非清髓性造血干细胞移植后移植物抗宿主病的临床观察

目的 观察非清髓性造血干细胞移植（NST）后移植物抗宿主病（GVHD）的发生情况。方法 将18例患者分为3组：A组为6例重型再生障碍性贫血（SAA）成人患者，行无关供者脐血造血干细胞移植；B组为5例SAA患者，行同胞供者骨髓联合外周血造血干细胞移植；C组为7例肿瘤性血液病患者，其中3例行同胞供者骨髓移植，4例行外周血造血干细胞移植。均采用以抗胸腺细胞球蛋白或抗淋巴细胞球蛋白为基础的预处理方案。A组和B组应用环孢素A（CsA）和甲泼尼龙预防GVHD，C组应用CsA和甲氨蝶呤预防GVHD。C组形成混合性嵌合体后行供者淋巴细胞输注（DLI）。结果 A组有4例形成并维持混合性嵌合体状态，1例死于真菌性败血症，1例自动出院。移植后早期，B组有3例供者型嵌合体占94％以上，并在短期内转变并维持完全供者嵌合体状态，获得无病存活，其中1例在移植后8个月发生慢性GVHD；另2例行供者千细胞输注后，1例6个月后死于继发性纵隔淋巴瘤，1例造血功能恢复。C组患者早期均形成混合性嵌合体，获得血液学部分缓解，患者DLI前无急性GVHD发生，1例于2次DLI后死于严重感染，1例失访；另5例分别经过4、3、7、5、4次DLI，全部转为完全供者型嵌合体，并获得血液学完全缓解，4例并发慢性GVHD，2例并发急性GVHD。结论 对于SAA患者，NST的临床效果较好，GVHD的发生率较低；而对于肿瘤性血液病，NST后患者的早期死亡率低，急性GVHD发生率下降，但慢性GVHD和感染的发生率较高。     

供者淋巴细胞输注在恶性血液病非清髓性骨髓移植中的应用

目的探讨供者淋巴细胞输注(DLI)治疗非清髓性异基因造血干细胞移植后血液病复发的疗效。方法5例恶性血液病患者接受非清髓性造血干细胞移植,在形成混合性嵌合体和血液学部分缓解(例1～4)或进步(例5)后,进行DLI。移植后的4～5周进行第1次DLI,首次输注T淋巴细胞数量为(0.5～1.0)×105/kg,以后每隔3～4周逐渐增加输注的淋巴细胞数量,至(0.5～2.0)×108/kg,平均行DLI4.6次(3～8次)。结果例1～4分别经过7、3、2、3次DLI后,性染色体及DNA指纹图由混合性嵌合体转变为完全性嵌合体;例2、3经过DLI后消除了微小残留病,除例5仍然为混合性嵌合体和进步状态外,4例均达血液学完全缓解。例1、2和例3、4分别出现Ⅰ/Ⅱ度急性移植物抗宿主病和广泛/局限型慢性移植物抗宿主病,例2、4出现骨髓抑制。结论DLI可使异基因造血干细胞移植后短暂的混合性嵌合体向完全性嵌合体转变,并可清除微小残留病。     

非清髓性外周血干细胞移植后白血病复发的防治

目的探讨非清髓性造血干细胞移植后白血病复发的防治。方法7例合并有其它系统疾病的白血病患者接受非清髓性外周血干细胞移植,移植后采用环孢素A及短程甲氨蝶呤预防移植物抗宿主病(GVHD),造血细胞植入后,动态检测骨髓单个核细胞嵌合体的变化,根据嵌合体状态,采用供者淋巴细胞输注(DLI),并配合环孢素A用量的调整来防治白血病复发。结果7例患者移植后造血功能得到恢复,3例移植前合并的疾病有所加重,经处理缓解,移植早期相关并发症少而轻。移植后有3例嵌合体由混合嵌合体(MC)转为完全供者型嵌合体(CC),再转为MC,伴Ph染色体阳性,DLI5~6次后Ph染色体转为阴性,嵌合体状态又转为CC,其中2例发生广泛皮肤慢性GVHD;3例的嵌合体持续为CC,无复发,其中2例接受了1次DLI,此2例在环孢素A减量过程中发生GVHD;1例的嵌合体持续为MC,虽经3次DLI,但无效,患者死于白血病复发。结论非清髓性造血干细胞移植后应动态监测嵌合体状态,采用供者淋巴细胞输注,并配合环孢素A用量的调整,对白血病的复发有一定的效果。     

