CAR-T from cord blood in a patient with Ph+ acute lymphoblastic leukemia relapsing after hematopoietic stem cell transplantation

While there is intense interest in the production of allogeneic CAR-T cells from umbilical cord units, little is known about the reactivity and persistence of CAR-T cells of umbilical origin. We report the case of a patient at our hematological center with multiple relapsing Ph+ B-ALL, notably a Blinatunomab non-responder, who underwent therapy with Brexucabtagene Autoleucel following relapse on Ponatinib post-allogeneic hematopoietic stem cell transplantation. The patient achieved a rapid CAR-T expansion and durable remission presenting in good clinical conditions 6 months post-CAR-T infusion, without manifestations of graft-versus-host disease. The case report provides insight into the reactivity and persistence of CAR-T cells of umbilical origin, confirming the potential promise of allogeneic umbilical cord-derived CAR-T cells.

Unselected donor-derived hematopoietic stem cells boost for Chimeric Antigen Receptor T-cell associated hematotoxicity

Hematological toxicity following Chimeric Antigen Receptor-T therapy in a patient with a prior allogeneic stem cell transplantation was resolved by the infusion of unselected donor-derived stem cell boost. Due to the donor's lymphocytes, the patient experienced a well-controlled flare-up of acute graft versus host disease.

Risk factors for hemorrhagic cystitis after allogeneic hematopoietic stem cell transplantation in a letermovir-exposed CMV-free population receiving PTCy

Hemorrhagic cystitis (HC) is a highly impacting complication in allogeneic hematopoietic stem cell transplantation (HSCT), occurring in 12%-37% of patients. The impact of transplant- and patient-specific variables has been described, with a possible role for JCV and BKV, which may be cooperating with cytomegalovirus (CMV). Here, we analyze 134 letermovir-exposed, CMV-free patients, treated with the same cyclophosphamide-based graft-versus-host disease (GVHD) prophylaxis, describing risk factors for HC. The overall incidence of HC was 23%. Patients with HLA mismatched transplant, higher comorbidity score, and receiving three alkylating agents with TBF (thiotepa, busulfan, and fludarabine) conditioning regimen had a higher risk of HC in multivariate analysis (OR: 4.48, 6.32, and 1.32, respectively). A HC-score including male gender, TBF conditioning, and HLA-mismatch stratifies the risk of HC in the first 100 days after HSCT. The role of BKV and JCV was not highly impacting in those patients, suggesting a possible synergistic effect between CMV and JCV in causing HC. HC can be interpreted as the combination of patient-related factors, chemotherapy-related toxicities-especially due to alkylating agents-and immunological elements.

Hematopoiesis and immune reconstitution after CD19 directed chimeric antigen receptor T-cells (CAR-T): A comprehensive review on incidence, risk factors and current management

Impaired function of hematopoiesis after treatment with chimeric antigen T-cells (CAR-T) is a frequent finding and can interest a wide range of patients, regardless of age and underlying disease. Trilinear cytopenias, as well as hypogammaglobulinemia, B-cell aplasia, and T-cell impairment, can severely affect the infectious risk of CAR-T recipients, as well as their quality of life. In this review, we provide an overview of defects in hematopoiesis after CAR-T, starting with a summary of different definitions and thresholds. We then move to summarize the main pathogenetic mechanisms of cytopenias, and we offer insight into cytomorphological aspects, the role of clonal hematopoiesis, and the risk of secondary myeloid malignancies. Subsequently, we expose the major findings and reports on T-cell and B-cell quantitative and functional impairment after CAR-T. Finally, we provide an overview of current recommendations and leading experiences regarding the management of cytopenias and defective B- and T-cell function.

Acute graft versus host disease 1976-2020: reduced incidence and predictive factors

We studied the incidence of acute graft versus host disease (GvHD) and its outcome in three consecutive time frames (year <2000; 2000-2010; >2010), in 3,120 patients allografted in two transplant Centers between 1976 and 2020. The median age increased over the three periods from 32 to 42 to 54 years (p < 0.00001). The median day of onset of GvHD in the three periods was day +14, day +16, and day +30, respectively (p < 0.0001). The cumulative incidence (CI) of GvHD grades II-IV in the three periods was 47, 24, and 16%, respectively (p < 0.00001). The CI of GvHD grades III-IV was 13, 5, and 4% (p < 0.001). In multivariate analysis, significant predictive factors for GvHD II-IV, on top of year of transplant, were anti-thymocyte globulin (ATG) (RR 0.67, p > 0.001); post-transplant cyclophosphamide (PTCY) (RR 0.41, p < 0.001), a family mismatched donor (RR 1.31, p = 0.03) a matched unrelated donor (RR 2.1, p < 0.001), an unrelated mismatched donor (RR1.8, p = 0.001), donor age above 40 years (RR 1.27, p < 0.001), hematological malignancy-as compared to aplastic anemia (RR 2.3, p < 0.001). When selecting only GvHD grade II, in a multivariate analysis, there was a significant reduction of transplant-related mortality (TRM) for patients grafted in 2001-2010 (RR 0.62, p < 0.0001) and for patients grafted in 2011-2020 (RR 0.35, p < 0.0001) as compared to grafts before the year 2000. A similar reduction in time was seen for patients with GvHD grades III-IV. The overall TRM in the three periods was 30, 22, and 16% (p < 0.0001) and survival was 47, 51, and 58% (p < 0.0001). Relapse risk was unchanged. In conclusion, we showed improved prevention of acute GvHD with time, together with a significant delay in the onset of the disease. Treatment of GvHD has also improved over time, as suggested by both reduced TRM and improved survival in more recent transplant periods.

