Second early allogeneic stem cell transplantations for graft failure in acute leukaemia, chronic myeloid leukaemia and aplastic anaemia. French Society of Bone Marrow Transplantation

Graft failure in allogeneic hematopoietic stem cell recipients: diagnosis and treatment

Graft failure is a group of complications after allogeneic hematopoietic stem cell transplantation, which occurs according to different data up to 30%. The group of complications includes primary and secondary graft failure, primary, secondary and transient poor graft function and graft rejection. Diagnostic difficulties consist in the lack of unified diagnostic criteria accepted in the transplantation community and in the dual interpretation of these complications according to the foreign literature. The purpose of this literature review was to identify the most common criteria of different types of graft failure and determine the tactics of diagnosis and treatment. In this review we analyzed data from various literature sources, gave definitions of graft failure and poor graft function. We analyzed the literature data on the methods used to treat these conditions.

Infectious complications after second allogeneic hematopoietic cell transplant in adult patients with hematological malignancies

We conducted a retrospective review of the infectious complications and outcomes over a 2-year follow-up period of adult patients who received a second allogeneic hematopoietic cell transplant (2nd allo-HCT) during a five-year period at two cancer centers in Michigan. Sixty patients, of whom 44 (73%) had acute leukemia or myelodysplastic syndrome, were studied. The majority (n = 37,62%) received a 2nd allo-HCT because of relapsed leukemia. Infection episodes after the 2nd allo-HCT totaled 112. Bacteria were identified in 76 episodes, the majority of which occurred pre-engraftment. The most common infecting organisms were Enterococcus species and Clostridioides difficile. Viral infections, predominantly cytomegalovirus, accounted for 59 infection episodes and occurred mostly in pre-engraftment and early post-engraftment periods. There were 16 proven/probable fungal infections, of which 9 were invasive aspergillosis or candidiasis. Mortality was 45% (n = 27) at one year and 65% (n = 39) at 2 years after transplant, and 16 deaths (41%) were due to infection. Of those 16 infection deaths, 8 were bacterial, 4 fungal, 2 both bacterial and fungal, and 2 viral. Failure to engraft neutrophils or platelets was significantly associated with decreased survival, p < 0.0001 and p < 0.001, respectively. Infections are common after a 2nd allo-HCT and are associated with a high mortality rate.

Comparable Outcomes and Health-Related Quality of Life for Severe Aplastic Anemia: Haploidentical Combined With a Single Cord Blood Unit vs Matched Related Transplants

We retrospectively compared the outcomes and health-related quality of life (HRQoL) of severe aplastic anemia (SAA) patients who received haploidentical hematopoietic stem cell transplantation with a single unrelated cord blood unit (Haplo-cord HSCT) (n = 180) or matched related donor (MRD)-HSCT (n = 128). After propensity score matching, we were able to match 88 patients in each group and to compare the outcomes between the two matched-pair groups. Haplo-cord recipients exhibited a longer median days for neutrophil engraftment (12 vs 11, P = 0.001) and for platelet engraftment (15 vs 13, P = 0.003). Haplo-cord recipients a high cumulative incidence of grades II–IV acute graft-versus-host disease (GVHD) (29.8 vs 14.0%, P = 0.006), while similar III–IV acute GVHD, total chronic GVHD, and moderate to severe chronic GVHD at four-year (all P < 0.05). Among the Haplo-cord HSCT and MRD-HSCT groups, the four-year GVHD-free/failure-free survival rates were 73.5% and 66.9% (P = 0.388) respectively, and the overall survival rates were 81.5% and 77.2% (P = 0.484), respectively. Similar comparable results also were observed between the corresponding first-line, older or younger than 40 years old subgroups. The Haplo-cord HSCT group exhibited higher scores in the physical component summary, physical functioning, general health and social functioning than the MRD-HSCT group (all P < 0.05). In the multivariate analysis, young age and Haplo-cord HSCT were favorable factors for HRQoL, while moderate to severe cGVHD was associated with lower HRQoL. These results suggest that for SAA patients, Haplo-cord HSCT could achieve at least comparable efficacy and HRQoL to MRD-HSCT.

Graft failure after "ex-vivo" T-cell depleted haploidentical transplantation in pediatric patients with high-risk hematological malignancies. A risk factors and outcomes analysis

Risk factors and outcomes of GF after TCD haploidentical transplantation in children with hematological malignancies were analyzed. 148 TCD transplants were included. 78 patients were diagnosed of ALL and 70 patients of AML. 22 out of 148 patients developed GF. MVA showed that patient <9 years (HR: 5.0; 95% CI: 1.1-23.0; p = 0.03) and pre-transplant CD8+ ≥150/µL (HR: 12.0; 95% CI: 1.6-95.3; p = 0.01) were associated with GF. A score was assigned to each patient. The cumulative incidence of GF for patients with CD8+ ≥150/µL (2 points) was 6 ± 4% and 3 ± 2% for patients <9 years (1 point) while for patients with 3 points was 24 ± 6%, With a median follow-up of 48 months (range; 4-180 months), 14 (64%) of 22 patients with GF are alive and disease-free. DFS for GF patients was 53 ± 12%. In conclusion, patient age and pre-transplant CD3+/CD8+ are associated with GF in children undergoing TCD haploidentical transplantation.

Graft Failure in Patients With Hematological Malignancies: A Successful Salvage With a Second Transplantation From a Different Haploidentical Donor

Graft failure (GF) is a fatal complication of allogeneic stem cell transplantation, especially after haploidentical transplantation. The mortality of GF is nearly 100% without an effective salvage method. A second transplantation is usually necessary to save the patient's life. However, there is no standardized regimen, and the outcome is usually disappointing. We report on a prospective single-center study using a reduced-intensity conditioning regimen with different haploidentical donors (HIDs). Patients with GF after the first transplantation were enrolled in a prospective single-arm clinical trial (ClinicalTrials.Gov ID: NCT03717545) at the Peking University Institute of Hematology. The conditioning regimen consisted of fludarabine (30 mg/m²) (days-6 to-2) and cyclophosphamide (1,000 mg/m²/day) (days-5 to-4). Patients underwent a second transplant from a different HID using a granulocyte colony-stimulating factor primed bone marrow and peripheral blood stem cells. The primary outcome was neutrophil engraftment at day 28. The secondary outcomes included platelet engraftment at day 100, transplant-related mortality (TRM) at day 30, TRM at day 100, and overall survival (OS) at 1 year. From March 2018 to June 2020, 13 patients were enrolled in this clinical trial. Of the 13 patients, five had acute myeloid leukemia, five had acute lymphoblastic leukemia, two had myelodysplastic syndromes, and one had a non-Hodgkin lymphoma. The median age at first transplantation was 38 years (range, 8-55 years). As for the first transplantation, 11 patients underwent haploidentical transplantations and two underwent unrelated donor transplantations. At the time of GF, three patients had complete donor chimerism, five had mixed chimerism, and five had complete recipient chimerism. The median time from the first transplantation to the second transplantation was 49 (range 35-120) days. The medians of infused cell doses were as follows: mononuclear cells 7.93 (5.95-12.51) × 10⁸/kg and CD34 + cells 2.28 (0.75-5.57) × 10⁶/kg. All 13 patients achieved neutrophil engraftment after the second transplantation, with a median engraftment time of 11 (range 10-20) days after transplantation. The platelet engraftment rate on day 100 after transplantation was 76.9%. The TRMs at day 30, day 100, and 1-year were 0, 0, and 23.1%, respectively. The OS and disease-free survival at 1-year were 56.6 and 48.4%, respectively. For patients with GF after first transplantation, a second transplantation using a fludarabine/cyclophosphamide regimen from a different HID was a promising salvage option. Further investigation is needed to confirm the suitability of this method.