异基因造血干细胞移植后嵌合体的检测及临床意义

异基因造血干细胞移植后供者细胞是否成功植入，需要有可靠的证据。对移植后供者细胞植入证据的检测不仅对判断移植是否成功，而且对移植后免疫抑制剂的应用、供者淋巴细胞输注(DLI)、移植物抗宿主病(GVHD)的预防以及探讨移植后供、受者混合嵌合体形成、对疗效影响的评估皆有重要意义。     

急性移植物抗宿主病的诊断及治疗后再评价

随着非清髓性移植(NST)、供者淋巴细胞输注(DLI)等越来越多地被引入临床实践,人们逐渐认识到,仅以发病时间为依据进行移植物抗宿主病(GVHD)的分类诊断是不科学的,结合GVHD的临床表现和病理特点进行判别更为重要.以往急、慢性GVHD的鉴别主要基于免疫介导的靶器官损害是发生在移植后100 d以内还是100 d以后:当移植后100 d以内出现斑丘疹、红皮病样皮损、恶心呕吐、厌食、大量腹泻、肠梗阻或胆汁淤积性肝炎时,通常临床诊断为急性GVHD(aGVHD).     

异基因造血干细胞移植研究进展

异基因造血干细胞移植已成为治愈血液系统恶性肿瘤、骨髓衰竭性疾病、某些先天性及代谢性疾病等的重要方法。本文就外周血干细胞移植（PBSCT）、脐血造血干细胞移植（CBSCT）、非清髓性干细胞移植（NST）、移植物抗宿主病（GVHD）与移植物抗白血病（GVL）效应以及间充质干细胞（MSC）在异基因造血干细胞移植中的应用等方面的新进展进行介绍。     

非清髓性无关供者脐血移植与同胞供者骨髓移植治疗再生障碍性贫血的比较

目的 对非清髓性无关供者脐血移植与同胞供者骨髓移植治疗重型再生障碍性贫血(SAA)的临床效果进行评价和比较.方法 回顾性分析15例SAA患者进行非清髓性造血干细胞移植的临床资料,根据造血干细胞(HSC)来源的不同,将患者分为骨髓移植组(BMT组;6例)和脐血移植组(UCBT组;9例).对两组患者术后的外周血象、骨髓象、细胞嵌合体状态、移植物抗宿主病(GVHD)以及存活率等长期随访结果进行了统计学分析.结果 BMT组和UCBT组造血干细胞植入率分别为100%和66.7%,两组比较,差异有统计学意义(P＜0.05).UCBT组移植后大多数形成了供、受者型细胞混合嵌合体,BMT组大多数形成了供者型完全嵌合体.BMT组血象恢复正常的中位时间为25 d、UCBT组为120 d,BMT组骨髓象恢复正常的中位时间为25 d,UCBT组为150 d.BMT组慢性GVHD的表现以肝功能异常为主,而UCBT组则以皮疹为主.UCBT组术后早期感染率为33.3%,BMT组为16.7%.结论 非清髓性无关供者脐血移植和同胞供者骨髓移植均可成功治疗SAA;但与BMT比较,UCBT的造血功能恢复较慢、血型转变少而延迟、早期感染率较高、而慢性GVHD的程度却较轻.     

亲缘异基因造血干细胞移植治疗慢性髓细胞白血病的护理

对30例慢性髓细胞白血病患者行亲缘异基因造血干细胞移植.27例患者预处理采用经典或改良BuCy2方案,3例患者用非清髓方案;预防移植物抗宿主病(GVHD)采用短程甲氨蝶呤联合环孢素A方案;在常规护理的基础上针对感染、GVHD及心理问题实施重点护理.结果 所有患者均获造血功能重建;移植后100 d内发生Ⅱ～Ⅳ度急性GVHD 7例(23.3%),经对症处理好转出院.随访3～88个月,移植相关死亡7例,疾病复发死亡1例,22例移植成功.提出移植相关并发症及移植后感染的护理是保证疗效的关键.     

