Impact of hematopoietic chimerism at day +14 on engraftment after unrelated donor umbilical cord blood transplantation for hematologic malignancies

Background

Cord blood transplant is a feasible treatment alternative for adult patients with hematologic malignancies lacking a suitable HLA-matched donor. However, the kinetics of myeloid recovery is slow, and primary graft failure cannot be detected easily early after transplantation. We investigated the impact of hematopoietic chimerism status from unselected marrow cells 14 days after transplantation on predicting engraftment after a cord blood transplant.

Design and Methods

Seventy-one adult patients with hematologic malignancies undergoing single-unit unrelated donor cord blood transplantation after a myeloablative conditioning regimen were included in the study. All patients received conditioning regimens based on busulfan, thiotepa and antithymocyte globulin. Chimerism status was assessed analyzing short tandem repeat polymorphisms.

Results

The cumulative incidence of myeloid engraftment at 1 month was significantly lower in patients with mixed chimerism than in those with complete donor chimerism (55% vs. 94%; p<0.0001). For patients achieving myeloid recovery, the median time of engraftment was 16 days when donor chimerism at day + 14 was higher than 90%, compared with 24 days when donor chimerism was below this level (p<0.001). A donor chimerism level of 65% was found to be the best cut-off point for predicting primary graft failure, with a sensitivity of 97% and a specificity of 80%. The incidence of primary graft failure was 67% for patients with less than 65% donor chimerism at day +14 as compared to only 2% for those with more than 65% donor chimerism (p<0.001). Patients with mixed chimerism also had a lower cumulative incidence of platelet engraftment than those with complete chimerism (62% vs. 89%; p=0.01).

Conclusions

Donor-recipient chimerism status at day +14 predicts engraftment after a single-unit cord blood transplant in adults.     

Milestones in umbilical cord blood transplantation

Much has been learned about umbilical cord blood (UCB) since the first human cord blood transplant was performed back in 1988. Cord blood banks have been established worldwide for the collection, cryopreservation and distribution of UCB for allogeneic haematopoietic stem cell transplantation. UCB has now become one of the most commonly used sources of haematopoietic stem cells for allogeneic transplantation. Today, a global network of cord blood banks and transplant centres has been established with a large common inventory, allowing for more than 20000 transplants worldwide in children and adults with severe haematological diseases. Several studies have been published on UCB transplant, assessing risk factors such as cell dose and human leucocyte antigen mismatch. New strategies are ongoing to facilitate engraftment and reduce transplant-related mortality and include the use of reduced-intensity conditioning regimen, intra-bone injection of cord blood cells, double cord blood transplants or ex vivo expansion of cord blood cells. The absence of ethical concern and the unlimited supply of cells explain the increasing interest of using UCB for developing regenerative medicine.     

Outcomes after related and unrelated umbilical cord blood transplantation for hereditary bone marrow failure syndromes other than Fanconi anemia

Background

Allogeneic stem cell transplantation is the only curative option for patients with hereditary bone marrow failure syndromes. Umbilical cord blood is an alternative source of stem cells for allogeneic transplantation.

Design and Methods

This multicenter, retrospective study is based on data reported to the Eurocord Registry about patients with hereditary bone marrow failure syndrome who underwent umbilical cord blood transplantation.

Results

Sixty-four patients with hereditary bone marrow failure syndromes were transplanted from related (n=20) or unrelated donors (n=44). Diagnoses were Diamond-Blackfan anemia (21 patients), congenital amegakaryocytic thrombocytopenia (16 patients), dyskeratosis congenita (8 patients), Shwachman-Diamond syndrome (2 patients), severe congenital neutropenia (16 patients) and unclassified (1 patient). In the group of patients who received grafts from related donors, all patients but one received an HLA-matched sibling transplant. The median number of total nucleated cells infused was 5×10⁷/kg. The cumulative incidence of neutrophil recovery at 60 days was 95%. Two patients had grade II–IV acute graft-versus-host disease, while the 2-year cumulative incidence of chronic graft-versus-host disease was 11%. The 3-year overall survival rate was 95%. In the group of patients who received grafts from unrelated donors, 86% had HLA-mismatched grafts and three received two umbilical cord blood units. The median number of total nucleated cells infused was 6.1×10⁷/kg. The cumulative incidence of neutrophil recovery at day 60 in this group was 55%. The 100-day cumulative incidence of grade II–IV acute graft-versus-host disease was 24%, while the 2-year cumulative incidence of chronic graft-versus-host disease was 53%. The 3-year overall survival rate was 61%; better overall survival was associated with age less than 5 years (P=0.01) and 6.1×10⁷/kg or more total nucleated cells infused (P=0.05).

