Use Of Bone Marrow Research Articles

Hematologic health services and practical characteristics: report of a nationwide survey among Chinese hematologists.

In the past 40 years, China has experienced tremendous economic development, but the current situation of hematologists has rarely been reported. A landscape survey of human resources is essential for healthcare development and policy formulation in the future. The Chinese Society of Hematology initiated a survey of Chinese hematologists in mainland China for evaluating demographic and practice characteristics. Respondents were anonymous, and there were no limitations regarding their age, sex, etc. RESULTS: Totally 2032 hematologists responded, with a median age bracket of 36-45 years. Respondents were well engaged into subspecialties, and 28.1% acquired doctorates of philosophy. Hematopoietic cell transplantation (HCT) centers have been established all over China. Higher-GDP regions reported more advantages, including bigger scale of transplant centers (P < 0.001), younger age structure (P = 0.039), better education qualifications (P = 0.001) and less turnover intentions (P = 0.004), despite of increased risk of medical disputes (P = 0.028). Although females accounted for 65.5% of hematologists, males were older (P < 0.001), and had more senior professional titles (P < 0.001), academic positions (P < 0.001), opportunities for continuing education (P < 0.001), and paper publishing in the recent two years (P = 0.001). For turnover intention, the higher GDP regions led to an independently reduced risk (HR = 0.673, 95%CI [0.482-0.940], P = 0.020), whereas medical disputes resulted in an increased the risk (HR = 2.037, 95%CI [1.513-2.743], P < 0.001). Considering the impact of the COVID-19 pandemic, majority of respondents believed that the decline in patient visits and delay in treatment was within 30%. 67.9% of respondents reported a decrease of the use of bone marrow as grafts but 18.8% reported an increase of cord blood units. 35.0% of the respondents switched their daily work to support the anti-epidemic medical activities. We concluded the discipline of hematology in China has flourished in recent years with a young workforce, while regional economic and gender disparities warrant further continuous optimization. Joint efforts against the impact of COVID-19 are needed in the post-pandemic era.

Haploidentical stem cell donor choice for patients with acute myeloid leukemia: a study from the ALWP of the EBMT

AbstractThere is a paucity of information to guide the selection of the most suitable donor in haploidentical (Haplo) hematopoietic stem cell transplantation (HSCT). For this reason, from the Acute Leukemia Working Party of the European Society for Blood and Marrow Transplantation, we conducted a retrospective analysis to evaluate the impact of Haplo donor characteristics on outcomes in patients with acute myeloid leukemia (AML) who received graft-versus-host disease prophylaxis with posttransplant cyclophosphamide (PTCy). The primary end point was graft-versus-host disease (GVHD)-free and relapse-free survival (GRFS). Overall, 2200 patients were included. The median age of donors was 37 years (range, 8-71); 820 (37%) were females, including 458 (21%) who were used for male recipients. In addition, 1631 donors (74%) donated peripheral blood (PB). Multivariable analysis identified certain donor-related risk factors with a detrimental impact on transplant outcomes. The use of PB, older donors’ ages (>37 years), and female donors to male recipients negatively affected GRFS. Donor’s age and female donor-to-male recipient combination also affected nonrelapse mortality, leukemia-free survival, and overall survival. In conclusion, donor-related variables significantly influence outcomes in patients with AML after Haplo-HSCT with PTCy. When possible, younger donors and male donors for male recipients should be prioritized. The use of bone marrow can additionally prevent GVHD.

The Comparison between BM and PBSC for the Patients with Pre-Transplant Pulmonary Dysfunction in HLA-Matched Allo-HCT: Subgroup Analysis Exploring the Impact Based on HCT Factors

Introduction Pre-transplant pulmonary dysfunction is known as an important risk factor for lung complications and subsequent non-relapse mortality (NRM) after allogeneic hematopoietic cell transplantation (allo-HCT). However, it remains unknown which cell source would be optimal for the patients with pre-transplant pulmonary dysfunction and whether the impact of cell source would differ according to recipient age, donor relation, and conditioning regimens. Therefore, we evaluated the impact of stem cell sources in patients with pre-transplant pulmonary dysfunction and in the subgroups. Patients and methods We performed a retrospective analysis of clinical data on 3374 allo-HCT in Japan between 2016 and 2020 using Japanese registry database. All patients had standard-risk disease and underwent their first allo-HCT from an HLA-matched donor. Their clinical outcomes were compared between peripheral blood stem cells (PBSCs) and bone marrow (BM) grafts individually in two distinct cohorts, namely the Lung-scored (LS) cohort and the normal cohort, based on the presence of lung scores determined by the Hematopoietic Cell Transplantation-specific Comorbidity Index. In addition, we conducted subgroup analyses to explore potential differences in the impact of cell sources on these outcomes according to the recipient age (≥50 or &amp;lt; 50), donor relation (related or unrelated), and conditioning regimens (cyclophosphamide [CY] / total body irradiation [TBI]-based myeloablative conditioning [MAC], busulfan [BU]-based MAC, or reduced-intensity conditioning [RIC]). Results In the LS cohort, the 2-year overall survival (OS) tended to be higher in the BM group than that in the PBSCs group (71.9% vs 61.4%; P = 0.052). However, in the normal cohort, there was no significant difference between both the cell source types (71.6% vs 73.1%; P = 0.13). Multivariate analyses showed that PBSCs were significantly associated with inferior OS in the LS cohort (hazard ratio [HR], 1.60 [95% CI, 1.06-2.42], P = 0.026). On the other hand, cell source type did not significantly affect OS in the normal cohort (HR, 0.94 [95% CI, 0.78-1.14], P = 0.55). We also found that PBSCs were significantly associated with an increased risk of NRM in the LS cohort (HR, 1.90 [95% CI, 1.03-3.52], P = 0.041), while cell source types did not affect NRM in the normal cohort (HR, 0.85 [95% CI, 0.64-1.13], P = 0.26). PBSCs were not identified as a risk factor for relapse in both cohorts. When we focused on the LS cohort alone, the Figure 1 summarized the impact of the use of PBSCs in the subgroups according to age, donor relation, and conditioning regimens. Briefly, the use of PBSCs exhibited a significant adverse impact on OS (HR, 3.07 [95% CI, 1.16-8.11], P = 0.024) in patients younger than 50 years old. For recipients aged 50 years or older, PBSCs were not associated with inferior OS (HR, 1.49 [95% CI, 0.91-2.42], P=0.11), although it tended to be associated with an increased risk of NRM with a borderline significance (HR, 1.94 [95% CI, 0.99-3.78], P = 0.053, Figure 1). Focusing on the subgroup stratified according to their donor relation, the use of PBSCs were not associated with inferior OS or an increased risk of NRM in both allo-HCT groups from a related donor or unrelated donor. Furthermore, focusing on the subgroups stratified according to conditioning regimens, the use of PBSCs had a significantly negative impact on OS in the subgroup with CY/TBI-based MAC (HR, 7.48 [95% CI, 2.87-19.51], P &amp;lt; 0.001). On the other hand, the use of PBSCs had no significant impact on OS or NRM in the subgroups of BU-based MAC or RIC. Regarding relapse incidences, the impacts of the use of PBSCs were not different in any of the individual subgroups. Conclusion The use of PBSCs were associated with inferior survival in the LS cohort, but not in the normal cohort. When we focused on the subgroups of the LS cohort alone, the use of PBSCs were associated with inferior survival in the subgroup of younger recipients or those with CY/TBI-based MAC. These patients in the LS cohort might benefit from the use of BM. These results should be validated in another registry study, and further research would be warranted for the purpose of preventing adverse impact of PBSCs or the optimal cell source selection.

