异基因造血干细胞移植后纯红细胞再生障碍

ABO血型不合不影响异基因造血干细胞移植的成功进行。许多研究表明 ,与 ABO相合的移植相比 ,两者在植活时间 ,GVHD发生以及无病生存等方面差异不显著 〔1〕。尽管如此 ,在 ABO主要血型不合的异基因造血干细胞移植中 ,红系造血延缓甚至发生纯红细胞再生障碍 ( PRCA)时有发生。本文就异基因造血干细胞移植后 PRCA的特点 ,发病机理和防治措施作一综述。1　发病情况纯红细胞再生障碍性贫血是指因红系祖细胞受损衰竭而导致骨髓红系细胞显著减少 ,且不累及粒细胞和血小板的一种贫血。移植后 PRCA绝大多数发生于 ABO血型主要不合的骨髓…     

造血干细胞移植术后慢性肝脏移植物抗宿主病的危险因素

目的研究造血干细胞移植(HSCT)术后肝脏慢性移植物抗宿主病(cGVHD)的危险因素。方法回顾性分析2014年4月至2019年4月甘肃省第二人民医院收治的149例HSCT患者的一般资料,分析术后肝脏cGVHD发生情况,采用多因素logistic回归分析法分析HSCT术后并发肝脏cGVHD的独立影响因素。结果 149例HSCT患者中,患者术后发生肝脏cGVHD40例。多因素logistic回归分析显示,GVHD预防方案中加用ATG(OR=0.235,95%CI=0.113～0.490)、早期出现aGVHD(OR=2.089,95%CI=1.020～4.279)是HSCT患者术后肝脏cGVHD的独立影响因素(P0.05)。结论 HSCT术后肝脏cGVHD的发生与移植早期出现aGVHD有关,而早期GVHD预防方案中加用ATG能降低其发生率。     

ABO血型不合异基因造血干细胞移植临床观察

目的：探讨ABO血型不合异基因造血干细胞移植治疗血液病的临床疗效和近远期并发症。方法：对15例包括恶性血液病5例(多发性骨髓瘤1例、急性白血病3例、慢性粒细胞白血病1例)、再生障碍性贫血一阵发性睡眠性血红蛋白尿2例、重型再生障碍性贫血8例，进行同胞供者外周血干细胞移植、外周血联合骨髓造血干细胞移植和无关供者脐血造血干细胞移植。观察植入效果、血型的转变、以及移植近远期并发症。结果：15例患者均恢复造血功能，13例植入混合性嵌合体(MC)、其中5例由MC转变为供者完全性嵌合体(CC)，8例长期保持MC状态，2例未植入。所有患者在输注移植物时出现轻微短暂的血红蛋白尿，无严重急性溶血和迟发性溶血发生，无急性移植物抗宿主病(aGVHD)，1例局部型慢性移植物抗宿主病(cGVHD)，1例广泛型cGVHD。在造血植入的患者，脐血移植4例保持MC状态、血型未转变，其余干细胞移植血型在1～2个月转变。结论：ABO血型不合异基因造血干细胞移植治疗血液病疗效肯定，对移植物和供受者体内凝集素的处理十分重要。     

HLA相合同胞供者异基因外周血干细胞移植治疗急性白血病

目的:探讨HLA相合同胞供者异基因外周血干细胞移植(alloPBSCT)治疗急性白血病(AL)疗效。方法:52例AL患者,男33例,女19例,中位年龄33(13～54)岁。急性淋巴细胞白血病(ALL)24例,急性非淋巴细胞白血病(ANLL)28例;高危组16例,标危组36例。采用含TBI或不含TBI预处理方案。预防移植物抗宿主病(GVHD)采用环胞素(CsA)加短程甲氨蝶呤(MTX)或他克莫司(FK506)方案,2例二次移植未用免疫抑制剂预防GVHD。46例移植后白细胞降至最低时开始用GCSF5μg/(kg·d),直至中性粒细胞数(ANC)≥0.5×109/L;6例未用。结果:所有患者均重建造血,ANC≥0.5×109/L和血小板计数≥20×109/L的中位时间分别为移植后第11和17天。发生Ⅱ度及以上急性GVHD12例(23.0%)。慢性GVHD(cGVHD)发生率为60.9%,局限型43.5%,广泛型17.4%;发生cGVHD的复发率(18.5%)低于无cGVHD者(47.4%)(P<0.05);有cGVHD者5年无白血病生存率(DFS)[(58.7±9.7)%]高于无cGVHD者[(33.3±11.1)%,P<0.05]。100d内移植相关死亡率(TRM)为11.5%,100d后的TRM为23.9%。多因素分析结果显示,移植前缓解时间和cGVHD对DFS有显著影响(P<0.05),移植前缓解时间越长DFS越高,发生cGVHD的DFS较高;而供受者ABO血型不合DFS较低(P<0.05)。结论:alloPBSCT造血重建快,cGVHD发生率较高,移植前缓解时间较长和移植后发生cGVHD者生存率较高,ABO血型不合者生存率较低。     

