单倍体相合异基因造血干细胞移植治疗白血病

背景：对于无HLA全相合同胞供者的患者,采用单倍体相合造血干细胞移植面临移植物抗宿主病重、移植相关死亡率高的风险,但通过不同的移植模式,将有可能获取相近的疗效。 目的：观察亲缘HLA单倍体相合异基因造血干细胞移植治疗白血病的疗效,并与亲缘HLA全相合异基因造血干细胞移植相比较。 方法：45例白血病患者分为2组。单倍体组移植方式为外周血或联合骨髓干细胞移植,预处理方案为改良白消安与环磷酰胺或加抗胸腺细胞球蛋白,移植物抗宿主病的预防采用环孢素A+甲氨蝶呤+霉酚酸脂;全相合组移植方式为外周血干细胞移植,预处理方案为BuCY,移植物抗宿主病的预防采用环孢素A+甲氨蝶呤。 结果与结论：两组均获得造血重建时间差异无显著性意义。单倍体及全相合组急性移植物抗宿主病的累积发病率分别为73%对52%(P > 0.05);慢性移植物抗宿主病的累积发病率分别为56%对45%(P > 0.05);移植相关死亡率分别为36%对17%(P > 0.05);单倍体组无复发,全相合组复发2例;两组的预计3年累积无病生存率分别为61%对60%(P > 0.05)。结果提示,亲缘单倍体异基因造血干细胞移植的总体疗效与亲缘全相合异基因造血干细胞移植相似,但中重度急性移植物抗宿主病的发生率较后者为高。     

Successful allogeneic stem cell transplantation with nonmyeloablative conditioning in patients with relapsed hematologic malignancy following autologous stem cell transplantation.

The use of myeloablative preparative therapy and allogeneic stem cell transplantation (alloSCT) as salvage therapy for adult patients with relapsed hematologic malignancy after autologous stem cell transplantation (autoSCT) is generally unsuccessful due to very high treatment-related mortality rates. We evaluated the outcome of HLA-matched related donor alloSCT following nonmyeloablative preparative therapy in 13 patients (median age, 38 years) with relapsed hematologic malignancies (Hodgkin's disease, n = 4; Hodgkin's disease and advanced myelodysplastic syndrome, n = 1; non-Hodgkin's lymphoma, n = 6; multiple myeloma, n = 2) after initial autoSCT. Median time from autoSCT to alloSCT was 12 months (range, 3-24 months); 6 patients had chemotherapy-refractory disease following autoSCT, 6 were in untreated relapse, and 1 had a partial response from salvage chemotherapy. Preparative therapy consisted of cyclophosphamide, 150-200 mg/kg; peritransplantation anti-thymocyte globulin; thymic irradiation (in patients who had not received previous mediastinal irradiation); and a very short course of cyclosporine as GVHD prophylaxis. All patients achieved initial mixed chimerism as defined by greater than 1% donor peripheral white blood cells. Seven patients, who had no evidence of GVHD, received prophylactic DLI beginning 5 to 6 weeks after transplantation for conversion of mixed chimerism to full donor hematopoiesis and to optimize a graft-versus-tumor effect. Six patients showed conversion to full donor chimerism and 1 lost the graft. Grade II or greater acute GVHD occurred in 9 patients. Seven patients achieved a complete response; 6 had no response. The median survival time of the 13 patients is currently 10 months (range, 3-39 months), with an overall survival probability at 2 years of 45% (95% confidence interval [CI], 19%-73%) and a disease-free survival probability at 2 years of 37.5% (95% CI, 12%-65%). Thus, this novel nonmyeloablative alloSCT strategy followed by prophylactic DLI was well tolerated and can result in durable disease-free survival among patients with advanced hematologic malignancies after a failed autoSCT. Further follow-up and evaluation of additional patients are required to conclusively establish the role of this strategy in the treatment of hematologic malignancies after an autologous transplantation.     