Characterization of Bovine Bone Marrow Derived Mesenchymal Stem Cells and Immunostaining of Differentiated Neurospheres

Stem cell differentiation has been a key element for the therapeutical applications for various cases. The novel anti-inflammatory and angiogenic findings and potential applications for both autologous and allogenic studies have emphasized about the usage of mesenchymal stem cells in the clinical trials. The neurosphere differentiation studies and their role for peripheral nerve injuries have gained momentum. Following study emphasized on the isolation of stem cells from bovine bone marrow, their characterization by PCR and their differentiation into mesodermal lineages and into neurospheres under specific induction media. The generated neurospheres were durther investigated for their potential expressions of neuroprogenitor markers Sox2, Nestin and neurofilament protein β-III Tubulin by immunofluorescence staining. The results of following study highlight the use of bone marrow derived mesenchymal stem cells for translational research and regenerative therapy.

Use of bone marrow derived mesenchymal stem cells for the treatment of osteoarthritis: A retrospective long-term follow-up study

BackgroundAvailable studies suggest that bone marrow concentrate, highly enriched in mesenchymal stem cells, is a potentially encouraging treatment for knee osteoarthritis. The aim of this retrospective study was to evaluate the clinical outcome in patients affected by this condition after treatment with autologous bone marrow aspirate concentrate (BMAC). Methods55 patients who had undergone a single intra-articular injection of BMAC were administered two questionnaires to clinically evaluate their condition based on patient-reported outcome measures before treatment and at follow-up. ResultsAnalysis of the data collected indicates that patients experienced improvements in Tegner, VAS and WOMAC scores and that all outcomes at the follow-up improved in a statistically significant manner compared to outcomes at baseline. ConclusionsThe changes observed in the different scores examined suggest that a single BMAC injection seems to be a beneficial and safe treatment for knee osteoarthritis.

Outcomes of Allogeneic Hematopoietic Stem Cell Transplantation for Congenital Amegakaryocytic Thrombocytopenia, a PDWP/EBMT Study

Background: Congenital amegakaryocytic thrombocytopenia (CAMT) is a rare inherited bone marrow failure syndrome, which is characterized by a severe thrombocytopenia at birth without predictive stigmata and by a risk for progression into aplastic anemia and myeloid malignancy. CAMT is caused by a mutation of the thrombopoietin (THPO) receptor, c-Mpl. Allogeneic hematopoietic stem cell transplantation (HSCT) is currently the only potentially curative treatment option. The outcomes of transplanted patient for CAMT have not been well described. Design/Method We conducted an EBMT (European Society for Blood and Marrow Transplantation) registry-based retrospective study in patients diagnosed with CAMT receiving an allogeneic HSCT. Results 66 patients with CAMT could be included which were transplanted between 1998 and 2020. Median age at diagnosis was 1.3 years (0.1-2.8). The mutation was identified in 18 patients and absent in 7 patients. For the remaining patients, the genetic testing was not performed. The median age at transplant was 3.2 years (0.3-13). The median year of transplant is 2013. Bone marrow (BM) was the main stem cell source (59%) followed by peripheral blood (PB) (27%) and cord blood (CB (12%)) with 1 BM+CB from the same donor. The predominant donor type was HLA-matched (65% with matched-sibling donor (MSD) 34.8%, unrelated donor (UD) 10/10 22.7%, matched other relative 4.5% and umbilical cord blood (UCB) 6/6 3%)), followed by UD < 10/10 (15.1%), then the UCB< 6/6 (9%) then haploidentical (7.5%) and UD missing HLA (3%). The most frequently used conditioning regimen included busulphan and cyclophosphamide in 30% of cases, followed by the busulfan-fludarabine (14%) and treosulfan-fluradarabine-thiotepa (14%). Considering death and second transplant as competing event, platelet recovery (>= 20 000/mm3) occurred in 69.8% (95% confidence interval [CI] 56.6-79.7%) at day 60 and 71.4% (95% [CI] 58.2-81.1%) at day 180. Grade II-IV acute graft-versus-host disease (GvHD) was 20% (95% CI 11.3-30.5%), grade III-IV was 3.1% (95% CI 0.6-9.6%), and the 6-year cumulative incidence (CI) of chronic GvHD was 14.3% (95% CI 6.9-24.3%). The 6y-CI was 17.2% (95% [CI] 9.1-27.5%). Six-year overall survival (OS) was 85.6% (95% [CI] 74-92.3%) with a transplant related mortality of 8.0% (95% [CI] 2.9-16.6%). 6y-GVHD/-graft failure-free survival was 65.7% (95% [CI] 52.6-76%). OS was significantly lower after CB transplantation (6y OS: 37.5% with 95% [CI] 8.7-64.4%) than after BM (6y OS: 95% [CI] 81.5-98.7%) or PB (6y OS: 88.9% 95% [CI] 62.4-97.1%) transplantation (p<0.001). Conclusion: This study demonstrates that HSCT, the only available potentially curative option, has an acceptable 6-year overall survival and an acceptable rate of chronic GvHD. While the number of patients in such a rare disease does not allow to perform multivariable analyses, we can confirm that OS is better with the use of BM as the main stem cell source compared to the CB.