ABO血型不合的造血干细胞移植引起免疫性溶血的研究进展

临床造血干细胞移植（HCT）技术已广泛应用,其中存在一个关键性待解决的问题：ABO血型不合的造血干细胞移植引起的免疫性溶血。正常情况异体HCT患者应该接受ABO血型相同供体的干细胞。但人类白细胞抗原（HLA）和ABO血型基因分别位于不同的染色体,寻找HLA与ABO血型均相合的供体比较困难。临床干细胞移植治疗采用ABO血型不合的供体干细胞是安全的,     

ABO血型不合造血干细胞移植后血型物质变化的讨论

目的：探讨ABO血型不相容造血干细胞移植后患者红细胞抗原已成功转变为供者红细胞抗原时受者血型物质是否发生改变。方法：用血凝抑制试验的方法,检测21例ABO血型不合异基因造血干细胞移植后血型物质的转变。结果：当ABO血型不合血型抗原成功转型时间：主侧不相容时为53.5d,次侧不相容时为40.3d,主次侧均不相容时为112d,而受者骨髓植活后（以出现供者红细胞抗原为标记〔1〕）血型物质不转变。结论：对ABO血型不合造血干细胞患者移植植活后,血型物质没有随着血型的转变而变成供者的血型物质。     

供受者血型相合母亲供者和血型不合父亲供者对单倍体异基因造血干细胞移植预后的影响

目的 比较供受者血型相合母亲供者和血型不合父亲供者对单倍体异基因造血干细胞移植(haplo-HSCT)预后的影响.方法 回顾性纳入接受haplo-HSCT的恶性血液病患者160例,其中供受者血型相合母亲供者(母亲血型相合组)40例,供受者血型不合父亲供者(父亲血型不合组)120例(按1:3配对纳入).收集两组患者的临床...     

不同供体异基因造血干细胞移植一线治疗56例极重型再生障碍性贫血的疗效及安全性观察

目的：评价不同供体异基因造血干细胞移植（allo-HSCT）一线治疗极重型再生障碍性贫血（VSAA）的疗效与安全性。方法：回顾性分析接受一线allo-HSCT治疗的VSAA患者临床资料，统计分析总生存(OS)率、移植物抗宿主病（GVHD）发生率、植入成功率及无病生存(EFS)率等指标。结果：共纳入56例患者，男33例，女23例，中位年龄为25（14，36）岁。同胞全相合造血干细胞移植（MSD-HSCT）25例，替代供体造血干细胞移植（AD-HSCT）31例。56例患者均获得造血重建，MSD组、AD组中性粒细胞植入时间分别为12（10，15）、13（11，15）（P=0.140），血小板植入时间分别为11（9，16）、12（10，15）（P=0.372），急性GVHD（aGVHD）发生率分别为16.00%、45.16%（P=0.027），Ⅰ~Ⅱ度aGVHD发生率分别为12.00%、38.71%（P=0.025），Ⅲ/Ⅳ度aGVHD发生率分别为4.00%、6.45%（P=0.685），慢性GVHD(cGVHD)发生率分别为44.00%、22.58%（P=0.149），巨细胞病毒（CMV）血症发生率分别为40.00%、61.29%（P=0.133），EB病毒(EBV)血症发生率分别为68.00%、67.74%(P=0.984)。2组患者的3年预期OS率分别为92.00%、87.09%（P=0.682），EFS率分别为84.00%、77.42%（P=0.737）。结论：MSD-HSCT、AD-HSCT一线治疗VSAA的总体疗效和安全性大致相当。对于无同胞全相合供体的VSAA患者，一线接受AD-HSCT是一个可行的选择。     