伊马替尼联合供者淋巴细胞输注治疗造血干细胞移植后慢性粒细胞白血病复发

目的 探讨伊马替尼联合供者淋巴细胞输注(DLI)治疗异基因造血干细胞移植后慢性粒细胞白血病(CML)复发的效果.方法 3例CML(慢性期)患者,在接受预处理后,例1接受其胞妹外周血造血干细胞移植,例2接受其胞兄的骨髓移植,例3接受其胞弟的骨髓与外周血造血干细胞联合移植.例1移植后采用环孢素A(CsA)和霉酚酸酯(MMF)预防移植物抗宿主病(GVHD),例2采用CsA、短程甲氨蝶呤(MTX)、抗胸腺细胞球蛋白及抗CD25单克隆抗体预防GVHD,例3应用CsA、MTX和MMF预防GVHD.采用细胞遗传学及荧光原位杂交技术动态监测治疗效果.移植后发生血液学复发时,给予伊马替尼口服,并行DLI.结果 例1移植后30 d行DLI,输注CD3+T淋巴细胞0.5×107 /kg,移植后50 d和70 d,再次行DLI,分别输注CD3+ T淋巴细胞1.0 × 107 /kg和2.0×107 /kg,短串联重复序列(STR)检测提示为完全供者嵌合(DC).移植后120 d,疾病进展,给予伊马替尼400 mg/d,同时输注供者CD3+ T淋巴细胞2.5 × 107/kg.移植后180 d,STR检查提示仍为DC.患者最终于移植后17个月因髓外复发死亡.例2的染色体核型于移植后35 d转变为46,XY,XY为100%,BCR-ABL融合基因阴性.移植后100 d,原发病复发.停用免疫抑制剂,输入供者CD3+ T淋巴细胞3.9×107 /kg,同时口服伊马替尼500 mg/d.DLI联合伊马替尼治疗后30 d,患者的染色体核型为46,XY,XY为100%,BCR-ABL融合基因阴性,患者至今无病存活53个月.例3移植后5 d造血功能获得重建,移植后60 d,染色体核型为46,XY.移植后120 d,确诊CML复发,遂给予伊马替尼400 mg/d,并行DLI,共输注供者CD3+ T淋巴细胞8×107 /kg,1个月后,患者的染色体核型再次转为46,XY,患者至今无病存活50个月.结论 伊马替尼联合DLI对造血干细胞移植后CML复发具有一定的治疗效果.     

慢性移植物抗宿主病动物模型的研究

造血干细胞移植后慢性移植物抗宿主病(cGVHD)伴随着移植物抗白血病效应(GVL),能降低肿瘤复发,但由于cGVHD发生率高达25%～80%,并伴随严重的并发症,甚至导致受者死亡[1],降低了患者的生活质量,故cGVHD仍然是影响异基因造血干细胞移植(allo-HSCT)效果的重要因素之一.     

异基因造血干细胞移植治疗重型β珠蛋白生成障碍性贫血

目的 探讨异基因造血干细胞移植(allo-HSCT)治疗重型β珠蛋白生成障碍性贫血的临床疗效.方法 PesaroⅡ-Ⅲ度重型β珠蛋白生成障碍性贫血患者24例接受allo-HSCT治疗,其中男性18例,女性6例,患者年龄中位数为4岁(2～15岁).24例中,同胞供者23例,母亲供者1例;HLA 6个抗原全相合23例,5个抗原相合1例;骨髓混合外周血干细胞移植15例,脐带血移植9例.采用白消安+环磷酰胺+氟达拉滨的预处理方案.环孢素A(CsA)+甲氨蝶呤(MTX)+抗胸腺细胞球蛋白(ATG)+吗替麦考酚酯(MMF)联用预防移植物抗宿主病(GVHD).中位随访时间13个月(3～69个月).结果 移植后22例患者造血功能顺利恢复.至随访结束,无病存活21例;移植相关死亡1例(4.2%);移植物排斥反应2例(8.3%).21例的3年无病存活率为87.5%,3年总体存活率为91.7%.Ⅱ-Ⅳ度急性GVHD的累积发生率为16.7%,慢性GVHD的累积发生率为20.3%,广泛性慢性GVHD的发生率为5.0%.结论 异基因骨髓混合外周血干细胞移植治疗珠蛋白生成障碍性贫血可获得确切疗效,同时脐带血是珠蛋白生成障碍性贫血移植的重要干细胞来源.CsA+MTX+ATG+小剂量、短疗程MMF的方案可以有效地减少严重急性GVHD的发生,提高移植疗效.

