外周血干细胞移植治疗难治性系统性红斑狼疮

目的 观察自体外周血干细胞移植（APBSCT）治疗难治性系统性红斑狼疮（RSLE）的疗效及安全性。方法 RSLE3例，先给予血浆置换，环磷酰胺（CTX）和大剂量丙种球蛋白，然后用环磷酰胺和粒细胞集落刺激因子（G-CSF）动员造血干细胞（HSC），多功能加强型血细胞分离机采集外周血干细胞，-86℃超低温冻存，环磷酰胺预处理，经静脉回输干细胞，最后应用抗胸腺淋巴细胞球蛋白（ATG）行体内去T淋巴细胞。观察移植前后临床症状，体征和免疫学指标的变化。结果 APBSCT后患者的临床症状完全缓解，异常免疫学指标基本恢复正常，抗体全部转阴。结论 APBSCT对难治性系统性红斑狼疮有明显的疗效。尤其适用对各种药物治疗无效的患者，远期疗效还需长期随访。     

自体外周造血干细胞移植治疗进展型多发性硬化

目的观察自体外周造血干细胞移植(APBSCT)治疗进展型多发硬化(PMS)的疗效及安全性。方法对2001-09~2004-07对首都医科大学宣武医院13例PMS患者进行了自体外周造血干细胞移植,单独使用粒细胞集落刺激因子(G-CSF)动员造血干细胞,7名患者进行了采集物的CD3 4细胞纯化。预处理采用BEAM(卡氮芥、依托泊甙、阿糖胞苷、马法兰)方案。中位随访期为22(3~36)个月,移植前后应用扩充神经功能残疾量表(EDSS)、年平均发病次数进行疗效评价。结果患者移植后18个月EDSS评分较移植前降低[移植后(4.05±0.66),移植前(6.00±0.30),P<0.05],年平均发病次数减少[移植后(0.40±0.15),移植前(1.63±0.18),P<0.01]。移植后3年疾病无活动存活率为(63.64±14.50)%,EDSS评分无进展存活率为(72.73±13.43)%。无移植相关死亡,造血功能恢复迅速,未出现严重的毒性反应及并发症。结论APBSCT治疗PMS安全有效     

非清髓无关供体外周血干细胞移植治疗重型再生障碍性贫血

目的 探讨无关供体造血干细胞移植治疗重型再生障碍性贫血(SAA)的方法 和疗效.方法 对1例SAA的患者进行了无关供体HLA高分辨4/6相合的外周血干细胞移植.采用环磷酰胺(100 mg/kg) 氟达拉宾(150 mg/m2) 抗人淋巴细胞球蛋白(100 mg/kg)的非清髓性预处理后,回输粒细胞集落刺激因子(G-CSF)动员的外周血干细胞,共输注单个核细胞(MNC)6.77×108/kg,CD 34细胞1.95×106/kg.预防移植物抗宿主病(GVHD)采用环胞菌素A(CsA)联合短疗程甲氨蝶呤(MTX)的基础上加用霉酚酸酯(MMF)的方案.结果 患者移植后造血恢复顺利,于移植后第6天WBC植入,第8天PLT植入,第30天行患者骨髓STR-PCR检测显示为完全供者的基因型,第150天血型转变为供者型(O→A).未发生急性GVHD(aGVHD)及慢性GVHD(cGVHD),随访至移植后8个月,造血功能恢复良好,仍在继续随访中.结论 以氟达拉宾、环磷酰胺和抗人淋巴细胞球蛋白组成的非清髓性预处理方案用于无关供体外周血干细胞移植治疗SAA,能够获得稳定的植入,且并发症少,是有效移植方法之一.     

单倍体相合造血干细胞移植治疗慢性活动性EB病毒感染1例并文献复习

目的:探讨单倍体相合造血干细胞移植治疗慢性活动性EB病毒感染(CAEBV)的可行性。方法:采用马利兰+氟达拉滨+环磷酰胺+抗人T淋巴细胞球蛋白移植预处理方案,对1例8岁CAEBV患儿行HLA3/6母供女单倍体相合造血干细胞移植。结果:移植后第13天粒细胞植入,第16天血小板植入,第25天DNA指纹鉴定结果提示供者型完全植入。移植后第42天患者出现皮肤Ⅰ度移植物抗宿主病,治疗后皮疹完全消退。移植后CAEBV临床症状及体征消失,随访至移植后1年,多次复查EBV-DNA持续阴性。结论:单倍体相合造血干细胞移植可作为治疗CAEBV的有效手段。     

