非清髓性造血干细胞移植及嵌合体检测

目的评价非清髓性造血干细胞移植(NMSCT)的疗效及供受者嵌合体的检测。方法用氟达拉宾25mg/m2,-5d~-1d、马法兰140mg/m2?1d、抗胸腺细胞球蛋白15mg/(kg.d)-4d~ 5d作为预处理方案,环胞霉素3mg/(kg.d),麦考芬酸脂15mg/(kg.d)用于GVHD的预防。为17例患者做了,并对嵌合体进行检测。结果17例患者达到了早期植入,中性粒细胞恢复至0.5×109/L,中位时间为13d,血小板恢复至30×109/L,中位时间为17d。全部供者粒细胞嵌合体形成中位时间为4周,全部供者T细胞形成中位时间为8周。结论应用氟达拉宾、马法兰、抗胸腺细胞球蛋白作为非清髓性造血干细胞移植预处理方案,可获得供者早期植入,不良反应少。     

Autoimmunity and Glomerulonephritis After Neonatal Induction of Lymphoid Chimerism in Mice: Role of Donor B Cells and Host T Cells

Balb/c mice neonatally injected with semiallogeneic (A/J x Balb/c)F₁ or (C57 BL/6 x Balb/c) F₁ hybrid spleen cells develop autoantibodies,marked increase in serum levels of IgG₁ and IgE, lymphoid hyperplasia,and immune-complex glomerulonephritis. F₁ donor B cells playa dominant role in the pathogenesis of this autoimmune diseasesince B-cell chimerism is required for the occurrence of immunopathology,donor-specific allotype is expressed on serum anti-DNA antibodies,and substantial amounts of donor-derived immuno globulins arepresent in the kidney eluate of chimenc mice. In vitro experimentsindicate that I cells from diseased Balb/c mice induce activationof F₁ donor B cells with secretion of anti-DNA antibodies. Thesefindings suggest that a host-versus-graft reaction between recipientT cells and donor F₁ B cells is responsible for the secretionof pathogenic antibodies in this model.     

Establishment of chimerism in donor liver with recipient-type bone marrow cells prior to liver transplantation produces marked suppression of allograft rejection in rats

Abstract In this study, we investigated whether establishment of chimerism in donor liver with recipient-type bone marrow cells (BMCs) prior to liver transplantation could prolong the liver allograft survival. Donor female ACI rats were inoculated with recipient-type BMCs of male LEW rats via the portal vein, with or without irradiation as cytoablation, followed by intramuscular administration of FK506 for 5 days. At 1–2 months later, livers were harvested and transplanted into naive female LEW rats. No immunosuppressants were used. Chimerism in donor rats was confirmed by primers specific for the sex determinant Y chromosome of rats. With livers from rats pretreated with recipient-type BMCs, survival of liver allografts was significantly extended, irrespective of irradiation. These results showed that modification of the donor liver by intraportal injection of recipient-type BMCs and concomitant administration of FK506 prior to liver transplantation prolonged liver allograft survival in rats.     

Transfusion associated microchimerism: a heretofore little recognized complication following transfusion

Potent antiplatelet and antithrombotic agents have significantly reduced mortality in the setting of acute coronary syndromes and percutaneous coronary intervention. However these agents are associated with increased bleeding which is in turn associated with adverse clinical outcomes. In many centers, transfusion is often used to correct for blood loss. Blood transfusion in the setting of acute coronary syndrome has been associated with adverse clinical outcomes including increased mortality. Transfusion associated microchimerism (TA-MC) is a newly recognized complication of blood transfusion. There is engraftment of the donor’s hematopoietic stem cells in patients who then develop microchimerism. This article discusses the association of bleeding/blood transfusion with adverse outcomes and the potential role of TA-MC in clinical outcomes. The authors have received research grant support and consulting fees in the past from Eli Lilly, Schering Plough, and Astra Zeneca. Dr. Vijayalakshmi Kunadian has received unrestricted educational research grant support from South Cleveland Heart Fund, The James Cook University Hospital, Middlesbrough, United Kingdom.     

新生期移植耐受依赖嵌合体的形成

目的 研究新生期移植耐受机制,探讨免疫系统发育程度、嵌合体在诱导移植耐受中的作用.方法 雄性C57BL/6(或GFP-C57BL/6)小鼠与雌性BALB/c小鼠杂交获得F1(或GFP-F1)小鼠,不同剂量F1或GFP-F1小鼠脾脏细胞(辐照处理的细胞作为对照)静脉注射到新生24hC57BL/6小鼠体内诱导耐受,6周后皮肤移植、混合淋巴细胞反应实验检测小鼠耐受程度,流式细胞分析小鼠外周血细胞嵌合程度.结果 具有增殖活性的F1小鼠脾脏细胞可诱导新生C57BL/6小鼠嵌合体和针对F1小鼠皮肤移植物的特异性耐受;辐照处理的F1小鼠脾脏细胞不能诱导嵌合体,也没有耐受产生;长期耐受小鼠的嵌合程度明显大于慢性排斥小鼠的嵌合程度(分别为6.48％±4.02％和1.57％±0.89％),两组间的差异具有统计学意义;供体细胞剂量高则诱导小鼠的耐受程度高,3×107剂量F1小鼠脾脏细胞可诱导80％的小鼠长期耐受,0.7×107剂量诱导仅使移植物生存时间轻度延长.结论 新生期移植耐受依赖嵌合体的形成,嵌合体使同种异体反应性T细胞特异性克隆清除.     