Abstract：

Objective To investigate the effect of allgeneic hematopoietic stem cell transplantation (allo-HSCT) for β-thalassemia major. Methods Twenty-four β-thalassemia major patients with median age of 4 years (range: 2～15 years), 18 boys and 6 girls, received allo-HSCT.They were classified into class Ⅱ-Ⅲ according to Pesaro thalassemia classification. Twenty-three transplantations were from sibling donor and 1 was from mother, either HLA-identical (n = 23) or HLA-mismatched (5/6) (n = 1). Fifteen patients received bone marrow transplantation (BMT) plus peripheral blood stem cell transplantation (PBSCT), and 9 were subjected to umbilical cord blood transplantation (UCBT). The conditioning regimen consisted of busalphan, cyclophosphamide,fludarabine, plus hydroxyurea before transplantation. Graft-versus-host disease (GVHD) prophylaxis included CsA, methotrexate, antilymphpcute globulin, and mycophenolate mofetil. The median follow-up period was 13 months (range: 3～69). Results Of 24 patients, there were 21 cases (87. 5 %) of disease-free survival, 1 (4. 2 %) transplantation-related death, and 2 cases (8. 3 %) of rejection. Three-year overall survival and disease-free survival rate was 91.7 % and 87. 5 %respectively. The cumulative incidence of grade Ⅱ -Ⅳ acute GVHD and chronic GVHD was 16. 7 %and 20. 3 %, particularly cumulative extensive chronic GVHD was 5. 0 %. Conclusion The sibling donor BMT plus PBSCT is an effective and safe way to treat β-thalassemia major. Cord blood is an important source of hematopoietic stem cells for HSCT. The protocol GVHD prophylaxis of CsA,MTX, ATG with a low-dose and short course of MMF can effectively reduce the incidence of severe acute GVHD, improve the outcome of thalassemia transplantation.     

减低强度预处理造血干细胞移植联合低剂量环孢素A治疗恶性血液病

目的 探讨以减低强度的氟达拉滨、白消安(Bu)和环磷酰胺(CTX)为预处理方案的异基因外周血造血干细胞移植(HSCT)联合低剂量环孢素A(CsA)的疗效及并发症发生情况.方法 恶性血液病患者11例,接受同胞间HSCT,供、受者问HLA配型,HLA全相合10例.5个抗原相合1例.预处理包括移植前第9～4天给予氟达拉滨30～35 mg·m-2·d-1,移植前第4、3天给予白消安3.2 mg·kg-1·d1,移植前第2、1天给予CTX 60mg·kg1·d-1.移植后联合使用CsA和短程甲氨蝶呤(MTX)预防移植物抗宿主病(GVHD),供者细胞植入后,降低CsA用量.结果 移植后早期11例造血功能均获得重建,骨髓细胞为完全供者型.随访3～17个月,9例并发急性GVHD,主要侵犯肝脏和皮肤;9例并发慢性GVHD,均侵犯口腔和肝脏,其中1例为广泛性慢性GVHD,其余为局限性慢性GVHD.增加CsA用量或者加用甲泼尼龙后,急、慢性GVHD均能得到控制,仅1例需加用霉酚酸脂.11例中,2例的原发病复发,其中1例病情得到控制,1例失访.结论 HSCT时采用氟达拉滨、白消安和环磷酰胺(CTX)预处理方案,并将白消安的用量减为常用剂量的一半,移植后采用低剂量CsA,细胞的植入率高;急、慢性GVHD的发生率较高,但对糖皮质激素和CsA的治疗反应良好.     

HLA单倍体相合与全相合外周血造血干细胞移植治疗恶性血液病的疗效比较

目的 观察和比较亲属间人类白细胞抗原(HLA)单倍体相合与全相合外周血造血干细胞移植(PBSCT)治疗恶性血液病的临床疗效.方法 2004年5月至2009年2月,共111例恶性血液病患者进行了异基因PBSCT(allo-PBSCT),其中单倍体相合移植受者51例(单倍体组),同期全相合移植受者60例(全相合组).两组的预处理方案均为清髓性;两组预防移植物抗宿主病(GVHD)均以经典环孢素A加短程甲氨蝶呤作为基础方案,HLA 1个抗原不合时,加用吗替麦考酚酯,HLA 2～3个抗原不合时,再加用抗胸腺细胞球蛋白(ATG)及抗CD25单克隆抗体.移植物为经粒细胞集落刺激因子动员的、未进行体外去除T淋巴细胞的外周血造血干细胞(PBSC).结果 111例受者均获得完全、持久供者干细胞植入.单倍体组和全相合组受者中性粒细胞≥0.5×10~9/L的中位时间分别为14 d和12 d,血小板≥20×10~9/L的中位时间分别为15 d和13 d.单倍体组有25例受者发生急性GVHD(aGVHD),其中Ⅰ度20例,Ⅱ度5例;有33例发生慢性GVHD(cGVHD),其中局限型30例,广泛型3例;4年累积发病率为70.4%;无白血病存活40例,3年预期总无白血病存活率(LFS)为74.5%,其中标危型77.3%,高危型68.2%.全相合组有14例发生aGVHD,其中Ⅰ度10例,Ⅱ度2例,Ⅲ度2例;有37例发生cGVHD,其中局限型32例,广泛型5例;4年累积发病率为58.1%.无白血病存活46例,3年预期总LFS为72.1%,其中标危型77.6%,高危型52.7%.单倍体组受者移植后aGVHD发生率高于全相合组,差异有统计学意义(P<0.05);但cGVHD、原发病复发率和LFS差异均无统计学意义(P>0.05).结论 应用清髓性预处理联合多种免疫抑制剂进行非体外去T淋巴细胞的、亲属间HLA单倍体相合与全相合PBSCT均为治疗恶性血液病安全有效的方案.     