自体造血干细胞移植治疗难治性白血病疗效观察

目的观察自体外周血造血干细胞移植（Auto-PBSCT）对难治性白血病的疗效。方法15例难治性白血病患者均为髓性白血病,行Auto-PBSCT。预处理方案：BU／CY（马利兰＋环磷酰胺）（10例）或联合IA（去甲氧柔红霉素）（2例）或联合HD-Ara—C（大剂量阿糖胞苷）（3例）。移植后治疗：常规方案巩固化疗维持1a。结果15例患者Auto-PBSCT后全部获完全缓解,除1例移植后死于肺部真菌感染外,其余14例均好转出院,1例半年后复发,其余13例无病存活至今。结论Auto-PBSCT是治疗难治性白血病安全、有效的方法,可延长患者的生存期。     

间充质干细胞与造血干细胞移植相关研究的进展

骨髓中主要存在2种主要类型的干细胞:造血干细胞(hematopoietic stem cells,HSC)及非HSC或间充质干细胞(mesenchymal stem cells,MSC)。HSC移植可重建患者造血系统和免疫系统,因此,临床上HSC移植用于治疗各种恶性血液病、遗传性血液病、再生障碍性贫血及免疫缺陷病等。     

自体骨髓间充质干细胞联合造血干细胞共移植治疗恶性血液病五例疗效观察

目的 研究自体骨髓间充质干细胞(MSCs)与造血干细胞共移植治疗恶性血液病的安全性和可行性,及其对移植后造血重建的影响.方法 从无骨髓浸润的恶性血液病患者本人骨髓中分离、培养间充质干细胞,经放化疗等预处理后,与造血干细胞共移植治疗恶性血液病患者5例,其中恶性淋巴瘤4例,粒细胞肉瘤1例,并观察其对移植后造血重建的影响.结果 MSCs联合造血干细胞共移植治疗恶性血液病患者5例,MSCs输注过程顺利,未见明显不良反应.移植后造血恢复过程中,中性粒细胞≥0.5×109/L的中位时间为9.4(8～11)d、血小板≥20×109/L的中位时间为12.2(10～14)d.结论 MSCs联合造血干细胞共移植治疗恶性血液病安全性好,未见明显副作用.结果 提示输注MSCs可促进造血恢复,但其远期疗效仍有待于进一步观察.     

非清髓性自体外周血造血干细胞移植治疗系统性红斑狼疮的临床观察

目的采用非清髓性自体外周血造血干细胞移植(NAST)治疗系统性红斑狼疮(SLE),旨在用低于常规清髓性造血干细胞移植(HSCT)时的药物剂量和强度,达到既能重建SLE患者的免疫功能,又能避免因骨髓严重受抑而导致的严重并发症和高病死率。方法严格选择适合行NAST的4例SLE患者。造血干细胞的动员采用异环磷酰胺2000 mg/m2粒细胞集落刺激因子(G-CSF)。采集的干细胞量:单个核细胞(MNC)平均3.05×108/kg,CD34+细胞平均O.88×106/kg。非清髓性预处理方案:阿糖胞苷(200 mg·kg-1·d-1, -2～-1 d)及环磷酰胺(40 mg·kg-1·d-1,-2～-l d),均为静脉滴注。评价患者移植前后的相关症状、体征的改变．免疫指标的变化．造血重建的情况及并发症。结果4例患者均成功植入,外周血白细胞>1.0×109/L的平均时间为7.2 d,中性粒细胞>0.5×109/L的平均时间为8.O d,白细胞总数恢复正常的平均时间12 d,血小板>100×109/L的平均时间为IO d,血红蛋白>120 g/L的平均时间为22 d。NAST后4例患者临床症状和体征均消失,红细胞沉降率,C反应蛋白,补体C3、C4均恢复正常,尿蛋白转阴、24 h尿蛋白定量恢复正常．自身抗体大部分转阴,术前及术后淋巴细胞亚群检测显示:CD4+及CD4+/CD8+比值均有变化。并发症中1例出现败血症。随访时间为5个月～3.6年。结论与经典的清髓性HSCT治疗SLE比较,NAST造血重建快,外周血象受抑程度低,治疗安全、有效。但由于例数较少及时间有限,远期疗效尚需进一步观察。     