Eltrombopag for the treatment of poor graft function following allogeneic stem cell transplant: a retrospective multicenter study

This retrospective study assessed the effectiveness of eltrombopag (EPAG), a thrombopoietin receptor agonist, in the treatment of poor graft function (PGF) following an allogeneic haemopoietic stem cell transplantation (HSCT). Complete response was defined as normalization of blood counts, whereas partial response was defined as transfusion independence. A total of 48 patients with full donor chimerism after HSCT, received EPAG for a median of 120 days (range 10-591). Patients with uni- bi- or tri-lineage cytopenia started treatment at a median of 95 days (range 17-877) after HSCT. The overall response rate was 75%: 24 patients had a complete response and 12 had a partial response. Positive predictors of response were an HLA-matched donor, a CD34⁺ dose at transplant > 4 × 10⁶/kg, and starting EPAG treatment at least 90 days after HSCT. Patients with more than one positive predictor had a response rate of 92% for the overall patient cohort and 94% for patients with tri-lineage cytopenia. One-year survival was 89% for complete responders, 60% for partial responders and 20% for non-responders (p = 0.0004). EPAG improves peripheral blood counts in patients with poor graft function following HSCT. Response to EPAG can be predicted and has a significant impact on survival.

Prognostic factors for neutrophil engraftment after haploidentical cell transplantation with PT-Cy in patients with acute myeloid leukemia in complete remission, on behalf of the ALWP-EBMT

The use of haplo-HCT with posttransplant cyclophosphamide (PT-Cy) is a new standard in the treatment of hematological diseases. A paucity of data exists on risk factors for engraftment failure in haplo-HCT with PT-Cy. We analyzed 1939 adults with acute myeloid leukemia (AML) who received a first haplo-HCT from 2010 to 2019. Status at haplo-HCT was first complete remission (CR1) in 72.5% of patients, secondary AML was reported in 9.9%. Median follow-up was 24.4 months and median age at haplo-HCT was 51 years. Stem cell source was bone marrow (BM) in 42% and peripheral blood stem cell (PBSC) in 58%, and 64% of patients received a myeloablative conditioning (MAC) regimen. Cumulative incidence of primary graft failure (GF) was 6%; GF was reported in 110 patients and 54 died before day +30 with no sign of cell recovery. Overall, 33 patients underwent a second HCT in a median time of 45 days and 13 were alive at last follow-up, the 2-year overall survival (OS) after second HCT being 32.4%. In multivariate analysis, factors independently associated with the risk of nonengraftment were: secondary AML (HR 1.30, p = 0.003), use of RIC (HR 1.22, p < 0.001), and use of BM (HR 1.21, p < 0.001). At 2 years, leukemia-free survival (LFS) and OS for the entire population was 55.2% (95% CI: 52.6-57.6) and 60.9% (95% CI: 58.4-63.3), respectively. Incidence of GF after haplo-HCT with PT-Cy is lower than reported T-cell-depleted haplo-HCT. Optimization of conditioning regimen and graft source should be considered for reducing the risk of GF in haplo-HCT recipients using PT-Cy.

Advances in the understanding of poor graft function following allogeneic hematopoietic stem-cell transplantation

Poor graft function (PGF) following allogeneic hematopoietic stem-cell transplantation (allo-HSCT) is a life-threatening complication and is characterized by bilineage or trilineage blood cell deficiency and hypoplastic marrow with full chimerism. With the rapid development of allo-HSCT, especially haploidentical-HSCT, PGF has become a growing concern. The most common risk factors illustrated by recent studies include low dose of infused CD34+ cells, donor-specific antibody, cytomegalovirus infection, graft versus host disease (GVHD), iron overload and splenomegaly, among others. Because of the poor prognosis of PGF, it is crucial to uncover the underlying mechanism, which remains elusive. Recent studies have suggested that the bone marrow microenvironment may play an important role in the pathogenesis of PGF. Deficiency and dysfunction of endothelial cells and mesenchymal stem cells, elevated reactive oxygen species (ROS) levels, and immune abnormalities are believed to contribute to PGF. In this review, we also discuss recent clinical trials that evaluate the safety and efficacy of new strategies in patients with PGF. CD34+-selected stem-cell boost (SCB) is effective with an acceptable incidence of GVHD, despite the need for a second donation. Alternative strategies including the applications of mesenchymal stem cells, N-acetyl-l-cysteine (NAC), and eltrombopag have shown favorable outcomes, but further large-scale studies are needed due to the small sample sizes of the recent clinical trials.

