低剂量ATG用于父母HLA 10/10相合造血干细胞移植患者的临床分析

目的:探讨父母HLA 10/10相合不去除T细胞的外周血造血干细胞移植治疗恶性血液病的植入情况、疗效和相关并发症。方法:预处理采用改良的Bu/Cy方案,用低剂量的兔抗人T淋巴细胞球蛋白、环孢素A、吗替麦考酚酯和短程甲氨蝶呤预防移植物抗宿主病(GVHD)。回输G-CSF动员的外周血干细胞,输注单个核细胞中位数为7.830(7.320~10.004)×108/kg,CD34+细胞中位数为4.59(3.68~5.32)×106/kg。结果:4例患者均达完全供者植入,粒系植入时间为16(11~16)d,血小板植入时间为22(11~29)d。发生Ⅱ度急性GVHD1例,发生率25%。发生慢性GVHD 3例,广泛型1例。中位随访267(178~1903)d,死亡1例(非复发死亡),复发1例(为高危患者),无复发存活2例。结论:低剂量ATG用于父母HLA 10/10相合供者异基因造血干细胞移植治疗高危恶性血液病是比较安全、有效的方案。     

异基因外周血造血干细胞移植治疗难治性白血病(附1例报告)

对 1例难治性急性粒 -单细胞白血病 (AML - M4 b)患者施行异基因外周血造血干细胞移植 (allo-PBSCT ) ,以 Cy/ TBI方案预处理后 ,输注 HL A完全相合的同胞供者经 G- CSF动员的外周血单个核细胞(PBMNCs) 9.0× 10 8/ kg,其中 CD34 细胞 6 .2 5× 10 6 / kg;移植物抗宿主病 (GVHD)的预防用 Cs A MTX方案。结果 : 15天时 ,外周血中性粒细胞 >0 .5× 10 9/ L,血小板 >5 0× 10 9/ L; 30天时 ,外周血三系均完全恢复正常。仅有 度皮肤 GVHD发生。认为对于难治性白血病 ,如有 HL A相合供者 ,应及早行异基因造血干细胞移植 (allo-HSCT)特别是 allo- PBSCT,具有受者造血与免疫功能重建快等优点     

CD34~+ CD38~-细胞对异基因造血干细胞移植的影响研究

目的观察CD34+CD38-细胞对异基因造血干细胞移植术后造血重建和移植物抗宿主病(GVHD)的影响。方法分析2004年1月至2009年12月河南省人民医院血液科全相合异基因外周血干细胞造血干细胞移植78例,CD34+、CD34+CD38-细胞输入量与血缘全相合异基因外周血造血干细胞移植术后造血重建及GVHD发生率间的相关性。结果粒细胞、血小板恢复时间与CD34+CD38-细胞输入量呈负相关(r分别为-0.521、-0.448,P<0.01),与CD34+细胞输入量也呈负相关(r分别为-0.405、-0.371,P<0.05)。急性GVHD、慢性GVHD的发生与CD34+、CD34+CD38-、CD3+、CD4+、CD8+细胞输入量无相关性。结论输入高数量的CD34+CD38-细胞有利于移植术后的粒细胞、血小板快速恢复;对于预测术后造血恢复,CD34+CD38-细胞亚群输入量可能优于CD34+细胞总数。     

造血干细胞移植治疗X-连锁重症联合免疫缺陷病临床观察

目的:探讨重症联合免疫缺陷(SCID)移植的经验。方法:对我院4例X-连锁SCID患者进行了5次造血干细胞移植(HSCT)。供者采用人类白细胞抗原(HLA)全相合同胞骨髓1例次,母亲半相合CD34+外周造血干细胞2例次,无关脐血2例次。2例次脐血移植者应用了清髓性预处理,并进行移植物抗宿主病(GVHD)预防,其余3例次未进行预处理和GVHD预防。结果:所有患者在活动性感染的基础上接受HSCT。骨髓和外周血移植物平均CD34+细胞为6.45×107/kg,脐血为1.38×106/kg。3例患者移植后2周左右出现Ⅰ～Ⅱ度急性GVHD。最终2例因移植后肺部感染加重死亡,1例因黄疸、肝功能不良放弃治疗,仅1例接受再次脐血移植者经历了首次移植失败、重度肝静脉阻塞病(VOD)、重症肺炎后幸存,该患儿移植后78d自然杀伤(NK)细胞数量接近正常,10个月免疫球蛋白数量恢复正常,13个月T细胞数量接近正常,目前已经随访到移植后15个月。结论:HSCT治疗SCID具有可行性,早期诊断并在严重感染前进行移植是提高移植成功的关键。     

