Peripheral blood stem cells used to augment autologous bone marrow transplantation.

Peripheral blood stem cells (PBSC) were used to augment autologous bone marrow transplantation (ABMT), aiming to hasten engraftment after high dose treatment in a group of heavily pretreated patients. PBSC were obtained by leukapheresis during the rebound after standard chemotherapy. In 11 patients aged 7-17 years, high dose chemotherapy consisted of busulphan 16 mg/kg orally with melphalan 160 mg/m2 intravenously for seven patients, and melphalan 200 mg/m2 intravenously alone for four. The median number of granulocyte-macrophage colony forming units in the reinfused PBSC was 3.42 x 10(4)/kg (3.03-18.01) and bone marrow 12.4 x 10(4)/kg (4.16-28.6). Neutrophil recovery to > or = 0.5 x 10(9)/l and platelet transfusion independence occurred at a median of 14 days (11-18) and 22 days (9-84) respectively. In five patients the early engraftment was transient with neutrophils again dropping below 0.5 x 10(9)/l then slowly recovering. There was one toxic death due to sepsis. PBSC harvesting in these children was undertaken without interrupting routine chemotherapy and without the use of bone marrow growth factors. In some patients PBSC failed to influence engraftment and the use of combined chemotherapy and growth factor priming for PBSC collection may give improved results.     

Peripheral blood stem cell transplantation in young children: experience with harvesting, mobilization and engraftment

The purpose of this study was to determine the feasibility and assess optimal timing of harvesting peripheral blood stem cells (PBSC) for transplantation in young children. Thirteen children with body weight less than 25 kg, mean age of 3.9 years (1-9 yrs) who had recurrent solid tumors and leukemia were given tumor specific chemotherapy followed by i.v. rhG-CSF (5 microg/kg/d) for stem cell mobilization. Cytaphereses were done through a central venous line (CVL) during the marrow recovery phase (WBC >0.5 x 10(9)/l). The phereses were analyzed separately and assigned to three groups depending on the WBC at the time of the pheresis: Group I (WBC <1.0 x 10(9)/l), Group II [WBC in the range 1.0-3.0 x 10(9)/l] and Group III (WBC >3.0 x 10(9)/l). Samples from each harvest were assayed for cell count, CFU-GM, BFU-E, CD34+ cell count, and tumor cell immunocytology in patients with neuroblastoma (NBL). A median of 3.2 x 10(8) mononuclear cells per kg (MNC/kg), [mean 2.8 x 10(8) MNC/kg, standard error of the mean (SEM) +/- 0.74 (1.1-4.7)] were infused following myeloablative therapy. 78 phereses were performed in 13 children with a median weight of 18 kg (10-25 kg). A median of 5 phereses were performed per patient. There were no significant differences in the percentage and number of CD34+ cells, CFU-GM or BFU-E colonies assayed by plating 0.5 x 10(5) cells. Differences could be found in the total number of MNC (p<0.008) and the number of MNC/kg (p<0.001) between Groups II and III. No tumor cell contamination was detected in the NBL patients by immunocytology. All patients were rescued with PBSC and achieved sustained white cell engraftment (ANC >0.5 x 10(9)/l) at a median of 13.5 d (10-25 d) and platelet engraftment (untransfused platelet count >20.0 x 10(9)/l) at a median of 29 d (12-63 d). The only toxicity encountered during the phereses was thrombocytopenia in 4 patients whose median post-pheresis platelet count was 6.0 x 10(9)/l (3.0-9.01). It is concluded that collection of PBSC in young children is feasible and safe and can be performed through a cuffed CVL at the time of WBC recovery post mobilization with chemotherapy and G-CSF. Cytopheresis can be effectively performed when the peripheral WBC count approaches 1.0 x 10(9)/l. Following stem cell infusion, engraftment was prompt and durable.     