[Effects of CD34(+) selected stem cells for the treatment of poor graft function after allogeneic stem cell transplantation]

目的

观察输注纯化供者CD34⁺细胞治疗单倍型造血干细胞移植后移植物功能不良的疗效和安全性。

方法

对2014年1月至2018年3月期间接受供者纯化CD34⁺细胞治疗的12例单倍型造血干细胞移植后移植物功能不良患者进行回顾性分析。

结果

12例患者中男9例、女3例，中位年龄26（14~54）岁；急性淋巴细胞白血病4例，急性髓系白血病5例，慢性髓性白血病2例，慢性粒-单核细胞白血病1例。分选产物CD34⁺细胞纯度为92.0%（44.0%~97.0%），回收率为55.0%（45.0%~96.7%），回输CD34⁺细胞的中位数为1.9（0.9~4.4）×10⁶/kg，CD3⁺细胞中位数为0.6（0.3~2.0）×10⁴/kg。中性粒细胞恢复中位时间为18（14~39）d，血小板恢复中位时间为29（16~153）d，红细胞恢复中位时间为60（9~124）d。12例患者输注过程中未发生严重不良反应，10例获得完全缓解，1例患者获得部分缓解，1例患者无效，未发生重症感染和重度GVHD。

结论

回输供者纯化CD34⁺细胞是单倍型造血干细胞移植后植入功能不良的一种安全、有效治疗方法。

Feasibility of salvage cord blood transplantation using a fludarabine, melphalan, and low-dose anti-thymocyte globulin conditioning regimen

Primary graft failure (PGF) is a lethal complication that occurs early after allogeneic stem cell transplantation (allo-SCT). Cord blood transplantation (CBT) is a potential re-transplantation option. Total body irradiation (TBI) is often incorporated into the pre-salvage CBT conditioning regimen following PGF; however, patients experiencing PGF are not always amenable to TBI, and non-TBI regimens for salvage CBT should be established. Here, we report five patients with hematologic malignancies who received salvage CBT for PGF following a non-TBI regimen using fludarabine (Flu), melphalan (Mel), and low-dose anti-thymocyte globulin (ATG). The median intervals between the failed allo-SCT and salvage CBT, as well as between the diagnosis of PGF and salvage CBT, were 37 days and 8 days, respectively. The median neutrophil recovery period was 21 days (range 18-21 days). Four of five patients achieved neutrophil engraftment following salvage CBT; all four exhibited sustained engraftment with complete donor chimerism. Three of the five patients were alive after a median follow-up time of 907 days (range 315-909 days) post-salvage CBT; two patients died of causes unrelated to recurrence. These data suggest that CBT following the non-TBI regimen described here is feasible in patients with PGF.

Rescue haploidentical peripheral blood stem cell transplantation for engraftment failure: a single-centre case series

Graft failure affects approximately 5% of allogeneic stem cell transplants, with a poor prognosis. Salvage second allogeneic stem cell transplantation (alloSCT2) is limited by high rates of transplant-related mortality from infection and graft-versus-host disease. We report on five adult patients receiving rescue alloSCT2 using haploidentical peripheral blood stem cells. All patients achieved neutrophil engraftment, two subsequently died from sepsis and disease relapse, respectively. Three patients remain alive up to 2 years post-transplant. We suggest consideration of haploidentical alloSCT2 for patients with graft failure.

Immunosuppressive Total Nodal Irradiation-Based Reconditioning Regimens After Graft Rejection or Graft Failure in Pediatric Patients Treated With Myeloablative Allogeneic Hematopoietic Cell Transplantation

PURPOSE

This retrospective analysis aimed to address the efficacy of total nodal irradiation (TNI)-based reconditioning regimens in pediatric patients with graft failure/rejection after allogeneic hematopoietic cell transplantation.

METHODS AND MATERIALS

Thirty-three pediatric patients with malignant (n = 25) and nonmalignant diseases (n = 8) were treated with a TNI-based reconditioning regimen. All patients received a 7-Gy single dose combined with anti-T lymphocyte antibody OKT3 (n = 16), anti-thymocyte globulin (n = 24), fludarabine (n = 31), and/or thiotepa (n = 28), followed by an infusion of peripheral blood stem cells (n = 31) or bone marrow transplant (n = 2). Twenty-eight of 33 patients had haploidentical family donors.

RESULTS

After a median of 11 days, engraftment was seen in 32 of 33 children. Two children died 34 days after retransplantation because of either disease relapse or treatment-related multiple organ failure. Severe acute toxicity was reported in only 1 child (systemic inflammatory response syndrome-like reaction; recovery after cortisone treatment). The average follow-up was 60.2 months (range, 1.1-162.5 months). Event-free and overall survival rates at 2/5 years follow-up were 62.0%/58.6% and 65.1%/61.7%, respectively. Despite sustained engraftment, 12 patients died from disease relapse (n = 3), Moschkowitz syndrome (n = 1), or multiple organ failure (n = 8). Follow-up data were available for 18 of 21 survivors, with a median follow-up of 92.8 months (range, 3.6-162.5 months). Hypothyroidism was present in 78.6% of patients, and sex/growth hormonal insufficiencies were reported for 37.5%. Mean forced expiratory volume in 1 second after TNI was 84%; mean vital capacity was 79%. Severe growth failure (<3rd percentile) occurred in 28.6% (height) and 35.7% (weight) of patients. No secondary malignancies were reported.

CONCLUSIONS

In the high-risk group of patients with graft failure/rejection after allogeneic hematopoietic cell transplantation, the TNI-based reconditioning regimen seems to allow sustained engraftment combined with a favorable toxicity profile, leading to long-term event-free and overall survival. Late toxicity after a median follow-up of over 7.5 years includes growth failure, manageable hormonal deficiencies, and a low risk of decrease of lung function.

Outcomes after Second Hematopoietic Cell Transplantation in Children and Young Adults with Relapsed Acute Leukemia

Children with acute leukemia who relapse after hematopoietic cell transplantation (HCT) have few therapeutic options. We studied 251 children and young adults with acute myelogenous or lymphoblastic leukemia who underwent a second HCT for relapse after their first HCT. The median age at second HCT was 11 years, and the median interval between first and second HCT was 17 months. Most of the patients (n = 187; 75%) were in remission, received a myeloablative conditioning regimen (n = 157; 63%), and underwent unrelated donor HCT (n = 230; 92%). The 2-year probability of leukemia-free survival (LFS) was 33% after transplantation in patients in remission, compared with 19% after transplantation in patients not in remission (P = .02). The corresponding 8-year probabilities were 24% and 10% (P = .003). A higher rate of relapse contributed to the difference in LFS. The 2-year probability of relapse after transplantation was 42% in patients in remission and 56% in those in relapse (P = .05). The corresponding 8-year probabilities were 49% and 64% (P = .04). These data extend the findings of others showing that patients with a low disease burden are more likely to benefit from a second transplantation. Late relapse led to a 10% decrement in LFS beyond the second year after second HCT. This differs from first HCT, in which most relapses occur within 2 years after HCT.