Discrepancy between recipient and donor rs4364254 heparanase single nucleotide polymorphism impacts graft-versus-host disease after allogeneic stem cell transplant

INTRODUCTION

The heparanase (HPSE) gene is highly polymorphic, but only a minority of its single nucleotide polymorphisms (SNPs) have been studied. Among these, rs4693608 and rs4364254 SNPs are closely associated with mRNA expression and HPSE protein levels in healthy subjects. Given the association between HPSE and inflammatory response, we aimed to evaluate whether HPSE rs4693608 and rs4364254 SNPs could have an impact on graft-versus-host disease after allogeneic stem cell transplants (HSCT).

METHODS

A total of 228 consecutive patients who underwent HSCT at our center between 2005 and 2018 were included. The rs4693608 SNP was identified by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) analysis, while the rs4364254 was detected by allele-specific amplification.

RESULTS

The recipient-donor discrepancy for rs4364254 HPSE SNP was significantly associated with grade II-IV aGvHD (HR 1.75, p = 0.03). Patients were stratified into risk groups as follows: low-risk group (LDR) including TT-TT, TT-CT, CT-TT, CC-CC; high-risk group (HDR) including CC-CT, CC-TT, CT-CC, CT-CT, TT-CC. Day 100 cumulative incidence of grade II-IV aGvHD was 23.4% in the LDR group and 41.4% in the HDR group (p = 0.01). One-year cumulative incidence of moderate/severe cGvHD was 42.6% in the LDR group and 58.6% in the HDR group (p = 0.04). Independent variables for moderate/severe cGvHD in patients who received myeloablative conditioning included donor rs4693608 SNP (GA/AA vs. GG: HR 6.86, p = 0.008), rs4693608-rs4364254 SNP combination in recipient (HR/MR vs. LR: HR 3.67, p = 0.01), and previous grade II-IV aGvHD (HR 3.28, p = 0.0005). Finally, donors with rs4364254 SNP CC conferred increased transplant-related mortality (TRM) (39.1% vs. 25%, p = 0.03) and decreased graft-relapse free survival (GRFS) (23.5% vs. 34.4%, p = 0.04) compared with CT or TT genotypes.

CONCLUSION

The differences in incidence of GvHD according to recipient-donor genotype combinations suggests a possible role for rs4364254 HPSE SNP in predicting GvHD. A high level of HPSE, particularly linked to CC genotype of rs4364254 SNP may promote alloreactive T lymphocytes activation and migration toward target organs.

Deciphering treatment patterns in non-severe/moderate aplastic anemia: an international observational study

Non-severe aplastic anemia is a rare bone marrow failure disorder characterized by variable degrees and combination of cytopenias, with limited data on management and outcome. We describe a large multicentric series of 259 patients, focusing on clinical and molecular features, treatment, evolution, and survival. The majority required treatment with cyclosporine (CyA) alone (N = 84) or in combination with anti-thymocyte globulin (ATG,44) or eltrombopag (20), eltrombopag alone (10), or others (25) including androgens. Similar outcomes were observed across different strategies, with a 6-month overall response rate of 73% for CyA, 74% for ATG plus CyA, 68% for CyA plus eltrombopag, 87% for eltrombopag, and 79% for others. Notably, 56 patients (39%), mainly receiving CyA plus eltrombopag, achieved a trilineage response (p = 0.02). Progression to myeloid neoplasms was limited (8%) and not related to mutational status. Hemolytic PNH developed in 10% of cases, being predicted by detection of small clones at diagnosis. Survival was negatively impacted by age, male gender, LDH, platelets/erythrocyte transfusion need, and somatic mutations by NGS, and positively by higher neutrophils at diagnosis, PNH clones, and trilineage response at 6 and 12 months. Multivariable analysis confirmed the detrimental role of age and the favorable association with PNH clone and trilineage response at 6 months.

The Role of Fecal Microbiota Transplantation in the Allogeneic Stem Cell Transplant Setting

Microbiota changes during allogeneic hematopoietic stem cell transplantation has several known causes: conditioning chemotherapy and radiation, broad-spectrum antibiotic administration, modification in nutrition status and diet, and graft-versus-host disease. This article aims to review the current knowledge about the close link between microbiota and allogeneic stem cell transplantation setting. The PubMed search engine was used to perform this review. We analyzed data on microbiota dysbiosis related to the above-mentioned affecting factors. We also looked at treatments aimed at modifying gut dysbiosis and applications of fecal microbiota transplantation in the allogeneic stem cell transplant field, with particular interest in fecal microbiota transplantation for graft-versus-host disease (GvHD), multidrug-resistant and clostridium difficile infections, and microbiota restoration after chemotherapy and antibiotic therapy.

