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。     

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。     

非清髓性造血干细胞移植治疗血液病预处理中ATG／ALG的应用及作用

目的：探讨抗胸腺细胞球蛋白（ATG）和抗淋巴细胞球蛋白（ALG）在血液病非清髓性异基因造血干细胞移植中的作用，以及ATG/ALG的毒副作用，对移植并发症的影响。方法：以ATG／ALG为基础降低化疗剂量的非清髓性预处理方案，对16例恶性血液病、17例重型再生障碍性贫血（SAA）实施骨髓、骨髓加外周血造血干细胞或脐血造血干细胞移植；对5例恶性血液病实施逐渐增加剂量的供者淋巴细胞输注（DLI），1例S从实行供者干细胞输注（DSI）。GVHD的预防：恶性血液病采用环孢菌素A联合短程甲氨喋呤，SAA患者采用CSA联合甲泼尼龙。采用糖皮质激素和甾体类消炎药等防治ATG／ALG毒副作用和并发症。结果：3例患者在移植后早期感染死亡。其余30例患者恢复造血功能，ANC〉0．5×10^8/L和PLT〉20×10^9／l平均时间为12．2（3-35）d和20．1（5～80）d。移植后7例为供者型完全嵌合体（CC），3例无植入证据；23例为混合性嵌合体（MC），其中7例逐渐转为CC，6倒是在DLI或者DSI后实现MC向CC转变。移植后早期均无aGVHD，3～8次DLI并发Ⅰ度aGVHD1例、Ⅱ度aGVHD3例，2例皮肤局限型cGVHD、2例为广泛型cGVHD。并发严重的细菌感染3例、病毒感染4例、真菌感染5例。ATG／ALG使用过程中全部出现寒战、发热症状，大部分出现皮疹、一过性血压下降、少数出现一过性心律不齐，经积极防治不需中断治疗。结论：ATG／ALG促进异基因造血干细胞的植入，延迟和减少GVHD的发生率并降低严重程度．是否增加病毒、真菌感染的机会有待进一步观察。     

非清髓性造血干细胞移植加供者淋巴细胞输注治疗多发性骨髓瘤1例报告并文献复习

目的研究非清髓性造血干细胞移植(NST)治疗多发性骨髓瘤(MM)的疗效,观察移植相关并发症的发生.方法1例42岁MM患者,供者为其胞姐,HLA配型完全相合.动员方案粒细胞集落刺激因子(G-CSF)10 μg·kg-1·d-1×5 d.预处理方案抗胸腺细胞球蛋白(ATG)8 mg·kg-1·d-1×3 d,马法兰(MEL)120 mg/m2×1 d.移植单个核细胞数(MNC) 6.5×108/kg;CD34+细胞 4.4×106/kg.环胞菌素A(CsA)和短程甲氨蝶呤(MTX)预防移植物抗宿主病(GVHD).移植后分别于+41 d、+76 d和+112 d进行3次供者淋巴细胞输注(DLI).结果移植后15 d中性粒细胞计数> 0.5×109/L,21 d血小板计数>50×109/L,24 d性染色体和微卫星法DNA指纹图监测显示为混合嵌合体,随着DLI的进行,逐渐转为供者型完全嵌合体,骨髓瘤细胞和血清M蛋白均逐渐消失,移植后8个月达完全缓解.在+180 d(第三次DLI后68 d)发生II度急性GVHD,经甲泼尼龙和CsA治疗得以控制.现随访36个月,患者情况良好,仍处于完全缓解状态.结论非清髓性造血干细胞移植加供者淋巴细胞输注治疗MM是可行和有效的.     