Successful treatment of secondary poor graft function post allogeneic hematopoietic stem cell transplantation with eltrombopag

Poor graft function (PGF) is a life-threatening complication after allogeneic hematopoietic stem cell transplantation (allo-HSCT). Current treatment strategies include the use of growth factors, CD34⁺-selected stem cell boost, mesenchymal stem cell transfusion, and second allo-HSCT, but these treatments are not effective in all patients. Eltrombopag, an oral thrombopoietin receptor agonist, which showed promising results in severe aplasia anemia, may be an alternative choice for PGF patients. Therefore, we treated 12 patients who responded poorly to standard treatments for secondary PGF after allo-HSCT with eltrombopag. The median duration was 116 (35–1000) days from transplantation to PGF diagnosis and 59 (30–180) days from PGF diagnosis to eltrombopag treatment. Eltrombopag was started at a dose of 25 mg/d for 3 days and then increased to 50 or 75 mg/d. Median treatment duration was 8 (2–23) weeks. Ten patients (83.3%) responded to the treatment: 8 achieved complete response (CR), and the remaining 2 achieved partial response. In the 10 responding subjects, median platelet count was 18 (5–27) × 10⁹/L vs 74 (30–117) × 10⁹/L prior to and after treatment. Neutrophil count was 0.51 (0.28–0.69) × 10⁹/L vs 1.84 (0.78–4.90) × 10⁹/L. Hemoglobin was 88 (63–123) vs 101 (78–134) g/L. In the 8 patients who achieved CR, the time from eltrombopag initiation to achieving CR was 29 (10–49) days; the response lasted until the last follow-up in all 8 CR subjects (10–18 months). The 12-month overall survival rate was 83.3%. There was no treatment-related mortality and no evidence of cataract, thrombosis, or any other grade 3/4 toxicities.

The administration of polymerized human hemoglobin (pyridoxylated) to a jehovah's witness after submyeloablative stem cell transplantation complicated by delayed graft failure

A 55-yr-old woman with a history of B-cell lymphoma of the nasopharynx diagnosed in March 1999 eventually underwent submyeloablative allogeneic stem cell transplantation from a sibling donor in December 2002 after conventional treatment options were exhausted. The treatment approach was somewhat altered by the fact that the patient was a practicing Jehovah's Witness and refused blood-blood product transfusion. The course of her treatment was unremarkable until around day 100 posttransplant when she developed graft failure, leading to severe anemia. Blood transfusions were refused. Donor cells were re-infused. During this treatment period, the patient's hemoglobin dropped to a low of 2.7 g/dL, with the patient experiencing severe fatigue, dyspnea on exertion, headaches, and blurred vision. Polymerized human hemoglobin (pyridoxylated) (Poly- Heme, Northfield Laboratories Inc., Evanston, IL) was given under an emergency, compassionate use protocol and successfully bridged the patient's hemoglobin and relieved symptoms during her marrow recovery period.

T cell replete-haploidentical second hematopoietic stem cell transplantation for primary graft failure in pediatric patients with hematologic malignancies

GF is one of the fatal complications of allogeneic HSCT. To rescue patients with primary GF, a second HSCT should be conducted as soon as possible, but the optimal donor source and technique have yet to be established. In this study, we retrospectively analyzed six children with hematologic malignancies who received TCR-haploidentical second HSCT for primary GF. The median interval between the prior HSCT and the second HSCT was 37.5 days. All patients received fludarabine and ATG containing reduced-intensity re-conditioning before the second HSCT. All patients, except one who died early, achieved both neutrophil and Plt engraftment at a median time of 15 and 33 days, respectively. Chimerism analysis showed that all engrafted patients achieved complete donor chimerism within 3 weeks. Four patients developed acute GVHD, and three patients developed chronic GVHD. TRM occurred in two patients. Median follow-up of the four survivors was 6.8 years, and all remained in sustained remission until the last follow-up. These results suggested that a TCR-haploidentical second HSCT for pediatric patients is feasible, and this approach may provide a potent option for children with primary GF.

Optimizing peripheral blood stem cells transplantation outcome through amend relapse and graft failure: a review of current literature

Allogeneic hematopoietic stem cell transplantation (allo-HSCT) has been considered as a valuable approach in treatment of numerous malignant and none malignant hematologic disorders. However, relapse and poor graft function (PGF) after allo-SCT remain to be controversial issues which may affect the transplantation outcome. Relevant articles were searched in MEDLINE database (2000–2016) using keywords and phrases: donor lymphocyte infusions, allogeneic stem cells transplantation, relapsed hematologic malignancies, booster schedules, cell dose, laboratory monitoring protocols and technical aspects of apheresis. Relapse of disease and PGF could be reduced via noting some main points such as choosing the suitable time and patient for donor lymphocyte infusion (DLI) and also determination of patients who ought to candidate for second allogeneic HSCT or for the use of stem cell boost. DLI and stem cell booster are promising treatment strategies noted in this review. Finally, this paper discusses indications and technical aspects of DLI and stem cell booster in hematological malignancies and emphasizes their therapeutic or pre-emptive potentials.

Major Histocompatibility Mismatch and Donor Choice for Second Allogeneic Bone Marrow Transplantation

Large alternative donor pools provide the potential for selecting a different donor for a second allogeneic (allo) bone or marrow transplant (BMT). As HLA disparity may contribute to the graft-versus-tumor effect, utilizing new mismatched haplotype donors may potentially improve the antitumor activity for relapsed hematologic malignancies despite a previous alloBMT. Data from patients who received a second alloBMT for relapsed hematologic malignancies at Johns Hopkins were analyzed. Outcomes were compared between patients who received a second allograft with the same MHC composition and those who received an allograft with a new mismatched haplotype. Loss of heterozygosity analysis was performed for patients with acute myeloid leukemia (AML) whose first allograft was haploidentical. Between 2005 and 2015, 40 patients received a second BMT for a relapsed hematologic malignancy. The median follow-up is 750 (range, 26 to 2950) days. The median overall survival (OS) in the cohort is 928 days (95% confidence interval [CI], 602 to not reached [NR]); median event-free survival (EFS) for the cohort is 500 days (95% CI, 355 to NR). The 4-year OS is 40% (95% CI, 25% to 64%), and the 4-year EFS is 36% (95% CI, 24% to 55%). The cumulative incidence of nonrelapsed mortality by 2 years was 27% (95% CI, 13% to 42%). The cumulative incidence of grade 3 to 4 acute graft-versus-host disease (GVHD) at 100 days was 15% (95% CI, 4% to 26%); the cumulative incidence of extensive chronic GVHD at 2 years was 22% (95% CI, 9% to 36%). The median survival was 552 days (95% CI, 376 to 2950+) in the group who underwent transplantation with a second allograft that did not harbor a new mismatched haplotype, while it was not reached in the group whose allograft contained a new mismatched haplotype (hazard ratio [HR], .36; 95% CI, .14 to .9; P = .02). EFS was also longer in the group who received an allograft containing a new mismatched haplotype, (NR versus 401 days; HR, .50; 95% CI, .22 to 1.14; P = .09). Although the allograft for this patient's second BMT contained a new mismatched haplotype, AML nevertheless relapsed a second time. Second BMTs are feasible and provide a reasonable chance of long-term survival. An allograft with a new mismatched haplotype may improve outcomes after second BMTs for relapsed hematologic malignancies.