HLA半相合非清髓性造血干细胞与间充质干细胞共移植治疗重症再生障碍性贫血1例

目的:观察HLA半相合非清髓性造血干细胞与间充质干细胞(MSC)共移植治疗重症再生障碍性贫血(SAA)的疗效及安全性。方法:1例24岁男性SAA患者。应用非清髓性预处理方案,进行HLA半相合异基因外周血造血干细胞和MSC共移植。移植rhG-CSF动员的供者外周血单个核细胞9.22×108/kg,CD34 细胞8.56×106/kg,及体外扩增培养的供者骨髓MSC2.12×105/kg。结果:移植后 12d中性粒细胞数>0.5×109/L, 21d WBC4.5×109/L,Hb99g/L,PLT108×109/L。经HLA配型,红细胞亚型和VNTR检测,为供者型完全嵌合体。随访14个月,无急、慢性移植物抗宿主病(GVHD)发生。结论:HLA半相合非清髓性造血干细胞与MSC共移植治疗SAA是安全有效的方法。     

异基因造血干细胞移植治疗重型再生障碍性贫血Ⅱ型22例的疗效分析

目的:评估异基因造血干细胞移植(allo-HSCT)治疗重型再生障碍性贫血(SAA)Ⅱ型的疗效和安全性。方法:回顾性分析接受allo-HSCT治疗的22例SAAⅡ患者的临床资料,其中同胞相合供者移植10例,无关供者移植12例;18例行外周血造血干细胞移植,4例行骨髓联合外周血造血干细胞移植。预处理方案为环磷酰胺+抗人胸腺细胞球蛋白±氟达拉滨±白消安±低剂量TBI;采用环孢霉素A或他克莫司、短疗程甲氨蝶呤±霉酚酸酯预防移植物抗宿主病(GVHD)。回输单个核细胞中位数13.55(5.12~25.90)×10~8/kg,CD34~+细胞中位数7.30(2.19~40.32)×10~6/kg。结果:20例(90.91%)患者获得造血重建,可评估患者的中性粒细胞和血小板的中位植入时间分别为12(9~22)d和13(9~28)d。移植后2年急性GVHD、慢性GVHD和移植排斥、移植相关死亡累积发生率分别为40.00%、30.00%、9.09%和22.73%。细菌血流感染率22.73%,肺部侵袭性真菌病发生率40.91%,巨细胞病毒和EBV感染率分别为75.00%和50.00%;心、肝、肾功能不全发生率分别为45.45%、13.64%和36.36%。中位随访23(10~68)个月,17例患者生存,预期2年总生存率77.27%,预期2年无病生存率72.73%。单因素分析结果显示,移植后发生严重(Ⅱ~Ⅳ度)急性GVHD和重要脏器功能不全可显著降低allo-HSCT治疗SAAⅡ的疗效(P=0.018、0.009)。结论:同胞相合供者和无关HLA匹配供者alloHSCT是治疗SAAⅡ的有效手段。     