Impact of Covid 19 pandemic on hematopoietic stem cell transplantation activities: Report from a single center

The current COVID-19 pandemic has placed unprecedented stress on the healthcare system, including HSCT. Several international organizations have created guidelines for managing different aspects of HSCT in the context of the pandemic. Comparing 2019 and 2020, our transplant center performed the same number of transplants. In both periods, transplants were mainly for patients with acute leukemia; thus, the urgency criteria was respected in light of pandemic restraints. Transplants by sibling donors and cord blood units remained the same, while transplants by unrelated donors were increased, in particular from European registries, and transplants by haploidentical donors were decreased. This change was made in light of the necessity of cryopreserving all apheresis products. We decided against cryopreserving bone marrow products due to the greater risk of drastic reduction in CD34 + cell count during the process. For urgent cases with only a haploidentical donor available, we opted for the use of PBSC following stimulation with G-CSF. GvHD prophylaxis was performed with PTCY on days + 3 + 5, cyclosporine with tapering from day + 100, and mycophenolic acid until day + 90 post-HSCT. Post-transplant outcomes such as graft failure, sepsis, and GVHD were not affected by the changes implemented. As a result of logistic difficulties, we halted our Car-T program from the start of the lockdown in March 2020 until September 2020. In accord with international guidelines, we were able to continue our HSCT program in the order to ensure a lifesaving treatment for patients with hematologic diseases for whom this procedure cannot be postponed.

Peripheral Blood Allogeneic Stem Cell Mobilization: Can We Predict a Suboptimal Mobilization?

Allogeneic peripheral blood stem cells mobilization is now the basis of most stem cell transplants. In a very limited number of cases, mobilization is suboptimal leading to further collection procedures, to suboptimal cell doses infusion with delayed engraftment time, increased risks of transplant procedure and of related costs. To date we have no recognized and shared criteria for early estimating the probability of poor mobilization in healthy donors. We then analyzed allogeneic peripheral blood stem cell donations performed at the Fondazione Policlinico Universitario A.Gemelli IRCCS Hospital from January 2013 to December 2021 in order to identify premobilization factors associated with successful mobilization. The following data were collected: age, gender, weight, complete blood cell count at baseline, G-CSF dose, number of collection procedures, CD34+ cell count in peripheral blood on the first day of collection, CD34+ cell dose per kg body weight of recipient. Mobilization efficacy was defined according to the number of CD34+ cells in peripheral blood on day +5 of G-CSF administration. We classified donors as sub-optimal mobilizers or good mobilizers according to the achievement of the 50 CD34+ cell/μL threshold. We observed 30 suboptimal mobilizations in 158 allogeneic peripheral blood stem cell donations. Age and baseline white blood cell count were factors significantly associated with negative or positive impact on mobilization, respectively. We did not find significant differences in mobilization based on gender or G-CSF dose. Using cut-off values of 43 years and 5.5×10⁹/L WBC count, we built a suboptimal mobilization score: donors who reach 2, 1 or 0 points have a 46%, 16% or 4% probability of suboptimal mobilization, respectively. Our model explains 26% of the variability of mobilization confirming that most of the mobilization magnitude depends on genetically determined factors; however, suboptimal mobilization score is a simple tool providing an early assessment of mobilization efficacy before G-CSF administration begins in order to support allogeneic stem cells selection, mobilization and collection. Through a systematic review, we looked for confirmation of our findings. According to the published articles, all the variables we included in our model are confirmed to be strongly related to the success of mobilization. We believe that score system approach could be applied in clinical practice to assess the risk of mobilization failure at baseline allowing for a priori intervention.

Endothelial activation predicts disseminated intravascular coagulopathy, cytokine release syndrome and prognosis in patients treated with anti‐CD19 CAR‐T cells

Cytokine release syndrome (CRS) and consumptive coagulopathy can complicate the treatment with chimeric antigen receptor T (CAR-T) cells. The modified version of the Endothelial Activation and Stress Index (mEASIX), a score derived from haematopoietic stem cell transplantation, combines platelets, C-reactive protein (CRP), and lactate dehydrogenase (LDH) and has been correlated with CRS and endothelial biomarkers. In 38 consecutive patients with aggressive lymphoproliferative disease we measured a coagulative laboratory panel at baseline and early after infusion of anti-CD19 CAR-T. The panel was investigated also in the presence of CRS graded 2 or higher, or immune effector cell-associated neurotoxicity syndrome (ICANS). Moreover, we examined the relationship between mEASIX, coagulation biomarkers, and toxicities of CAR-T cells. During CRS grade 2 or higher, we found increased prothrombin time (PT) and activated partial thromboplastin time (aPTT), fibrinogen, D-dimer, factor VIII (FVIII), and von Willebrand factor (vWF) antigen levels, and decreased platelet count and antithrombin levels. The occurrence of immune effector cell-associated neurotoxicity syndrome was associated with higher PT values, D-dimer, FVIII, and vWF levels, and decreased fibrinogen levels and platelet count. A higher mEASIX score correlated with increased aPTT values, fibrinogen, D-dimer, FVIII and vWF levels, and decreased antithrombin levels. Baseline mEASIX was predictive for consumptive coagulopathy and CRS graded 2 or higher, and for progression-free survival and overall survival.