Uric acid as a novel biomarker for bone-marrow function and incipient hematopoietic reconstitution after aplasia in patients with hematologic malignancies

PURPOSE

Prolonged aplasia and graft failure (GF) represent life-threatening complications after hematopoietic cell transplantation (HCT) requiring suitable biomarkers for early detection and differentiation between GF and poor graft function (PGF). Uric acid (UA) is a strong immunological danger signal.

METHODS

Laboratory results were analyzed from patients undergoing either allogeneic or autologous HCT or induction chemotherapy for acute leukemia (n = 50 per group, n = 150 total).

RESULTS

During therapy, UA levels declined from normal values to hypouricemic values (all p < 0.001). Alongside hematopoietic recovery, UA serum levels returned to baseline values. During aplasia, UA levels remained low and started steadily increasing (defined as >two consecutive days, median one 2-day increase) at a median of 1 day before rising leukocytes in allogeneic HCT (p = 0.01) and together with leukocytes in autologous HCT (median one 2-day increase). During induction chemotherapy, a UA increase was also observed alongside rising leukocytes/neutrophils but also several times during aplasia (median 3 increases). Most HCT patients had no detectable leukocytes during aplasia, while some leukocytes remained detectable after induction therapy. No increase in UA levels was observed without concomitant or subsequent rise of leukocytes.

CONCLUSIONS

Changes in UA serum levels can indicate incipient or remaining immunological activity after HCT or induction therapy. They may, therefore, help to differentiate between PGF and GF.

Fresh or Cryopreserved CD34+-Selected Mobilized Peripheral Blood Stem and Progenitor Cells for the Treatment of Poor Graft Function after Allogeneic Hematopoietic Cell Transplantation

CD34⁺-selected stem cell boost (SCB) without conditioning has recently been utilized for poor graft function (PGF) after allogeneic hematopoietic stem cell transplantation with promising results. Unfortunately, many patients have been unable to receive the boost infusion as their donors were unwilling or unable to undergo an additional stem cell collection. Therefore, we conducted this study utilizing either fresh or cryopreserved peripheral blood stem cell products to create CD34⁺-selected boost infusions for the treatment of PGF. Additionally, to explore relationship of CD34⁺ dose and response, we included a cohort of donors mobilized with plerixafor in addition to the standard granulocyte colony-stimulating factor (G-CSF). Twenty-six patients with PGF were included in this study. Seventeen donor-recipient pairs were enrolled onto the prospective study; an additional 9 patients treated off protocol were reviewed retrospectively. Three different donor products were used for CD34⁺ selection: (1) fresh mobilized product using G-CSF only, (2) fresh mobilized products using G-CSF and plerixafor, and (3) cryopreserved cells mobilized with G-CSF. CD34⁺ cell selection was performed using a CliniMACS. The infusion was not preceded by administration of any chemotherapy or conditioning regimen. The primary objective was hematologic response rate and secondary objectives included CD34⁺ yields, incidence and severity of acute and chronic graft-versus-host disease (GVHD), overall survival (OS), and relapse-free survival (RFS). The median post-selection CD34⁺ counts per kilogram of recipient weight were 3.1 × 10⁶, 10.9 × 10⁶, and 1 × 10⁶ for G-CSF only, G-CSF plus plerixafor, and cryopreserved products, respectively. The median CD34⁺ yields (defined as the number of CD34⁺ cells after selection/CD34⁺ cells before CD34⁺ selection) were 69%, 66%, and 28% for G-CSF only, G-CSF plus plerixafor, and cryopreserved products, respectively. After SCB, 16 of the 26 recipients (62%) had a complete response, including 5 of 8 (63%) who received cryopreserved products. Five had a partial response (19%), resulting in an overall response rate of 81%. One-year RFS and OS were 50% and 65%, respectively. There was no treatment-related toxicity reported other than GVHD: 6 (23%) developed acute GVHD (2 grade I and 4 grade II) and 8 (31%) developed chronic GVHD (2 limited and 6 extensive). Cryopreserved products are viable alternatives to create SCB for the treatment of PGF. When collecting fresh products is an option, the addition of plerixafor increases CD34⁺ yield over G-CSF alone; however, it is currently unclear if the CD34⁺ cell dose impacts the efficacy of the SCB.

Treatment of graft failure with TNI-based reconditioning and haploidentical stem cells in paediatric patients

Graft failure is a life‐threatening complication after allogeneic haematopoietic stem cell transplantation (HSCT). We report a cohort of 19 consecutive patients (median age: 8·5 years) with acute leukaemias (n = 14) and non‐malignant diseases (n = 5) who experienced graft failure after previous HSCT from matched (n = 3) or haploidentical donors (n = 16) between 2003 and 2012. After total nodal irradiation (TNI)‐based reconditioning combined with fludarabine, thiotepa and anti‐T cell serotherapy, all patients received T cell‐depleted peripheral blood stem cell grafts from a second, haploidentical donor. Median time between graft failure and retransplantation was 14 d (range 7–40). Sustained engraftment (median: 10 d, range 9–32) and complete donor chimerism was observed in all evaluable patients. 5 patients additionally received donor lymphocyte infusions. Graft‐versus‐host disease (GvHD) grade II and III occurred in 1 patient each (22%); no GvHD grade IV was observed. 2 patients had transient chronic GvHD. The regimen was well tolerated with transient interstitial pneumonitis in one patient. Treatment‐related mortality after one year was 11%. Event‐free survival and overall survival 3 years after retransplantation were 63% and 68%. Thus, a TNI‐based reconditioning regimen followed by transplantation of haploidentical stem cells is an option to rescue patients with graft failure within a short time span and with low toxicity.

Poor graft function can be durably and safely improved by CD34+-selected stem cell boosts after allogeneic unrelated matched or mismatched hematopoietic cell transplantation

PURPOSE

Insufficient production of leukocytes, thrombocytes and erythrocytes after allogeneic peripheral blood stem cell transplantation (PBSCT) represents a life-threatening complication.

METHODS

In 20 adult patients with poor graft function (PGF defined as transfusion-dependent platelet counts <20,000/µl, or leukocytes <1500/µl, or transfusion-dependent anemia) and variable causes of PGF after allogeneic PBSCT, immunomagnetically selected CD34(+) stem cell boosts (SCB) from matched unrelated (n = 8), mismatched unrelated (n = 11) or haploidentical (n = 1) donors were applied without prior conditioning.