异基因造血干细胞移植治疗重型再生障碍性贫血Ⅱ型22例的疗效分析

目的:评估异基因造血干细胞移植(allo-HSCT)治疗重型再生障碍性贫血(SAA)Ⅱ型的疗效和安全性。方法:回顾性分析接受allo-HSCT治疗的22例SAAⅡ患者的临床资料,其中同胞相合供者移植10例,无关供者移植12例;18例行外周血造血干细胞移植,4例行骨髓联合外周血造血干细胞移植。预处理方案为环磷酰胺+抗人胸腺细胞球蛋白±氟达拉滨±白消安±低剂量TBI;采用环孢霉素A或他克莫司、短疗程甲氨蝶呤±霉酚酸酯预防移植物抗宿主病(GVHD)。回输单个核细胞中位数13.55(5.12~25.90)×10~8/kg,CD34~+细胞中位数7.30(2.19~40.32)×10~6/kg。结果:20例(90.91%)患者获得造血重建,可评估患者的中性粒细胞和血小板的中位植入时间分别为12(9~22)d和13(9~28)d。移植后2年急性GVHD、慢性GVHD和移植排斥、移植相关死亡累积发生率分别为40.00%、30.00%、9.09%和22.73%。细菌血流感染率22.73%,肺部侵袭性真菌病发生率40.91%,巨细胞病毒和EBV感染率分别为75.00%和50.00%;心、肝、肾功能不全发生率分别为45.45%、13.64%和36.36%。中位随访23(10~68)个月,17例患者生存,预期2年总生存率77.27%,预期2年无病生存率72.73%。单因素分析结果显示,移植后发生严重(Ⅱ~Ⅳ度)急性GVHD和重要脏器功能不全可显著降低allo-HSCT治疗SAAⅡ的疗效(P=0.018、0.009)。结论:同胞相合供者和无关HLA匹配供者alloHSCT是治疗SAAⅡ的有效手段。     

供者用粒细胞集落刺激因子单倍体骨髓移植的临床研究

目的探讨供者用粒细胞集落刺激因子(G-CSF)和受者联合应用多种免疫抑制剂治疗的单倍体骨髓移植在降低重症移植物抗宿主病(GVHD)和改善无病生存的疗效.方法单倍体骨髓移植治疗白血病13例(单倍体移植组),移植后结果和连续完成的13例白血病HLA匹配异基因移植 (相合移植组) 相比较,单倍体移植方法是供者应用G-CSF 250 μg/d,连用7 d后采髓, 受者GVHD预防除环孢素A(CSA)和甲氨蝶呤(MTX)外,在移植前4～1 d用抗胸腺细胞球蛋白(ATG) 5 mg*kg-1*d-1, 移植后7 d始加服霉酚酸酯(MMF).结果单倍体移植组植入物CD+34细胞中位数6.1×106/kg,是相合移植组输入CD+34细胞中位数2.5×106/kg的2倍多(P＜0.01),单倍体移植组和相合移植组植入物CD+3细胞中位数分别是50.5×106/kg和47.0×106/kg(P＞0.05).移植后无1例发生植入失败,两组造血重建速度无差异(P＞0.05),所有患者经骨髓植活直接证据检测证实为完全供者造血.单倍体移植组发生急性Ⅱ～Ⅳ GVHD 5例(38.5%),可评价的8例中7例发生慢性GVHD(87.5%),为局限性慢性GVHD,这与相合移植组差异无显著性 (P＞0.05).单倍体移植组中位随访453 d(180～690),移植相关死亡5例,无复发死亡病例,剩余8例无病存活(61.5%).相合移植组中位随访510 d(220～810),移植相关死亡2例,复发死亡2例,9例无病存活(69.2%),通过比较两组差异无显著性(P＞0.05).结论本研究单倍体骨髓移植治疗白血病是一种安全和有效方法,在降低重症急性GVHD 及改善无病生存方面和HLA相合同胞供者移植相当.     

单个核细胞计数对异基因外周血干细胞移植后造血重建的预测研究

目的探讨单个核细胞(MNC)计数作为造血干(祖)细胞含量的独立指标预测异基因外周血干细胞移植(allo-PBSCT)后造血重建的可行性。方法将暨南大学附属第一医院血液科2000年1月至2008年12月120例allo-PBSCT患者分为MNC组(83例)和CD34+细胞组(37例),MNC组以≥4×108/kg为采集目标,CD34+细胞组以≥4×106/kgCD34+细胞为采集目标。比较两种计数指标对造血重建和供者采集次数的影响,并分析不同MNC剂量对造血重建的影响。结果MNC组受者输入MNC的中位数为6.81×108/kg,CD34+细胞组受者输入CD34+细胞的中位数为5.05×106/kg;两组造血重建率均为100%;两组中性粒细胞植活的中位时间均为移植后第11天(P0.05),血小板植活的中位时间均为移植后第12天(P0.05);两组供者1次采集率分别为100%和37.84%(P0.05);MNC组中HLA全相合与不全相合移植受者中性粒细胞植活的中位时间分别为移植后第11天和移植后第12天(P0.05),血小板植活的中位时间分别为移植后第12天和移植后第14天(P0.05);MNC剂量在(3～5.99)×108/kg递增时,剂量与造血重建呈正相关,而MNC剂量在达到6×108/kg后递增,则并未使植活时间随之进一步缩短。结论MNC计数单独作为造血干(祖)细胞含量的计数指标,不仅能可靠预示allo-PBSCT(包括HLA全相合与不全相合移植)后造血重建,其植活率和植活速度可与CD34+细胞相比拟,而且其供者1次采集率(100%)显著高于后者(37.84%),allo-PBSCT时MNC计数可取代CD34+细胞作为造血干(祖)细胞含量的独立指标。     

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.     