Pre-transplant gene profiling characterization by next-generation DNA sequencing might predict relapse occurrence after hematopoietic stem cell transplantation in patients affected by AML

Background

In the last decade, many steps forward have been made in acute myeloid leukemia prognostic stratification, adding next-generation sequencing techniques to the conventional molecular assays. This resulted in the revision of the current risk classification and the introduction of new target therapies.

Aims and methods

We wanted to evaluate the prognostic impact of acute myeloid leukemia (AML) mutational pattern on relapse occurrence and survival after allogeneic stem cell transplantation. A specific next-generation sequencing (NGS) panel containing 26 genes was designed for the study. Ninety-six patients studied with NGS at diagnosis were included and retrospectively studied for post-transplant outcomes.

Results

Only eight patients did not show any mutations. Multivariate Cox regression revealed FLT3 (HR, 3.36; p=0.02), NRAS (HR, 4.78; p=0.01), TP53 (HR, 4.34; p=0.03), and WT1 (HR 5.97; p=0.005) mutations as predictive variables for relapse occurrence after transplantation. Other independent variables for relapse recurrence were donor age (HR, 0.97; p=0.04), the presence of an adverse cytogenetic risk at diagnosis (HR, 3.03; p=0.04), and the obtainment of complete remission of the disease before transplantation (HR, 0.23; p=0.001). Overall survival appeared to be affected only by grade 2-4 acute GvHD occurrence (HR, 2.29; p=0.05) and relapse occurrence (HR, 4.33; p=0.0001) in multivariate analysis.

Conclusions

The small number of patients and the retrospective design of the study might affect the resonance of our data. Although results on TP53, FLT3, and WT1 were comparable to previous reports, the interesting data on NRAS deserve attention.

Immunogenicity of SARS-CoV-2 vaccination in patients undergoing autologous stem cell transplantation. A multicentric experience

COVID-19 disease has a strong impact on hematological patients; those receiving autologous hematopoietic stem cell transplantation (aHSCT) represent a particularly vulnerable group, in which the effectiveness of vaccination is very variable. Chiarucci et al. showed that patients affected by non-Hodgkin lymphoma (NHL) and treated with rituximab experienced a lower rate of immunization against SARS-CoV-2 (54%), as well as significantly lower IgG antibody titers. In our multicenter retrospective observational study, we included 82 patients who underwent aHSCT, divided into two groups: 58 patients vaccinated after aHSCT (group A) and 24 vaccinated before getting transplantation (group B). In group A, 39 (67%) patients had positive serology, and the rate of positivity increased with time after aHSCT. In the subgroup of patients with NHL, the administration of rituximab predicted negative serology, particularly when administered in the 6 months before vaccination (13% response rate). Patients affected by plasma cells had a higher rate of positivity (83% overall), independently of the time to aHSCT. In group B, no patient who initially showed positive serology became negative after transplantation, so the aHSCT did not affect the response to the vaccination. Our study confirmed the role of rituximab as a negative predictor of response to SARS-CoV-2 vaccination, whereas the conditioning and transplantation procedure itself seemed to be less important.

Day +60 WT1 assessment on CD34 selected bone marrow better predicts relapse and mortality after allogeneic stem cell transplantation in acute myeloid leukemia patients

The aim of this study was to evaluate the role of WT1 expression after allogeneic stem cell transplantation (alloHSCT) in patients with acute myeloid leukemia (AML). We studied WT1 expression in bone marrow cells from 50 patients in complete remission on day +60 after transplant. WT1 was assessed on unfractionated bone marrow mononuclear cells (MNC) and on CD34+ selected cells (CD34+). A ROC curve analysis identified 800 WT1 copies on CD34+ selected cells, as the best cut-off predicting relapse (AUC 0.842, p=0.0006, 85.7% sensitivity and 81.6% specificity) and 100 copies in MNC (AUC 0.819, p=0.007, 83.3% sensitivity and 88.2% specificity). Using the 800 WT1 copy cut off in CD34+ cells, the 2 year cumulative incidence of relapse was 12% vs 38% (p=0.005), and 2 year survival 88% vs 55% (p=0.02). Using the 100 WT1 copy cut off in unfractionated MNC, the 2 year cumulative incidence of relapse 13% vs 44% (p=0.01) and the 2 year survival 88% vs 55% (p=0.08). In a multivariate Cox analysis WT1 expression in CD34 cells proved to highly predictive of relapse (p=0.004); also WT1 expression on unfractionated cells predicted relapse (p=0.03). In conclusion, day-60 WT1 expression after allogeneic HSCT is a significant predictor of relapse, particularly when tested on CD34+ selected bone marrow cells.