Allogeneic peripheral blood stem cell transplantation in children with hematologic malignancies from HLA-matched siblings

BACKGROUND: Despite the ethical problem of using granulocyte colony-stimulating factor (G-CSF) in normal children, allogeneic peripheral blood stem cell transplantation (PBSCT) might have advantages over allogeneic bone marrow transplantation (BMT). PROCEDURE: Eleven HLA-matched sibling donors aged 2-16 years received 10 microg/kg/day G-CSF for 5 days and underwent apheresis to harvest peripheral blood stem cells (PBSC). PBSC were then cryopreserved until infusion. The 11 corresponding patients aged 8 months to 14 years with high-risk hematological malignancies received busulfan (16 mg/kg or 600 mg/m(2)) and melphalan (210 mg/m(2)) as a preparative regimen. Graft-versus-host disease (GVHD) prophylaxis consisted of cyclosporine and methylprednisolone. RESULTS: All of the donors tolerated G-CSF administration and apheresis procedures. The patients received a median of 5.8 (range 1. 4-11.5) x 10(6)/kg CD34(+) cells, 17.2 (3.8-36.0) x 10(5)/kg colony forming units-granulocyte/macrophage (CFU-GM), and 3.5 (1.4-7.1) x 10(8)/kg CD3(+) cells. All of the patients showed prompt engraftment, with a median time to reach an absolute neutrophil count (ANC) above 0.5 x 10(9)/liter of 10 (9-13) days. Grade I acute GVHD occurred in seven patients (64%), whereas grade II-IV acute GVHD was not seen. Chronic GVHD occurred in four patients (40%) among 10 patients evaluable for chronic GVHD. Three patients showed extensive chronic GVHD. Currently, eight patients (73%) are alive and disease-free for a median follow-up of 775 (103-1,069) days. CONCLUSIONS: Allogeneic PBSCT is feasible in the pediatric population, and PBSC harvest is an alternative to BM harvest in donors who are not eligible for BM harvest. Furthermore, PBSC were successfully collected in pediatric donors with peripheral access. The choice of a stem cell source should be based on the risk/benefit assessment for both patients and donors.     

Bone marrow transplantation from matched related donors for patients with Fanconi anemia using low-dose busulfan and cyclophosphamide as conditioning

Seventeen patients with Fanconi anemia (FA) underwent allogeneic bone marrow transplantation (BMT) from matched related donors (MRD) between January 1999 and June 2003. Median age at BMT was 11 years. Conditioning regimen consisted of low-dose cyclophosphamide (CY; 40 mg/kg) and busulfan (BU; 6 mg/kg) with the addition of lymphoglobulin (20 mg/kg) in two patients. Graft-versus-host disease (GVHD) prophylaxis included cyclosporine A (CsA) and methotrexate (MTX; 5 mg/m(2) at day 1, 3, 6). All patients engrafted (for an absolute neutrophil count >0.5 x 10(9)/L) after a median time of 12 days (range 10-16 days). Fourteen patients (82%) had sustained grafts, whereas three others (18%) rejected grafts between day +39 and +80 after transplantation. Two of them are still alive after successful second PBSC transplantation and one died. Acute and chronic GVHD occurred in 23% and 13% of patients, respectively. With a median follow-up of 16 months (range 3-53 months), survival rate was 72% and Karnofsky score was at least 90%. The low-dose BU/CY regimen, in FA patients allografted from an HLA-matched related donor, allowed engraftment with relative low toxicity. Early graft failure (GF) remains a problem and may require modification of this regimen.     

Feasibility study of IL-11 and granulocyte colony-stimulating factor after myelosuppressive chemotherapy to mobilize peripheral blood stem cells from heavily pretreated patients

PURPOSE: Pediatric patients with solid tumors treated with prolonged dose-intensive chemoradiotherapy are poor mobilizers of peripheral blood stem cells (PBSC). We have conducted a pilot study to mobilize PBSC in eight pediatric patients with relapsed solid tumors using ifosfamide, carboplatin, and etoposide (ICE) followed-up by IL-11 plus granulocyte colony-stimulating factor (G-CSF). PATIENTS AND METHODS: Patients received ifosfamide 1.8 g/m2 per day for 5 days, carboplatin 400 mg/m2 per day for 2 days, and etoposide 100 mg/m2 per day for 5 days. After completion of ICE chemotherapy, patients received daily subcutaneous injections of G-CSF (5 microg/kg per day) and IL-11 (50-100 microg/kg per day) until peripheral stem cell apheresis. RESULTS: The median age was 11 years. Diagnosis included three relapsed Hodgkin disease, three relapsed central nervous system tumors, one relapsed Wilms tumor, and one relapsed rhabdomyosarcoma. The median number of apheresis procedures required to obtain 5 x 10(6) CD34+ cells/kg was one. The mean +/- standard error of mean (SEM) total CD34+ cells collected was 14.0+/-2.7 x 10(6)/kg. The mean +/- SEM total CD34+/CD41+ cells collected was 4.6+/-1.9 x 10(6)/kg. Seven of the eight patients have subsequently undergone myeloablative chemotherapy with autologous PBSC transplantation and have reconstituted hematopoiesis with a median time to neutrophil recovery of 10 days and platelet recovery of 15.5 days. CONCLUSIONS: We conclude that the regimen of ICE/IL-11 plus G-CSF is successful in mobilizing large numbers of CD34+ PBSC cells with a limited number (one) of apheresis collections in patients that have previously been heavily pretreated with chemotherapy/radiotherapy.     