Successful application of nonmyeloablative transplantation for paroxysmal nocturnal hemoglobinuria

OBJECTIVE: Paroxysmal nocturnal hemoglobinuria (PNH) is an acquired clonal hematopoietic stem cell disorder that manifests as hemolytic anemia, venous thrombosis, and deficient hematopoiesis. Although allogeneic hematopoietic stem cell transplantation is considered the only curative therapeutic measure, transplant-related mortality is not negligible. Several studies supported the use of nonmyeloablative stem cell transplantation (NST) for patients of advanced age or with organ dysfunction. Hence, we used NST in a PNH patient who suffered from acute renal failure due to repeated episodes of hemolysis. MATERIALS AND METHODS: We performed NST using a conditioning regimen consisting of cladribine 0.11 mg/kg x 6, busulfan 4 mg/kg x 2, and rabbit anti-thymocyte globulin 2.5 mg/kg x 2. He received peripheral blood stem cells from his human leukocyte antigen-matched brother. Prophylaxis against graft-vs-host disease was performed with cyclosporine A alone. Chimerism of peripheral blood mononuclear cells was evaluated serially using short tandem repeat analysis and flow cytometry. RESULTS: No meaningful regimen-related toxicities were documented. Donor chimerism of 90 to 100% was achieved on day 14 and thereafter. The patient is doing well, without any recurrence of hemolysis 6 months after transplant. Follow-up chimerism studies confirmed stable and functioning donor-type hematopoiesis. CONCLUSIONS: NST may become a safe and curative approach in patients with PNH. Further studies are needed to establish the role of NST for treatment of PNH.     

HLA-haploidentical nonmyeloablative stem cell transplantation: induction to tolerance without passing through mixed chimaerism

There are few reports of unmanipulated HLA-haploidentical nonmyeloablative stem cell transplantation (NST) using only pharmacological acute graft-vs.-host disease (GVHD) prophylaxis. We present here a successful case of unmanipulated HLA-haploidentical NST for mediastinal large B cell lymphoma that was resistant to autologous peripheral blood stem cell transplantation (PBSCT). The conditioning regimen consisted of fludarabine, busulfan and rabbit anti-T-lymphocyte globulin (ATG) in addition to rituximab. GVHD prophylaxis was performed using tacrolimus and methylprednisolone 1 mg/kg. The patient had rapid engraftment, with 100% donor chimaerism in the lineages of both T cells and granulocytes on day +12, but developed no GVHD clinically. The patient is still in complete remission past day +1020, with no sign of chronic GVHD without receiving immunosuppressive agents. HLA-haploidentical NST may be performed without utilizing mixed chimaerism.     

HLA‐haploidentical nonmyeloablative stem cell transplantation: induction to tolerance without passing through mixed chimaerism

There are few reports of unmanipulated HLA‐haploidentical nonmyeloablative stem cell transplantation (NST) using only pharmacological acute graft‐vs.‐host disease (GVHD) prophylaxis. We present here a successful case of unmanipulated HLA‐haploidentical NST for mediastinal large B cell lymphoma that was resistant to autologous peripheral blood stem cell transplantation (PBSCT). The conditioning regimen consisted of fludarabine, busulfan and rabbit anti‐T‐lymphocyte globulin (ATG) in addition to rituximab. GVHD prophylaxis was performed using tacrolimus and methylprednisolone 1 mg/kg. The patient had rapid engraftment, with 100% donor chimaerism in the lineages of both T cells and granulocytes on day +12, but developed no GVHD clinically. The patient is still in complete remission past day +1020, with no sign of chronic GVHD without receiving immunosuppressive agents. HLA‐haploidentical NST may be performed without utilizing mixed chimaerism.     