RESULTS

Patients received a median of 4.6 × 10(6) CD34(+) cells per kilogram bodyweight (1.9-9.1 × 10(6)) and low T cell numbers (median 0.2 × 10(4), range 0.04-0.6 × 10(4)). All patients showed responses in at least one hematopoietic lineage. Engraftment for platelets, leukocytes and hemoglobin was 88, 88 and 100 % after a median of 14, 13 and 18 days, respectively. With regard to the complete cohort, 90 % (n = 18) showed an increase in platelets (median 76,500/µl, range -7000 to 223,000/µl), 95 % (n = 19) had an increase in leukocytes (median 3110/µl, range 150-13,740/µl) and 90 % (n = 18) improved with regard to hemoglobin (median 1.9 g/dl, range -0.9 to 5.1 g/dl). Due to effective T cell depletion, only one patient developed graft versus host disease (GvHD, grade III) after SCB. Patients were followed for a median of 7.5 months (1-74 months) with 11 patients being alive and disease free with normalized peripheral blood counts at the end of follow-up.

CONCLUSIONS

CD34(+)-selected SCB are safe and effective and can durably improve PGF even in patients receiving grafts from unrelated matched or mismatched donors with low incidence of GvHD.

Second allogeneic transplantation for relapse of malignant disease: retrospective analysis of outcome and predictive factors by the EBMT

In patients treated with allogeneic stem cell transplantation (SCT) for malignant disease who suffer from a relapse after the transplantation, the role of second allogeneic SCT is often uncertain. In a retrospective analysis, 2632 second allogeneic transplantations carried out for a relapse after the first transplantation were analyzed to define indications and identify predictive factors. Fifteen percent of the patients remained relapse-free until 5 years after the second SCT. Patients with CML had a better survival than patients with other diseases. In a multivariate analysis, factors associated with better survival were low disease burden, longer remission duration after the first transplantation, longer interval between the transplantations, younger age, absence of grade II-IV acute GvHD or chronic GvHD after the first transplantation, and later year of transplantation. The European Society for Blood and Marrow Transplantation risk score predicted the outcome. Using the same donor as in the first transplantation vs another donor had no predictive value for survival. Sibling donor was a favorable predictive factor. In conclusion, second allogeneic SCT offers a reasonable option especially for young patients with a long remission after the first transplantation and a low disease burden. The present findings do not support the usefulness of changing the donor for the second transplantation.

Outcomes and management strategies for graft failure after umbilical cord blood transplantation

Graft failure is a life-threatening complication after allogeneic hematopoietic stem cell transplantation (HSCT). Graft failure is more prevalent after umbilical cord blood transplantation (UCBT) compared with conventional adult stem cell sources. We identified 21 consecutive patients who experienced graft failure after UCBT at our center between 2004 and 2013 and describe their treatment strategies and outcomes. Two patients experienced early death. Seven patients had return of autologous hematopoiesis including 1 patient who was given previously collected autologous stem cells. Twelve patients received a second early HSCT, six from separate UCB units and six from a haploidentical donor. With a median follow-up of 33.2 months for surviving patients, 3-year PFS is 23% and 3-year OS is 37%. Of the six long-term survivors without relapse, four received a second HSCT from a haploidentical donor with post-HSCT high-dose cyclophosphamide based GVHD prophylaxis. This strategy appears safe and merits further investigation in this setting.

Engraftment kinetics and graft failure after single umbilical cord blood transplantation using a myeloablative conditioning regimen

Umbilical cord blood transplant recipients are exposed to an increased risk of graft failure, a complication leading to a higher rate of transplant-related mortality. The decision and timing to offer a second transplant after graft failure is challenging. With the aim of addressing this issue, we analyzed engraftment kinetics and outcomes of 1268 patients (73% children) with acute leukemia (64% acute lymphoblastic leukemia, 36% acute myeloid leukemia) in remission who underwent single-unit umbilical cord blood transplantation after a myeloablative conditioning regimen. The median follow-up was 31 months. The overall survival rate at 3 years was 47%; the 100-day cumulative incidence of transplant-related mortality was 16%. Longer time to engraftment was associated with increased transplant-related mortality and shorter overall survival. The cumulative incidence of neutrophil engraftment at day 60 was 86%, while the median time to achieve engraftment was 24 days. Probability density analysis showed that the likelihood of engraftment after umbilical cord blood transplantation increased after day 10, peaked on day 21 and slowly decreased to 21% by day 31. Beyond day 31, the probability of engraftment dropped rapidly, and the residual probability of engrafting after day 42 was 5%. Graft failure was reported in 166 patients, and 66 of them received a second graft (allogeneic, n=45). Rescue actions, such as the search for another graft, should be considered starting after day 21. A diagnosis of graft failure can be established in patients who have not achieved neutrophil recovery by day 42. Moreover, subsequent transplants should not be postponed after day 42.

Complications of allogeneic hematopoietic stem cell transplantation

Infection, graft-versus-host disease (GVHD), and to a lesser extent sinusoidal obstructive syndrome (SOS) represent the major causes of morbidity and mortality in patients undergoing allogeneic hematopoietic stem cell transplantation (AHSCT). During the last decade, progress in prevention and treatment of these complications led to improvement in the outcome of these patients. Despite the fact that nonmyeloablative regimens have been increasingly used in elderly patients and in patients with co-morbidities, the nonrelapse related mortality remains a challenge and long-term follow-up is required. The objective of this manuscript is to provide an updated concise review of the complications of AHSCT and of the available treatment interventions.

Dynamics of Graft Function Measured by DNA-Technology in a Patient with Severe Aplastic Anemia and Repeated Stem Cell Transplantation

Although bone marrow transplantation (BMT) from an HLA identical sibling is considered as treatment of choice in pediatric patients with severe aplastic anemia (SAA), a significant number of them experience graft failure (GF) after BMT. We report a case of an 8-year-old male patient with SAA who presented with a complicated posttransplant course due to parvovirus B19 infection and GF. A subsequent attempt to support the graft by antithymocyte globulin (ATG) and a peripheral stem cell boost resulted in transitory autologous recovery of hematopoiesis followed by mixed chimerism, supported by donor lymphocyte infusions (DLIs) and finally graft rejection with relapse of SAA. Permanent complete chimerism was achieved by a second BMT. Dynamics of graft function, measured by a single nucleotide polymorphism (SNPs) analysis, are discussed.