Low toxicity and efficacy of (153)samarium-EDTMP and melphalan as a conditioning regimen for secondary acute myelogenous leukemia

We report the case of a 15-yr-old girl who developed secondary acute myelogenous leukemia (AML) 4 yr after completion of therapy for metastatic Ewing sarcoma (primary right acetabulum with metastatic disease to the lungs). Peripheral blood stem cells were collected after the second cycle of chemotherapy with the plan for future consolidation with high-dose chemotherapy and autologous stem cell rescue; however, because of the patient's excellent response to chemotherapy and surgery, therapy was completed without the need for high-dose chemotherapy. No human leukocyte antigen (HLA)-matched related donor was available for a bone marrow transplant. Because of previous lung radiation, high-dose samarium [30 mCi/kg of samarium-153 ethylenediaminetetramethylenephosphonate ((153)Sm-EDTMP) day -14] and melphalan (140 mg/m(2) day -2) were chosen as the conditioning regimen to avoid potential lung complications. The patient received an infusion of 6.1 x 10(8)/kg mononuclear autologous cells on day 0. She achieved engraftment on day +23. Three years after transplantation, she continues to have complete remission. Samarium and melphalan constitute a well-tolerated regimen with potential antileukemic activity.     

非亲缘异基因骨髓移植治疗儿童白血病

目的　评价非亲缘异基因骨髓移植 (URD BMT)治疗儿童急性和慢性白血病的临床疗效。方法　 6例白血病患儿 ,其中慢性髓系白血病 2例 ,急性淋巴细胞白血病 3例 (第 1次完全缓解 ) ,急性早幼粒细胞白血病 1例 (第 2次完全缓解 ) ,由台湾慈济骨髓捐赠中心提供无关供者骨髓。预处理方案为马利兰 环磷酰胺 (Bu/Cy2 )方案 ,急性移植物抗宿主病 (aGVHD)预防为霉酚酸酯(MMF)、环孢菌素A(CsA)加氨甲喋呤 (MTX)联合方案 ;以前列素E1预防肝静脉闭塞病 (VOD) ,以巨细胞病毒 (CMV)抗原血症监测和更昔洛韦预防CMV病。供、受者间HLA基因位点型全相合 3例 ,1个基因位点型不合 2例 ,2个基因位点型不合 1例。结果　 6例患儿经DNA短串联重复序列多态性分析证明为供髓植入 ,中性粒细胞 >0 5× 10 9/L的中位天数为 14 5 (13～ 18)d ,血小板 >2 0×10 9/L的中位天数为 16 (11～ 2 3)d。发生Ⅱ～Ⅳ度aGVHD 2例 (33% ) ,局限性慢性移植物抗宿主病(cGVHD) 3例 ,未发生广泛性cGVHD。中位随访时间 4 12 (187～ 1338)d ,全部患儿均无病生存。结论非亲缘异基因骨髓移植是治疗儿童急性和慢性白血病的有效方法。     

Recombinant human granulocyte-macrophage colony-stimulating factor in children with chemotherapy-induced neutropenia.