免疫清除性化疗结合自体外周血造血干细胞移植治疗重症系统性红斑狼疮

目的 观察免疫清除性化疗结合自体外周血造血干细胞移植（移植）治疗重症系统性红斑狼疮（SLE）的疗效及安全性。方法 重症SLE4例，分别合并狼疮性肾炎，狼疮脑，狼疮心或股骨头坏死，干细胞的动员采用环磷酰胺加重组人粒细胞集落因子（G－CSF）；预处理为回输前3天每天应用环磷酰胺50mg/kg 回输后3天每天应用抗胸腺细胞球蛋白（ATG）5mg/kg。观察移植前后临床症状，体征，狼疮相关抗体等指标的改变，并动态观察移植后免疫功能的重建。结果 移植后患者的临床症状完全缓解，狼疮相关抗体全部转阴，移植后患者的免疫功能均明显降低，约半年后恢复正常，但不伴有临床症状的复发。结论 免疫清除性化疗结合自体外周血造血干细胞移对难治性SLE有明显的疗效，尤其适用对各种药物治疗无效者，治疗是安全的，远期疗效还需长期随访。     

自体外周血干细胞移植治疗难治性系统性红斑狼疮的临床研究

目的探讨自体外周血干细胞移植(APBSCT)治疗难治性系统性红斑狼疮(SLE)的临床疗效。方法对难治性SLE患者进行APBSCT治疗。采用环磷酰胺(CTX) 粒细胞集落刺激因子(G-CSF)方案动员,CS-3000血细胞分离机采集外周血干细胞并保存于-80℃冰箱;用CTX50mg/(kg.d)×3～4d方案预处理后,解冻后回输冻存的干细胞的治疗方法。观察APBSCT前后临床表现及免疫学指标的变化。结果动员后获得单个核细胞数(MNC)(3.383～3.704)×108/kg;CD34 细胞数(4.4～11.12)×106/kg。3例均获得造血重建,中性粒细胞>0.5×109/L、血小板>20×109/L的中位数时间分别是8.3d、10d。移植后患者临床症状消失,1例并肾功能不全、难治性高血压和重度贫血的患者移植后恢复正常。3例患者自身抗体转阴或滴度减低,尿蛋白定性消失,SLE疾病活动指数(SLE-DAI)由移植前的平均15分下降为移植后6个月的平均4分。结论APBSCT治疗难治性SLE安全有效,近期疗效好,远期疗效有待进一步观察。     

儿童难治性自身免疫性疾病自体外周血干细胞动员采集和分选的临床研究

目的 探讨儿童难治性自身免疫性疾病进行自体外周血干细胞动员采集的安全性和CD34+细胞分选纯化的可行性及其临床意义.方法 8例儿童难治性自身免疫性疾病,包括4例系统性红斑狼疮、2例皮肌炎,1例幼年型类风湿关节炎和1例多发性硬化,予行CD34+细胞纯化的自体外周血干细胞移植.首先采用环磷酰胺(CTX)联合粒细胞集落刺激因子(G-CSF)方案动员外周血干细胞,然后采用CS-3000血细胞分离机采集外周血,通过CliniMACS细胞分选仪分选自体外周血CD34+细胞,将其用保养液配置冻存于-80℃冰箱.采用非清髓内去除T的预处理方案,即卡氮芥+足叶乙苷+阿糖胞苷+马法兰+抗胸腺球蛋白(ATG)或CTX+ATG或CTX+马法兰+ATG,于第0天回输自体外周血CD34+细胞.结果 儿童能够耐受自体外周血干细胞动员采集过程,无动员相关死亡,动员后获得的单个核细胞数和CD34+细胞数的平均值分别为8.35×108/kg和7.92×106/kg,纯化后的白体外周血CD34+和CD3+细胞数的平均值分别为6.28×106/kg和0.71×105/kg.回输后中性粒细胞和血小板的植入中位时间分别为+11d和+15 d.结论 经CTX联合G-CSF方案可动员出足量的外周血干细胞,经CS-3000血细胞分离机采集可获得足够的单个核细胞,在动员过程中原发病无明显进展恶化,患儿能耐受动员方案,采集过程顺利安全;经CliniMACS细胞分选仪分选的自体外周血CD34+细胞纯度高,移植后造血恢复;采用CD34+细胞纯化的自体外周血移植治疗是常规治疗无效的儿童难治性自身免疫性疾病的可选择治疗措施之一.     