Allogenic stem cell transplantation after non-myeloablative conditioning regimen (mini-allogenic" stem cell transplantation)

Allogeneic stem cell transplantation is able to cure many hematologic malignancies, through, at least partially, a graft versus disease effect of the donor's immune system transfer. However, the toxicity of this technique limits its use to selected patients. The aim of non-myeloablative stem cell transplantation is to reduce the toxicity of the conditioning regimen while allowing the engrafement of donor's stem cells and the immunological antitumoral activity of the donor's immune system. Several reports have already demonstrated the validity of this concept. This new multi-step therapeutic strategy is complex, raises many questions and deserves further studies to be fully applicable to a greater number of patients.     

HLA单倍体与全相合异基因造血干细胞移植治疗恶性血液病

背景：异基因造血干细胞移植是治疗恶性血液病的一种非常有效的方法。单倍体相合的造血干细胞移植扩大了移植的应用范围,是无HLA相合供者患者的一种重要选择。 目的：比较HLA单倍体相合与全相合异基因造血干细胞移植治疗恶性血液病的临床疗效。 方法：回顾性分析接受异基因造血干细胞移植79例恶性血液病患者的临床资料,其中HLA单倍体相合组26例、全相合组53例,对比两组受者移植物抗宿主病的发生率、复发率、2年生存率等。 结果与结论：78例受者获得完全、持久供者干细胞植入;1例受者在移植后28 d尚未植入,后因感染死亡。两组慢性移植物抗宿主病发生率、复发率和2年无病生存率差异无显著性意义(P > 0.05)。单倍体相合组急性移植物抗宿主病发生率高于全相合组(P < 0.05);2年总生存率低于全相合组(P < 0.05)。提示血缘HLA单倍体相合移植治疗恶性血液病的安全性及疗效接近于全相合移植,在缺乏HLA相合供者的情况下,行HLA单倍体相合造血干细胞移植治疗恶性血液病是切实可行的选择。     

HLA单倍体相合与全相合外周血造血干细胞移植后的急性移植物抗宿主病

背景：异基因外周血造血干细胞移植成为造血干细胞移植的主要方式,近年来HLA单倍体相合造血干细胞移植因供者来源广泛在临床应用较多,急性移植物抗宿主病仍是影响移植成功率的主要因素。 目的：观察亲缘HLA单倍体相合与全相合异基因外周血造血干细胞移植后急性移植物抗宿主病的发生特点,探讨降低急性移植物抗宿主病发生率的方法及单倍体造血干细胞移植应用于临床的意义。 方法：行异基因外周血造血干细胞移植的患者52例,其中HLA全相合组31例,单倍体组21例。HLA单倍体组采用改良马利兰/环磷酰胺+兔抗人胸腺T细胞免疫球蛋白预处理方案,HLA全相合组采用改良马利兰/环磷酰胺预处理方案。移植物抗宿主病的预防采用短程甲氨蝶呤+环孢素A+吗替麦考酚酯的方案。 结果与结论：52例患者均获得完全持久干细胞植入。其中,急性移植物抗宿主病发病率为48%(25/52),Ⅲ-Ⅳ度急性移植物抗宿主病发病率为23%(12/52);全相合组及单倍体组急性移植物抗宿主病累积发病率分别为39%(12/31)和62%(13/21)(P > 0.05);全相合组及单倍体组Ⅲ-Ⅳ度急性移植物抗宿主病累积发病率分别为10%(3/31)和43%(9/21)(P < 0.05);发生于移植后+30 d、+31 d-+60 d、+61 d-+100 d的急性移植物抗宿主病类型分布差异无显著性意义(P > 0.05);发生在移植后+30 d内的急性移植物抗宿主病发生率高于移植后   +31 d-+60 d和+61 d-+100 d;发生急性移植物抗宿主病组和无急性移植物抗宿主病组复发率、2年无病生存率差异无显著性意义(P > 0.05),全相合组与单倍体组相比复发率差异无显著性意义(P > 0.05),2年无病生存率前者高于后者(P < 0.05)。说明采用上述移植方案,单倍体组安全性与疗效接近全相合组;在缺乏HLA相合供者时,单倍体造血干细胞移植是治疗恶性血液病的重要方法。中国组织工程研究杂志出版内容重点：干细胞;骨髓干细胞;造血干细胞;脂肪干细胞;肿瘤干细胞;胚胎干细胞;脐带脐血干细胞;干细胞诱导;干细胞分化;组织工程全文链接：     