Effects of different serum-levels of ATG after unrelated donor umbilical cord blood transplantation

We determined total rabbit-IgG (r-ATG) levels in serum samples before (day 0) and after (day 11 and day 25) unrelated donor umbilical cord blood transplantation (UCBT). Most patients (27/41) suffered from a haematological malignancy. There were 25 children and 16 adults. All patients received rabbit anti-thymocyte globulin (ATG) at a total dose of 6 or 8mg/kg as part of the conditioning. No correlation between the dose of ATG and serum r-ATG levels post UCBT was found. The cumulative incidence of acute GVHD grades III-IV in patients given the 6 and 8mg/kg ATG dose was 15% and 13% (ns), respectively. Patients with r-ATG≤40μg/mL 11days after UCBT (n=19) had a higher incidence of grades III-IV acute GVHD (32% vs. 0%, p<0.01), higher TRM (69% vs. 7%, p=0.005), less relapse (17% vs. 82%, p<0.01) but similar relapse-free survival (RFS) (10% vs. 18%, p=0.4) compared to those with r-ATG>40μg/mL (n=17). Low serum-levels of r-ATG early after transplantation seem to be a strong predictor for acute GVHD grades III-IV, TRM and a low incidence of relapse in patients treated with thymoglobulin before unrelated donor UCBT.     

Long‐term outcomes of antithymocyte globulin in patients with hematological malignancies undergoing myeloablative allogeneic hematopoietic cell transplantation: a systematic review and meta‐analysis

Antithymocyte globulin (ATG) has shown efficacy in preventing acute GVHD (aGVHD) in allogeneic hematopoietic cell transplantation (allo‐HCT), but its efficacy in chronic GVHD (cGVHD) and long‐term outcomes remains controversial. We conducted a systematic review and meta‐analysis to evaluate potential benefit and risk of prophylactic ATG use in myeloablative HCT. We searched Pubmed, EMBASE, Cochrane databases, and included 10 trials (two RCTs and eight retrospective) comparing ATG use vs. control with a total of 1859 patients. The median follow‐ups were over two yr. Outcomes assessed included overall cGVHD, extensive cGVHD, overall survival (OS), disease‐free survival, relapse, and causes of death. Our results showed ATG significantly decreased overall cGVHD (RR = 0.59; 95% CI: 0.53–0.66, p < 0.00001), extensive cGVHD (RR = 0.34; 95% CI: 0.25–0.47, p < 0.00001). Pooled results also showed ATG use was associated with a marginal increased risk of relapse (RR = 1.28; 95% CI: 1.01–1.63, p = 0.04), and a non‐inferior OS (HR = 0.86; 95% CI: 0.74–1.01, p = 0.06). We conclude prophylactic use of ATG exerts a favorable effect in reducing cGVHD without survival impairment in a long term, although a higher relapse rate is a major threat.     