ABO血型不合同胞间异基因外周血干细胞移植后纯红细胞再生障碍性贫血3例报告

目的：探讨ABO血型不合异基因外周血干细胞移植后纯红细胞再生障碍性贫血(PRCA)的治疗。方法：报道3例病例并进行文献复习。结果：3例HLA配型完全相合、ABO血型主要不合的患者进行同胞间异基因外周血干细胞移植获得成功,但移植后均出现PRCA。1例经大剂量糖皮质激素联合大剂量免疫球蛋白治疗,2例经大剂量糖皮质激素联合血浆置换治疗后血型均转为供者血型,血红蛋白逐渐恢复正常。结论：大剂量糖皮质激素联合血浆置换或大剂量免疫球蛋白是治疗ABO血型不合异基因外周血干细胞移植后PRCA的有效方法。     

异基因造血干细胞移植治疗恶性血液病(附9例报告)

9例恶性血液病患者 ,采用异基因外周血干细胞移植 ( allo- HSCT)治疗 7例 ,外周血与骨髓干细胞混合移植 2例 ;供者均为人白细胞相关抗原 ( HL A)完全相合同胞兄妹。预处理方案用马利兰 ( BU)、环磷酰胺( CY) ,环孢霉素 A ( Cs A)联合短程甲氨蝶呤 ( MTX)预防移植物抗宿主病 ( GVHD)。结果 :患者治疗后均重建造血 ,中性粒细胞≥ 0 .5× 10 9/ L 的中位数为 14天 ,血小板≥ 2 0× 10 9/ L 的中位数为 16天。发生急性 GVHD5例 ,慢性 GVHD2例 ,肝静脉闭塞病 ( VOD) 1例 ,巨细胞病毒血症 9例。2例 ABO血型不合者移植后未发生溶血及纯红再障。1例耐药复发淋巴瘤 ,供、受者均为乙肝病毒携带者 ,移植后达完全缓解。中位随访时间 15个月 ,无病生存 8例。认为 allo- HSCT是治疗恶性血液病 (尤其是耐药复发者 )的有效方法 ,ABO血型不合及乙肝供者不是移植的障碍     

异基因造血干细胞移植治疗高龄恶性血液病的疗效分析

目的探讨异基因造血干细胞移植治疗年龄较大的白血病患者安全性和疗效。方法采用HSCT治疗10例45—63岁恶性血液病患者,HLA6／6位点相合8例,5／6位点相合2例。以清髓性方案预处理4例,减低强度方案预处理6例。HLA不全相合患者加用ATG。采用环孢素联合霉酚酸酯预防移植物抗宿主病（GVHD）。结果本组10例受者均获造血重建。中性粒细胞绝对计数≥0．5×10^9／L,血小板≥20×10^9／L的中位时间分别为移植后12（9～16）天和15（12～21）天。3例发生了急性GVHD（30％）,Ⅱ度以上2例。可评估的9例患者中2例出现了慢性GVHD（22％）。复发2例,死亡3例。可评估的2年无病生存率为70％。结论造血干细胞移植对于高龄白血病患者是一种有效、安全的根治疗法。     

Effect of acute and chronic GVHD on relapse and survival after reduced-intensity conditioning allogeneic transplantation for myeloma

We evaluated the effect of acute and chronic GVHD on relapse and survival after allogeneic hematopoietic SCT (HSCT) for multiple myeloma using non-myeloablative conditioning (NMA) and reduced-intensity conditioning (RIC). The outcomes of 177 HLA-identical sibling HSCT recipients between 1997 and 2005, following NMA (n=98) or RIC (n=79) were analyzed. In 105 patients, autografting was followed by planned NMA/RIC allogeneic transplantation. The impact of GVHD was assessed as a time-dependent covariate using Cox models. The incidence of acute GVHD (aGVHD; grades I-IV) was 42% (95% confidence interval (CI), 35-49%) and of chronic GVHD (cGVHD) at 5 years was 59% (95% CI, 49-69%), with 70% developing extensive cGVHD. In multivariate analysis, aGVHD (≥ grade I) was associated with an increased risk of TRM (relative risk (RR)=2.42, P=0.016), whereas limited cGVHD significantly decreased the risk of myeloma relapse (RR=0.35, P=0.035) and was associated with superior EFS (RR=0.40, P=0.027). aGVHD had a detrimental effect on survival, especially in those receiving autologous followed by allogeneic HSCT (RR=3.52, P=0.001). The reduction in relapse risk associated with cGVHD is consistent with a beneficial graft-vs-myeloma effect, but this did not translate into a survival advantage.     