Twenty children 1-17 (median, 5.5) years of age received GM-CSF during chemotherapy-induced neutropenia at the dose of 5 micrograms/kg/day, continued until the absolute neutrophil count (ANC) exceeded 500 x 10(6)/liter. Twelve children with solid tumors received GM-CSF after courses of conventional chemotherapy (VP-16 + ifosfamide or "6 in 1"). One course followed by GM-CSF was compared to identical courses without GM-CSF in the same patients. Eight children with recurrent/poor risk malignancies received GM-CSF after marrow-ablative therapy and autologous bone marrow transplantation (ABMT). Their engraftment data were compared to matched historical controls. In both groups GM-CSF accelerated myeloid recovery, which was preceded by the appearance of immature myeloid elements in bone marrow. The ANC levels of 200, 500, and 1,000 x 10(6)/liter were exceeded 2, 3 (P < 0.05), and 6 (P < 0.005) days earlier with GM-CSF in the conventional chemotherapy group, and 6, 10 (P < 0.05), and 9 days earlier in the ABMT group, as compared to the controls. All adverse effects observed were mild, including skin rashes, nasal stuffiness, general achiness, nausea, and fever. We conclude that GM-CSF is well tolerated in children and accelerates myeloid recovery in chemotherapy-induced neutropenia.     

Low risk of graft-versus-host disease with transplantation of CD34 selected peripheral blood progenitor cells from alternative donors for Fanconi anemia

OBJECTIVES: Transplant results for Fanconi anemia with alternative-donor bone marrow transplantation currently entail a high incidence of graft failure and graft-versus-host disease (GVHD). The authors sought to improve outcome in this disease category with alternative donors with a 5-6/6 antigen match by transplantation of highly purified peripheral blood progenitor cells (PBPC) using the Isolex 300i v2.5 device as a means of T-cell depletion to lessen the risk of GVHD. METHODS: All Fanconi anemia patients (n = 8) received the same preparative regimen that included total body irradiation (450 cGy), Cytoxan (20 mg/kg), ATGAM, and fludarabine (120 mg/m2). The cell dose of CD34+ cells was a median of 11.4 x 10(6)/kg; the cell dose of CD3+ cells was a median of 1.9 x 10(4)/kg. Primary engraftment was rapid in all patients, with neutrophil recovery occurring at a median of day 10 and platelet count more than 50,000 on day 27. Two patients subsequently had secondary graft failure. Despite lack of cyclosporine GVHD prophylaxis, only two patients developed acute GVHD (both grade I), and no patients developed chronic GVHD. Three patients died: one at day 59 secondary to disseminated fungal infection, the second at day 196 during a second transplant, and the third at day 202 due to graft failure. With a median follow-up of 12 months, the overall survival was 58 +/- 18%. CONCLUSIONS: Transplantation of CD34-selected PBPCs from alternative donors results in a very low risk of GVHD in patients with Fanconi anemia.     

Umbilical cord blood transplantation in Chinese children with beta-thalassemia

To evaluate factors affecting outcome of sibling umbilical cord blood transplantation in Chinese children with thalassemia. The authors conducted a retrospective review of all patients undergoing such transplants in a single institution. Nine children with thalassemia major were diagnosed at a median age of 12 months. They received irregular blood transfusions and suboptimal iron chelation therapy before transplant. Sibling cord blood transplant was performed at a median of 5.5 years (range 3.5-10 years). Six donors were HLA-identical; three were one- to three-antigen mismatched. The mean number of nucleated cells infused was 6.6 x 10(7)/kg (range 3.4-12.7); the mean number of CD34+ cells infused was 3.8 x 10(5)kg (range 0.6-11.7). Seven patients had engraftment of donor cells. The median number of days to achieve a neutrophil count of > 0.5 x 10(9)/L was 19 days (range 10-25); the median number of days to achieve a platelet count of > 20 x 10(9)/L was 33 days (range 19-63). Of the six patients who received HLA-identical transplants, one developed grade 2 and two developed grade 1 acute graft-versus-host disease. Two of the three patients receiving mismatched cord blood did not achieve engraftment, and the other one engrafted but developed grade 4 acute graft-versus-host disease. Two patients subsequently developed secondary graft rejection and had autologous marrow regeneration before day 60 posttransplantation. With a median follow-up of 49 months (range 38-64), eight patients survived but only four were transfusion-independent. Umbilical cord blood transplant appears to have a higher chance of nonengraftment and secondary rejection. A more intensive immunosuppressive conditioning regimen may be required.     