非清髓异基因造血干细胞移植治疗慢性粒细胞白血病

目的　探讨非清髓异基因造血干细胞移植 (NST)治疗慢性粒细胞白血病 (CML)的临床效果。方法　对 4例慢性粒细胞白血病患者进行了非清髓异基因造血干细胞移植 ,均采用以氟达拉宾为基础的非清髓预处理方案。回输CD+ 3 4 细胞分别为 9.78× 10 6/Kg、16.5 6× 10 6/Kg、2 .5 6×10 6/Kg和 2 .0 6× 10 6/Kg。结果　 4例均顺利渡过造血抑制期。 4例患者移植后WBC >1.0× 10 9/L ,中性粒细胞 >0 .5× 10 9/L ,时间分别为 +19天、+16天、+13天和 +14天 ;血小板 >2 0× 10 9/L时间分别为 +8天、+12天、+18天和 +2 2天。 2例骨髓细胞混合嵌合体形成 +15～ +2 3天 ,完全嵌合体形成 +2 3～ +4 3天 ;另 2例均于 +17天形成完全嵌合体。 4例均未发生急性移植物抗宿主病 ,例 1于第 5次供者淋巴细胞输注后发生皮肤慢性移植物抗宿主病 ,例 3于第 7次供者淋巴细胞输注后发生慢性移植物抗宿主病。 3例于非清髓异基因造血干细胞移植后 6～ 12个月出现移植物抗白血病。 4例均未发生肝静脉阻塞病、出血性膀胱炎及间质性肺炎。随诊 2～ 2 4个月 ,仍全部存活。结论　非清髓异基因造血干细胞移植治疗慢性粒细胞白血病简便、安全、并发症及支持治疗少、疗效较好。     

单倍体HLA不相合非清髓性异基因造血干细胞移植治疗血液病临床研究

目的:探讨组织相融抗原(HLA)不相合,主要血型不合的非清髓性异基因外周造血干细胞移植(NASCT)治疗血液病的可行性。方法:对7例血液病患者接受2～3个位点不合,ABO主要血型不合的未去T细胞NASCT,连续接受免疫抑制治疗。其中男3例,女4例,中位年龄41(21～58)岁。7例中,急性白血病第1次完全缓解(CR1)3例,CR2 1例,骨髓增生异常综合征(MDS)1例,极重症再生障碍性贫血(SSAA)1例,再障-阵发性睡眠性血红蛋白尿(AA-PNH)1例。结果:7例患者均取得三系重建造血,移植后粒细胞>0．5×109／L及血小板>20×109／L的中位时间分别为移植后第14天和第21天,植入直接证据检测证实完全供者造血,2例发生急性移植物抗宿主病,2例发生慢性移植物抗宿主病。结论:经粒细胞集落刺激因子动员的外周造血干细胞采用NASCT及持续性免疫抑制剂应用特别是ATG应用于未去T细胞的NASCT成功率高,疗效好,为扩大供者来源治愈血液病提供了新手段。     

非清髓单倍体造血干细胞移植联合格列卫治疗慢性粒细胞白血病

目的:探讨格列卫联合非清髓性单倍体造血干细胞移植在治疗慢性粒细胞白血病(CML)中的作用。方法:4例CML患者,采用移植前、后口服格列卫,以环磷酰胺、阿糖胞苷、抗胸腺细胞球蛋白、赛尼派、环胞素A等作非清髓性预处理的单倍体异基因外周血造血干细胞移植。结果:移植过程顺利,4例患者均植入成功,嵌合性植入。中性粒细胞>0.5×109/L天数,16(10~21)d;血小板>20×109/L天数,10(4~15)d。3例发生Ⅰ~Ⅱ度皮肤急性移植物抗宿主病(GVHD),1例发生Ⅳ度皮肤慢性GVHD。1例+27d死于肺部感染并多脏器功能衰竭,1例死于Ⅳ度皮肤慢性GVHD并发感染。2例无病存活(随访16个月仍健在),且Ph+染色体,bcr-abl融合基因转阴。结论:非清髓单倍体造血干细胞移植联合格列卫治疗CML,具有降低移植前白血病细胞负荷,抑制残留白血病细胞增殖,促进供者完全嵌合状态的转变,增强抗移植物白血病(GVL)效应的作用,是一种有效的治疗方法,值得进一步临床研究。     

