrastim) 16 mu g/kg subcutaneously for 4 days in five n ormal subjects (age 18-31, M=3, F=2), previously selected as HLA-ident ical donors of siblings with leukemia. Ah the donors gave written info rmed consent. On days 4 and 5 (in one donor on day 6 too), 10:11leukap heretic collection was performed with a CS-3000 (Baxter) or an AS-104 (Fresenius) cell separator through the antecubital vein. Results. The WBC count reached a median peak of 57.0x10(9)/L, on day 5. The periphe ral blood CFU-GM peaked to a median level of 8908/mL on day 5 with a m edian increase over baseline values of 39.1 times. The CD34(+) cells p eaked to (median) 147.0x10(6)/L on day 4 with a median increase of 65. 3 times. A lesser enrichment was recorded for BFU-E (median increase 1 2.7 times) and CFU-GEMM (median increase 15.2 times). Even CD3(+) and CD56(+)CD3(-) cells increased (median 1.7 and 1.5 times, respectively) . A median of 771x10(8) MNC (range 672-1378), 116.4x10(6) CFU-GM (rang e 47.7-145.1) and 754x10(6) CD34(+) cells (range 477-2599) were aphere tically collected. Concerning side effects, mild to moderate back pain and general minor discomfort were reported by all donors. The platele t level regularly but transiently decreased after completion of the ap heretic procedures with a median nadir of 69x10(9)/L (range 43-126) on (median) day 7, but in no case did thrombocytopenia cause bleeding. T he thrombocytopenia was more pronounced with the CS-3000 than the AS-1 04 apparatus. Conclusions. rhG-CSF 16 mu g/kgx4 days is an efficient s chedule for PBSC mobilization in healthy donors, but lower doses and e ven a single apheresis procedure might prove similarly adequate.