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Introduction: Despite the generally mild course of COVID-19 in children, immunocompromised patients may experience complications or severe infection. This study reports the clinical outcomes of pediatric patients treated with nirmatrelvir and ritonavir (N/R) for SARS-CoV-2 infection., Methods: We retrospectively reported the data of children with any immunodeficiency with COVID-19 who received N/R treatment between March 2022 and June 2023 at the Bambino Gesù Children's Hospital. Patients were treated with N/R for 5 days. We compared liver and kidney function before and after treatment with N/R and looked for a relationship between the duration of COVID-19 infection and the time from positivity to administration of N/R administration., Results: A total of 85 pediatric immunocompromised patients with COVID-19 were included in the study, with a mean age of 10.7 years (SD 4.8), mostly males (60%). We found a significant difference in the viral load before and after N/R administration. Four patients (4.7%) experienced adverse events related to N/R therapy. One of these had to discontinue N/R administration. Three patients (3.5%) experienced negative effects of drug interactions during N/R therapy, namely an increase of sirolimus and ciclosporin serum levels. A significant positive correlation was found between the time from SARS-CoV-2 positivity to N/R administration and the duration of SARS-CoV-2 swab positivity (R = 0.78, P < 0.001), suggesting that the earlier N/R is administered, the shorter the duration of COVID-19 in the study sample., Conclusion: Our experience shows that N/R is reasonably safe in the pediatric population and could favor viral clearance, thus reducing the duration of infection., Competing Interests: The authors have no conflict of interest to disclose., (Copyright © 2024 Wolters Kluwer Health, Inc. All rights reserved.)

γδ T-cells represent key players in the immune-surveillance after TCR alpha/beta (αβ)/CD19-depleted HLA-Haploidentical Stem Cell Transplantation (haplo-HSCT). Although encouraging data are available on the impact of Vδ2-targeting-therapy in improving HSCT-clinical outcomes, their role in providing antimicrobial immunity is largely unexplored. This study aimed to investigate the antiviral protective profile of Vδ2 T-cells in pediatric patients given this type of allograft. The characterization of γδ T-cells was performed by flow cytometry in haplo-HSCT-pediatric patients (n=26) in the donor graft and after 30, 60 and 120 days post-HSCT. The antiviral activity of Vδ2 T-cells was assessed on CMV-infected-fibroblasts and the CMV-specific αβ T-cell immunity was analyzed by flow cytometry. Early after HSCT, frequency of Vδ2 T-cells was significantly higher in patients who did not experience viral reactivation (No-VR) than in patients with CMV reactivation (CMV-R). Interestingly, this difference was already present in the grafts. Clustering analysis identified a protective subset of Vδ2 T-cells in No-VR patients, which expresses CD16, NKG2D, and CD107a and produces high levels of IFN-γ. This subset directly correlated with IL-15 and inversely with the CMV-DNA level. Stimulated Vδ2 T-cells inhibit CMV replication, acquired CD86/HLA-DR molecules, induced HLA-DR on monocytes, and improved the αβ CMV-specific T-cell response. Altogether, these results identify an antiviral protective profile displayed by Vδ2 T-cells early after HSCT, and define their ability to inhibit CMV replication, to induce antigen-presenting cell maturation and to improve αβ virus-specific T-cell response, opening a new application of Vδ2-targeting immunotherapy after HSCT, adding the antiviral to the antitumor potential., (Copyright © 2024 American Society of Hematology.)

Blinatumomab has remarkable efficacy in patients with relapsed/refractory (r/r) or measurable residual disease (MRD)-positive B-cell acute lymphoblastic leukemia (B-ALL). In many patients, blinatumomab treatment is followed by allogeneic hematopoietic stem cell transplantation (HSCT). However, the influence of blinatumomab on HSCT outcomes in children and young adults (YA) remains to be fully elucidated. We conducted a single-center, retrospective analysis on patients given blinatumomab as last treatment before HSCT. Seventy-eight pediatric and YA patients were evaluated. With a median follow-up of 23.23 months, the 2-year disease-free (DFS) and overall survival (OS) probability were 72.2% and 89.2%, respectively, with a 2-year cumulative incidence (CI) of non-relapse mortality (NRM) of 2.6%. A trend toward improved 2-year DFS, but not OS, was noted in patients transplanted in first complete remission (CR1) (92.9%) compared to those in second or greater remission (CR2/3) (68.5%, p=0.18) due to a lower CI of relapse (0% vs. 29.9%, p=0.05). Among CR2/3 patients, those receiving the sequential combination of inotuzumab and blinatumomab had a significantly lower CI of relapse as compared to those who did not receive inotuzumab (9.5% vs. 40.4%, p=0.023). Relapse after HSCT occurred in 16 patients, all exhibiting CD19-positive blasts; 10 of them received anti-CD19 chimeric antigen receptor T-cell (CAR-T) therapy and 2 inotuzumab as salvage therapy, leading to a 2-year post-relapse OS of 52.7%. Our results indicate that HSCT following blinatumomab in children and YA with B-ALL is highly effective, being associated with low NRM and not affecting the efficacy of subsequent salvage immunotherapies, including CAR-T cells.