Autografting with bone marrow exposed to multiple courses of very high dose cyclophosphamide in vivo and to 4-hydroperoxycyclophosphamide in vitro

Intensive chemotherapy prior to harvesting autologous bone marrow may be advantageous for cancers that infiltrate the bone marrow. This approach, however, may deplete hemopoietic reserves or damage the hemopoietic microenvironment and thereby jeopardize posttransplant engraftment; in vitro treatment of bone marrow to ensure a tumor-free state may enhance the risk of nonengraftment. We addressed these concerns in a pilot study of patients with disseminated neuroblastoma. Bone marrow was harvested after initial intensive therapy that included 1) three to six courses of very high dose cyclophosphamide (CPM) (100-140 mg/kg in five patients, 140-160 mg/kg in nine patients), plus doxorubicin and vincristine, followed by 2) a median of three strongly myelosuppressive courses of cisplatin/VP16. The median interval between courses was 23 days. The marrow was treated in vitro with the CPM congener 4-hydroperoxycyclophosphamide (4-HC) and cryopreserved. It was infused after a massive cytoreduction regimen of melphalan 180 mg/m2 (n = 7) or thiotepa 900 mg/m2 (n = 7), plus cisplatin, BCNU, VP16, and local radiation. All 14 patients reconstituted hemopoiesis (median of 37 days to neutrophils greater than or equal to 500/microliter and of 63 days to platelets greater than 50,000/microliters). The number per kilogram body weight of hemopoietic progenitor cells (CFU-GM, BFU-E) in the autografts correlated significantly with the rate of hematologic recovery. Preharvest CPM dosage, however, did not. The use of thiotepa, as opposed to melphalan, was associated with a significantly slower posttransplant platelet recovery, suggesting a possible adverse effect of high-dose thiotepa on posttransplant hemopoiesis. In sum, while reinforcing evidence of a stem cell sparing effect of CPM, this pilot study more importantly delineates the degree to which high-dose alkylator therapy can be exploited to attain maximal dose intensity beginning at diagnosis. This aggressive treatment approach may have wide applicability, since CPM is among the most active agents against a spectrum of pediatric cancers.     

Clinical outcomes and graft characteristics in pediatric matched sibling donor transplants using granulocyte colony-stimulating factor-primed bone marrow and steady-state bone marrow

Matched sibling donor (MSD) transplant is a life-saving procedure for children with various hematological malignancies and non-malignancies. Traditionally, steady-state bone marrow (S-BM) has been used as the source of stem cells. More recently, peripheral blood stem cell (PBSC) after granulocyte-colony stimulating factor (G-CSF) mobilization has gained popularity. Adult studies of G-CSF-primed BM (G-BM) have shown that it produces rapid white blood cell engraftment like PBSC, but with less chronic graft-vs.-host disease. No such study has been published in pediatric patients. We conducted a pilot clinical trial of G-BM for pediatric patients. Ten patients were enrolled and were compared to a contemporaneous group of 12 patients who received S-BM. Patients in the G-BM group received a higher dose of total nucleated cells/kg (7.01 vs. 3.76 x 10(8), p = 0.0009), higher granulocyte-macrophage colony-forming units (CFU-GM)/kg (7.19 vs. 3.53 x 10(5), p = 0.01) and had shorter inpatient length of stay (28 vs. 40 days, p = 0.04). The engraftment, transfusion requirement and disease-free survival between the two groups were similar. We concluded that G-BM should be considered as an alternative graft source to S-BM, with the benefits of larger graft cell dose, higher CFU-GM dose and shorter length of stay.     

A pilot trial of tandem autologous peripheral blood progenitor cell transplantation following high-dose thiotepa and carboplatin in children with poor-risk central nervous system tumors