Predicted indirectly recognizable HLA epitopes are not associated with clinical outcomes after haploidentical hematopoietic stem cell transplantation

Haploidentical stem cell transplantation (haplo-SCT) provides an alternative method to cure patients with malignant and nonmalignant hematologic diseases who lack a human leukocyte antigen (HLA) matched related or unrelated donor. HLA disparity between donor and patient was the main reason causing lots of clinical immune response. The aim of this study was to investigate whether indirect recognition of mismatched HLA could predict the clinical outcomes in haplo-SCT. The probability of indirect recognition was predicted by the Predicted Indirectly ReCognizable HLA Epitopes (PIRCHE) model. 577 patients with acute leukemia or myelodysplastic syndrome receiving haplo-SCT were enrolled in the study. Patients were divided into 4 quartiles according to PIRCHE-Ⅰ or PIRCHE-Ⅱ. Although the cumulative incidences of chronic graft-versus-host disease (GVHD) were significantly different among the 4 PIRCHE-Ⅰgroups, with 20.4% for group 0–6, 40.5% for group >6–11, 26.1% for group >11–19 and 23.9% for group >19 (P?=?.007), PIRCHE-Ⅰ was not significantly associated with chronic GVHD in multivariate models (RR, 0.993; 95% CI, 0.858–1.149; P?=?.926). And no significant associations were observed between PIRCHE-Ⅰ or PIRCHE-Ⅱ and other clinical outcomes. In summary, PIRCHE did not correlate with clinical outcomes and could not predict haplo-SCT outcomes.     

Allogeneic hematopoietic stem cell transplant using mismatched/haploidentical donors.

Haploidentical hematopoietic stem cell transplantation (HSCT) provides an opportunity for nearly all patients to benefit from HSCT when a human leukocyte antigen (HLA) genotypically matched sibling is not available. Initial results with the use of mismatched allografts led to limited enthusiasm because of graft-versus-host disease (GVHD) and infectious complications, resulting in an unacceptable treatment-related morbidity and mortality. Recent advances with effective T cell depletion, the use of a "megadose" of stem cells, earlier detection of severe infections, combined with better antimicrobial therapy and reduced-intensity conditioning (RIC) has significantly decreased the early transplant-related mortality and GVHD, whereas enabling prompt engraftment, hence advancing the therapeutic benefit of haploidentical transplantation. However, the cardinal problems related to delayed immune reconstitution allowing posttransplant infectious complications and relapse remain, limiting the efficacy of haploidentical HSCT. Preliminary data has demonstrated the potential for use of adoptive cellular immunity and selective allodepletion in rapidly reconstituting immunity without GVHD. The encouraging reports from haploidentical transplant using noninherited maternal antigen (NIMA)-mismatched or natural killer (NK) alloreactive donors may greatly increase the donor availability and open the way to more appropriate donor selection in HLA-haploidentical HSCT. Future challenges remain in determining the safest approach for haploidentical transplant to be performed with minimal risk of GVHD, whereas preserving effective graft-versus-leukemia activity and promoting prompt immune reconstitution.     

HLA-matched unrelated donor hematopoietic cell transplantation after nonmyeloablative conditioning for patients with chronic myeloid leukemia.