Efficacy and Tolerability of First Line Arsenic Trioxide in Combination With All-Trans Retinoic Acid in Patients With Acute Promyelocytic Leukemia: Real Life Experience

Acute promyelocytic leukemia is a variant of acute myeloid leukemia characterized by t(15;17) and PML/RAR alfa fusion gene. The discovery of the molecular pathogenesis has led to entitle all-trans retinoic acid (ATRA) as the first targeted therapy for acute leukemia. It is usually associated to anthracycline-based chemotherapy with high response rates, but potential long-term sequelae including therapy-related malignancies have been observed. Arsenic trioxide (ATO) was added to obviate these complications and investigational trials aimed to a new strategy with the incorporation of arsenic trioxide (ATO) into initial therapy instead of chemotherapy in selected patients. ATRA plus ATO without chemotherapy was the first attempt to treat low and intermediate-risk patients with APL. Our study aims to describe a monocentric cohort of patients with newly diagnosed APL effectively treated with ATO plus ATRA underlying its efficacy together with the high grade of tolerability of this association. From January 2009 to December 2019 23 APL patients were diagnosed and treated with ATO plus ATRA regimen: 14 males and 9 females patients with a median age of 45 years (range 18-72), for the majority intermediate risk (15 patients, 65%). The treatment was well tolerated and all patients achieved molecular remission after a median time of 3 months (range 1-6 months). All patients proceeded to consolidation phase as outpatients, they maintained complete molecular response at a median time of 44 months (range 15-127) except for 1 patient. All but one patient are alive and in response at a median follow-up of 48 months (range 9-141) without late effects. ATO plus ATRA regimen shows advantages in comparison to chemotherapy; in fact it allowed to treat patients in which chemotherapy could even not be applicable and it did not show secondary hematological diseases. The association of ATO to ATRA as chemo-free regimen enabled to treat APL even without chemotherapy.

Coronavirus disease 2019 pandemic and allogeneic hematopoietic stem cell transplantation: a single center reappraisal

BACKGROUND

The coronavirus disease 2019 (COVID-19) pandemic has deeply modified the complex logistical process underlying allogeneic hematopoietic stem cell transplant practices.

AIM

In light of these changes, the authors compared data relative to allogeneic transplants carried out from 2018 at their center before (n = 167) and during the pandemic (n = 45).

METHODS

The authors examined patient characteristics, donor and graft types, cell doses and main transplant outcomes. Moreover, the authors evaluated the rise of costs attributable to additional COVID-19-related procedures as well as the risk of adverse events these procedures conveyed to grafts or recipients.

RESULTS

Overall, the number of transplants did not decrease during the pandemic, whereas patients at high relapse risk were prioritized. Transplants were mainly from matched unrelated donors, with a significant decrease in haploidentical related donors. Moreover, the use of bone marrow as a graft for haploidentical transplant was almost abandoned. Cryopreservation was introduced for all related and unrelated apheresis products, with a median storage time of 20 days. Notably, transplant outcomes (engraftment, acute graft-versus-host disease and non-relapse mortality) with cryopreserved products were comparable to those with fresh products.

CONCLUSIONS

Considering that the emergency situation may persist for months, cryopreserving allogeneic grafts can offer a lifesaving opportunity for patients whose allogeneic transplant cannot be postponed until after the end of the COVID-19 pandemic.

Allogeneic Hemopoietic Stem Cell Transplantation for Myelofibrosis: 2021

The aim of this review is to update the current status of allogeneic hemopoietic stem cell transplants (HSCT) for patients with myelofibrosis (MF). We have first summarized the issue of an indication for allogeneic HSCT, discussing several prognostic scoring systems, developed to predict the outcome of MF, and therefore to identify patients who will benefit of an allogeneic HSCT. Patients with low risk MF are usually not selected for a transplant, whereas patients with intermediate or high risk MF are eligible. A separate issue, is how to predict the outcome of HSCT: we will outline a clinical molecular myelofibrosis transplant scoring system (MTSS), which predicts overall survival, ranging from 90% for low risk patients, to 20% for very high risk patients. We will also discuss transfusion burden and spleen size, as predictors of transplant outcome. The choice of a transplant platform including the conditioning regimen, the stem cell source and GvHD prophylaxis, are crucial for a successful program in MF, and will be outlined. Complications such as poor graft function, graft failure, GvHD and relapse of the disease, will also be reviewed. Finally we discuss monitoring the disease after HSCT with donor chimerism, driver mutations and hematologic data. We have made an effort to make this review as comprehensive and up to date as possible, and we hope it will provide some useful data for the clinicians.