Mucosal-associated invariant T (MAIT) cells are innate-like T cells implicated in the response to fungal and bacterial infections. Their contribution to restoring T-cell immunity and influencing hematopoietic stem cell transplant (HSCT) outcomes remains poorly understood. We retrospectively studied MAIT-cell recovery in 145 consecutive children and young adults with hematologic malignancies undergoing allogeneic (allo)-HSCT between April 2019 and May 2022, from unrelated matched donor (MUD, N=52), with standard graft-versus-host-disease (GvHD) prophylaxis, or HLA-haploidentical (Haplo, N=93) donor after in vitro αβT/CD19-cell depletion, without post-HSCT pharmacological prophylaxis. With a median follow-up of 33 months (range, 12-49 months), overall survival (OS), disease-free survival (DFS), and non-relapse mortality (NRM) were 79.5%, 72%, and 7%, respectively; GvHD-free relapse-free survival (GRFS) was 63%, while cumulative incidence of relapse was 23%. While αβT cells were reconstituted 1-2 years post HSCT, MAIT cells showed delayed recovery and prolonged functional impairment, characterized by expression of activation (CD25, CD38), exhaustion (PD1, TIM3) and senescence (CD57) markers, and suboptimal ex vivo response. OS, DFS, and NRM were not affected by MAIT cells. Interestingly, higher MAIT cells at day +30 correlated with higher incidence of grade II-IV acute GvHD (19% vs. 7%, P=0.06). Furthermore, a greater MAIT-cell count tended to be associated with a higher incidence of chronic GvHD (cGvHD) (17% vs. 6%, P=0.07) resulting in lower GRFS (55% vs. 73%, P=0.05). Higher MAIT cells also correlated with greater cytomegalovirus (CMV) reactivation and lower late blood stream infections (BSI) (44% vs. 24%, P=0.02 and 9% vs. 18%, P=0.08, respectively). Future studies are needed to confirm the impact of early MAIT-cell recovery on cGvHD, CMV reactivation, and late BSI.

Letermovir prophylaxis revolutionized the approach to Cytomegalovirus infection in adult hematopoietic stem cell transplant (HCT), while data in pediatric setting are still lacking. We retrospectively analyzed 87 HCT children transplanted in 11 AIEOP centers receiving letermovir as off-label indication between January 2020 and November 2022. Letermovir was used as primary, secondary prophylaxis or CMV treatment in 39, 26 and 22 cases, respectively; no discontinuation due to toxicity was reported. Median duration was 100 days (14-256) for primary and 96 days (8-271) for secondary prophylaxis, respectively. None of the patients experienced CMV-clinically significant reactivation during Letermovir primary prophylaxis; one patient developed breakthrough infection during secondary prophylaxis, and 10 and 1 patient experienced asymptomatic CMV-reactivation and CMV-primary infection after drug discontinuation, respectively. Median duration of letermovir in CMV treatment was 40 days (7-134), with 4/22 patients suffering CMV-pneumonia, with an overall response rate of 86.4%. With a median follow-up of 10.7 months (8.2-11.8), estimated 1-year overall survival was 86%; no CMV-related deaths were reported in prophylaxis groups. This is the largest report on Letermovir use in pediatric HCT; real-life data confirm an excellent toxicity profile, with high efficacy as CMV prophylaxis; results in CMV-infection treatment should be investigated in larger, prospective trials., (© 2024. The Author(s), under exclusive licence to Springer Nature Limited.)

