胚細胞腫瘍患者に対する末梢血造血幹細胞採取法の検討

Abstract

1996～1999年1に治療した胚細胞腫瘍15例を対象に検討した.施行した化学療法は22回で, 骨髄回復期に43回の末梢血幹細胞採取を施行した.2回の大量療法に必要なCD34陽性細胞数を4×1000000/kgとするとBEP療法4回で必要量の幹細胞を採取できなかった.しかし, nadirにおける末梢白血球数が2000/ml以上であっても必要量の採取は可能であった.BEP療法時にはday 14, 15から5μg/kgのG-CSFを採取日まで投与し, day 19～21にアフェレーシスを行うのが良いと考えられた.VIP療法では1回のアフェレーシスあたり1.7×1000000/kgのCD34陽性細胞しか採取できなかった.大量エトポシド療法は骨髄回復期のばらつきが少なく, 1回のアフェレーシスあたり7.9×1000000/kgのCD34陽性細胞を採取できた.大量エトポシド療法はBEP, VIP中に必要量が採取できない場合には, 極めて有用な幹細胞動員方法であると考えられた

From January 1996 to December 1999, fifteen patients with germ cell tumors underwent peripheral blood stem cell harvest during 15 courses of bleomycin, etoposide, cisplatin (BEP), 4 courses of etoposide, ifosfamide, cisplatin (VIP) and 3 courses of high-dose etoposide mobilization at Nagoya University Hospital. We performed 29 aphereses during BEP, eight during VIP, and six during high-dose etoposide. Although we were able to harvest 4.4 x 10(6)/kg of median CD34 positive cells per apheresis during BEP, the number of stem cells (more than 4 x 10(6)/kg of CD34 positive cells), which are needed for tandem high-dose chemotherapy, could not be obtained during four courses of BEP. For three patients in whom white blood cell counts at nadir were 2, 000/microL or more, however, the required number of CD34 positive cells were harvested. VIP provided only 1.7 x 10(6)/kg of median CD34 positive cells per apheresis, while, 7.3 x 10(6)/kg of CD34 positive cells were harvested during high-dose etoposide mobilization. The dose of G-CSF was a significant factor for the number of CD34 positive cells harvested during BEP (p = 0.02); however, there might be some relationship between the harvest and the number of the peripheral white blood cells on the day of apheresis (p = 0.08), the day to start G-CSF (p = 0.13), or the day to initiate apheresis (p = 0.27). Based on our experience, it is recommended that 5 micrograms/kg of G-CSF should be started from the 14th or 15th day of BEP until the last apheresis and that aphereses should be performed between the 19th and 21st day, especially at the days when the peripheral white blood cell count increases beyond 10, 000/microL.