We evaluated 10/10 HLA antigen-matched unrelated hematopoietic cell transplantation (HCT) after nonmyeloablative conditioning with fludarabine 3 x 30 mg/m2 and 2 Gy of total body irradiation as treatment for patients with chronic myeloid leukemia who were ineligible for conventional HCT. Data from 21 consecutive patients in first chronic phase (CP1; n = 12), accelerated phase (AP; n = 5), second CP (CP2; n = 3), and blast crisis (n = 1) were analyzed. Stem cell sources were bone marrow (n = 4) or granulocyte colony-stimulating factor-mobilized peripheral blood mononuclear cells (G-PBMCs; n = 17). The patient who underwent transplantation in blast crisis died on day 21 (too early to be evaluated for engraftment) from progressive disease. Sustained engraftment was achieved in 5 of 12 patients who underwent transplantation in CP1, 4 of 5 patients who underwent transplantation in AP, and 2 of 3 patients who underwent transplantation in CP2, whereas 9 patients rejected their grafts between 28 and 400 days after HCT. Specifically, 1 of 4 marrow recipients and 10 of 17 G-PBMC recipients achieved sustained engraftment. Graft rejections were nonfatal in all cases and were followed by autologous reconstitution with persistence or recurrence of chronic myeloid leukemia. Seven of 11 patients with sustained engraftment--including all 5 patients in CP1, 2 of 4 patients in AP, and neither of the 2 patients in CP2--were alive in complete cytogenetic remissions 118 to 1205 days (median, 867 days) after HCT. Two of the remaining 4 patients died of nonrelapse causes in complete (n = 1) or major (n = 1) cytogenetic remissions, and 2 died of progressive disease. Further efforts are directed at reducing the risk of graft rejection by exclusive use of G-PBMC and increasing the degree of pretransplantation immunosuppression.     

Radiation dose determines the degree of myeloid engraftment after nonmyeloablative stem cell transplantation.

A multivariate analysis of 121 dogs conditioned with 200, 100, or 50 cGy of total body irradiation (TBI) followed by hematopoietic stem cell transplantation from matched littermates showed that TBI dose was the only factor examined that was statistically significantly associated with the percentage of donor myeloid engraftment in stable long-term chimeras ( P = .008). To understand the direct effects of low-dose irradiation on hematopoietic stem/progenitor cells, nonirradiated and irradiated human CD34 + cells were evaluated for competitive repopulating ability in nonobese diabetic/severe combined immunodeficiency beta2m -/- mice. As expected, the results showed a radiation dose-dependent loss of competitive repopulating ability. Flow cytometric analysis indicated that, within a viable cell gate, there was reduced expression of P-selectin glycoprotein ligand-1 and L selectin on irradiated compared with nonirradiated CD34 + cells; this suggests that irradiated stem/progenitor cells may be compromised in their ability to home to or interact with the marrow microenvironment. However, the CD34 + /P-selectin glycoprotein ligand-1 dim cells also showed activation of caspase-3, indicating that they were destined to die. These results suggest that the TBI dose determines the degree of myeloid engraftment by compromising the resident stem/progenitor cell compartment.     

父母供子女单倍型造血干细胞移植治疗恶性血液病

背景：单倍型造血干细胞移植是治疗恶性血液病的一种有效方法,合适的供者及快速查找到合适的供者有助于提高移植的成功率。 目的：比较父母供子女单倍型造血干细胞移植治疗恶性血液病的临床疗效。 方法：对郑州大学第一附属医院92例恶性血液病患者行父母为供者的单倍型造血干细胞移植治疗,分为父供子移植、父供女移植、母供子移植、母供女移植4组,对比4组患者移植物抗宿主病的发生率、复发率、2年无病生存率及总生存率等。 结果与结论：92例患者均完全植入并获得造血重建,4组急性移植物抗宿主病发生率、慢性移植物抗宿主病发生率和复发率差异无显著性意义(P > 0.05)。但4组Ⅲ、Ⅳ度急性移植物抗宿主病发生率、2年无病生存率、2年总生存率差异有显著性意义(P < 0.05)。其中父供子移植组、母供女移植组的Ⅲ、Ⅳ度急性移植物抗宿主病发生率低于父供女移植组和母供子移植组;同时父供子移植组和母供女移植组的2年无病生存率、2年总生存率高于父供女移植组和母供子移植组。可见父母供子女单倍型造血干细胞移植是安全可行的,供受者性别相同比供受者性别不同的疗效好。     