Impact of human leucocyte antigen mismatch on graft-versus-host disease and graft failure after reduced intensity conditioning allogeneic haematopoietic stem cell transplantation from related donors

The impact of human leucocyte antigen (HLA) incompatibility between donor and recipient on graft-versus-host disease (GVHD) and graft failure after reduced-intensity conditioning stem cell transplantation (RICT) remains to be elucidated. We retrospectively analysed outcome in 341 patients who underwent RICT from related donors for haematological malignancies. The overall cumulative incidence of grade II-IV acute GVHD (aGVHD) was 40% for all subjects; 39% in recipients with HLA-matched donors, 44% in those with one-locus-mismatched donors, and 50% in those with two- to three-loci-mismatched donors. In a Cox regression model adjusted for potential confounders, the tendency for grade II-IV aGVHD (P=0.01), chronic GVHD (cGVHD) (P=0.05) and graft failure (P=0.033) increased with HLA disparity. Use of peripheral blood grafts instead of marrow was a risk factor for cGVHD. Use of antithymocyte globulin was associated with reduced aGVHD and cGVHD. Overall survival (OS) in recipients of two- to three-loci-mismatched RICT at 2 years (18%) was significantly worse than that in patients who received one-locus-mismatched RICT (51%) and HLA-matched RICT (48%) (P<0.0001). A two- to three-loci mismatch was identified as an independent risk factor for OS (P<0.001), but there was no significant difference in OS between HLA-matched and one-locus-mismatched RICT. HLA incompatibility between the donor and recipient is an important risk factor for graft failure, aGVHD, cGVHD and OS after RICT. RICT from a one-locus-mismatched donor may represent an effective alternative approach in patients with high-risk malignancies who lack HLA-matched related donors.     

HLA-DPB1 mismatch and acute graft-versus host disease in HLA-identical sibling donors

Allogeneic hematopoietic stem cell transplantation (HSCT) is an established curative therapy for a variety of hematologic malignancies. Genotypically HLA-identical sibling donors (ISDs)--who are available for about 30% of white patients are still considered as the best donors for HSCT. HLA-DPB1 is characterized by a high polymorphism, weak linkage disequilibrium with HLA-DR and -DQ loci, and its role as a transplantation antigen is controversial. We investigated the impact of HLA-DPB1 mismatch in HLA-identical sibling donor transplantation on a Graft-versus-host disease (GVHD). We Typed HLA-DPB1 by Innolipa in 33 patient-donor pairs with different hematologic diseases. Four (12.2 %) pairs with HLA-DPB1 mismatched were identified without identity. The incidence of grades II-IV aGVHD was higher in the HLA-DPB1 mismatched group (p=0.014, OR=26). Univariate analysis of risk factor for aGVHD II-IV showed that HLA-DPB1 is the only significant association (p=0.014), while non significant association was found between the age and sex of the patient, age of the donor, disease of the patient, and ABO compatibility, and positive CMV serology in patients and donors. It is concluded that HLA-DPB1 can mediate alloreactive responses and that HLA-DPB1 mismatch increases the risk of aGVHD in sibling donor stem cell transplantation.     

Kinetics of pDCs, mDCs, γδT cells and regulatory T cells in association with graft versus host disease after hematopoietic stem cell transplantation

Introduction: Although the roles of each low‐frequency immunocompetent cells such as dendritic cells (DCs), γδT cells, and Treg cells in induction of acute or chronic graft versus host disease (GVHD) have been discussed in several reports, there are few papers dealing with an evaluation of these immunocompetent cells together and simultaneously in patients with hematopoietic stem cell transplantation (HSCT) and explored the kinetics of these cells in association with GVHD. Methods: In the present study, we assessed the number of plasmacytoid DCs (pDCs), myeloid DCs (mDCs), γδT cells and Treg cells serially in patients who received allogeneic HSCT and analyzed the relationship of these cells with acute or chronic GVHD (cGVHD) by using flow cytometry. Results: The percentages and numbers of pDCs, mDC1s and γδT cells were significantly lowered in the patients with acute GVHD (aGVHD) compared with those with no GVHD. On the contrary, the percentages and numbers of Treg cells were significantly elevated in the patients with aGVHD compared with those with no GVHD. As to the association with cGVHD, Treg cells were elevated in the patients with cGVHD, compared with those with no GVHD. Conclusion: The present study revealed an association of pDCs, mDCs, γδT cells and Treg cells with induction or treatment of GVHD.     