Handling of Allogeneic HPC Grafts in European Transplant Centers during the COVID-19 Pandemic - a Survey from the Infectious Diseases and Cellular Therapy & Immunobiology Working Parties of the EBMT

Background: For more than two years, the COVID-19 pandemic has had detrimental impact on medical practices. Because of its intrinsic complexity, the delivery of allogeneic hematopoietic cell transplantation (HCT) in this context represents an enormous challenge. Transplant centers have adapted promptly and developed strategies to enable safe HCT, by introducing significant changes in their procedures, e.g. through changes in donor types and an unprecedented use of cryopreservation for allogeneic hematopoietic progenitor cell (HPC) grafts. Methods: To explore how centers modified their strategies in terms of donor selection and implementation of new procedures (e.g. SARS-CoV-2 test strategy, cryopreservation), a 14-item survey was developed by the Infectious Disease (IDWP) & Cellular Therapy & Immunobiology (CTIWP) working parties of the European Society for Blood and Marrow Transplantation (EBMT). The survey was sent to 509 EBMT-affiliated allogeneic HCT in Q2, 2011 and re-opened between January 31st and March 18th, 2022 to also cover changes during to the infection period with the Omicron variant. Results: One hundred thirty-five of 509 (27%) centers from 31countries responded. Seventy-four percent of centers introduced COVID-19 mitigation measures for their donors (e.g. physical and social distancing) to minimize the risk of infection. Thirty-four percent of centers changed their donor search strategy, and favored recruitment of related haploidentical donors over unrelated donors (URD). In addition, 33% and 50% of centers searched for a backup donor in the related and URD settings, respectively. Only 10 (7.4 %) of centers resorted to cord blood (CB) as an alternative source to URD. Of these, four centers where pediatric centers and three, pediatric and adult transplant centers. Before COVID-19, only ten of 135 centers (7.4%) were routinely cryopreserving HPC products, whereas this percentage increased to 90% (122/135) during the pandemic. In details, 84/122 (69%) of centers cryopreserved both related and URD grafts, 34 (28%) only URD and 4 (3%) related grafts only. One hundred twenty centers responded during the re-opening of the survey to cover the situation during the Omicron wave. Of those, 78% were still considering graft cryopreservation, whereas 18/26 (70%) of centers not using cryopreservation during the Omicron wave used it before that period. In the majority of centers, changes in policies were introduced based on EBMT recommendations (88/117; 75%) and/or national guidelines (73/117; 62%). Bone marrow (BM) grafts were avoided by 52 (39%) centers (possibly because of the notorious low recovery percentage of cryopreserved BM progenitor cells). In the study period, a total of 4,443 related and 4,586 URD transplants have been reported. Of these transplants, 62% (n=2,748) related and 71% (n=3,254) of URD grafts have been cryopreserved pre-emptively and infused in the vast majority of cases. Sixty-four (2.3 %) related and hundred-eight (3.3 %) URD cryopreserved products have not been infused during the observation period. Release criteria for cryopreserved products in terms of COVID-19 were based on a negative SARS-CoV-2 test (not further specified) in 58/121 (48%), interview of the donor (medical history) in 4/121 (3%), and both in 38/121 (31%) of centers. Eighty-eight centers reported on their test strategy for related donors (multiple answers possible). A SARS-CoV-2 test was performed during check-up in 43% (38/88), before HPC mobilization in 63% (55/88) and before HPC collection in 41% (36/88) centers. Test strategies for URD were not covered by the survey. Conclusions: These data are limited by the low number of respondents, but show a historical increase in cryopreservation of allogeneic HPC grafts during the first three waves of the SARS-CoV-2 pandemic, more in URD than in related donor grafts. The use of BM decreased, and CB grafts were not used as an alternative at most centers. A significant proportion of cryopreserved products (2.8%) were not infused. The reason for this is under investigation. The clinical impact of allogeneic cryopreserved HPCs has to be further analyzed in a larger cohort of patients.