单倍体相合造血干细胞移植治疗高危白血病

背景：异基因造血干细胞移植是治疗高危白血病的主要方法,单倍体相合的造血干细胞移植扩展了移植的应用范围。 目的：观察“改良Bu/Cy+ATG”为预处理方案的单倍体相合造血干细胞移植治疗高危白血病的疗效。 方法：对19例高危白血病患者,均采用“改良Bu/Cy+ATG”预处理方案,采用外周血造血干细胞移植5例,外周血+骨髓造血干细胞移植14例。应用甲氨蝶呤,环孢素A,吗替麦考酚酯预防移植物抗宿主病。 结果与结论：①短期疗效：中性粒细胞恢复的中位时间为12(8~20) d;血小板恢复的中位时间为13(10~31) d;移植后100 d内,移植相关死亡率为(15.8±8.4)%。②移植物抗宿主病发生情况：Ⅰ~Ⅳ度急性移植物抗宿主病总发生率(63.1±11.1)%,慢性移植物抗宿主病发生率(54.54±15.0)%。③远期疗效：2年无病生存率为(28.2±15.5)%,2年总体生存率为(46.9±16.5)%。结果提示,高危白血病无人类白细胞抗原相合血缘供者及无人类白细胞抗原相合非血缘供者,而又急需进行挽救性移植时,“改良Bu/Cy+ATG”为预处理方案的单倍体相合造血干细胞移植是一种可行的选择。     

Unrelated donor hematopoietic stem cell transplantation for patients with hematologic malignancies using a nonmyeloablative conditioning regimen of fludarabine, low-dose total body irradiation, and rabbit antithymocyte globulin.

Hematopoietic stem cell chimerism can be established after low-dose conditioning regimens, although the risk of donor cell rejection increases for unrelated donor transplantations. We added pretransplantation rabbit antithymocyte globulin (6 mg/kg) to an established conditioning regimen of fludarabine (90 mg/m2) and single-fraction total body irradiation (200 cGy) followed by postgrafting immunosuppression with cyclosporine A and mycophenolate mofetil for 22 patients with hematologic malignancies. One patient rejected the graft and successfully underwent transplantation with cells from a second donor by using the same conditioning regimen. The actuarial probability of developing acute graft-versus-host disease grade II to IV before day 100 was 40%, although 9 of 14 patients who survived beyond 100 days developed chronic graft-versus-host disease. These data support a hypothesis that the addition of antithymocyte globulin decreases the risk of graft-versus-host and host-versus-graft reactions when combined with a nonmyeloablative conditioning regimen of fludarabine and total body irradiation.     

Role of alloreactive KIR2DS1(+) NK cells in haploidentical hematopoietic stem cell transplantation

In allo-HSCT, donor-derived, "alloreactive" NK cells have been shown to play a crucial role in the treatment of acute leukemia, contributing to eradication of leukemic blasts (GvL effect) and to clearance of residual recipient DCs and T lymphocytes (thus, preventing GvHD and graft rejection, respectively). Such alloreactive NK cells do not express CD94/NKG2A but express inhibitory KIRs, specific for HLA class I allotypes, present in the donor but lacking in the recipient. This review is focused on the role of the activating KIR2DS1 receptor (specific for the C2-epitope of HLA-C) in haplo-HSCT. Recent data indicate that KIR2DS1 expression in HSC donors may represent a remarkable advantage in alloreactive NK responses. This is a result of a substantial increase in the NK-mediated capability to kill, not only recipients' leukemic cells but also DCs and T cell blasts. The beneficial effects mediated by alloreactive KIR2DS1(+) NK cells may occur after de novo expression of CCR7 upon interaction with allogeneic, KIR ligand-mismatched CCR7(+) cells. As a consequence, they can be redirected to LNs, where they can prevent priming of donor T cells and induction of GvHD. Finally, KIR2DS1 expression may also significantly amplify the size of the alloreactive NK cell subset by switching a subset of "not alloreactive" NK cells into potent alloreactive cells.     