Second transplant from the same donor without conditioning for bone marrow aplasia after non-myeloablative hematopoietic stem cell transplantation for chronic myeloid leukemia

We describe a 56-year-old woman with chronic myeloid leukemia (CML) and a past history of stroke, who underwent nonmyeloablative hematopoietic stem cell transplantation (NST) with conditioning consisting of fludarabine and cyclophosphamide. The regimen related toxicity was minimal and patient did not require transfusions of any blood products nor did she have any infections after the NST Since mixed chimerism was observed in both lymphocytes (70% were donor type) and granulocytes (none were donor type) at 56 days after NST, donor lymphocyte infusion (DLI) was performed on day 68 and then immunosuppressant therapy was discontinued. DLI resulted in graft versus leukemia (GVL) effect, causing pancytopenia and bone marrow aplasia. A second hematopoietic stem cell transplantation was performed without conditioning on day 157, and complete donor type hematopoiesis and molecular remission of CML were achieved. Although engraftment of donor hematopoietic stem cells was not obtained after the first transplantation, donor lymphocytes were engrafted by nonmyeloablative conditioning and immunosuppression. That is, the same result might have been achieved even if the patient had received transfusion of only donor lymphocyte subsets in the first step. Based on this case report, a potential cell therapy is proposed composed of the preceding donor lymphocyte infusion alone, which induces GVL effects, and subsequent donor hematopoietic stem cell transplantation.     

ABO主血型不合的非清髓性异基因造血干细胞移植2例

目的：观察ABO主血型不合的非清髓性异基因造血于细胞移植(NST)治疗2例慢性髓细胞自血病(CML)患者的耐受性、疗效及其ABO血型转变。方法：采用氟达拉宾、白消安、抗人淋巴细胞球蛋白和骁悉的非清髓性预处理，异基因造血干细胞移植，移植后2周开始供者淋巴细胞输注(DLI)，每例5～6次；应用STR—PCR及染色体核型分析检测供者嵌合体；每半月～1个月监测血型。结果：2例患者移植后造血恢复较快，骨髓细胞混合嵌合体形成分别为 15～ 23d，完全嵌合体形成为 23～ 43d；例1血型为O型，于 388d血型转变为供者血型A型，移植后6个月细胞遗传学水平复发．DLI后Ph染色体转阴，但发生皮肤慢性移植物抗宿主病。例2于 45d血型由A型转变为供者血型AB型，移植后5个月与1年2次出现纯红细胞再生障碍性贫血表现，均用DLI后红系造血恢复，Ph染色体转阴。结论：ABO主血型不合的NST易出现红系造血延迟及纯红细胞再生障碍性贫血，DLI具有促进供者嵌合体形成，防治复发效应。     

Nonmyeloablative allogeneic hematopoietic stem cell transplantation for congenital sideroblastic anemia

Congenital sideroblastic anemia (CSA) is a dyserythropoietic disorder that leads to transfusion dependency and subsequent iron overload. Nonmyeloablative allogeneic hematopoietic stem cell transplantation (NST) was performed for a patient with CSA, who had contraindications to conventional allografting. Conditioning was fludarabine, low-dose total body irradiation and antithymocyte globulin, followed by peripheral blood stem cell transplant. Cyclosporine and mycophenolate mofetil were used for graft-versus-host disease prophylaxis. Complete donor chimerism was observed day +131. Early after transplant, the patient became transfusion independent, allowing a regular phlebotomy program. On day +190, refractory lactic acidosis followed by fatal cardiovascular collapse developed, without evidence of infection. Data from this case demonstrates that NST may correct the erythropoietic defect of CSA.     

Delayed donor red cell chimerism and pure red cell aplasia following major ABO-incompatible nonmyeloablative hematopoietic stem cell transplantation