Donor source and post-transplantation cyclophosphamide influence outcome in allogeneic stem cell transplantation for GATA2 deficiency

GATA2 deficiency was described in 2011, and shortly thereafter allogeneic hematopoietic stem cell transplantation (HSCT) was shown to reverse the hematologic disease phenotype. However, there remain major unanswered questions regarding the type of conditioning regimen, type of donors, and graft-versus-host disease (GVHD) prophylaxis. We report 59 patients with GATA2 mutations undergoing HSCT at National Institutes of Health between 2013 and 2020. Primary endpoints were engraftment, reverse of the clinical phenotype, secondary endpoints were overall survival (OS), event-free survival (EFS), and the incidence of acute and chronic GVHD. The OS and EFS at 4 years were 85·1% and 82·1% respectively. Ninety-six percent of surviving patients had reversal of the hematologic disease phenotype by one-year post-transplant. Incidence of grade III-IV aGVHD in matched related donor (MRD) and matched unrelated donor recipients (URD) patients receiving Tacrolimus/Methotrexate for GVHD prophylaxis was 32%. In contrast, in the MRD and URD who received post-transplant cyclophosphamide (PT/Cy), no patient developed grade III-IV aGVHD. Six percent of haploidentical related donor (HRD) recipients developed grade III-IV aGVHD. In summary, a busulfan-based HSCT regimen in GATA2 deficiency reverses the hematologic disease phenotype, and the use of PT/Cy reduced the risk of both aGVHD and cGVHD.     

Contribution of TNF-alpha and IL-10 gene polymorphisms to graft-versus-host disease following allo-hematopoietic stem cell transplantation

Some cytokines are believed to play a role in the development of acute and chronic GVHD after allo-hematopoietic stem cell transplantation. It has been reported that TNF-alpha and IL-10 gene polymorphisms are associated with the production of those cytokines and the development of graft failure after organ transplantation and systemic lupus erythematosus. We examined whether TNF-alpha and IL-10 gene polymorphisms affect the severity of acute GVHD (aGVHD) and chronic GVHD (cGVHD). Sixty-two and 54 patients were available for the analysis of aGVHD and cGVHD, respectively. We analyzed the gene polymorphisms derived from pre- and post-transplant blood cells. Donor-derived TNF2 allele (A) was more frequently detected in patients with aGVHD III/IV than those aGVHD 0-II (2/6 vs 2/56) (P = 0.04). The donors of the patients with cGVHD more frequently possessed a greater number of alleles (allele 13 or more which contain 26 or more CA repeats) in IL-10.G than those without (13/26 vs 5/28) (P = 0.02), and the patients with cGVHD had more CA repeats in donor-derived IL-10.G than those without (mean = 25.2 vs 23.4) (P = 0.01). Donor-derived TNF-308 and IL-10.G alleles may contribute to severe aGVHD and cGVHD, respectively, and will help us distinguish those patients at high risk for GVHD.     

What is the outcome in patients with acute leukaemia who survive severe acute graft‐versus‐host disease?

Background

Acute graft‐versus‐host disease (aGVHD ) is a major complication of allogeneic haematopoietic stem cell transplantation (HSCT ). With new promising therapies, survival may improve for severe aGVHD .

Objectives

We wanted to analyze the long‐term outcome in patients who survive severe aGVHD .

Methods

This study was a landmark analysis of 23 567 patients with acute Leukaemia who survived for more than 6 months after HSCT , 2002–2014. Patients alive after severe aGVHD (n = 1738) were compared to controls.

Results

Patients with severe aGVHD had higher non‐relapse mortality (NRM ) and higher rate of extensive chronic GVHD (cGVHD ) than the controls (P < 10^?5). The probability of relapse was significantly lower in the severe aGVHD group, but Leukaemia‐free survival (LFS ) and overall survival were significantly lower than for the controls (P < 10^?5). Five‐year LFS in patients with severe aGVHD was 49%, as opposed to 61% in controls with no or mild GVHD and 59% in patients with moderate GVHD.