Early peripheral blood and T-cell chimerism dynamics after umbilical cord blood transplantation supported with haploidentical cells

Single-unit umbilical cord blood (CB) SCT is limited by low total nucleated cell (TNC) dose. Co-infusion of CD34+ cells from a third party HLA-mismatched donor, known as dual or haplo-cord transplant, reduces the period of post-transplant neutropenia and related complications. The aim of this study was to analyze the value of early post-transplant peripheral blood (PB) and T cell chimerism after 28 dual transplants regarding CB engraftment. Cumulative incidence of myeloid engraftment at 30 days was 93% with a median time to engraftment of 14 days (10-29). Patients who developed CB graft failure (n=5) showed very low percentages of CB cells on days +14, +21 and +28 with decreasing dynamics. On the other hand, percentages of CB cells in patients who achieved CB engraftment increased over time. Interestingly, such patients showed two distinct chimerism dynamics in PB, but all of them showed a predominance of CB T cells early after SCT with increasing dynamics over time. Early post-transplant chimerism dynamics in PB and T cells predicts CB graft failure enabling rapid therapeutic measures to be applied. On the other hand, early increasing percentages of CB T cells correlates with ultimate CB engraftment.

Successful rescue of early graft failure in pediatric patients using T-cell-depleted haploidentical hematopoietic SCT

Graft failure (GF) is a significant complication after allogeneic hematopoietic stem cell transplantation (HCT) and is associated with a high mortality rate. We performed re-transplantation using haploidentical-related donors to rescue children with early GF. Between 2008 and 2013, 10 patients received re-transplantation from haploidentical family donors. The median age at HCT was 13.5 years and the median time between transplantations was 52.5 days. Conditioning regimen with fludarabine and CY was used in seven patients, and TBI was added in three patients. All 10 patients received T-cell-depleted grafts using CD3 or CD3/CD19 MoAb. The median numbers of CD34(+) and CD3(+) cells were 5.52 × 10(6)/kg and 1.08 × 10(6)/kg, respectively. For GVHD prophylaxis, mycophenolate mofetil (MMF) and tacrolimus or MMF and CYA were used. All 10 patients achieved a sustained neutrophil engraftment and maintained a complete donor chimerism at the time of analysis (median 23 months, range 6-62 months). Nine of 10 patients were alive, and one patient with moyamoya disease with AML died of encephalopathy 7 months post transplant. This study suggests that fludarabine- and CY-based conditioning with T-cell-depleted haploidentical HCT is a feasible option to rescue pediatric patients with primary GF.

Costs of second allogeneic hematopoietic cell transplantation

BACKGROUND

A second allogeneic transplantation after a prior allogeneic (allo-allo) or autologous (auto-allo) hematopoietic cell transplantation (HCT) is usually performed for graft failure, disease recurrence, secondary malignancy, and, as planned, auto-allo transplantation for some diseases.

METHODS

We sought to describe the costs of second allogeneic HCT and evaluate their relationship with patient characteristics and posttransplantation complications. Clinical information and medical costs for the first 100 days after transplantation of 245 patients (allo-allo, 55; auto-allo, 190) who underwent a second HCT between 2004 and 2010 were collected.

RESULTS

Median costs of the second allogeneic HCT were U.S. $151,000 (range, U.S. $62,000-405,000) for the allo-allo group and U.S. $109,000 (range, U.S. $26,000-490,000) for the auto-allo group. Median length of hospital stay was 23 days (range, 0-76) for the allo-allo group and 9 days (range, 0-96) for the auto-allo group. Only the year of transplantation and posttransplantation complications were significantly associated with costs in both groups when both pre- and posttransplantation variables were considered. The overall costs of the second HCT were higher than the first in the allo-allo group. For the auto-allo group, there was no difference between the costs whether preformed as a planned tandem or as salvage for relapse.

CONCLUSIONS

Our results suggest that second allogeneic HCT is costly, particularly if it follows a prior allogeneic transplantation, and is driven by the costs of complications.

Matched and mismatched unrelated donor transplantation: is the outcome the same as for matched sibling donor transplantation?

The outcome of allogeneic stem cell transplantation has improved over the past decades due to a significant reduction of nonrelapse mortality, whereas our ability to control underlying malignant diseases has remained unchanged. Reduction of nonrelapse mortality has been achieved in matched sibling donor transplantation, but perhaps more so with unrelated donor transplantation, in part due to the advances in HLA matching between donor and recipient, but also as a result of improved supportive care, better GVHD prophylaxis, and tailored conditioning regimens. Therefore, over the past decade, results of matched sibling donor and unrelated donor grafts have grown more similar, and the difference in 1-year survival for patients with leukemia has gone from 21% in 1988 in favor of MSD to 9% in 2008. However, due to the significant and combined effect of patient, transplantation, and donor variables, comparisons are made here in the context of defined subsets of patients and specific diseases and in some circumstances also looking at separate studies in children and adults.

Haploidentical allogeneic haematopoietic stem cell transplantation as salvage therapy for engraftment failure after unrelated and autologous stem cell transplantation: a case report and review of the literature

Engraftment failure is a rare but life-threatening complication of haematopoietic stem cell transplantation (HSCT) and treatment of this condition is often challenging. This case report describes a patient with acute myeloid leukaemia and engraftment failure after unrelated donor allogeneic stem cell transplantation. Rescue treatment with granulocyte-colony stimulating factor and reinfusion of autologous 'back-up' stem cells failed, but transplantation of haploidentical donor stem cells following a fludarabine and antithymocyte globulin (ATG)-based conditioning regimen resulted in haematological reconstitution and long-term disease-free survival. The use of haploidentical donor stem cell transplantation as salvage therapy after engraftment failure in adult patients has not, to the authors' knowledge, been previously reported. Additionally, a review of the relevant literature is presented. This case report and literature review suggest that reinfusion of cryopreserved 'back-up' haematopoietic stem cells is a safe and effective salvage therapy for engraftment failure after allogeneic HSCT. Haploidentical donor stem cell transplantation after a fludarabine and ATG-based conditioning regimen could provide effective second-line therapy in adult patients.

Outcome of second allogenic stem cell transplantation in pediatric patients with non-malignant hematological and immune deficiency disorders

BACKGROUND

Second stem cell transplantation (SCT) is usually associated with high morbidity and mortality and the data on its outcome in pediatric patients with non-malignant disorders are scarce.

PATIENTS AND METHODS

We present 30 children with non-malignant conditions who underwent second SCT at our institution for graft failure after the first SCT; 20 had a non-malignant hematological disorder and 10 had an immune deficiency disorder. Median age at the second SCT was 6.1 years (range, 0.4-13 years) and median time from the first SCT to the second SCT was 6.2 months (range, 1.2-96 months).