Delayed donor red cell engraftment and pure red cell aplasia (PRCA) are well-recognized complications of major ABO-incompatible hematopoietic stem cell transplantation (SCT) performed by means of myeloablative conditioning. To evaluate these events following reduced-intensity nonmyeloablative SCT (NST), consecutive series of patients with major ABO incompatibility undergoing either NST (fludarabine/cyclophosphamide conditioning) or myeloablative SCT (cyclophosphamide/high-dose total body irradiation) were compared. Donor red blood cell (RBC) chimerism (initial detection of donor RBCs in peripheral blood) was markedly delayed following NST versus myeloablative SCT (median, 114 versus 40 days; P <.0001) and strongly correlated with decreasing host antidonor isohemagglutinin levels. Antidonor isohemagglutinins declined to clinically insignificant levels more slowly following NST than myeloablative SCT (median, 83 versus 44 days; P =.03). Donor RBC chimerism was delayed more than 100 days in 9 of 14 (64%) and PRCA occurred in 4 of 14 (29%) patients following NST, while neither event occurred in 12 patients following myeloablative SCT. Conversion to full donor myeloid chimerism following NST occurred significantly sooner in cases with, compared with cases without, PRCA (30 versus 98 days; P =.008). Cyclosporine withdrawal appeared to induce graft-mediated immune effects against recipient isohemagglutinin-producing cells, resulting in decreased antidonor isohemagglutinin levels and resolution of PRCA following NST. These data indicate that significantly delayed donor erythropoiesis is (1) common following major ABO-incompatible NST and (2) associated with prolonged persistence of host antidonor isohemagglutinins. The clinical manifestations of these events are affected by the degree and duration of residual host hematopoiesis.     

Comparative outcome of nonmyeloablative and myeloablative allogeneic hematopoietic cell transplantation for patients older than 50 years of age

Nonmyeloablative stem cell transplantation (NST) is increasingly used in older patients. The impact of the shift from myeloablative transplantation to NST on relapse, transplant complications, and outcome has yet to be fully examined. We performed a retrospective analysis of 152 patients older than 50 years undergoing NST or myeloablative transplantation. Seventy-one patients received nonmyeloablative conditioning, fludarabine (30 mg/m(2)/d x 4) and intravenous busulfan (0.8 mg/kg/d x 4); 81 patients received myeloablative conditioning, primarily cyclophosphamide and total body irradiation. NST patients were more likely to have unrelated donors (58% versus 36%; P = .009), a prior transplant (25% versus 4%; P = < .0001), and active disease at transplantation (85% versus 59%; P = < .001). Despite the adverse characteristics, overall survival was improved in the NST group at 1 year (51% versus 39%) and 2 years (39% versus 29%; P = .056). There was no difference in progression-free survival (2 years, 27% versus 25%; P = .24). The incidence of grade 2 to 4 graft-versus-host disease was similar (28% versus 27%). The nonrelapse mortality rate was lower for NST patients (32% versus 50%; P = .01), but the relapse rate was higher (46% versus 30%; P = .052). Our experience suggests that, in patients over age 50, NST with fludarabine and low-dose busulfan leads to an overall outcome at least as good as that following myeloablative therapy.     

Nonmyeloablative stem cell transplantation in patients with ALL and AML results in low nonrelapse mortality despite high rate of infections and GVHD

28 patients with high-risk acute lymphoblastic (ALL) or acute myelogenous leukemia (AML) underwent nonmyeloablative stem cell transplantation (NST) from HLA-identical donors because of one or several contraindications against myeloablative conditioning. Out of 28 patients, nine (32%) had pulmonary or hepatosplenic infiltrates due to invasive fungal infections (IFI) before NST. Out of a total of 28 patients, 17 (61%) had uncontrolled leukemia before NST. Conditioning was performed with fludarabine 180 mg/m(2), busulfan 8 mg/kg and antithymocyte globulin 40 mg/kg. After NST, fever of unknown origin, sepsis or pneumonia developed in 18/28 patients (64%) overall. IFI reactivated in 3/9 patients after NST. Out of, 28 patients, 13 (46%) had late onset of acute graft-versus-host disease (GvHD), which developed at a median of 83 days after NST. GvHD frequently developed after donor lymphocyte infusions. After a median follow-up of 8 months (2-46 months), 14/28 patients (50%) have died from relapse and 1/28 patients (4%) has died from sepsis. Among 28 patients, 13 (46%) are alive in complete remission (CR). Six of 17 patients (35%) with uncontrolled disease and 7/11 patients (63%) with CR before NST are alive in CR. Probability of overall survival at 2 years is 38%. In summary, NST offers a therapeutic alternative to patients with high-risk ALL or AML, who have contraindications against conventional high-dose conditioning. Low NRM was encountered despite high morbidity, but relapse rate was high. Therefore, controlled studies are necessary to elucidate the place of NST in the therapy of high-risk acute leukemias.