Hematopoietic Stem Cell Transplantation in Juvenile Myelomonocytic Leukemia: A Case Report and Literature Review

Juvenile myelomonocytic leukemia (JMML) is a rare hematological malignancy of early childhood, classified by the World Health Organization as a myelodysplastic/myeloproliferative disease and is associated with a poor prognosis. Allogeneic hematopoietic stem cell transplantation is the only curative treatment. A two-year-old male child was diagnosed with JMML and was given induction chemotherapy. One year after diagnosis, the patient received allogeneic hematopoietic stem cell transplantation from an HLA sibling donor after a myeloablative conditioning regimen. The patient remained free of disease after 5 years of follow-up, healthy, with complete clinical, immunologic and hematologic recovery, without signs of JMML. Transplantation is the only modality to achieve a cure in JMML patients. The most widely practiced approach is the use of bone marrow or peripheral blood stem cells after a myeloablative conditioning regimen. Post-transplant monitoring chimerism can help identify the patients who are at risk of relapse.

CT-275 Incidence and Characteristics of Chronic GVHD in Haploidentical Stem-Cell Transplantation With Post-Transplantation Cyclophosfamide: Experience of the Spanish Group of Hematopoietic Transplantation and Cell Therapy (GETH-TC)

Chronic graft-versus-host-disease (cGVHD) is a relevant cause of late morbidity and mortality related to allogenic-stem-cell transplantation in long-term survivors. GVHD prophylaxis using post-transplantation cyclophosphamide (PTCy) has improved haploidentical stem-cell transplantation (haplo-HSCT) outcomes; however, data related to characteristics, risk factors, or cGVHD outcomes are limited. In this study, we analyze the incidence, risk factors and disability related to cGVHD in patients undergoing haplo-HSCT PTCy. Retrospective multicenter analysis of 389 consecutive patients that underwent haplo-HSCT-PTCy at 7 Spanish transplant centers from 2007 to 2020. cGVHD diagnosis was made following the NIH criteria and Disability related to cGVHD was defined as Fatobene et al criteria. Median age was 48 years (5-74), and 62% were males. AML and HL were the most common indications for transplantation (37%, 22%). 36% received a previous transplant. The median follow-up was 35 months (3-102). Cumulative incidence of aGVHD and aGVHD III-IV at day +180 was 66% and 20%. The 2-year OS was 59%, 2-year PFS 54%, 2 year-GRFS was 45%. 95 patients developed cGVHD, cumulative incidence of cGVHD and cGVHD moderate-severe was 34% and 10% at 3 years. 42 patients required systemic treatment. In the univariate analysis of risk factors for cGVHD in patients alive on day +100, female donor (p=0.034), female donor and male recipient (p=0.041), DRI low (p=0.026), myeloablative conditioning (p=0-047), previous aGVHD (p=0.014), and the use of radiotherapy in conditioning (p=0.004) were identified. Busulfan conditioning was identified as a protective factor (p=0.036). In multivariate analysis, the presence of previous GVHD (p=0.031) and the protective power of conditioning with busulfan (p=0.036) remains statistically significant. cGVHD according to NIH at 3 years, moderate cGVHD showed a higher OS (p=0.054), higher PFS (p=0.004) and lower relapse than the rest of the groups (p=0.035). Receiving one line of treatment (p=0.043) and use of bone marrow were the only risk factors identified for these patients. Haplo-HPT with Cy-post shows a low, but not negligible incidence of cGVHD, and its use represents an alternative for some patients. The development of moderate cGVHD is a protective factor in this transplant modality. The characterization of predictive factors of this subgroup is relevant given the results.

Reorientation technique has benefits in bone marrow aspiration of stem cells

We treated patients with osteoarthritis of the knee using injections of bone marrow aspirate concentrate (stem cell therapy). Since multiple controversial harvesting methods using different sites, needles, volumes and techniques have been described, we aimed to compare those methods. Four different harvesting sites at the iliac crest, three different types of needles, three different types of volumes and two different harvesting techniques were compared in 48 bone marrow aspirations. The conventional technique (Group 1) was compared with a reorientation technique (Group 2). The number of leucocytes and CD34 + cells and the viability in bone marrow aspirate (BMA) were analysed with a CytoFLEX Flow Cytometer. The reorientation technique showed significantly higher cell counts than the conventional technique in all parameters. Leucocytes per nl increased from 5 ± 2 to 12 ± 4 (p < .001), and CD 34 + cells per μl increased from 40 ± 40 to 140 ± 98 (p = .003). There was no difference between anterior and posterior harvesting at the iliac crest or between use of a thick and use of a thin needle. Use of the reorientation technique, compared to employing the conventional technique, has a significant advantage since the number of leucocytes and CD34 + cells can be tripled. For the use of bone marrow aspirate in the case of arthritis, it might therefore be a future option to harvest a maximum cell yield through the new reorientation technique and to omit centrifugation. However, the clinical relevance of these findings remains the subject of future studies.Level of Evidence: Level I.Clinical relevance: Enhanced technique of BMA for knee surgeons to ensure the maximum cell yield for stem cell therapy in regenerative medicine.

Human leukocyte antigen-haploidentical transplantation for relapsed/refractory acute myeloid leukemia: Better leukemia-free survival with bone marrow than with peripheral blood stem cells in patients ≥55 years of age.