Comparison between granulocyte colony-stimulating factor and granulocyte-macrophage colony-stimulating factor in the mobilization of peripheral blood stem cells

Peripheral blood stem cells (PBSC) have become the preferred source of stem cells for autologous transplantation because of the technical advantage and the shorter time to engraftment. Mobilization of CD34+ into the peripheral blood can be achieved by the administration of granulocyte colony-stimulating factor (G-CSF), granulocyte-macrophage colony-stimulating factor (GM-CSF), or both, either alone or in combination with chemotherapy. G-CSF and GM-CSF differ somewhat in the number and composition of PBSCs and effector cells mobilized to the peripheral blood. The purpose of this review is to give a recent update on the type and immunologic properties of CD34+ cells and CD34+ cell subsets mobilized by G-CSF or GM-CSF with emphasis on (1) relative efficacy of CD34+ cell mobilization; (2) relative toxicities of G-CSF and GM-CSF as mobilizing agents; (3) mobilization of dendritic cells and their subsets; (4) delineation of the role of adhesion molecules, CXC receptor 4, and stromal cell-derived factor-1 signaling pathway in the release of CD34+ cell to the peripheral blood after treatment with G-CSF or GM-CSF.     

An antecedent diagnosis of refractory anemia with excess blasts has no influence on mobilization of peripheral blood stem cells and hematopoietic recovery after autologous stem cell transplantation in acute myeloid leukemia

Several studies have reported data on factors influencing mobilization of peripheral blood stem cells (PBSC) in non-myeloid malignancies. On the contrary, data from patients with acute myeloid leukemia (AML) are very limited, in particular, as the impact of an antecedent diagnosis of refractory anemia with excess blasts (RAEB) on mobilization of PBSCs as well as hematopoietic recovery after autologous stem cell transplantation (ASCT) is concerned. We retrospectively analyzed a cohort of 150 consecutive AML patients in first complete remission in order to make a comparison between patients with de novo AML and secondary AML (s-AML) in terms of CD34 positive (CD34+) cells mobilization and number of leukapheresis needed to collect at least one single stem cell graft. Data concerning hematopoietic recovery after ASCT were also compared. The successful mobilization rate (>2 x 10(6) CD34+ cells/kg) was comparable between de novo AML patients (87%) and those with s-AML (76%), P:0.21. No statistically significant difference was found in terms of either median number of CD34+ cells collected (P:0.44) or CD34+ cells peak in peripheral blood (P:0.28). Both groups of patients needed a median of two apheresis (P:0.45) and no difference was found on the median number of CD34+ cells collected per single apheresis (P:0.59). Finally, neutrophil and platelet recovery after ASCT were comparable between the two groups. An antecedent diagnosis of RAEB has no impact on mobilization and collection of PBSCs in AML as well as on hematopoietic recovery after ASCT.     

Blood stem cell collection using chemotherapy with or without systematic G-CSF: experience in 52 patients with multiple myeloma.

Harvesting of peripheral blood stem cells (PBSCs) following chemotherapy and G-CSF administration is currently performed for hematological therapies. However, a procedure based on the use of a large quantity of G-CSF is relatively costly. Therefore, we retrospectively compared the effects of two PBSC mobilization procedures in a population with recently diagnosed multiple myeloma. The first procedure consisted of chemotherapy and systematic G-CSF administration (group 1: 24 patients). The second consisted of chemotherapy alone, G-CSF having been administered only in the case of failure of PBSC mobilization or delayed white blood cell (WBC) recovery (group 2: 28 patients). Leukapheresis was performed when WBC recovery reached 1 x 10(9)/l if the peripheral blood CD34+ cell count was over 10/microl. Leukapheresis was maintained until a total of 2.5 x 10(6) CD34+ cells/kg was harvested. A significant difference was observed between the two groups only in regard to the median period of WBC recovery (delayed for group 2) and the number of CD34+ cells/kg collected on the first leukapheresis (higher for group 1) but not to the proportion of patients with failure of PBSC collection. Ten group 2 patients, who had insufficient CD34+ cells after WBC recovery or delayed WBC recovery, received G-CSF which resulted in sufficient PBSC harvesting in nine. To obtain a sufficient CD34+ cell level, the patients without systematic G-CSF administration had more leukaphereses (2.1 vs 1.5) but the mean consumption of G-CSF per patient was eight times less than in the other group. Nonsystematic use of G-CSF before WBC recovery or preferentially its introduction just after, could be an interesting economical alternative in PBSC mobilization but should be assessed by a prospective controlled study of cost/efficacy.     