Full donor chimerism after allogeneic hematopoietic stem cells transplant for myelofibrosis: The role of the conditioning regimen

The aim of this retrospective study was to assess the rate of full donor chimerism (F-DC) in patients with myelofibrosis, prepared for an allogeneic stem cell transplant, with one or two alkylating agents. We analyzed 120 patients with myelofibrosis, for whom chimerism data were available on day +30. There were two groups: 42 patients were conditioned with one alkylating agent (ONE-ALK), either thiotepa or busulfan or melphalan, in combination with fludarabine, whereas 78 patients were prepared with two alkylating agents, thiotepa busulfan and fludarabine (TBF). Patients receiving TBF were older (57 vs 52 years), were less frequently splenectomized pre-HSCT (31% vs 59%), had more frequently intermediate-2/high DIPSS scores (90% vs 74%), were grafted more frequently from alternative donors (83% vs 33%) and received more frequently ruxolitinib pre-HSCT (26% vs 7%). The proportion of patients with F-DC on day +30, in the TBF vs the ONE-ALK group, was respectively 87% vs 45% (P < .001). The 5-year cumulative incidence of relapse was 9% in the TBF group, vs 43% for the ONE-ALK group (P < .001). The 5-year actuarial disease-free survival was 63% for TBF and 38% for the ONE-ALK group (P = .004). In conclusion, early full donor chimerism is a prerequisite for long term control of disease in patients with myelofibrosis, undergoing an allogeneic HSCT. The combination of two alkylating agents in the conditioning regimen, provides a higher chance of achieving full donor chimerism on day+30, and thus a higher chance of long term disease free survival.

Second haploidentical stem cell transplantation for primary graft failure

We report the outcome of 19 patients who experienced primary graft failure (PrGF) after a haploidentical (HAPLO), unmanipulated bone marrow transplant. The median age of patients was 52 years; the conditioning regimen of the first HAPLO transplant was either full dose total body irradiation (TBI) or fludarabine, busulfan, and thiotepa (TBF); PTCY was given to all patients together with cyclosporine and mycophenolate. All 19 patients with PrGF received a second HAPLO graft, at a median interval of 42 days (34-82) after HSCT, using the Baltimore protocol and G-CSF mobilized PB from the same (n = 13) or another HAPLO family donor (n = 6). GvHD prophylaxis was again PTCY-based; 14/19 patients had trilineage recovery (74%) and 1-year survival was 66%. Engraftment at second HAPLO was seen in 7/8 patient with, and in 5/7 patients without donor-specific antibodies (DSA). In a multivariate logistic regression analysis on the original group of 503 patients, there was a trend for a reduced dose of busulfan, to increase the risk of PrGF (p = 0.1). In conclusion, patients with PrGF following a HAPLO transplant, can be rescued with a second early HAPLO transplant, using the same or a different donor.

Inline and offline extracorporeal photopheresis: Device performance, cell yields and clinical response

BACKGROUND

Extracorporeal photopheresis (ECP) is an effective treatment for graft-vs-host-disease (GvHD). Photopheresis can be performed in offline or inline method. The first uses a conventional cell separator for collection of mononuclear-cells that are photoactivated by a separate device and manually reinfused; the second one involves a dedicated device performing the entire procedure (collection, photoactivation and reinfusion).

STUDY DESIGN AND METHODS

The objective was to compare the two methods and cell product features to highlight key process, devices performance, and to evaluate ECP clinical response. Patients developing steroid-resistant GvHD underwent ECP as second-line treatment using either inline (Therakos CellEx) or offline system (Terumo BCT Spectra or Optia and UVA PIT system). Data about patients' features, pre-apheresis blood-count, cell product characteristics and clinical response were collected for analysis.

RESULTS

We evaluated 494 procedures performed on 28 patients from April 2018 to March 2019. The offline procedure allows to achieve greater cell yield, it is characterized by larger processed blood volume, longer runtime, and higher ACD consumption. The inline procedure shows shorter runtime, high mononuclear-cells percentage and low percentage of granulocytes in cell product. We observed a significant difference in cell yields between inline and offline system; furthermore we did not find a significant relationship between cell dose and clinical response.

CONCLUSION

Inline ECP is fast, highly automated and productive, making it particularly suitable for ECP treatments. Offline ECP collects high cell yields implying longer procedure and greater operator intervention. Our study did not find a significant relationship between cell dose and GVHD response.

Bone marrow haploidentical transplant with post-transplantation cyclophosphamide: does graft cell content have an impact on main clinical outcomes?