This is a pilot study performed to determine the maximum tolerated number of courses of high-dose thiotepa and carboplatin with autologous peripheral blood progenitor cell (PBPC) transplantation in poor-risk pediatric central nervous system (CNS) tumor patients. Twelve patients were enrolled and a total of 24 PBPC transplants were performed. The median age was 7.7 years. All patients had CNS tumors: 4 relapsed CNS PNET, 2 high-risk PNET in first remission, 2 relapsed/progressive brainstem tumor, 2 relapsed/progressive anaplastic astrocytoma, 1 relapsed GBM, and 1 recurrent ependymoma. The regimen consisted of thiotepa 250 mg/m2/day x 3 days and carboplatin 400 mg/m2/day x 3 days. No toxic deaths occurred. All patients were hospitalized for a median duration of 17 days. The median number of CD34 cells infused was 5.4 x 10(6)/kg (2.1-29.7 x 10(6)/kg) per course. Median time to ANC > 0.5 x 10(9)/L was 9 days, and platelets > 20 x 10(9)/L was 13.5 days. Four patients came off protocol after only one course of PBPC (2 had tumor progression, 2 parental choice); 4 patients underwent two, and 4 patients three courses of PBPC. Major nonhematologic complications were mucositis that necessitated infusion of narcotics (11/24 courses), fever of unknown origin (12/24), documented infection (9/24), and hemorrhagic cystitis (3/24). TPN was administered during 22 of 24 courses with a median duration of 15 days. It isfeasible to administer 2-3 courses of tandem high-dose thiotepa and carboplatin with PBPC transplant with prompt engraftment and manageable toxicities in pediatric CNS tumor patients.     

Feasibility and safety of peripheral blood stem cell collection in children with poor-prognosis solid tumors: a single center experience.

This study reports the data of 32 children with poor-prognosis solid tumors who had 78 PBSC harvests on Fenwall CS-3000plus after mobilization mainly by different treatment protocol chemotherapy regimens followed by G- or GM-CSF (92% of patients) or by G-/GM-CSF alone (8%). Timing of procedure was predicted by studying the blood count. When the white blood cell and platelet count reached a median of 8.1 (0.9-37.3) and 95 (16-338) x 10(9)/L, respectively, the median number of 2.7 (0.005-16.8) x 10(6) CD34+/kg with 1.5 (0.005-11.6) x 10(6) CD34+/kg for 1 blood volume processed was obtained per procedure. In the group of 13 patients with low body weight (median 14 [10-20] kg) 32 leukophereses were performed. The extracorporal line was primed with donor red blood cells in the patients with the weight below 15 kg. No difference was observed in CD34+ content in harvests whether GM-CSF was begun on day +1 or on day +3 after chemotherapy.     

Autologous peripheral stem cell transplantation in children

19 children between 3 and 23 years underwent 79 leukapheres for collection of blood stem cells. In children suffering from acute lymphoblastic leukemia (ALL), Non Hodgkin's Lymphoma (NHL) and Ewing's Sarcoma (ES) we collected 6.87 x 10(4) CFU-GM/kg (range 2,65-21.7), if collections were started with the first platelet rise. In children with peripheral primitive neuroectodermal tumors (PNET) and neuroblastoma (NBL) we gained only 1.20 x 10(4) CFU-GM/kg (range 0.09-2.24). 17 children received high dose chemoradiotherapy and peripheral stem cell +/- bone marrow rescue. 9 suffered from solid tumors, 8 from hematopoietic malignancies. 9 were transfused with peripheral stem cells only, 8 received bone marrow in addition. Time to reach 0.5 x 10(9)/l granulocytes was very short-median 31 days (12-65), in 4 children receiving more than 5 x 10(4) CFU-GM/kg 12 to 13 days, only. On January 31st, 1989 6/17 children are alive in complete remission after a median observation time of 14.5 months (3-26) after autologous stem cell transfusion, one child is alive in "no remission", 7 died with relapse, 3 died because of infections (2 x aspergillosis, 1 x pseudomonas septicemia). The collection of blood derived stem cells by leukaphereses was well tolerated even in very small children and easily repeatable. With optimal timing high stem cell numbers were obtainable, resulting in a very short duration of posttransplant granulocytopenia.     

Unrelated cord blood transplant experience by the pediatric blood and marrow transplant consortium