Conclusions

HSCT patients who survive severe aGVHD have higher risk of developing extensive cGVHD , a higher NRM , a lower relapse probability, and lower LFS than other HSCT patients. This study is a platform for outcome analysis in patients treated with novel therapies for acute GVHD.

     

异基因造血干细胞移植治疗NK／T细胞淋巴瘤

目的：探讨异基因造血干细胞移植（allo—HSCT）治疗NK／T细胞淋巴瘤的疗效。方法：对1例NK／T细胞淋巴瘤患者进行allo-HSCT,采用改良马利兰（Bu）／环磷酰胺（Bu／Cy）预处理方案进行了亲缘HLA全相合的外周血干细胞移植,移植物抗宿主病（GVHD）的预防采用环孢素A联合短疗程甲氨蝶呤的方案。移植后予鼻窦及颈部淋巴结区局部放疗,早期减停环孢素A和供者淋巴细胞输注防治复发。结果：患者移植后造血恢复顺利,中性粒细胞绝对数（ANC）〉0．5×10 9／L时间为＋13d,血小板〉20×10 9／L时间为＋15d。移植后未发生急性GVHD,发生肝脏及口腔的慢性GVHD,使用小剂量甲氨蝶呤和泼尼松后控制。随访至移植后8月余,造血功能恢复良好,病情处于持续完全缓解状态,仍在继续随访中。结论：allo-HSCT对NK／T细胞淋巴瘤可能是一种有效的根治方法,移植后的局部放疗及供者淋巴细胞输注能预防复发。

Abstract：

Objective： To explore the therapeutic effect of allogeneic hematopoietic stem cell transplantation （allo HSCT） for NK/T cell lymphoma. Methods： One patient with NK/T-cell lymphoma received allo-HSCT. The patient received conditioning regimens of improved busulfan/cyclophosphamide and relative HLA-identical peripheral blood stem cell transplantation. Graft versus host disease （GVHD） prophylaxis consisted of cyclosporin-A （CsA） and short course of methotrerate. The sinus and cervical lymph node area were received local ra diotherapy, and it followed by early cyclosporine tapering and donor lymphocyte infusion to prevent relapse after allo HSCT. Results： The hematopoietic stem cell was transplanted successfully. The ANC and PLT were grafted respectively in ＋ 13d and ＋ 15d. None of the acute GVHD was observed. The chronic GVHD involved liver and oral after transplantation, and it was controlled by low dose of methotrerate and prednisone. The patient was followed up for 8 months after allo-HSCT, and the state of illness retained continuous complete remission. Conclusions： Treatment of allo-HSCT was an effective radical cure for NK/T-cell lymphoma, and local radio therapy and donor lymphocyte infusion were used to prevent relapse post transplant.     

Chronic graft-versus-host disease in children: incidence,risk factors,and impact on outcome

Chronic graft-versus-host disease (cGVHD) remains the major cause of late morbidity and mortality after allogeneic hematopoietic stem cell transplantation (HSCT). However, only a few studies specifically focused on children, and little information is available on the antileukemic effect of cGVHD and its impact on disease-free survival (DFS) in children. We retrospectively analyzed 696 children given allogeneic HSCT for malignant (n = 450) or nonmalignant (n = 246) diseases. The donor was an HLA-identical sibling in 461 cases and an alternative donor in 235. Bone marrow was the stem cell source in 647 cases, peripheral blood in 17, and cord blood (CB) in 32. cGVHD developed in 173 children (25%) at a median of 116 days after HSCT. Three-year cGVHD probability was 27%. In multivariate analysis, variables predicting cGVHD were donor and recipient age, grade II to IV acute GVHD, female donor for male recipient, diagnosis of malignancy, and use of total body irradiation; CB transplants had a very low risk of cGVHD (RR = 0.07, P =.0001). cGVHD occurrence increased transplant-related mortality (P <.05). Nevertheless, in hematologic malignancies, patients with cGVHD had a reduced relapse probability compared with children without cGVHD (16% +/- 3% versus 39% +/- 3%, P =.0001) and a better DFS (68% +/- 4% versus 54% +/- 3%, P =.01). The antileukemic effect of cGVHD was observed mainly in patients with acute lymphoblastic leukemia (ALL). This study provides novel data on cGVHD in childhood. Use of CB stem cells and preparative regimens without radiotherapy may prevent its development. In patients affected by ALL, cGVHD was associated with a strong graft-versus-leukemia effect, improving DFS.