减低剂量预处理方案在亲缘HLA单倍体相合造血干细胞移植中的应用

背景：近年来减低剂量预处理异基因造血干细胞移植已被证明是安全有效的治疗手段,在同胞全相合和无关供者中应用逐年增多,它特别适合老年人或年轻人合并器官功能障碍的患者,然而由于找到HLA配型相合供体的概率不高,使得同胞全相合和无关供者减低剂量预处理异基因造血干细胞移植开展受限,而HLA不相合/单倍体供体则可以迅速找到,但减低剂量预处理的单倍体造血干细胞移植应用的报道还较少,国内尚未见报道,因此对减低剂量预处理的单倍体造血干细胞移植的开展情况进行综述非常重要。 目的：综述减低剂量预处理在亲缘HLA单倍体造血干细胞移植中的应用现状。 方法：以“减低剂量预处理方案、非清髓性预处理方案、HLA单倍体相合、造血干细胞移植和No-nmyeloablative  conditioning,Reduced-intensity conditioning,HLA-haploidentical,Hematopoietic stem cell transplantation”为检索词,应用计算机检索1997至2014年万方数据库、CNKI和PubMed数据库、外文医学信息资源检索平台检索关于减低剂量预处理在亲缘HLA单倍体造血干细胞移植中应用的相关文献,根据纳入标准和排除标准,最终选取25篇文献进行分析,全部为英文。 结果与结论：减低剂量预处理异基因造血干细胞移植在HLA同胞全相合及无关供者中开展的较多且效果愈来愈好。减低剂量预处理的单倍体造血干细胞移植开展的较晚且报道较少,其植入、感染、移植相关死亡、移植物抗宿主病、长期无病生存率和总生存率等各个研究的结果差异较大,早期结果稍差,而近期总体情况有明显改善。目前看减低剂量预处理的单倍体造血干细胞移植是可行的,尤其对于找不到同胞相合及无关全相合供者的患者来说,HLA单倍体相合的血缘关系亲属成为最有潜力的干细胞来源。减低剂量预处理的单倍体造血干细胞移植保留较强的移植物抗白血病效应,且寻找供者容易,有足够的细胞后续治疗如供者淋巴细胞输注,同时通过发挥移植物抗白血病效应,可有效清除患者体内的肿瘤细胞,为处在疾病进展期或经历多次治疗失败的患者,尤其是老年患者、合并器官功能障碍及并发症患者,提供有效的挽救治疗手段。但由于开展的时间较短,今后在应用中该如何选择最佳方案、最佳时机以及减低移植物抗宿主病、移植相关死亡率及复发率等尚需进一步深入的研究。中国组织工程研究杂志出版内容重点：干细胞;骨髓干细胞;造血干细胞;脂肪干细胞;肿瘤干细胞;胚胎干细胞;脐带脐血干细胞;干细胞诱导;干细胞分化;组织工程全文链接：     

Engraftment syndrome after nonmyeloablative allogeneic hematopoietic stem cell transplantation: incidence and effects on survival.

Engraftment syndrome (ES) encompasses a constellation of symptoms that occur during neutrophil recovery after both autologous and allogeneic hematopoietic stem cell transplantation (HCT). Although it is well characterized after conventional myeloablative procedures, limited data exist on this complication after nonmyeloablative allogeneic HCT. The clinical manifestations, incidence, and risk factors associated with ES were investigated in a consecutive series of patients undergoing cyclophosphamide/fludarabine-based nonmyeloablative allogeneic HCT from a related HLA-compatible donor. Fifteen (10%) of 149 patients (median age, 53 years; range, 27-66 years) developed ES; the onset of symptoms occurred at a median of 10 days (range, 3-14 days), and they consisted of fever (100%), cough (53%), diffuse pulmonary infiltrates (100%), rash (13%), and room air hypoxia (87%). ES was more likely to develop in patients who received empiric amphotericin formulations after transplant conditioning (Fisher exact test; P=.007). In a multivariate analysis, older patient age, female sex, and treatment with amphotericin were predictors for the development of ES. Intravenous methylprednisolone led to the rapid resolution of ES; however, transplant-related mortality was significantly higher (cumulative incidence, 49% versus 16%; P=.0005), and median survival was significantly shorter (168 versus 418 days; P=.005) in patients with ES compared with non-ES patients. In conclusion, ES occurs commonly after cyclophosphamide/fludarabine-based nonmyeloablative transplantation and responds rapidly to corticosteroid treatment, but it is associated with a higher risk of nonrelapse mortality and with shorter overall survival.     