Transplantation of allogeneic CD34+ blood cells

Pluripotent stem cells of hematopoiesis and lymphopoiesis are among the CD34+ cells in blood or bone marrow. After granulocyte-colony stimulating factor (G-CSF) treatment, 1% to 2% of the mononuclear cells in blood are CD34+ cells, which can be procured by leukapheresis. We investigated the potential of CD34+ blood cells for reconstituting hematopoiesis and lymphopoiesis after allogeneic transplantation. HLA- identical sibling donors of 10 patients with hematologic malignancies were treated with G-CSF (filgrastim), 5 microgram/kg subcutaneously twice daily for 5 to 7 days. CD34+ cells were selected from the apheresis concentrates by immunoadsorption, concomitantly the number of T cells was reduced 100- to 1,000-fold. After transplantation, five patients received cyclosporine A for graft-versus-host disease (GvHD) prophylaxis (group I); five patients additionally received methotrexate (group II). G-CSF and erythropoietin were given to all patients. Mean numbers of 7.45 x 10(6) CD34+ and 1.2 x 10(6) CD3+ cells per kilogram were transplanted. In group I, the median times of neutrophil recovery to 100, 500, and 1,000 per mm3 were 10, 10, and 11 days, respectively. Group II patients reached these neutrophil levels after 10, 14, and 15 days, respectively. Platelet transfusions were administered for a median of 18 days in group I and 30 days in group II, and red blood cells for 9 and 12 days, respectively. Between day 30 and 60, lymphocytes reached levels of 353 +/- 269 cells per mm3. The median grades of acute GvHD were III in group I and I in group II. Two patients in group I died from acute GvHD. Two leukemic relapses occurred in group II. Complete and stable donor hematopoiesis was shown in all patients with a median follow up of 370 (45 to 481) days. Allogeneic blood CD34+ cells can successfully reconstitute hematopoiesis and lymphopoiesis. Reduction of T cells by CD34+ blood cell enrichment and cyclosporine A alone might not be sufficient for prophylaxis of severe acute GvHD.     

Molecular remission in adult T cell leukemia after autologous CD34+ peripheral blood stem cell transplantation.

This report describes a patient with acute-type adult T cell leukemia/lymphoma (ATLL) successfully treated by autologous CD34+ peripheral blood stem cell transplantation after fractionated total body irradiation and high-dose cytarabine and cyclophosphamide. A newly established inverse polymerase chain reaction method was used to demonstrate the disappearance of ATLL clonal cells. The patient achieved a sustained molecular remission after transplantation, but died from opportunistic infection 4 months after transplantation. Thus, autologous CD34+ peripheral blood stem cell transplantation is promising for this type of malignancy. However, a prudent clinical attitude toward immunological fragility after transplantation is needed for better outcome.     

Evidence for naive T-cell repopulation despite thymus irradiation after autologous transplantation in adults with multiple myeloma: role of ex vivo CD34+ selection and age

Immunodeficiency following autologous CD34+-purified peripheral blood stem cell (PBSC) transplantation could be related to T-cell depletion of the graft or impaired T-cell reconstitution due to thymus irradiation. Aiming to assess the role of irradiated thymus in T-cell repopulation, we studied 32 adults with multiple myeloma, randomly assigned to receive high-dose therapy including total body irradiation (TBI) followed by autologous transplantation with either unselected or CD34+-selected PBSCs. The median number of reinfused CD3+ cells was lower in the selected group (0.03 versus 14 x 10(6)/kg; P =.002). Lymphocyte subset counts were evaluated from month 3 to 24 after grafting. Naive CD4+ T cells were characterized both by phenotype and by quantification of T-cell receptor rearrangement excision circles (TRECs). The reconstitution of CD3+ and CD4+ T cells was significantly delayed in the CD34+-selected group, but eventually led to counts similar to those found in the unselected group after month 12. Mechanism of reconstitution differed, however, between both groups. Indeed, a marked increase in the naive CD62L+CD45RA+CD4+ subset was observed in the selected group, but not in the unselected group in which half of the CD45RA+CD4+ T cells appear to be CD62L-. Age was identified as an independent adverse factor for CD4+ and CD62L+CD45RA+CD4+ T-cell reconstitution. Our results provide evidence that infusing PBSCs depleted of T cells after TBI in adults delays T-cell reconstitution but accelerates thymic regeneration.     

Peripheral blood stem cell transplantation as an alternative to autologous marrow transplantation in the treatment of acute myeloid leukemia?