异基因外周血干细胞移植后淋巴细胞和粒细胞嵌合体的动态改变

目的：探讨异基因外周血干细胞移植(allo-PBSCT)后T细胞、粒细胞嵌合体的动态改变及临床价值。方法：将多重PCR扩增短串联重复序列(STR—PCR)的法医试剂进行条件优化，间隔短时间抽取9例恶性血液病患者(5例清髓性PBSCT，4例非清髓性PBSCT)的外周血样，STR—PCR定量分析T细胞和粒细胞的嵌合体，并观察其对移植后应用免疫抑制剂的指导作用。结果：STR—PCR定量分析嵌合体的敏感性为5％，并具高度可重复性。清髓性PBSCT后10d( 10d)，5／5例患者的粒细胞迅速演变为完全供者嵌合体(CDC)， 14d，4，／5例患者的T细胞获得CDC。非清髓性PBSCT， 7～ 14d，供者T细胞信号的植入速度快于粒细胞；随后，供者粒细胞的比例突然增加，并迅速获得CDC，T细胞的植入却渐缓慢，最后，T细胞取得CDC的时间迟于粒细胞。依据供者T细胞信号的植入程度，及时调整非清髓性PBSCT后环孢素A(CsA)的用量，移植早期T细胞即获CDC，随访2～16个月，T细胞和粒细胞均呈稳定的供者植入状态。结论：供者T细胞的完全植入迟于粒细胞．动态监测T细胞嵌合体，可能有助于免疫抑制剂的调整。     

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。     

非清髓造血干细胞移植治疗再生障碍性贫血

目的:探讨非清髓性造血干细胞移植(NST)治疗再生障碍性贫血(再障)的方法及疗效。方法:采用非清髓预处理方案进行造血干细胞移植治疗再生障碍性贫血2例。1例为同胞间HLA配型6个位点完全相合的异基因外周血造血干细胞移植,另1例为同胞间HLA配型6个位点完全相合的脐血移植。预处理方案主要由抗胸腺细胞球蛋白(ATG)和环磷酰胺组成。用环孢素A和霉酚酸酯(MMF)预防移植物抗宿主病(GVHD)。结果:2例患者均获造血重建(分别为 5及 9d),2例均未发生GVHD。1例患者在治疗期间未出现感染表现,另1例患者出现CMV感染,给予更昔洛韦病情得以完全控制。2例分别无病生存8及17个月。结论:非清髓造血干细胞移植简便安全,并发症少,疗效好,为治疗再生障碍性贫血有效方法。     

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.     

The effect of donor leukocyte infusion on refractory pure red blood cell aplasia after allogeneic stem cell transplantation in a patient with myelodysplastic syndrome developing from kostmann syndrome

We describe the clinical course of a patient who experienced refractory pure red cell aplasia (PRCA) after undergoing HLA-matched allogeneic peripheral blood stem cell transplantation (allo-PBSCT) for refractory anemia with an excess of blasts in transformation that had evolved from Kostmann syndrome. The treatment for patients with myelodysplastic syndrome (MDS) or acute myeloid leukemia (AML) developing from Kostmann syndrome has not been standardized. We treated this patient with allo-PBSCT using a regimen combining high-dose cytosine arabinoside with granulocyte colony-stimulating factor, in addition to total body irradiation and cyclophosphamide without preceding intensive chemotherapy. The donor was ABO incompatible. Myeloid and platelet recoveries were achieved rapidly. Erythroid engraftment was not evident, however, and the patient was given a diagnosis of PRCA. Regimen-related toxicity and graft-versus-host disease (GVHD) were limited. The PRCA did not respond to various therapies, including the discontinuation of immunosuppressants for the induction of chronic GVHD, human recombinant erythropoietin, immunosuppressive treatment with steroids, cyclosporin A, and human anti-CD20 antibody (rituximab). The patient received transfusions 48 times until the resolution of his anemia by donor leukocyte infusion (DLI) at 25 months after PBSCT. He is now clinically well (performance status, 100%) with normal blood cell counts at 5 years after SCT. An in vitro study demonstrated that serum from the recipient blocked the differentiation of erythroid cells in the bone marrow. The results indicate that the conditioning regimen we describe seems safe and effective for those who have MDS/AML and that DLI might be a valuable approach for refractory PRCA after ABO-incompatible SCT.     

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.     