The best stem cell source for T-cell replete human leukocyte antigen (HLA)-haploidentical transplantation with post-transplant cyclophosphamide (PTCy) remains to be determined. In this European Society for Blood and Marrow Transplantation retrospective study, we analyzed the impact of stem cell source on leukemia-free survival (LFS) in adult patients with primary refractory or relapsed acute myeloid leukemia (AML) given grafts from HLA-haploidentical donors with PTCy as graft-versus-host disease (GVHD) prophylaxis. A total of 668 patients (249 bone marrow [BM] and 419 peripheral blood stem cells [PBSC] recipients) met the inclusion criteria. The use of PBSC was associated with a higher incidence of grade II-IV (HR=1.59, p=.029) and grade III-IV (HR=2.08, p=.013) acute GVHD. There was a statistical interaction between patient age and the impact of stem cell source for LFS (p < .01). In multivariate Cox models, among patients <55 years, the use of PBSC versus BM resulted in comparable LFS (HR=0.82, p=.2). In contrast, in patients ≥55 years of age, the use of PBSC versus BM was associated with higher non-relapse mortality (NRM) (HR=1.7, p=.01), lower LFS (HR=1.37, p=.026) and lower overall survival (HR=1.33, p=.044). In conclusions, our data suggest that in patients ≥55 years of age with active AML at HLA-haploidentical transplantation, the use of BM instead of PBSC as stem cell source results in lower NRM and better LFS. In contrast among younger patients, the use of PBSC results in at least a comparable LFS.

CONDITIONING REGIMEN FOR LANGERHANS HISTIOCYTOSIS

Langerhans cell histiocytosis (LCH) is a rare disease, with an estimated incidence of 0.5 per 100,000 children in the United States of America1. HCL occurs due to differentiation of myeloid precursors into CD1a+ / CD207+ cells and is characterized by constitutional activation of the MAPK2 signaling pathway, leading to a spectrum of organ involvement and dysfunction. Treatment of HCL is risk-adjusted: single lesions may respond to local treatment whereas multisystem disease requires systemic therapy. Although survival for patients without organ dysfunction is excellent3, mortality in those with compromised organs at risk (hematopoietic system, liver, and/or spleen) reaches 20%2,4. Despite the progress made in the treatment of HCL, disease reactivation rates remain above 30% and the best second-line treatment has not yet been established. Treatment failure is associated with increased morbidity and mortality, including an association with neurodegeneration2.&#x0D; As it is a rare disease and generally has a good prognosis, few scientific studies are evaluating the role of allogeneic hematopoietic stem cell transplantation (HSCT) in the treatment of this disease.&#x0D; In 2015 Veys et al5 published retrospective results of 87 high-risk patients transplanted between 1990 and 2013. Myeloablative conditioning regimens (MAC) based on total body irradiation or busulfan6 were the most used until the 2000s, and reduced-intensity conditioning regimens (RIC) – predominantly a combination of Melphalan and Fludarabine – were most used between 2000 and 2013. Transplant-associated mortality rates in 3 years were similar between RIC and MAC conditioning regimens (21% versus 15%, respectively). Recurrence was higher in the RIC group compared to the MAC group (28% versus 8%, respectively), however, the 3-year overall survival (OS) was similar (77% versus 71%, respectively), since the patients who relapsed after RIC transplantation could be rescued with chemotherapy.&#x0D; More recently, Kudo et al7 published a retrospective study with 30 patients with refractory LCH who underwent HSCT between 1996 and 2014. Eleven patients received myeloablative conditioning regimen based on total body radiotherapy (RCT) with a dose equal to or greater than 8 Gy or busulfan, and 19 of reduced intensity based on Fludarabine and Melphalan, associated or not with low dose of RCT. There was no significant difference between the conditioning regimen modalities, with OS of 56.8% for the RIC group and 63.6% for the MAC group. Disease status was the main prognostic factor, with a 5-year OS of 100% for patients who arrived at HSCT with disease in remission or with partial remission, versus 54.5% for those who had active disease at the time of the procedure.&#x0D; Regarding the type of donor used and the source of stem cells, there is great variation, with greater frequency for unrelated and extensive use of bone marrow and umbilical cord, and apparently, there is no impact on survival rates.5, 6&#x0D; There are few case reports and extremely restricted performance of autologous HSCT in HCL.

Cell therapy for osteonecrosis of femoral head and joint preservation

Osteonecrosis of femoral head (ONFH) is a disease of the femoral head and can cause femoral head collapse and arthritis. This can lead to pain and gait disorders. ONFH has various risk factors, it is often progressive, and if untreated results in secondary osteo-arthritis. Biological therapy makes use of bone marrow concentrate, cultured osteoblast and mesenchymal stem cell (MSC) obtained from various sources. These are often used in conjunction with core decompression surgery. In this review article, we discuss the current status of cell therapy and its limitations. We also present the future development of biological approach to treat ONFH.

IL-10R Inhibition Selects for Jak2V617F Hematopoiesis By Augmenting Inflammation Induced Exhaustion of Wild-Type but Not Jak2V617F Hematopoietic Stem Cells