Abstract: TCRαβ/CD19 cell depletion is a promising graft manipulation technique frequently used in the context of human leukocyte antigen (HLA)-haploidentical hematopoietic stem cell transplantation (HSCT). We previously reported the results of a phase I-II clinical trial (NCT01810120) to assess the safety and the efficacy of this type of exvivo T-cell depletion in 80 children with acute leukemia, showing promising survival outcomes. We now report an updated analysis on a cohort of 213 children with a longer follow-up (median, 47.6 months for surviving patients). With a 5-year cumulative incidence of nonrelapse mortality of 5.2% (95% confidence interval [CI], 2.8%-8.8%) and a cumulative incidence of relapse of 22.7% (95% CI, 16.9%-29.2%), projected 10-year overall and disease-free survival (DFS) were 75.4% (95% CI, 68.6%-80.9%) and 71.6% (95% CI, 64.4%-77.6%), respectively. Cumulative incidence of both grade II-IV acute and chronic graft-versus-host disease were low (14.7% and 8.1%, respectively). In a multivariable analysis for DFS including type of disease, use of total body irradiation in the conditioning regimen (hazard ratio [HR], 0.5; 95% CI, 0.26-0.98; P = .04), disease status at HSCT (complete remission [CR] ≥3 vs CR 1/2; HR, 2.23; 95% CI, 1.20-4.16; P = .01), and high levels of pre-HSCT minimal residual disease (HR, 2.09; 95% CI, 1.01-4.33; P = .04) were independently associated with outcome. In summary, besides confirming the good outcome results already reported (which are almost superimposable on those of transplant from HLA-matched donors), this clinical update allows the identification of patients at higher risk of treatment failure for whom personalized approaches, aimed at reducing the risk of relapse, are warranted., (© 2024 American Society of Hematology. Published by Elsevier Inc. All rights are reserved, including those for text and data mining, AI training, and similar technologies.)

Background: Recently, increasing attention has been paid to the use of microsampling techniques for therapeutic drug monitoring (TDM) in neonatal and pediatric populations. Volumetric Absorptive Microsampling (VAMS) has been introduced in the market under the name Mitra® (Neoteryx). These devices consist of porous absorbent tips that allow collection of fixed blood volumes (10-30 µL) to overcome the DBS-related hematocrit effect. Here, the authors analyzed the concentrations of triazole agents (voriconazole, posaconazole, and isavuconazole) in VAMS and dried plasma spot (DPS) samples., Methods: Fifty whole blood samples were obtained from pediatric patients subjected to systemic anti-fungal therapy. VAMS were collected by dipping the tip into whole blood before centrifugation for plasma recovery. Then, 30 µL of plasma was carefully spotted on filter paper to obtain DPS. Anti-fungal concentrations were measured using a validated LC-MS/MS kit (MassTox® Antimycotic Drugs/EXTENDED) provided by Chromsystems (Chromsystems Instruments & Chemicals). Drug concentrations in VAMS and DPS samples were compared to those in fresh plasma using Passing-Bablok and Bland-Altman tests., Results: Plasma concentrations of voriconazole, posaconazole, and isavuconazole were positively and significantly correlated with those obtained in VAMS and DPS samples (Spearman r range, 0.82-0.94, p < 0.001). Data were further analyzed using the Bland-Altman test, which showed a % mean difference compared to fresh plasma of -15.06-10.98 (range). The stability of both VAMS and DPS was ensured for at least 14 d at room temperature., Conclusions: These results demonstrate that VAMS and DPS can be used for the TDM of anti-fungal agents. Owing to their stability, both sampling devices can be easily stored and shipped, without the need for refrigeration, to TDM laboratories that facilitate remote TDM applications. Finally, VAMS could be particularly suitable for pediatric and neonatal patients because they allow the collection of a few microliters of blood, thus improving ethical and compliance limitations., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier B.V. All rights reserved.)

Background: Immunotherapy with chimeric antigen receptor (CAR)-expressing T cells that target the disialoganglioside GD2 expressed on tumor cells may be a therapeutic option for patients with high-risk neuroblastoma., Methods: In an academic, phase 1-2 clinical trial, we enrolled patients (1 to 25 years of age) with relapsed or refractory, high-risk neuroblastoma in order to test autologous, third-generation GD2-CAR T cells expressing the inducible caspase 9 suicide gene (GD2-CART01)., Results: A total of 27 children with heavily pretreated neuroblastoma (12 with refractory disease, 14 with relapsed disease, and 1 with a complete response at the end of first-line therapy) were enrolled and received GD2-CART01. No failure to generate GD2-CART01 was observed. Three dose levels were tested (3-, 6-, and 10×10 6 CAR-positive T cells per kilogram of body weight) in the phase 1 portion of the trial, and no dose-limiting toxic effects were recorded; the recommended dose for the phase 2 portion of the trial was 10×10 6 CAR-positive T cells per kilogram. Cytokine release syndrome occurred in 20 of 27 patients (74%) and was mild in 19 of 20 (95%). In 1 patient, the suicide gene was activated, with rapid elimination of GD2-CART01. GD2-targeted CAR T cells expanded in vivo and were detectable in peripheral blood in 26 of 27 patients up to 30 months after infusion (median persistence, 3 months; range, 1 to 30). Seventeen children had a response to the treatment (overall response, 63%); 9 patients had a complete response, and 8 had a partial response. Among the patients who received the recommended dose, the 3-year overall survival and event-free survival were 60% and 36%, respectively., Conclusions: The use of GD2-CART01 was feasible and safe in treating high-risk neuroblastoma. Treatment-related toxic effects developed, and the activation of the suicide gene controlled side effects. GD2-CART01 may have a sustained antitumor effect. (Funded by the Italian Medicines Agency and others; ClinicalTrials.gov number, NCT03373097.)., (Copyright © 2023 Massachusetts Medical Society.)