The clinical use of autologous marrow transplantation in acute myeloid leukemia (AML) has been hampered by the inability to collect adequate numbers of cells after remission induction chemotherapy and the notably delayed hematopoietic regeneration following autograft reinfusion. Here we present a study in which the feasibility of mobilizing stem cells was investigated in newly diagnosed AML. Among 96 AML patients, 76 patients (79%) entered complete remission. Mobilization was undertaken with low dose and high dose schedules of G-CSF in 63 patients, and 54 patients (87%) were leukapheresed. A median of 2.0 x 10(6) CD34+ cells/kg (range 0.1-72.0) was obtained in a median of three leukaphereses following a low dose G-CSF schedule (150 microg/m2) during an average of 20 days. Higher dose regimens of G-CSF (450 microg/m2 and 600 microg/m2) given during an average of 11 days resulted in 28 patients in a yield of 3.6 x 10(6) CD34+ cells/kg (range 0-60.3) also obtained following three leukaphereses. The low dose and high dose schedules of G-CSF permitted the collection of 2 x 10(6) CD34-positive cells in 46% and 79% of cases respectively (P = 0.01). Twenty-eight patients were transplanted with a peripheral blood stem cell (PBSC) graft and hemopoietic repopulation was compared with the results of a previous study with autologous bone marrow. Recovery of granulocytes (>0.5 x 10(9)/l, 17 vs 37 days) and platelets (>20 x 10(9)/l; 26 vs 96 days) was significantly faster after peripheral stem cell transplantation compared to autologous bone marrow transplantation. These results demonstrate the feasibility of PBSCT in the majority of cases with AML and the potential advantage of this approach with respect to hemopoietic recovery.     

Granulocyte colony-stimulating factor and lineage-independent modulation of VLA-4 expression on circulating CD34+ cells

Although the use of allogeneic transplants of peripheral blood stem/progenitor cells (PBSCs) is increasing, the precise mechanism of PBSC mobilization has not yet been fully clarified. We examined the expression of some adhesion molecules on CD34+ cells from steady-state bone marrow (BM), granulocyte colony-stimulating factor (G-CSF)-mobilized PBSCs, and cytotoxic drugs plus G-CSF-mobilized PBSCs. Irrespective of mobilization method, very late antigen (VLA)-4 expression on circulating CD34+ cells was significantly lower than on steady-state BM CD34+ cells. To elucidate the influence of lineage commitment on VLA-4 expression of circulating CD34+ cells, we analyzed VLA-4 expression on different subsets of CD34+ cells with or without CD33, CD38, CD5, or CD10 antigens, or Glycophorin A in G-CSF-mobilized PBSCs and steady-state BM from related donors, using 3-color flow cytometry. VLA-4 on circulating CD34+ subsets was less expressed than on each corresponding subset of steady-state BM CD34+ cells. Furthermore, VLA-4 positive rates showed no significant difference among the CD34+ subsets. Finally, the data comparing CD34+ cells from steady-state and G-CSF-mobilized PBSCs revealed no differences in terms of VLA-4 expression. These data suggest that reduced expression of VLA-4 may be a result of peripheralization of CD34+ cells from bone marrow, which occurs in a G-CSF- and lineage-independent fashion.     

Phenotypic changes in neutrophil granulocytes of healthy donors after G-CSF administration.

BACKGROUND AND OBJECTIVE: The aim of the present work was to analyze the immunophenotypic changes in neutrophil granulocytes (NG) and their evolution over time in 16 healthy donors who received G-CSF for stem cell mobilization for allogeneic peripheral blood stem cells (PBSC) transplantation. DESIGN AND METHODS: The mobilization schedule consisted of G-CSF (Filgrastimq, Amgen) 10 microg/kg, s.c. for five consecutive days. Apheresis began 16-24h after the last dose of G-CSF. Immunophenotypic analysis (CD10, CD14, CD15, CD16, CD71, CD34 and HLA-DR) of NG and measurement of G-CSF serum levels were performed before G-CSF administration (day 0), on the fifth day of G-CSF treatment and days +7 and +30 after the last dose of G-CSF. RESULTS: After G-CSF administration, peripheral blood NG presented increased expression of HLA-DR, CD34, CD14, and CD71, in addition to decreased expression of CD10 and CD15 and CD16 fluorescence mean intensity. The phenotypic changes on NG were parallel to serum G-CSF levels. All the phenotypic changes returned to the baseline values by one month after the end of G-CSF treatment. No changes were found in the expression of HLA-DR on T and B-lymphocytes. INTERPRETATION AND CONCLUSIONS: These immunophenotypic changes suggest that after G-CSF administration NG from healthy donors who received G-CSF for stem cell mobilization carry transient features of immature phenotype and have increased functional activity.