An emerging theme among clonal hematopoiesis (CH) associated mutations is that these mutations endow hematopoietic stem cells (HSC) protection from chronic inflammatory stress. Specific inflammatory stressors may select for specific mutants, such that presence of particular mutant clones could be leveraged as a biomarker to herald the presence of a specific stressor. JAK2 V617F clonal hematopoiesis is less common among the general aging population but clusters within families suggesting that a specific stressor present among members of myeloproliferative neoplasm (MPN) families selects for JAK2 V617F mutant cells. We have recently found that monocytes from MPN patients and their unaffected family members have defective negative regulation of Toll Like Receptor Ligand (TLR) signaling due to a dampened response to the anti-inflammatory cytokine Interleukin-10 (IL-10) which leads to persistent TLR signaling and increased TNF production.We hypothesized that IL-10 serves to curtail TLR signaling in HSCs just as it does in monocytes. Therefore, we assessed activation and proliferation of HSCs in WT mice treated with the TLR agonist lipopolysaccharide (LPS) versus mice treated with LPS + IL-10 receptor (IL-10R) blocking antibody (Fig 1A). As expected, LPS treatment induced proliferation of HSCs at day 1 which returned to dormancy by day 3. However, with IL-10R blockade, WT HSCs remained highly active and proliferative even at 3 days post stimulation (Fig 1A). In contrast, blockade of IL-10R in Jak2 V617F HSC did not extend the time period that HSC were actively proliferating post-LPS stimulation (Fig 1B).To assess how chronic inhibition of IL-10R signaling impacts HSC fitness, we treated WT mice with twice weekly IL-10R blocking antibody and after 8 weeks harvested bone marrow for use in competitive repopulation assays. Bone marrow from mice exposed to chronic IL-10R blockade was inferior to untreated bone marrow (Fig 2A). We next tested whether blockade of IL-10R results in a functional decline in HSC when exposed to a short course of LPS exposure which would not otherwise result in defective competitive potential. We treated mice with 2 weeks of LPS +/- IL-10R blocking antibody before harvesting bone marrow for competitive repopulation assays. Whereas bone marrow from mice treated with 2 weeks of LPS competed equivalently to unexposed bone marrow, bone marrow from mice treated with 2 weeks of LPS + IL-10R blocking antibody were inferior to bone marrow from unexposed mice (Fig 2B). This demonstrates that IL-10R blockade accelerates inflammation induced exhaustion of WT HSC.Reasoning that blockade of IL-10R signaling may lead to an inflammatory state that allows for Jak2 V617F mutant cells to gain a selective advantage, we injected bone marrow mosaic mice twice weekly with IL-10R blocking antibody starting at 50 days post-transplant. We observed an increase in the chimerism of Jak2 V617F mutant cells in mice exposed to IL-10R blocking antibody as compared to mice exposed to PBS, both in peripheral blood (Fig 3A) as well as in the stem and progenitor cell compartment of the bone marrow (Fig 3B). Moreover, IL-10R blockade exaggerated the MPN phenotype, with increased spleen size (Fig 3C) and increased megakaryocytes in the bone marrow and spleen (data not shown).Together, these data demonstrate that IL-10R blockade accelerates inflammation induced exhaustion of WT HSC, likely due to increased cycling. Jak2 V617F HSC are protected from this accelerated exhaustion of HSC from IL-10R blockade, allowing them to gain a selective advantage in the context of chronic inflammation when IL-10R is blocked. [Display omitted] DisclosuresNo relevant conflicts of interest to declare.

Higher Efficacy of TBI + Cyclophosphamide Than TBI + Fludarabine As Conditioning Prior to Allogeneic Hematopoietic Cell Transplantation for Acute Lymphoblastic Leukemia: An Analysis By the Acute Leukemia Working Party of the EBMT

BACKGROUNDAllogeneic hematopoietic cell transplantation (allo-HCT) is a standard of care for adults with high-risk acute lymphoblastic leukemia (ALL) in first or subsequent complete remission (CR). Myeloablative total body irradiation (TBI) combined with cyclophosphamide (Cy) is the most frequently used conditioning regimen. In order to reduce toxicity Cy may be replaced by fludarabine (Flu). The goal of this registry-based, retrospective study was to compare outcomes of allo-HCT following TBI/Cy vs. TBI/Flu conditioning. PATIENTS AND METHODSIncluded in the analysis were 2255 patients aged 18-65 years, treated with allo-HCT from either a matched sibling (43%) or unrelated (57%) donor in CR1 (83%) or CR2 (17%), between the years 2010-2020. Patients with Ph(-) B-ALL, Ph(+) B-ALL, and T-ALL were represented in equal proportions. TBI 12Gy + Cy was used in 2105 cases while TBI 12Gy + Flu was administered to 150 patients. Patients treated with TBI/Flu were significantly older (median 35 years vs. 33 years, p=0.006), with poorer Karnofsky performance score (<90, 27% vs. 20%, p=0.03), more frequently transplanted from unrelated donors (71% vs. 57%, p=0.0007) with less frequently use of bone marrow as a source of stem cells (5% vs. 21%, p<0.0001), and in more recent year (median 2018 vs. 2015, p<0.0001). RESULTSEngraftment rate was 99% for both TBI/Cy and TBI/Flu patients. In a univariate analysis the use of TBI/Cy as compared to TBI/Flu was associated with a tendency to reduced incidence of relapse (24% vs. 29% at 2 years, p=0.1), increased incidence of grade 2-4 acute graft versus host disease (GVHD, 35.5% vs. 28%, p=0.08) and improved leukemia-free survival (LFS, 62% vs. 57%, p=0.18). The rates and causes of non-relapse mortality (NRM) did not differ significantly between the two conditioning groups. In a multivariate model adjusted for other prognostic factors, TBI/Cy conditioning was associated with reduced risk of relapse (HR=0.69, p=0.049) and increased risk of grade 2-4 acute GVHD (HR=1.57, p=0.03) without significant effect on other transplantation outcomes.An additional analysis was performed with TBI/Cy treated patients (n=132) matched strictly to those treated with TBI/Flu (n=132) in terms of disease subtype, disease status and donor type with the nearest neighbor for patient age, patient and donor sex, in vivo T-cell depletion, Karnofsky score and source of stem cells; the use of TBI/Cy as compared to TBI/Flu was associated with significantly reduced rate of relapse (18% vs. 30% at 2 years, p=0.015) and a tendency to an improved LFS (65% vs. 59%, p=0.07) and overall survival (OS, 73% vs. 68%, p=0.16) without effect on NRM and GVHD. CONCLUSIONSThe use of myeloablative TBI/CY as conditioning prior to allo-HCT for adult patients with ALL in CR1 or CR2 is associated with stronger anti-leukemic effect leading to significantly lower relapse rate compared to TBI/Flu and therefore should be likely considered a preferable regimen. DisclosuresGiebel: Janssen: Honoraria, Speakers Bureau; Pfizer: Consultancy, Honoraria, Speakers Bureau; Novartis: Consultancy, Honoraria, Speakers Bureau; Amgen: Consultancy, Honoraria, Speakers Bureau. Labopin: Jazz Pharmaceuticals: Honoraria. Socie: Alexion: Research Funding. Yakoub-Agha: Jazz Pharmaceuticals: Honoraria. Kröger: Novartis: Research Funding; Riemser: Honoraria, Research Funding; Sanofi: Honoraria; Neovii: Honoraria, Research Funding; Jazz: Honoraria, Research Funding; Gilead/Kite: Honoraria; Celgene: Honoraria, Research Funding; AOP Pharma: Honoraria. Forcade: Novartis: Consultancy, Other: Travel Support, Speakers Bureau; Gilead: Other: Travel Support, Speakers Bureau; Jazz: Other: Travel Support, Speakers Bureau; MSD: Other: Travel Support. Huynh: Jazz Pharmaceuticals: Honoraria. Spyridonidis: Menarini: Current Employment. Perić: therakos: Honoraria; servier: Honoraria; MSD: Honoraria; Astellas: Honoraria; NOVARTIS: Honoraria; Abbvie: Honoraria; Pfizer: Honoraria. Mohty: Pfizer: Honoraria; Celgene: Honoraria, Research Funding; Amgen: Honoraria; Astellas: Honoraria; Gilead: Honoraria; Jazz: Honoraria, Research Funding; Janssen: Honoraria, Research Funding; Novartis: Honoraria; Bristol Myers Squibb: Honoraria; Takeda: Honoraria; Sanofi: Honoraria, Research Funding; Adaptive Biotechnologies: Honoraria.