We analyzed data relative to cell content in 88 consecutive patients receiving HLA haploidentical bone marrow (BM) transplants with post-transplantation cyclophosphamide (PT-CY). Median age was 54.5 (range, 17-72); diagnoses were acute leukemia (n = 46), lymphoproliferative disorders (n = 24), myelofibrosis (n = 11) and myelodysplastic syndromes (n = 5). Total nucleated cell (TNC) and CD34+, CD3+, CD4+ and CD8+ cell doses were stratified as higher than first, second and third quartile and the dose effect on various clinical outcomes was assessed. Median time to engraftment was 17 days for neutrophils and 24 days for platelets. To receive a dose of TNC ≥3.2 x 10⁶/kg or CD34+ cells ≥2.7 x 10⁶/kg significantly shortened the time to neutrophil and platelet engraftment and reduced the blood product requirements in the 30-day period after transplantation. Overall, TNC and CD34+ cell doses had no effect on acute graft-versus-host disease (GVHD) incidence, whereas patients receiving higher CD3+ and CD8+ cell doses seemed to have less chronic GVHD. No effect on non-relapse mortality, progression-free survival and overall survival was observed at different cell dose thresholds. These data suggest that in HLA haploidentical BM transplant with PT-CY, appropriate cell doses are relevant to the engraftment. The association between low CD3+/CD8+ cells and chronic GVHD deserves further investigation.

Use of eltrombopag in aplastic anemia in Europe

Eltrombopag (ELT), an oral thrombopoietin receptor agonist, has recently emerged as a promising new drug for the treatment of aplastic anemia (AA). How ELT is used outside of clinical trials in the real-world setting and results of this treatment are not known. We conducted therefore a retrospective survey on the use of ELT in AA among EBMT member centers. We analyzed the 134 patients reported in our survey together with 46 patients recently published by Lengline et al. The median follow-up from start of ELT treatment was 15.3 months, with 85.6% patients alive at last follow-up. Importantly, only 28.9% of our patients received ELT according to the FDA/EMA label as monotherapy in the relapsed/refractory setting, whereas 16.7% received ELT upfront. The overall response rate in our cohort was 62%, very similar to the results of the pivotal ELT trial. In multivariate analysis, combination therapy with ELT/cyclosporine/ATG and response to previous therapy were associated with response. Overall survival was favorable with a 1-year survival from ELT start of 87.4%. We identified age, AA severity before ELT start and response to ELT as variables significantly associated with OS. Two patients transformed to MDS; other adverse events were mostly benign. In sum, ELT is used widely in Europe to treat AA patients, mostly in the relapsed/refractory setting. Response to ELT is similar to the clinical trial data across different age groups, treatment lines, and treatment combinations and results in favorable survival.

Haploidentical donor transplants for severe aplastic anemia

Haploidentical stem cell transplantation (HAPLO) is being increasingly used, and significant progress has been made both with ex vivo T-cell depleted grafts as well as with unmanipulated marrow or peripheral blood grafts. We here review the current status of HAPLO grafts in patients with acquired severe aplastic anemia. Several transplant platforms have been tested, to overcome graft severe rejection and graft vs host disease (GvHD): these include differences in the conditioning regimen, in graft source and graft manipulation, and in GvHD prophylaxis. The latter include ex vivo T-cell depletion and/or antithymocyte globulin and/or high dose post-transplant cyclophosphamide. Some programs also include the use of marrow or cord blood mesenchymal stem cells, infused at the time of transplantation. Extremely encouraging results are being reported especially in the pediatric population, but also in young adults: we will review reports on 375 patients, with an average rejection rate of 6%, grade II-IV GvHD of 23% and 1-year survival of 80%. Finally we will discuss the place of HAPLO transplants in the context of alternative donor grafts for acquired aplastic anemia.

First line treatment of aplastic anemia with thymoglobuline in Europe and Asia: Outcome of 955 patients treated 2001-2012

The aim of this study was to assess the outcome of patients with aplastic anemia (AA), receiving rabbit anti‐thymocyte globulin (Thymoglobulin, SANOFI) and cyclosporin, as first line treatment. Eligible were 955 patients with AA, treated first line with Thymoglobulin, between 2001 and 2008 (n = 492), or between 2009 and 2012 (n = 463). The median age of the patients was 21 years (range 1‐84). Mortality within 90 days was 5.7% and 2.4%, respectively in the two time periods (P = .007).The actuarial 10‐year survival for the entire population was 70%; transplant free survival was 64%. Predictors of survival in multivariate analysis, were severity of the disease, patients age and the interval between diagnosis and treatment. Survival was 87% vs 61% for responders at 6 months versus nonresponders (P < .0001). The 10‐year survival of nonresponders at 6 months, undergoing a subsequent transplant (n = 110), was 64%, vs 60% for patient not transplantated (n = 266) (P = .1). The cumulative incidence of response was 37%, 52%, 65% respectively, at 90, 180, and 365 days. In multivariate analysis, negative predictors of response at 6 months, were older age, longer interval diagnosis treatment, and greater severity of the disease. In conclusion, early mortality is low after first line treatment of AA with Thymoglobulin, and has been further reduced after year 2008. Patients age, together with interval diagnosis—treament and severity of the disease, remain strong predictors of response and survival.