High genetic heterogeneity in the human leukocyte antigen (HLA) increases the likelihood of efficient immune response to pathogens and tumours. As measure of HLA diversity, HLA evolutionary divergence (HED) has been shown to predict the response of tumours to immunotherapy and haematopoietic stem cell transplantation (HSCT) in adults. We retrospectively investigated the association of HED with outcomes of 153 paediatric/young adults patients, treated for malignant disorders with HSCT from 9-10/10 HLA-matched unrelated donors. HED was calculated as pairwise genetic distance between alleles in patient HLA-A, -B, -C, -DRB1, -DQB1 and -DPB1, using the locus median to stratify patients with 'high' or 'low' HED. Patients with high HED-B and -DRB1 showed significantly improved disease-free survival (DFS), especially when combined (70.8% vs 53.7% p = 0.008). High HED-B + -DRB1 was also associated with improved overall survival (OS) (82.1 vs 66.4% p = 0.014), and concomitant reduction of non-relapse-mortality (5.1% vs 21.1% p = 0.006). The impact on OS and DFS of combined HED-B + -DRB1 was confirmed in multivariate analysis [hazard ratio (HR) 0.39, p = 0.009; and HR 0.45, p = 0.007 respectively]. Only high HED scores for HLA-DPB1 were associated, in univariate analysis, with reduced incidence of relapse (15.9% vs 31.1%, p = 0.03). These results support HED as prognostic marker in allogeneic HSCT and, if confirmed in larger cohorts, would allow its use to inform clinical risk and potentially influence clinical practice., (© 2022 The Authors. British Journal of Haematology published by British Society for Haematology and John Wiley & Sons Ltd.)

Children are prone to bloodstream infections (BSIs), the rapid and accurate diagnosis of which is an unmet clinical need. The T2MR technology is a direct molecular assay for identification of BSI pathogens, which can help to overcome the limits of blood culture (BC) such as diagnostic accuracy, blood volumes required, and turnaround time. We analyzed results obtained with the T2Bacteria (648) and T2Candida (106) panels in pediatric patients of the Bambino Gesù Children's Hospital between May 2018 and September 2020 in order to evaluate the performance of the T2Dx instrument with respect to BC. T2Bacteria and T2Candida panels showed 84.2% and 100% sensitivity with 85.9% and 94.1% specificity, respectively. The sensitivity and specificity of the T2Bacteria panel increased to 94.9% and 98.7%, respectively, when BC was negative but other laboratory data supported the molecular result. T2Bacteria sensitivity was 100% with blood volumes <2 mL in neonates and infants. T2Bacteria and T2Candida provided definitive microorganism identification in a mean time of 4.4 and 3.7 h, respectively, versus 65.7 and 125.5 h for BCs ( P  < 0.001). T2 panels rapidly and accurately enable a diagnosis of a pediatric BSI, even in children under 1 year of age and for very small blood volumes. These findings support their clinical use in life-threatening pediatric infections, where the time to diagnosis is of utmost importance, in order to improve survival and minimize the long-term sequalae of sepsis. The T2 technology could be further developed to include more bacteria and fungi species that are involved in the etiology of sepsis.