Predictors of improved progression-free survival after nonmyeloablative allogeneic stem cell transplantation for advanced chronic lymphocytic leukemia.

Although chronic lymphocytic leukemia (CLL) remains an incurable disease with standard chemotherapy, the appropriate role and timing of transplantation are unclear. In this analysis, we report the outcomes of 46 patients with advanced CLL who underwent nonmyeloablative stem cell transplantation (NST) from HLA-matched unrelated (67%) or related (33%) donors. Fludarabine (30 mg/m2 x 4) and low-dose intravenous busulfan (0.8 mg/kg/day x 4) were used for conditioning. The 2-year overall survival (OS) and progression-free survival (PFS) rates in this refractory patient population were 54% and 34%, respectively, with a median follow-up of 20 months. The primary cause of treatment failure was relapse, with a 2-year cumulative incidence of 48%. High hematopoietic donor chimerism > or = 75% at day +30 was a significant predictor of 2-year PFS (47% vs 11%; P = .03). In multivariate analysis, chemotherapy-refractory disease at transplantation was associated with a 3.2-fold risk of progression (P = .01) and a 4.6-fold risk of death (P = .02). Increasing number of previous therapies and increasing bone marrow involvement were also associated with decreased PFS and OS. These results suggest that NST using fludarabine and low-dose intravenous busulfan is a reasonable treatment option for patients with advanced CLL, but that NST earlier in the disease course will likely be needed to achieve long-term disease control in a high proportion of patients.     

Dynamic immune profiling identifies the stronger graft-versus-leukemia (GVL) effects with haploidentical allografts compared to HLA-matched stem cell transplantation

Haploidentical stem cell transplantation (haplo-SCT) achieves superior or at least comparable clinical outcomes to HLA-matched sibling donor transplantation (MSDT) in treating hematological malignancies. To define the underlying regulatory dynamics, we analyzed time courses of leukemia burden and immune abundance of haplo-SCT or MSDT from multiple dimension. First, we employed two nonirradiated leukemia mouse models which carried human AML-ETO or MLL-AF9 fusion gene to establish haplo-identical and major histocompatibility (MHC)-matched transplantation models and investigated the immune cell dynamic response during leukemia development in vivo. We found that haplo-matching the MHCs of leukemia cells with recipient mouse T cells prolonged leukemic mice survival and reduced leukemia burden. The stronger graft-versus-leukemia activity in haplo-SCT group mainly induced by decreased apoptosis and increased cytotoxic cytokine secretion including tumor necrosis factor–α, interferon-γ, pore-forming proteins and CD107a secreted by T cells or natural killer cells. Furthermore, we conducted a prospective clinical trial which enrolled 135 patients with t(8;21) acute myeloid leukemia that displayed minimal residual disease before transplantation and underwent either haplo-SCT or MSDT. The results showed that the haplo-SCT slowed the kinetics of the leukemia burden in vivo and reduced the cumulative incidence of relapse compared with MSDT. Ex vivo experiments showed that, 1 year after transplantation, cytotoxic T lymphocytes from the haplo-SCT group had higher cytotoxicity than those from the MSDT group during the same period. Our results unraveled the role of immune cells in superior antileukemia effects of haplo-SCT compared with MSDT.Keywords: Graft-versus-leukemia, Haplo-SCT, MSDT, AML, MRDSubject terms: Acute myeloid leukaemia, Allotransplantation

Reinforced immune cell function contributes to superior anti-leukemia effects of haplo-SCT compared with MSDT based on mouse models and clinical study.