Mesenchymal stem cells for the treatment of refractory pure red cell aplasia after major ABO-incompatible hematopoietic stem cell transplantation

Pure red cell aplasia (PRCA) is a well-known, although infrequent, hematological complication after allogeneic hematopoietic stem cell transplantation (HSCT). PRCA occurs in cases of major ABO mismatch between donor and recipient and is believed to be due to inhibition of donor erythroid progenitors by residual host isohemagglutinins. The purpose of our study was to further evaluate the efficacy of human adipose tissue-derived mesenchymal stem cells (AMSC) as the salvage therapy for refractory PRCA after major ABO-incompatible HSCT. Two patients with refractory pure red cell aplasia received intravenous infusions of AMSC at a dose of 1.5 × 10⁶/kg of the patients’ weight, and rapid recovery from PRCA without any side effects was observed. We conclude that AMSC seems to be a promising therapeutic option in patients with PRCA after ABO-mismatched HSCT, in whom conventional treatment fails.     

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。     

Clinical features and risk factors of pure red cell aplasia following major ABO-incompatible allogeneic hematopoietic stem cell transplantation

The objective of this paper was to study the incidence, risk factors, clinical outcome, management and prevention of pure red cell aplasia (PRCA) following major ABO-incompatible allogeneic hematopoietic stem cell transplantation (allo-HSCT). We retrospectively analyzed 11 cases of PRCA from a series of 42 patients undergoing major ABO-incompatible allo-HSCT from April 1997 to December 2005. Eleven out of the 42 patients developed PRCA (26.1%). All the 11 cases of PRCA were in blood group O recipients of grafts from blood group A donor (n = 9) or blood group B donor (n = 2). The following factors were associated with an increased risk of PRCA: (1) blood group O recipient; (2) blood group A donor; and (3) blood group O/A in recipient/donor pair. Only blood group a/A in recipient/donor pair was identified as being significantly associated with the occurrence of PRCA by multivariate analysis. Six patients who received donor-type plasma exchange did not develop PRCA and among them 5 cases were the blood group O recipients. Eight patients obtained spontaneous remission and in the remaining 3 patients 2 with long-lasting PRCA were successfully treated with plasma exchange with donor-type plasma replacement and the other one who was also complicated by EBV-associated lymphoproliferative disorder (EBV-PTLD) responded rapidly to anti-CD20 monoclonal antibody and achieved complete resolution of clinical finding and symptom of both EBV-PTLD and PRCA. We conclude that blood group A/O in donor/recipient pair is identified as being significantly associated with the occurrence of PRCA by multivariate analysis. Donor-type plasma exchange and anti-CD20 monoclonal antibody is an effective approach for the treatment of PRCA. PRCA could be prevented by plasma exchange prior to transplantation.     

Clinical features and risk factors of pure red cell aplasia following major ABO-incompatible allogeneic hematopoietic stem cell transplantation

The objective of this paper was to study the incidence, risk factors, clinical outcome, management and prevention of pure red cell aplasia (PRCA) following major ABO-incompatible allogeneic hematopoietic stem cell transplantation (allo-HSCT). We retrospectively analyzed 11 cases of PRCA from a series of 42 patients undergoing major ABO-incompatible allo-HSCT from April 1997 to December 2005. Eleven out of the 42 patients developed PRCA (26.1%). All the 11 cases of PRCA were in blood group O recipients of grafts from blood group A donor (n = 9) or blood group B donor (n = 2). The following factors were associated with an increased risk of PRCA: (1) blood group O recipient; (2) blood group A donor; and (3) blood group O/A in recipient/donor pair. Only blood group O/A in recipient/donor pair was identified as being significantly associated with the occurrence of PRCA by multivariate analysis. Six patients who received donor-type plasma exchange did not develop PRCA and among them 5 cases were the blood group O recipients. Eight patients obtained spontaneous remission and in the remaining 3 patients 2 with long-lasting PRCA were successfully treated with plasma exchange with donor-type plasma replacement and the other one who was also complicated by EBV-associated lymphoproliferative disorder (EBV-PTLD) responded rapidly to anti-CD20 monoclonal antibody and achieved complete resolution of clinical finding and symptom of both EBV-PTLD and PRCA. We conclude that blood group A/O in donor/recipient pair is identified as being significantly associated with the occurrence of PRCA by multivariate analysis. Donor-type plasma exchange and anti-CD20 monoclonal antibody is an effective approach for the treatment of PRCA. PRCA could be prevented by plasma exchange prior to transplantation.     