供者NK细胞及其嵌合状态在异基因造血干细胞移植中的研究进展

目前,异基因造血干细胞移植(allo-HSCT)已广泛应用于造血系统疾病的治疗,但移植术后也存在一系列并发症。NK细胞的运用为改善allo-HSCT受者预后带来希望,供者来源NK细胞通过其细胞膜上的杀伤细胞免疫球蛋白样受体与其配体错配发挥同种异体反应,该过程具有保留移植物抗白血病和减少移植物抗宿主病双重效应。NK细胞是allo-HSCT后受者体内最早重建的免疫细胞群,因此移植后供、受者NK细胞嵌合状态评估对预测疾病预后及指导干预治疗具有重要意义。基于NK细胞嵌合状态的供者NK细胞输注免疫干预疗法可改善疾病预后,在血液系统疾病治疗中表现出良好的应用前景。本文就近年来供者NK细胞及其嵌合状态在allo-HSCT中的研究进展作一综述。     

化疗联合亲缘HLA不全相合造血干细胞输注治疗血液系统恶性疾病

 目的　明确化疗联合亲缘HLA不全相合造血干细胞输注治疗血液系统恶性疾病的疗效及安全性。 方法　9例血液系统恶性疾病患者化疗后36 h回输亲缘HLA不全相合造血干细胞,评价其疗效、造血恢复时间及并发症。结果　9例患者包括4例急性髓系白血病、1例急性B淋巴细胞白血病、2例多发性骨髓瘤、1例霍奇金淋巴瘤、1例弥漫大B细胞淋巴瘤;年龄29～67岁;共接受治疗19例（次）,每个疗程平均回输单个核细胞计数（3.12±1.29）×108／kg,CD+34 细胞计数（1.71±1.00）×106／kg;CD+3 细胞计数（2.13±0.99）×108／kg。完全缓解4例,部分缓解1例,疾病进展4例。随访2～14个月,生存4例,死亡5例。9例患者输注亲缘HLA不全相合造血干细胞过程顺利,无病例检测到供者嵌合状态,未出现移植物抗宿主病。结论　化疗联合亲缘HLA不全相合造血干细胞输注治疗血液系统恶性疾病操作简单且经济,供者来源丰富且易获得,具有良好的安全性和耐受性。     

Role of minimal residual disease and chimerism after reduced-intensity and myeloablative allo-transplantation in acute myeloid leukemia and high-risk myelodysplastic syndrome

We evaluated the impact of detection of minimal residual disease by flow cytometry (FCMRD) and CD3 chimerism in relapse in a cohort of 87 patients with acute myeloid leukemia or myelodysplastic syndrome undergoing stem cell transplantation. Patients with a positive FCMRD at day +100 after transplantation showed higher relapse rates and worse overall survival. In multivariate analysis, a positive FCMRD after transplantation was a significant predictor of relapse. Mixed chimerism showed a trend to statistical signification. We conclude that FCMRD at day 100 after SCT is the best predictor of relapse after SCT in patients with aggressive myeloid malignancies.     

Intracellular disposition of fludarabine triphosphate in human natural killer cells

Purpose  Fludarabine is a key component of several reduced-intensity conditioning regimens for hematopoietic cell transplantation (HCT). Shortly after reduced-intensity conditioning, the percent of donor natural killer (NK) cells has been associated with progression-free survival. Insufficient suppression of the recipient’s NK cells by fludarabine may lead to lower donor chimerism; however, the effect of fludarabine upon NK cells is poorly understood. Thus, in purified human NK cells we evaluated the uptake and activation of fludarabine to its active metabolite, fludarabine triphosphate (F-ara-ATP), and assessed the degree of interindividual variability in F-ara-ATP accumulation. Methods  Intracellular F-ara-ATP was measured in purified NK cells isolated from healthy volunteers (n = 6) after ex vivo exposure to fludarabine. Gene expression levels of the relevant transporters and enzymes involved in fludarabine uptake and activation were also measured in these cells. Results  F-ara-ATP accumulation (mean ± SD) was 6.00 ± 3.67 pmol/1 × 10⁶ cells/4 h, comparable to average levels previously observed in CD4⁺ and CD8⁺ T-lymphocytes. We observed considerable variability in F-ara-ATP accumulation and mRNA expression of transporters and enzymes relevant to F-ara-ATP accumulation in NK cells from different healthy volunteers. Conclusions  Human NK cells have the ability to form F-ara-ATP intracellularly and large interindividual variability was observed in healthy volunteers. Further studies are needed to evaluate whether F-ara-ATP accumulation in NK cells are associated with apoptosis and clinical outcomes.     

供体脾细胞输注诱导小鼠移植耐受及其机理的研究

目的以持续供体脾细胞输注的方法建立异基因嵌合体动物模型,并探讨移植耐受形成的机制。方法BALB/c（H-2