RESULTS

Twenty patients (70%) engrafted; severe acute GVHD developed in four patients (13%), and chronic GVHD developed in two patients of those at risk (10%). Thirteen deaths occurred and nine were considered treatment related. The 5-year overall (OS) and event free survival (EFS) for all patients were 53% and 47% respectively. The interval between the two transplants seemed to affect the outcome; patients who had the second SCT ≥ 6 months from the first SCT had better survival; the 5-year OS for the two groups (<6 months and ≥ 6 months) respectively were 30% and 74% (P = 0.004), and the 5-year EFS were 27% and 66% (P = 0.004). The underlying disease did not affect the outcome nor did the use of radiation in the conditioning regimen for the second SCT.

CONCLUSIONS

Second SCT for graft failure should be considered for children with non-malignant hematological and immune deficiency disorders.

Graft failure in cord blood transplantation successfully treated with short-term reduced-intensity conditioning regimen and second allogeneic transplantation

Graft failure (GF) remains a major problem in cord blood transplantation (CBT). In 36 adult patients undergoing CBT at our hospital between July 2003 and December 2009, six patients developed GF (primary, n = 5; secondary, n = 1). All six patients underwent second stem cell transplantation (SCT). Three patients had acute myeloid leukemia, one had acute lymphoblastic leukemia, one had chronic myeloid leukemia, and one had aplastic anemia. Five patients were complicated with sepsis before the second SCT. The median elapsed time from first CBT to the diagnosis of primary GF was 27 days. Secondary GF was diagnosed on day 567. The median elapsed time from primary GF to second SCT was 9 days. In the patient with secondary GF, the elapsed time was 35 days. Cord blood grafts were used in 5 patients and a matched sibling donor in one patient. All 6 patients underwent second transplantation following a modified '1-day'-based preparative regimen consisting of fludarabine (30 mg/m(2), 1 day, n = 2; 2 days, n = 1; 3 days, n = 3), cyclophosphamide (2 g/m(2)), and total body irradiation (2 Gy). All patients achieved neutrophil engraftment, and the median elapsed time from second SCT to engraftment was 35 days. Four patients remain alive between 5 and 38 months after second SCT. '1-day'-based short-term conditioning may be a promising salvage regimen.

Feasibility of reduced-intensity cord blood transplantation as salvage therapy for graft failure: results of a nationwide survey of adult patients

To evaluate whether rescue with cord blood transplantation (CBT) could improve the poor survival after graft failure (GF), we surveyed the data of 80 adult patients (median age, 51 years) who received CBT within 3 months of GF (primary 64, secondary 16), with fludarabine-based reduced-intensity regimens with or without melphalan, busulfan, cyclophosphamide, and/or 2-4 Gy total-body irradiation (TBI). A median number of 2.4 × 10(7)/kg total nucleated cells (TNC) were infused, and among the 61 evaluable patients who survived for more than 28 days, 45 (74%) engrafted. The median follow-up of surviving patients was 325 days, and the 1-year overall survival rate was 33% despite poor performance status (2-4, 60%), carryover organ toxicities (grade 3/4, 14%), and infections (82%) prior to CBT. Day 100 transplantation-related mortality was 45%, with 60% related to infectious complications. Multivariate analysis showed that the infusion of TNC ≥2.5 × 10(7)/kg and an alkylating agent-containing regimen were associated with a higher probability of engraftment, and that high risk-status at the preceding transplantation and grade 3/4 organ toxicities before CBT were associated with an increased risk of mortality. In conclusion, in an older population of patients, our data support the feasibility of CBT with a reduced-intensity conditioning regimen for GF.

Haploidentical stem cell transplantation as a salvage therapy for cord blood engraftment failure in a patient with Fanconi anemia

A 7-year-old male with Fanconi Anemia who developed primary graft failure following one antigen-mismatched unrelated cord blood transplantation and a nonradiation-based conditioning, underwent a second hematopoietic stem cell transplantation (HSCT) from his 2-loci mismatched haploidentical father, using a nonradiation-based regimen, 79 days after the first HSCT. A sustained hematological engraftment was achieved at 9 days post-second HSCT. At 15 months post-second HSCT; the patient demonstrated normal blood counts, sustained donor chimerism, and no evidence of GVHD. Haploidentical HSCTs as primary or secondary sources of stem cells, with appropriate T-cell depletion, may be a readily available option in the absence of HLA-matched related or unrelated donors.

Second unrelated donor hematopoietic cell transplantation for primary graft failure

Failure to engraft donor cells is a devastating complication after allogeneic hematopoietic cell transplantation (HCT). We describe the results of 122 patients reported to the National Marrow Donor Program between 1990 and 2005, who received a second unrelated donor HCT after failing to achieve an absolute neutrophil count of >or=500/microL without recurrent disease. Patients were transplanted for leukemia (n = 83), myelodysplastic disorders (n = 16), severe aplastic anemia (n = 20), and other diseases (n = 3). The median age was 29 years. Twenty-four patients received second grafts from a different unrelated donor. Among 98 patients who received a second graft from the same donor, 28 received products that were previously collected and cryopreserved for the first transplantation. One-year overall survival (OS) after second transplant was 11%, with 10 patients alive at last follow-up. We observed no differences between patients who received grafts from the same or different donors, or in those who received fresh or cryopreserved product. The outcomes after a second allogeneic HCT for primary graft failure are dismal. Identifying risk factors for primary graft failure can decrease the incidence of this complication. Further studies are needed to test whether early recognition and hastened procurement of alternative grafts can improve transplant outcomes for primary graft failure.

Successful second transplantation with non-myeloablative conditioning using haploidentical donors for young patients after graft failure following double umbilical cord cell transplantation

GF is a common and life-threatening complication of UCBT. Here, we report that successful second transplantation of five patients using G-CSF-mobilized maternal stem cells with non-myeloablative conditioning after GF following double UCBT. The median interval between the two transplants were 38 days. The first transplantation was administered after myeloablative conditioning for hematologic malignancies (n=3), and rabbit ATG in combination with cyclophosphamide for SAA (n=2). The second conditioning consisted of Flu and ATG-based non-myeloablative regimen. All five patients acquired quick and sustained engraftment after the second transplant. Treatment-related toxicity was minimal. Three patients developed acute GVHD (>grade II=1). Three patients developed chronic GVHD (limited=1, extensive=2). Severe infectious episodes were significant but manageable. With a median follow-up of 713 days (592-1127), all patients have currently had an event-free survival. These results indicate that a second transplant with non-myeloablative conditioning using mother as the donor for young patient after GF is feasible.