非血缘关系造血干细胞移植61例分析

目的 探讨非血缘关系造血干细胞移植(URD-HSCT)的临床疗效,移植相关并发症及影响预后的危险因素.方法 回顾性分析61例接受URD-HSCT患者的临床资料.所有患者根据原发病分别给予非清髓性及清髓性预处理;供、受者HLA配型6/6抗原位点全相合21例,5/6相合5例,1个基因亚型不合24例,2个基因亚型不合11例;供、受者间ABO血型相合18例,不合43例;受者接受供者的有核细胞中位数为4.5×108/kg,CD34+细胞中位数为4.3×106/kg.术后移植物抗宿主病(GVHD)的预防采用以短程甲氨蝶呤+环孢素A+霉酚酸酯为基础的方案,49例加用抗CD25单克隆抗体,9例加用抗淋巴细胞或抗胸腺细胞免疫球蛋白;并常规采用促进造血功能恢复、抗感染等治疗.术后观察受者的造血功能重建、并发症以及预后情况.结果 61例患者中,59例术后经血型、染色体及DNA多态性检测证实供者细胞植活.术后23例受者发生Ⅱ～Ⅳ度急性GVHD,25例发生慢性GVHD;术后100 d内,48例受者发生细菌和(或)真菌感染,36例发生巨细胞病毒感染,以下呼吸道感染较多.术后有18例受者死亡,受者总的2年无病存活率为(68.0±6.4)%,其中12例因移植相关并发症死亡,移植相关死亡率19.7%;6例原发病复发的受者均死亡,复发率9.8%.其余受者经治疗后好转.结论 URD-HSCT是治疗造血系统恶性疾病的有效方法.急性GVHD和感染是严重影响移植疗效和预后的危险因素,需早期预防.     

Graft versus host disease after stem cell allotransplantation with low-dose total body irradiation, fludarabine, and antithymocyte globulin

BACKGROUND: We previously showed that antithymocyte globulin (ATG) given with total body irradiation (TBI) 200 cGy and fludarabine results in high rate of donor engraftment. Its influence on acute and chronic graft versus host disease (GVHD) and on graft versus tumor effect is less known. METHODS: Sixty-five patients underwent nonmyeloablative stem cell transplant with ATG, TBI 200 cGy, and fludarabine. GVHD prophylaxis was mycophenolate mofetil and cyclosporine. Forty-two patients (pts) (65%) had match related donors, 18 (27%) match unrelated, 1 (1.5%) mismatch related, and 4 (6%) mismatch unrelated donors. RESULTS: At a median follow-up of 862 days, 24 patients (37%) developed GVHD. The median age of the patients with and without GVHD was 56 years respectively. Acute GVHD grade II-IV developed in 19 pts (29%). Fatal GVHD of liver and/or gut occurred in nine pts (14%). Forty-one pts survived more than 100 days. Five pts (12%) had chronic GVHD, two had extensive, and three had limited involvement. Relapsed disease was observed in 22 pts (34%). Infections occurred in 15 pts (23%) and were fatal in 13 (20%). CONCLUSIONS: The addition of ATG to TBI 200cGy and fludarabine resulted in a modest incidence of GVHD. The best transplant outcomes were observed in pts with lymphoid malignancies.     

A comparison of nonmyeloablative and reduced-intensity conditioning for allogeneic stem-cell transplantation

BACKGROUND: Nonmyeloablative (NM) conditioning and reduced-intensity conditioning (RIC) are increasingly used for allogeneic hematopoietic stem-cell transplantation. Such regimens have not been compared. METHODS: The primary endpoint was graft-versus-host disease (GVHD). Secondary endpoints included transfusions, engraftment, and transplant-related mortality (TRM). NM conditioning (n=24) consisted of fludarabine and 2-Gy total-body irradiation followed by immunosuppression with cyclosporine A (CsA) combined with mycophenolate mofetil (MMF). The RIC (n=34) protocol consisted of fludarabine combined with busulfan or cyclophosphamide, antithymocyte globulin, and posttransplant immunosuppression CsA plus methotrexate. Diagnoses included hematologic malignancies and solid tumors. Donors were 34 human leukocyte antigen-identical siblings and 24 unrelated donors. Chimerism was analyzed by polymerase chain reaction of minisatellites. RESULTS: Graft failure occurred in 6 of 24 in the NM group and in 1 of 34 in the RIC group, which was a significant difference (odds ratio [OR], 22.6; P=0.02). The NM group also had less leukopenia and required fewer erythrocyte and platelet transfusions than the RIC group. The time to and proportion of CD3, CD19, and CD45 donor chimerism were similar in both groups. The cumulative incidence of grades II to IV acute GVHD was higher in the NM group (59% vs. 12%; OR, 26.9; P<0.001), but we found no difference in the cumulative incidence of chronic GVHD (41% vs. 61%). TRM was 42% in the NM group and 20% in the RIC patients (relative hazard, 11.6; P=0.03). CONCLUSIONS: NM conditioning with posttransplant immunosuppression using CsA and MMF resulted in less leukopenia and fewer transfusions, but resulted in more cases of graft failure, acute GVHD, and TRM than in RIC patients.