FLAMSA-Busulfan-Melphalan as a Sequential Conditioning Regimen in HLA-Matched or Haploidentical Hematopoietic Stem Cell Transplantation for High-Risk Myeloid Diseases

Given the poor prognosis of relapsed/refractory myeloid malignancies, the concept of sequential conditioning before allogeneic hematopoietic stem cell transplantation (allo-HSCT) has proven to be an effective approach. We sought to evaluate a sequential scheme combining fludarabine, amsacrine, and cytarabine (FLAMSA) for cytoreduction, followed by reduced-intensity conditioning with busulfan and melphalan (FLAMSA-BuMel), which was designed to be suitable for both HLA-matched and haploidentical HSCT. This single-center retrospective study included 36 adult patients with high-risk myeloid malignancies who underwent allo-HSCT from HLA-matched (n=19) or haploidentical (n=17) donors. Along with the standard prophylaxis for graft-versus-host disease (GVHD), patients with a haploidentical donor received post-transplantation high-dose cyclophosphamide. A post-transplantation consolidation treatment with low-dose 5-azacytidine and prophylactic donor lymphocyte infusions was provided whenever possible. Thirty patients (83%) achieved complete remission on day +30. With a median follow-up of 30.0 months, the 2-year overall survival was 89% in the HLA-matched group versus 34% in the haploidentical group (P=.0018). The 2-year disease-free survival in these 2 groups was 68% and 34%, respectively (P=.013). At 2 years, the probability of relapse was 32% and 20%, respectively, and nonrelapse mortality was 0% and 58%, respectively (P=.0003). The leading cause of death was relapse in the HLA-matched group (3 of 19) and hemorrhagic events (5 of 17) in the haploidentical group, favored by significantly delayed platelet reconstitution and a severe GVHD context. These data confirm the feasibility of FLAMSA-BuMel as a sequential conditioning in allo-HSCT for high-risk myeloid malignancies. The use of bone marrow as the preferred graft source might reduce the incidence of acute GVHD and nonrelapse mortality in the haploidentical transplantation setting.

Archival bone marrow smears are useful in targeted next-generation sequencing for diagnosing myeloid neoplasms.

Gene abnormalities, including mutations and fusions, are important determinants in the molecular diagnosis of myeloid neoplasms. The use of bone marrow (BM) smears as a source of DNA and RNA for next-generation sequencing (NGS) enables molecular diagnosis to be done with small amounts of bone marrow and is especially useful for patients without stocked cells, DNA or RNA. The present study aimed to analyze the quality of DNA and RNA derived from smear samples and the utility of NGS for diagnosing myeloid neoplasms. Targeted DNA sequencing using paired BM cells and smears yielded sequencing data of adequate quality for variant calling. The detected variants were analyzed using the bioinformatics approach to detect mutations reliably and increase sensitivity. Noise deriving from variants with extremely low variant allele frequency (VAF) was detected in smear sample data and removed by filtering. Consequently, various driver gene mutations were detected across a wide range of allele frequencies in patients with myeloid neoplasms. Moreover, targeted RNA sequencing successfully detected fusion genes using smear-derived, very low-quality RNA, even in a patient with a normal karyotype. These findings demonstrated that smear samples can be used for clinical molecular diagnosis with adequate noise-reduction methods even if the DNA and RNA quality is inferior.