Cord blood (CB) has emerged as a potential source of hematopoietic stem cells for patients who are in need of hematopoietic stem cell transplant (HSCT). The authors analyzed the Pediatric Blood and Marrow Transplant Consortium's (PBMTC) data of consecutive unrelated CB transplants performed during the initial 2 years of using placental blood grafts. From January 1995 to December 1996 PBMTC performed a total of 44 unrelated CB transplant for a variety of diseases consisting of acute leukemias (n = 29), congenital conditions (n = 9), and bone marrow failure (n = 6). There were 15 females and 29 males with median age of 5 years (range 0.4-20.6 years) and median weight of 18.2 kg (range 6.3-70 kg). The median volume of CB units was 80 mL (range 44.5-215 mL) and the median cell dose given was 4.3 x 10(7)/kg of recipient weight (range 1.1-23 x 10(7)/kg). Techniques used for human leukocyte antigen (HLA) matching were serologic typing for class I HLA antigens and high-resolution molecular typing for HLA-DRB1 alleles. HLA disparities were as follows: 4 were 6/6 matches, 21 were 5/6, 15 were 4/6, and 4 were 3/6. Twenty-nine (66%) of CB units were DRB1 matched with recipients. Conditioning regimens consisted of either total body irradiation containing (n = 31) or chemotherapy only (n = 11) regimens. All but 3 patients receive cyclosporine as part of graft vs. host disease (GvHD) prophylaxis in combination with either methotrexate (MTX) or methylprednisolone (Pred). The other 3 patients had FK506 and MTX for GvHD prophylaxis. Myeloid engraftment (absolute neutrophil count > or = 500) occurred at a median of 21 days (range 10-43 days) and platelet > or = 50,000/mm3 was noted at a median of 44 days (range 16-102 days). Eight patients died too early (< day + 28) for evaluation of engraftment (5 for infection, 2 for multiorgan failure, 1 for toxic epidermolysis). The probability of having grade II-IV acute GvHD for all patients was 44 +/- 0.7%. The incidence of a GvHD is similar for 4/6 and 5/6 antigen when DRB1 matched, at 47 and 52%, respectively. Chronic GvHD was noted in 28% of patients surviving > 90 days. The Kaplan-Meier estimate of 4-year event-free survival was 43%. A Cox model for analysis of factors associated with survival was DRB1 matching, p = .001; cell dose, p = .009; and younger age, p = .03. In conclusion, CB transplant offers a good alternative to bone marrow transplant Although GvHD occurs, it is usually of low severity despite the high frequency of multiple HLA antigen mismatches. It also appears that a 4/6 is as good as a 5/6 matched antigen CB unit when DRB1 matched especially in the pediatric setting.     

Haploidentical stem cell transplantation in patients with pediatric solid tumors: preliminary results of a pilot study and analysis of graft versus tumor effects

Pediatric patients with relapsed metastatic tumors have a poor prognosis and new treatment strategies are warranted. We present preliminary results of a pilot study, evaluating the feasibility and toxicity of transplantation of haploidentical T and B cell depleted grafts with high numbers of NK cells. 6 patients with relapsed metastatic neuroblastomas (n = 4), rhabdomyosarcoma (n = 1) or Ewing's sarcoma (n = 1) after previous autologous transplantation received CD3/CD19 depleted grafts from mismatched family donors with a median number of 16 x 10 (6)/kg stem cells, 167 x 10 (6)/kg Natural Killer cells and only 5.4 x 10 (4)/kg residual T cells. A melphalan-based, reduced intensity conditioning was used. Despite pretransplant chemotherapy, patients entered transplantation with significant tumor burden. Primary engraftment occurred in 6/6 patients. One patient had secondary graft failure. Hematopoietic recovery was rapid (ANC > 0.5 x 10 (9)/L: 11 days (9-12); independence from platelet substitution: 8 days (7-11)). Four patients had acute GvHD grade II, limited chronic GvHD was observed in 2 patients. No transplant-related mortality and only low toxicity occurred. Four patients died from progression, two patients are alive. Overall median survival time is 6 months (2-11) to date. Analysis of posttransplant NK cell function revealed stable cytotoxic activity against K562 targets, whereas activity against neuroblastoma targets was low. Stimulation with cytokines and use of appropriate antibodies clearly enhanced specific lysis in vitro. In summary, these preliminary results indicate the feasibility and low toxicity even in intensively pre-treated patients with neuroblastomas/sarcomas. This approach may form the basis for posttransplant immunomodulation and other therapeutic strategies. Further experience is warranted to evaluate the method.     