Conclusions

In patients with hereditary bone marrow failure syndromes, related umbilical cord blood transplantation is associated with excellent outcomes while increasing cell dose and better HLA matching might provide better results in unrelated umbilical cord blood transplantation.     

Risk factors affecting outcome of unrelated cord blood transplantation for children with familial haemophagocytic lymphohistiocytosis

Allogeneic haematopoietic stem cell transplantation is still the only available curative option for Familial Haemophagocytic Lymphohistiocytosis (FHLH). Most studies report outcomes after bone marrow or peripheral blood stem cell transplantation. We analysed the outcomes of 118 children with FHLH undergoing single-unit umbilical cord blood transplantation performed from 1996 to 2014. Myeloablative conditioning regimen was given to 90% of the patients, and was mostly busulfan-based (n = 81, 76%), including anti-thymocyte globulin or alemtuzumab (n = 102, 86%). The cumulative incidence of Day 60 neutrophil engraftment was 85%; and that of non-relapse mortality and acute graft-versus-host disease (GvHD) was 21% and 33% at 100 days, respectively. The 6-year cumulative incidence of chronic GvHD was 17% and the 6-year probability of overall survival was 55%. In multivariate analysis, children receiving a graft with a total nucleated cell dose greater than 9·9 × 10⁷/kg had a better overall survival (hazard ratio [HR]: 0·49, 95% CI: 0·27–0·88, P = 0·02). Degree of human leucocyte antigen (HLA) matching was associated with improved disease-free survival (5/6 vs. 6/6 HR: 2·11, 95% confidence interval [CI]: 1·01–4·4, P = 0·05 and ≤4/6 vs. 6/6, HR: 2·82, CI: 1·27–6·23, P = 0·01). Umbilical cord blood transplantation with a high cell dose and good HLA match is a suitable alternative option to haematopoietic stem cell transplantation in children with FHLH who lack a HLA-matched donor.     

Pre-engraftment syndrome after unrelated donor umbilical cord blood transplantation in patients with hematologic malignancies

Pre-engraftment syndrome (PES) after umbilical cord blood transplantation (CBT) remains poorly characterized, and the prognosis and appropriate management are unclear. Therefore, we retrospectively analyzed the incidence, risk factors, manifestations, and clinical outcomes of PES in CBT recipients, who had been treated for hematologic malignancies at our transplantation center. PES was defined as unexplained fever higher than 38.3°C that is not associated with documented infection and unresponsive to antimicrobial manipulations and/or unexplained erythematous skin rash occurring prior to neutrophil engraftment. A total of 81 patients (median 18 yr, range 3-48) received either myeloablative (n=72) or non-myeloablative (n=9) conditioning. Neutrophil engraftment was achieved in 69 of the 81 cases [86.2%, 95% confidence interval (CI)=78.9-94.1%], and the median time to more than 0.5 × 10(9) /L ANC was 19 d (range, 12-39). Fifty-one patients (63.0%) developed PES at a median of 7d (range 3-15) post-transplant: 46 patients had both rash and unexplained fever; one patient had unexplained fever alone; and four patients had rash only. Forty-seven patients (92.2%) received IV methylprednisolone (MP) at a median dose of 1 mg/kg (range 0.4-3). All patients treated with MP responded as evidenced by fever resolution combined with resolution of rash. All patients with PES had high serum levels of C-reactive protein (CRP), which were significantly reduced after effective steroid treatment. Univariate analysis identified myeloablative conditioning and younger age as significant risk factors for developing PES. Cumulative incidence of grade II-IV acute graft-versus-host disease (aGVHD) in the PES+ and PES- groups was 51.5% (95% CI=38.0-70.0%) and 17.0% (95% CI=6.9-41.7%), respectively. In a multivariate analysis, we found significantly increased risk of grade II-IV aGVHD among PES patients (P=0.041). However, PES was not associated with sustained donor engraftment, the day to neutrophil recovery, chronic graft-versus-host disease, transplant-related mortality at day 180, and overall survival. Despite of the inherent limitations of this small retrospective study, PES seemed to be common after CBT and associated with high incidence of aGVHD.     