Allogeneic Haematopoietic Cell Transplantation in Aplastic Anaemia: A Dataset of 240 Cases

Objective: To analyse factors associated with survival, rejection and graft versus host disease in aplastic anaemia patients undergoing allogeneic haematopoietic stem cell transplantation (HSCT) from related donors.Patients & Methods: The study included 240 consecutive aplastic anaemia patients undergoing haematopoietic stem cell transplantation from HLA matched sibling donors at this centre from July 2001 to April 2016. Potential risk factors affecting overall survival, rejection, disease free survival and graft versus host disease were analysed.Results: One hundred and eighty eight male and fifty two female AA patients were included in the study. Median age was 18 years (3-55 years), conditioning regimens used were cyclosphosphamide (Cy) plus antilymphocyte globulin (ALG) or antithymocyte globulin (ATG) (n=105), Fludarabine (FLU)+CY+ATG (n=128), and Campath 1-H +CY in 6 cases respectively. While haplo-identical transplantation was carried out in one patient. Methotrexate was added to GVHD prophylaxis in 101 patients while the rest received only CSA plus prednisolone. At a median follow up of 1485 days OS & DFS were 76% & 70% respectively. Factors associated with better OS were male sex, Cy plus ALG/ATG conditioning and use of bone marrow as stem cell source. In a comparison between ATG and ALG-based regimens (n=205), ATG-containing regimens was found superior to the one those with ALG, in both OS (78.7% vs69.4%) and DFS (75% vs 55.6%) [p=0.018].Conclusion: Cy plus ALG/ATG conditioning regimen, bone marrow as stem cell source and GVHD prophylaxis with CSA minus methotrexate were associated with better survival in AA. DisclosuresNo relevant conflicts of interest to declare.

Post-Transplant Cyclophosphamide (PT-Cy) for Graft Versus Host Disease (GVHD) Prophylaxis in Allogeneic Transplantation from HLA Identical Sibling and Matched Unrelated Donor for Patients with Acute Leukemia, on Behalf of ALWP-EBMT

Background: Post-transplant Cyclophosphamide (PT-Cy) is being used successfully in the setting of unmanipulated haploidentical transplant as graft versus host disease (GVHD) prophylaxis. Experience with the application of PT-Cy for prevention of GVHD post allogeneic stem cell transplantation (HSCT) from matched sibling donors (MSD) or unrelated donor (UD) is rather limited and it involves mainly single center experience and small numbers of patients.Methods: Study aim was to evaluate the yield of PT-Cy as GVHD prophylaxis post HSCT from MSD and UD transplants for acute leukemia. We analyzed 423 patients (pts) with acute leukemia who received PT-CY alone or in combination to other drugs as GVHD prophylaxis and reported to the ALWP of the EBMT. 78 pts received PT-Cy alone (group 1); 204 received PT-CY in combination with one immunosuppressive (IS) drug -cyclosporine A (CSA) or and methotrexate (MTX) or mycophenolate mofetil (MMF)(group 2), while 141 pts received PT-Cy in combination with 2 IS drugs- CSA+MTX or CSA+MMF (group 3). Transplants were performed from 2007-2015 and median follow up is 16 months.Results: There were some differences among groups: pts in group 1 were younger (median age 37 years, p<0.001) were transplanted in more recent year (2014, p<0.001), with a MSD (80%, p<0.001), and CMV positive donor (73%, p=0.008), received more frequently a reduced intensity conditioning (RIC) (56%, p<0.001) and bone marrow (BM) as source of stem cells (74%, p<0.001), with no ATG (100%, p<0.001). Probability of OS at 2 year was 50%, 52.2% and 62.4%, for the 3 groups, respectively, p=0.06.Overall the cumulative incidence (CI) of grade II-IV acute GVHD was 27.9%, and the CI of chronic GVHD was 33.4%, and 16.5% the CI of extensive cGVHD. The CI of relapse at 2 years was 33.5% and non-relapse mortality (NRM) 18.5%, disease recurrence and GVHD were the most common causes of death in the whole cohort.At 2 years the probability of leukemia free survival (LFS) and overall survival (OS) was 48% and 55%.In multivariate analysis, the addition of IS to the PT-CY did not impact the risk of acute GVHD. Diagnosis of ALL (HR 0.57, p<0.001), unrelated donor (HR 1.65, p=0.02), RIC regimen (HR 1.72, p=0.01) and donor CMV positive (HR 1.77, p=0.01) were associated with the risk of grade II-IV acute GVHD. The use of PBSC (HR 2.41, p=0.01) and the absence of ATG (HR 1.69, p=0.03) were independently associated with an higher risk of chronic GVHD (p=0.005). In comparison to PT-Cy alone the addition of 1 or 2 IS drugs as GVHD prophylaxis were associated with reduced risk of extensive chronic GVHD (PT Cy+ 1 drug, HR 0.25, p=0.02, PT Cy+ 2 drugs, HR 0.77, p=0.01) as well the use of BM (HR 0.21, p<0.001) and the use of ATG (HR 0.22, p<0.001). Notably, the addition of 1 or 2 IS drugs to PT-CY did not impact the risk of relapse. Advance disease status (HR 2.42, p<0.001), was the only factor associated with increased risk of relapse. As for NRM addition of CSA+MTX or CSA+MMF to the PT-Cy (HR 0.35, p=0.04), diagnosis of AML (HR 0.35, p=0.001), and disease status at transplant (HR 2.94, p<0.001), and patients CMV serology (HR 2.04, p=0.04), influenced the NRM.Factors associated with increased OS were the use of PT-Cy in combination with CSA+MTX or CSA+MMF (HR 0.49, p=0.02), diagnosis of AML (HR 0.59, p=0.001), and disease status at HSCT ((CR1 vs CR2 HR 0.58, p=0.02), (CR1 vs advanced disease (HR 0.40, p<0.001)).Conclusions: PT-CY is effective GVHD prophylaxis in MSD and MUD HSCT for acute leukemia. The addition of IS drugs CSA+MTX or CSA+MMF to the PT-Cy shapes its effect and further decrease the risk of severe chronic GVHD, reducing transplant related mortality and improving overall survival. DisclosuresMohty:Sanofi: Honoraria, Speakers Bureau.

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.