Autologous bone marrow transplantation in children with acute lymphoblastic leukemia

We report 25 children with acute lymphoblastic leukemia (ALL) treated with purged autologous bone marrow transplantation (ABMT) at a single center. Two children with high-risk ALL were transplanted in first remission and 23 with relapsing ALL were transplanted in second (n = 21) or third (n = 2) remission. There was no procedure-related mortality. The median time to engraftment (i.e. to reach a polymorphonuclear cell count of 0.5 x 10(9)/l) was 25 days (range 16-45 days). Seven children relapsed, four within five months after ABMT: 18 of 25 children (72%) are in continuous complete remission after a median follow-up period of 50 months (range 5-71 months). The predicted long-term disease-free survival is 65% in the whole group and 61% in those transplanted after relapse. Relapse-free children returned to normal activities within three months after ABMT. The major side effects were development of cataract and gonadal insufficiency. We consider the results promising, but our data do not allow comparison with results reported from treatment with chemotherapy alone, since some of our patients were referred from other centers and represent a selected patient group. Long-term follow-up of well-defined patient populations is necessary to evaluate the effect of ABMT.     

High-dose chemotherapy and autologous blood stem cell transplantation in children with metastatic neuroblastoma

High-dose chemotherapy (HDC) followed by autologous blood stem cell transplantation (ABSCT) was performed to improve the prognosis of children with metastatic neuroblastoma over 1 year of age at diagnosis. Seven stage IV neuroblastoma patients with a median age of 3.9 years (range 1.6–11.4 years) received conventional chemotherapy before leukapheresis for ABSCT. The median duration of chemotherapy before harvest was 8 months (range 3–23 months). Peripheral blood stem cells (PBSC) were harvested from them after the use of cytotoxic drugs plus granulocyte colony-stimulating factor. The median number of granulocyte-macrophage colony forming units collected after harvest was 23.2 × 10⁴/kg (range 10.1–45.3 × 10⁴/kg). The patients were administered HDC consisting of carboplatin, etoposide, and melphalan followed by ABSCT. Hematopoietic reconstitution after ABSCT was favorable; recovery of granulocytes count > 0.5 × 10⁹/L occurred within 2 weeks and stable platelet engraftment occurred at a median duration of 23 days (range 7–33 days). The toxicity of ABSCT was well tolerable. Two of the four patients who received ABSCT at their first complete remission remained in remission 67 and 68 months after ABSCT. One with partial remission also showed a good response for 8 months. The other two at first relapse showed a transient regression of the tumor. The prognosis of seven patients who received ABSCT was significantly better than that of 13 patients who received conventional therapy alone. These findings suggest that HDC followed by ABSCT is safe and useful as consolidation therapy for the treatment of patients with metastatic neuroblastoma.     

CD25抗体预防移植物抗宿主病在儿童白血病半匹配骨髓移植中的应用

目的　探讨CD2 5抗体用于预防儿童白血病半匹配未去除T细胞骨髓移植重度移植物抗宿主病 (GVHD)的疗效。方法　 10例儿童白血病患者接受人类白细胞抗原 (HLA) 2～ 3个位点不合半匹配骨髓移植 ,移植方法除了供者用粒细胞集落刺激因子 (G CSF)及受者应用环孢素A(CSA)、氨甲蝶呤 (MTX)、抗胸腺细胞球蛋白 (ATG ,FreseniusHemocare ,Germany)和霉酚酸酯 (MMF)预防GVHD的综合措施外 ,加用抗CD2 5单克隆抗体 (舒莱 ,novartispharmaswitzerland)预防GVHD ,剂量各为 2 0mg ,在移植前 2h和移植后第 4天应用 ,观察移植后的疗效 ,移植结果与前期未用CD2 5抗体移植组作回顾性比较。结果　 10例移植后均获造血重建 ,粒细胞 >0 5× 10 9/L的中位天数是 19d ,血小板大于 2 0× 10 9/L的中位天数是 2 2d ,骨髓植活直接证据检测证实为完全供者造血。无一例发生急性Ⅱ～Ⅳ度GVHD ,未用CD2 5抗体对照组 8例中发生急性Ⅱ～Ⅳ度GVHD有 4例 ,差异有显著性(P =0 0 14 7)。可评价慢性GVHD的 8例均发生慢性GVHD ,为局限性慢性GVHD。中位随访 12个月 (范围 9～ 2 4个月 ) ,2例为移植相关死亡 ,1例移植后 14个月因复发死亡 ,实际无病生存率是70 %。结论　儿童半匹配未去除T细胞骨髓移植中应用舒莱 ,明显降低急性重症GVHD发生 ,临床