Current status of umbilical cord blood transplantation in children

The first umbilical cord blood (UCB) transplantation was performed 30 years ago. UCB transplantation (UCBT) is now widely used in children with malignant and non-malignant disorders who lack a matched family donor. UCBT affords a lower incidence of graft-versus-host disease compared to alternative stem cell sources, but also presents a slower immune recovery and a high risk of infections if serotherapy is not omitted or targeted within the conditioning regimen. The selection of UCB units with high cell content and good human leucocyte antigen match is essential to improve the outcome. Techniques, such as double UCBT, ex vivo stem cell expansion and intra-bone injection of UCB, have improved cord blood engraftment, but clinical benefit remains to be demonstrated. Cell therapies derived from UCB are under evaluation as potential novel strategies to reduce relapse and viral infections following transplantation. In recent years, improvements within haploidentical transplantation have reduced the overall use of UCBT as an alternative stem cell source; however, each may have its relative merits and disadvantages and tailored use of these alternative stem cell sources may be the optimal approach.     

A prospective multicenter phase II study of intrabone marrow transplantation of unwashed cord blood using reduced‐intensity conditioning

Cord blood transplantation (CBT) is associated with delayed hematopoietic recovery and graft failure. To overcome these problems, we conducted a prospective, multicenter phase II study of intrabone marrow transplantation in which patients received reduced‐intensity conditioning without anti‐thymocyte globulin (ATG). The primary endpoint was the probability of full donor engraftment. Forty patients with hematologic malignancies were enrolled. Cord blood (CB) cells were injected without washing into 4 iliac bone sites (2 at each hemipelvis), at which approximately 6 mL of CB was administered at one site with local anesthesia. Full donor engraftment rate was 86.8%. The cumulative incidence of neutrophil and platelet engraftment was 86.4% and 85.5%, respectively. The median time to neutrophil (>0.5 × 10⁹/L) and platelet (2.0 × 10⁹/L) recovery was 17.5 and 44 days, respectively. The probability of severe acute graft‐vs‐host disease (GVHD) was 47.5%. The cumulative incidence of extensive chronic GVHD was 3.0%. The probability of relapse and non‐relapse mortality was 30.4% and 28.0%, respectively. The survival rate at 3 years was 45.6%, although most patients were at an advanced stage. These results suggest that our intrabone marrow‐CBT procedure without using ATG improves hematopoietic recovery and decreases the incidence of chronic GVHD, but does not decrease the incidence of acute GVHD.     

非血缘脐血移植失败行二次单倍型造血干细胞移植成功治疗骨髓增生异常综合征1例并文献复习

目的：探讨非血缘脐血移植治疗骨髓增生异常综合征失败后立即行半相合型造血干细胞二次移植作为解救方法的可能性和安全性。方法：1例骨髓增生异常综合征难治性血细胞减少伴多系增生异常（MDS-RCMD）3年余患者,进行非血缘HLA不全相合双份脐血造血干细胞移植,移植后＋30dSTRPCR检测移植物未植入,立即予患者进行半相合造血干细胞干细胞移植以挽救患者生命。供者为患者母亲,采用“骨髓加外周血联合造血干细胞移植”,预处理方案采用“抗胸腺细胞球蛋白＋福达拉滨”。结果：二次移植物成功植入,形成完全供者来源的造血与免疫功能,二次移植后12dANC〉0．5&#215;10^5／L,＋15dPLT〉20&#215;10^9／L,无急慢性GVHD等并发症的发生,随访19月余,患者获得长期无病生存。结论：非血缘脐血移植失败后,50d内行半相合型造血干细胞移植治疗骨髓增生异常综合征是安全、有效的挽救治疗措施。     

Improving the outcome of cord blood transplantation: use of mobilized HSC and other cells from third party donors