Changes in protein serum levels during stem cell transplantation

BACKGROUND

GvHD is one of the major complication after stem cell transplantation affecting transplant-related mortality. Throughout the last years, many serum proteins were been proposed as possible biomarkers for GvHD.

AIMS

We studied the trend of five of the most studied serum proteins to evaluate whether a correlation exists between proteins concentration and post-HSCT outcomes.

MATERIALS AND METHODS

We measured serum concentration of REG3α, ST2, B-cell activating factor (BAFF), CXCL9 and elafin in a cohort of 77 patients submitted to Hematopoietic allogeneic stem cell transplantation (HSCT) in our department. Blood samples were been collected at baseline, day +30, GvHD onset and GvHD resolution.

RESULTS

REG3α levels showed an association only with acute GvHD. Elafin and ST2 levels varied according to both acute and chronic GvHD occurrence. BAFF concentration showed an inverse association with acute GvHD development. Interestingly, baseline BAFF and ST2 levels predicted post-HSCT survival. No associations were found for CXCL9.

CONCLUSIONS

Except for CXCL9, the protein levels seem to change according to GvHD development, independently from organ involvement and grading. Pretransplant ST2 and BAFF appeared to be predictors for survival after HSCT.

Fecal but not serum calprotectin is a potential marker of GVHD after stem cell transplantation

Gastrointestinal graft-versus-host disease (GvHD) represents a life-threatening complication after stem cell transplantation. Differential diagnosis between gut GvHD and other causes of diarrhea after HSCT is still subjected to endoscopy and histological findings. The research for a reliable biomarker for gut GvHD might allow an early diagnosis of this condition and a consequent prompt treatment that could reduce unfavorable outcomes. Recently, fecal calprotectin was reported as reliable marker of gut involvement. We would evaluate if serum instead of fecal calprotectin could be considered a possible biomarker of gut GvHD. Serum calprotectin was measured in a cohort of 54 patients submitted to allogeneic stem cell transplantation using ELISA assay. For a subset of 21 patients, calprotectin serum levels were compared with fecal calprotectin detection. Contrary to fecal calprotectin, we found only a trend to high level of serum calprotectin for GvHD development and gut involvement, but statistical difference was not reached. Fecal but not serum calprotectin could be considered as possible biomarker for gut GvHD.

The role of MTHFR and RFC1 polymorphisms on toxicity and outcome of adult patients with hematological malignancies treated with high-dose methotrexate followed by leucovorin rescue

PURPOSE

In the last years, the influence of different genes involved in metabolism of chemotherapeutic agents has been studied. Methotrexate (MTX) is a key compound of chemotherapeutic regimens used in the treatment of acute lymphoblastic leukemia (ALL), primary central nervous system lymphoma (PCNSL) and Burkitt's lymphomas (BL). This study aims to evaluate the role of MTHFR C677T and A1298C polymorphisms and G80A reduced folate carrier gene (RFC1) in a cohort of adult patients with lymphoproliferative malignancies submitted to high-dose MTX followed by leucovorin rescue.

METHODS

We performed the analysis of these polymorphisms on genomic DNA with RFLP-PCR.

RESULTS

Patients carrying MTHFR A1298C variant showed decreased hepatic and hematological toxicity (P = 0.03). Overall survival (OS) and progression-free survival (PFS) between homozygous wild-type and variant patients for the RFC1 G(80)A were significantly different (P = 0.035 and P = 0.02, respectively). A significant correlation between hematological toxicity and age (P = 0.003) was observed. There was no significant influence of MTHFR C677T genotype on toxicity, OS and PFS.

CONCLUSIONS

Leucovorin rescue given after high-dose MTX probably accounts for the lack of influence of C677T polymorphism. To better define a role of RFC1 polymorphism on patients outcome, it would be worthwhile to perform a study on intracellular MTX level and RFC1 substrate binding affinities in different genotypes.

The role of HLA--G 14-bp polymorphism in allo-HSCT after short-term course MTX for GvHD prophylaxis

HLA-G molecules are HLA class Ib antigens characterized by tolerogenic and immunoinhibitory functions. The HLA-G 14-bp insertion/deletion (ins/del) polymorphism controls protein expression and seems to be implicated in both MTX treatment response and SCT outcome. The aim of our study is to evaluate the role of HLA-G 14 bp polymorphism in subjects affected by hematological malignancies undergoing allo-SCT and receiving MTX therapy for GvHD prophylaxis. We performed a retrospective analysis of HLA-G 14 bp polymorphism using a specific PCR in 47 recipients and in their respective donors, and evaluated the correlation with the incidence of aGvHD, OS and disease-free survival (DFS) after allo-SCT. We did not observe any correlation between this polymorphism and the risk of aGvHD occurrence. On the contrary, we found that the recipients with a 14 bp ins/14 bp ins genotype were characterized by a lower OS and DFS in univariate and multivariate analysis (OS=OR: 3.235; DFS=OR: 3.302). These data indicate a role for recipient HLA-G 14 bp polymorphism in allo-SCT immunotolerance status and follow-up.