Reduced intensity conditioning and prophylactic DLI can cure patients with high-risk acute leukaemias if complete donor chimerism can be achieved

23 patients with ALL (n=9) and AML (n=14) underwent nonmyeloablative stem cell transplantation (NST) from an HLA-identical donor after conditioning with fludarabine (180 mg/m(2)), busulfan (8 mg/kg) and anti-T-lymphocyte globulin (40 mg/kg). After NST, 20/23 patients engrafted. Ten out of 14 patients with uncontrolled disease reached complete remission. A multiplex-PCR using short tandem repeats was used for chimerism analysis and detected mixed chimerism (MC) in 14/22 evaluable patients (64%) after NST. Prophylactic donor lymphocyte infusions (DLI) were given to 11/14 patients with MC; MC converted to complete donor chimerism (CC) in 6/11 patients within 2-6 weeks. All patients with persistent MC with or without DLI relapsed during further follow-up. MC predicted impending relapse 4-52 weeks before clinical diagnosis. Ten of 23 patients (43%) are alive 2-34 months after stem cell transplantation. 12 of 23 patients (52%), have died from leukaemia after NST. One out of 23 patients has died from severe sepsis. In conclusion, NST leads to stable engraftment and complete remission in patients with advanced acute leukaemias. NST can cure a substantial proportion of these patients, but the relapse rate is still high. Repeated chimerism analysis is a useful tool to detect recipient cells, especially in patients without molecular markers of disease and can be used to monitor immunomodulatory therapies. MC is unstable in these patients and predicts impending relapse. Prophylactic DLI can convert MC to CC, which seemed to lower relapse risk.     

Resistant pure red cell aplasia after allogeneic stem cell transplantation with major ABO mismatch treated by escalating dose donor leukocyte infusion

We report a case of pure red cell aplasia (PRCA) following allogeneic stem cell transplantation (SCT) with major ABO mismatch which proved resistant to all standard treatment options such as change in immunosuppressive treatment, high-dose erythropoietin (EPO) or plasma exchange. We therefore proceeded to administer five cycles of Rituximab therapy, without success. Finally, escalating doses of donor-derived leukocyte infusion (DLI) resolved the PRCA of our patient 415 d after bone-marrow transplantation (BMT) and 140 d after the first infusion of donor leukocytes. A review of the literature shows the efficacy of various treatments; the role of DLI and other treatment options are discussed. Furthermore, the underlying pathophysiological mechanisms especially with regard to the role of NK cells in alloreactivity after allogeneic SCT are explained.     

Autologous del(20q)-positive erythroid progenitor cells, re-emerging after DLI treatment of an MDS patient relapsing after allo-SCT, can provide a normal peripheral red blood cell count

A 54-year-old RhD-negative male with del(20q)-positive myelodysplastic syndrome was transplanted with bone marrow from an HLA-identical RhD-positive sibling donor. Cytogenetic relapse was detected 21 months after stem cell transplantation (SCT), with reappearance of the original del(20q)-positive clone and reversion to recipient RhD-negative blood group. The patient received sequential donor lymphocyte infusions (DLIs), resulting in mild graft-versus-host disease and pure red cell aplasia. At 2 years post DLI, the patient remains in a stable condition, despite a dominance of recipient-derived erythro- and granulopoiesis originating in del(20q)-carrying progenitor cells. We conclude that reappearance of autologous erythropoiesis, upon relapse after allogeneic SCT, may be predictive of erythropenia after DLI and that re-emerging autologous del(20q)-positive erythropoiesis post DLI can provide a normal peripheral red blood cell count. Furthermore, in patients relapsing after blood-group-mismatched transplantation, a possible reversion to recipient blood group should be considered prior to blood transfusion or DLI.