We developed the strategy of umbilical cord blood transplants (UCBT) with co-infusion of a limited number of highly purified mobilized haematopoietic stem cells (MHSC) from a human leucocyte antigen (HLA) unrestricted third party donor (TPD). Short post-transplant periods of neutropenia were usually observed in adults with haematological neoplasms receiving UCBT with a relatively low cell content and 0–3 HLA mismatches after myeloablative conditioning. This resulted from an early and initially predominant engraftment of the TPD–MHSC. After a variable period of double complete TPD + UCB chimerism, final full UCB chimerism was achieved (cumulative incidence >90%) within 100 d. Early recovery of the circulating neutrophils resulting from the 'bridge transplant' of the TPD–MHSC reduced the incidence of serious neutropenia-related infections, also facilitating the use of drugs with myelosuppressive side effects to combat other infections. The observed incidence of graft- versus -host disease and relapses was low, with overall and disease-free survival curves comparable to those of HLA identical sibling transplants. Post-transplant recovery of natural killer cells occurred soon after the transplant and B cells recovered around 6 months, but T-cell recovery took more than 1 year. Available data show that T cell recovery derives from UCB–HSC through thymic differentiation and that cytomegalovirus (CMV)-specific lymphocytes develop following CMV reactivations.     

Switching of donor cells after urgent second cord blood transplantation for suspected graft failure

Cord blood transplantation (CBT) is being increasingly performed in adults and is now becoming a standard therapeutic alternative to bone marrow transplantation; however, graft failure is one of the associated problems of CBT in adults. A 44-year-old woman with acute myelogenous leukemia in partial remission received an unrelated CBT. Suspected veno-occlusive disease developed, however, and hemopoietic recovery was delayed. A bone marrow examination on the 27th day revealed empty marrow with a relative increase in macrophages, and the serum ferritin concentration was extremely high. Impending failure of the graft due to a hemophagocytic syndrome-like condition was strongly suspected, although donor cells were dominant according to a fluorescence in situ hybridization analysis. A second CBT was performed on the 30th day after a preparatory regimen of methylprednisolone and low-dose fludarabine (total dose, 90 mg/m2). Unexpectedly, the the first donor's cells recovered on the fourth day after the second CBT; however, the cells to finally engraft were those of the second donor. This case is informative as an example of rescue management for suspected graft failure.     

Expanding the role of umbilical cord blood transplantation

Umbilical cord blood has become a valuable alternative source of haematopoietic stem cells for allogeneic transplantation. However, largely because of the impact of cell dose on engraftment, risk of transplant-related mortality and survival, progress in the field has been largely restricted to children. Nevertheless, substantial clinical experience with umbilical cord blood transplantation clearly establishes its safety and effectiveness in young patients with a variety of malignant and non-malignant diseases. Although less well established in adults, new strategies are now being explored to address the obstacle of cell dose. This article reviews the state of the art and future directions with umbilical cord blood as a source of haematopoietic stem cells for transplantation in both children and adults.     

Novel adopted immunotherapy for mixed chimerism after unrelated cord blood transplantation in Omenn syndrome

Omenn syndrome is a variant form of severe combined immunodeficiency. It is fatal unless treated by allogeneic stem cell transplantation (SCT), which is the only curative approach. However, both treatment-related complications and graft rejection are major obstacles to treatment success. This report describes a case with Omenn syndrome who developed mixed chimerism after unrelated cord blood transplantation (UCBT). This case was successfully treated by altering the patient's immunosuppression and donor lymphocyte infusion (DLI) with donor cord blood-derived activated CD4+ T cells ex vivo expanded from the cord blood cell residues in an infused bag. This novel development to expand CD4+ T-lymphocytes from the donor cord blood unit for the use of DLI would serve as a useful method to overcome the risk of graft rejection in SCT for primary immunodeficiency disorders with residual cell-mediated immunity without compounding graft-vs.-host disease, especially in the UCBT setting.     

Cord blood transplantation for adults

Allogeneic haematopoietic stem cell transplant has become an import tool for the treatment of high risk and advanced haematological diseases. However, allogeneic transplantation has been limited by the availability of suitable related and unrelated donors. The positive results with umbilical cord blood as an alternative source of haematopoietic stem cells for transplantation in the paediatric setting encouraged studies in adult patients. In adults, however, the progress of cord blood transplantation has been slower, in part limited by the limitation of cell dose. We review here the current state of the art on cord blood transplantation for adults, and discuss some of the newer strategies being pursued in order to improve its safety and efficacy.     

异基因脐血干细胞移植治疗失代偿期肝硬化的疗效观察

目的观察异基因脐血干细胞移植治疗失代偿期肝硬化患者的临床疗效。方法失代偿期肝硬化患者50例,其中乙型、丙型肝炎肝硬化36例,酒精性肝硬化12例,胆汁性肝硬化2例;Child-Pugh分级：A级2例,B级32例,C级16例。所有患者治疗前均行肝功能及影像学等检查,排除肝癌,严格筛查产妇,无菌采取脐血并分离出干细胞,通过导管经肝固有动脉将干细胞混悬液植入肝脏,分别在术后2、4、12、24w复查肝功能,观察实验室指标、影像学改变、临床症状及不良反应等情况。结果干细胞移植后患者症状改善明显,Alb2周时短暂下降,由均值28.4g/L降至26.3g/L（P〉0.05）,24周Alb升至37.3g/L（P〈0.01）,ALT由56.9U/L降至46.3U/L（P〈0.05）,AST由75.3U/L降至50.0U/L（P〈0.05）,TBil由45.3μmol/L降至31.2μmol/L（P〈0.05）,PTA由41%升至70%（P〈0.01）;腹水患者36例腹水消失,5例腹水明显减少,1例腹水变化不明显;24周复查CT,肝脏最大截面积均值由132cm2增至178cm2（P〈0.01）,肝脏平扫CT值由52.6降至49.3（P〉0.05）,肝裂缩小。50例患者均未发生不良反应。结论异基因脐血干细胞移植治疗失代偿期肝硬化安全可行,可明显改善肝硬化患者的临床症状、肝功能、凝血功能和肝脏大小。     

脐血移植治疗恶性血液病的临床研究

目的 :研究脐血移植 (CBT)在恶性血液病长期造血重建和移植物抗宿主病 (GVHD)及其他移植相关并发症发生情况。方法 :用CBT治疗恶性血液病 11例。供者均为患儿同胞 ,并于产前HLA配型 ,其中 9例完全相合 ,2例 4个位点相合。预处理选用Bu/Cy方案。仅用环孢素A(CsA)预防GVHD。脐血平均采集量 14 1(76～ 2 0 8)ml,输入有核细胞 (NCs)中位数 3.5 (1.5～ 10 .0 )× 10 7/kg。 结果 :9例造血重建 ,ANC >0 .5× 10 9/L的中位时间为 17(13～ 4 2 )d ,>1.0× 10 9/L中位时间为 2 1(16～ 5 0 )d ,PLT >2 0× 10 9/L中位时间为 2 6 (2 1～ 4 8)d ,>5 0× 10 9/L的中位时间为 4 5 (31～ 80 )d。DNA微卫星位点检测 ,2 8～ 90d呈现完全嵌合。其中 3例发生Ⅰ～Ⅱ度急性GVHD ,1例Ⅲ～Ⅳ度急性GVHD ,3例发生慢性局限性GVHD ,2例未植活。结论 :①同胞HLA相合脐血移植安全、有效。②CBT造血恢复时间与输入有核细胞数有关 ,最好NCs≥ 3.5× 10 7/kg。③Bu/Cy方案副作用小 ,是儿童造血干细胞移植安全有效的预处理方案。④HLA相合者仅用CsA即可预防GVHD。     

Infectious complications following unrelated cord blood transplantation

INTRODUCTION: Infections following cord blood transplantation are just beginning to be defined in the literature. This review will outline infections at death, the epidemiology of individual infections, and the impact of stem cell source. METHODS: A review of studies published since 2000. RESULTS: Based on registry data, most studies demonstrate an approximate rate of infection at death of 30-40% among cord blood recipients. Bacterial infections often occur prior to engraftment and increase among patients with graft failure. In addition, there is delayed recovery of the immune response among patients with graft-versus-host disease that leads to viral infections at later time points. The risk of serious infection among children receiving umbilical cord blood (UCB) grafts is comparable to that of children receiving unmanipulated marrow and is lower than that of recipients of a T-cell-depleted stem cell source. Among adult patients, despite an overall higher incidence of serious infections after UCB transplantation as compared with unrelated donor grafts, non-relapse mortality and overall survival were not significantly different between haematopoietic stem cell sources. CONCLUSIONS: Further studies are needed to confirm these observations and determine whether the risk of infection for cord blood recipients is comparable to that of recipients of unmanipulated marrow.     

High incidence of engraftment syndrome after haploidentical allogeneic stem cell transplantation

We determined the incidence, clinical manifestations, and outcomes of engraftment syndrome (ES) in haploidentical stem cell transplantation (SCT) recipients. We compared the incidence of ES between the patient group that received haploidentical SCT (n = 516) and the patient group that received HLA‐identical sibling SCT (n = 393). The transplantations were performed in the Peking University People's Hospital in the period between October 2001 and October 2012. The ES incidence data were collected retrospectively. Patients that presented non‐infectious fever or skin rash within the 24‐h window before or after the beginning of neutrophil recovery were diagnosed with ES in accordance with the Maiolino criteria. ES incidence in haploidentical SCT recipients (21.9%) was significantly higher than that in HLA‐identical sibling SCT recipients (2.0%; P < 0.001). Major symptoms included fever (119/121, 98.3%), skin rash (98/121, 81.0%), and diarrhea (51/121, 42.1%), with the median time of +10 d (range: 6–20 d). The median C‐reactive protein level of the ES group (99.0 mg/L; n = 13) was significantly higher than that of the non‐ES group (13.9 mg/L; n = 38; P < 0.001). Similarly, the results showed that the median C3 plasma concentration of the ES group (1.30 g/L) was higher than that of the non‐ES group (1.16 g/L, P = 0.003). ES was not associated with non‐relapse mortality or overall survival. High incidence of ES was observed in haploidentical SCT recipients; however, ES did not predict poor clinical outcomes.     

Unrelated umbilical cord blood transplantation for adults with haematological malignancies: results from a single Australian centre

Background: A number of haematological malignancies can be cured by allogeneic stem cell transplantation but only approximately 30% of Australians have a suitable histocompatible related donor. Matched donors can be found on international registries of unrelated volunteers for a proportion of the remaining patients. For those patients in need of an allogeneic transplant, but for whom a suitable matched related or unrelated adult donor cannot be found, the use of banked unrelated umbilical cord blood has emerged as a potential option. However, there is uncertainty about the applicability of this technique for the majority of adult patients as a result of limitations in the number of cells in banked cord blood units and the degree of mismatching for histocompatibility antigens. Aims: The aim of this study was to define the feasibility of allogeneic stem cell transplantation using single unrelated cord blood units in a cohort of adults with poor prognosis leukaemia or lymphoma. Methods: Nine patients with haematological malignancies (five with acute myeloid leukaemia, one with acute lymphoblastic leukaemia, one with Hodgkin lymphoma and two with non‐Hodgkin lymphomas) received transplants of cryopreserved cord blood after conditioning therapy with high‐dose cyclophosphamide, total body irradiation and antithymocyte globulin. Cord units contained a median 2.6 × 10⁷ nucleated cells/kg recipient bodyweight and were matched for four (seven cases) or five (two cases) major histocompatibility complex class 1 and 2 antigens. Patients were given post‐transplant immunosuppression with cycosporin and methylprednisolone. Results: Neutrophil recovery to 0.5 × 10⁹/L was seen by median day 30 after transplant in all seven patients who survived more than 1 month post‐transplant. Platelet recovery to 50 × 10⁹/L occurred by median day 81 in five evaluable patients. Acute graft versus host disease (GVHD) grades II–IV was seen in four of seven evaluable patients and limited chronic GVHD was seen in four of five. Infection was the most common complication. Four patients died before day 100 of infection (methicillin‐resistant Staphylococcus aureus septicaemia, respiratory syncitial virus pneumonia), GVHD and multi‐organ failure, and intracranial bleeding. Five patients survived 7–69 months post‐transplant, without evidence of relapse of the underlying malignancy. Conclusion: Unrelated cord blood transplantation is feasible in adults with high‐risk malignancy, with infection relating to immunocompromise being the major limitation.