Background: Innate lymphoid cells (ILCs) comprise cytotoxic natural killer (NK) cells and helper ILCs (hILCs). Human hILC development is less characterized as compared with that of NK cells, although all ILCs are developmentally related. It has been reported that the immunosuppressive drugs glucocorticoids (GCs) regulate ILC function, but whether they control ILC differentiation from hematopoietic stem cells (HSCs) is unknown., Objectives: This study sought to analyze the effect of GCs on ILC development from HSCs., Methods: This study exploited an in vitro system to generate and expand from peripheral blood HSCs a multipotent CD56 + ILC precursor able to differentiate into NK cells, ILC1s, and ILC3s. We also analyzed ex vivo, at different time points, the peripheral blood of recipients of allogeneic HSC transplantation who were or were not treated with GCs and compared ILC subset reconstitution., Results: Invitro, GCs favor the generation of NK cells from myeloid precursors, while they strongly impair lymphoid development. In support of these data, recipients of HSC transplantation who had been treated with GCs display a lower number of circulating hILCs, including the ILC precursor (ILCP) previously identified as a systemic substrate for tissue ILC differentiation., Conclusions: GCs impair the development of the CD117 + ILCP from CD34 + HSCs, while they do not affect the further steps of ILCP differentiation toward NK cells and hILC subsets. This reflects an association of GC treatment with a marked reduction of circulating hILCs in the recipients of HSC transplantation., (Copyright © 2021 The Authors. Published by Elsevier Inc. All rights reserved.)

The aim of this study was to develop a predictive score for moderate-severe chronic graft-versus-host disease (cGVHD) on day +100 after allogeneic stem cell transplantation (HSCT). We studied 1292 patients allografted between 1990 and 2016, alive on day +100 after transplant, without cGVHD, and with full biochemistry laboratory values available. Patients were randomly assigned to a training and a validation cohort (ratio 1:1). In the training cohort, a multivariate analysis identified 4 independent predictors of moderate-severe cGVHD: gamma-glutamyl transferase ≥75 UI/l, creatinine ≥1 mg/dl, cholinesterase ≤4576 UI/l, and albumin ≤4 g/dl. A score of 1 was assigned to each variable, producing a low (0 to 1), intermediate (2 to 3), and high (4) score. The cumulative incidence of moderate-severe cGVHD was 12%, 20%, and 52% (P < .0001) in the training cohort, and 13%, 24%, and 33% (P = .002) in the validation cohort, respectively. The 5-year cumulative incidence of transplant-related mortality (TRM) was 5%, 14%, 27% (P < .0001) and 5%, 16%, 31% (P < .0001), respectively. The 5-year survival was 64%, 57%, 54% (P = .009) and 70%, 59%, 42% (P = .0008) in the 2 cohorts, respectively. In conclusion, Day100 score predicts cGVHD, TRM, and survival and, if validated in a separate group of patients, could be considered for trials of preemptive therapy., (© 2022 by The American Society of Hematology. Licensed under Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International (CC BY-NC-ND 4.0), permitting only noncommercial, nonderivative use with attribution. All other rights reserved.)

Natural killer (NK) cells represent a promising cell type in antitumor immunotherapy for efficacy and safety, particularly in the treatment of hematologic malignancies. NK cells have been shown to exert antileukemia activity in the context of haploidentical hematopoietic stem cell transplantation (haplo-HSCT). Products have been developed to boost the activation of NK cells only when cross-linked by tumor cells, avoiding any off-target effect. Here, we tested the in vitro effect of different NK-cell engagers (NKCE), which trigger either NKp46 or NKp30 together with CD16A, and target either CD19 or CD20 to induce killing of pediatric B-cell precursor acute lymphoblastic leukemia (BCP-ALL). Target cells were NALM-16 and MHH-CALL-4 cell lines and four primary leukemias, while effector cells were resting NK cells derived from healthy donors and pediatric patients with leukemia after αβT/B-depleted haplo-HSCT. The NK cell-resistant MHH-CALL-4 was efficiently killed using all NKCEs. Boosting of NK activity against MHH-CALL-4 was also evident by degranulation and IFNγ production. Because of the lack of CD20 and high expression of CD19 on primary BCP-ALL, we focused on NKCEs targeting CD19. NKp46- and NKp30-based NKCEs displayed similar potency at inducing NK-cell activity, even when challenged with primary BCP-ALL blasts. Their efficacy was shown also using NK cells derived from transplanted patients. NKCE-induced activation against BCP-ALL can override HLA-specific inhibitory interactions, although the strongest response was observed by the alloreactive NK-cell subset. These data support the therapeutic use of NKp46/CD16A/CD19-NKCE to fight refractory/relapsed leukemia in pretransplantation or posttransplantation settings., (©2022 The Authors; Published by the American Association for Cancer Research.)

Vaccines represent the best tool to prevent the severity course and fatal consequences of the pandemic by the new Coronavirus 2019 infection (SARS-CoV-2). Considering the limited data on vaccination of pediatric oncohematological patients, we developed a Consensus document to support the Italian pediatric hematological oncological (AIEOP) centers in a scientifically correct communication with families and patients and to promote vaccination. The topics of the Consensus were: SARS-CoV-2 infection and disease (COVID-19) in the pediatric subjects; COVID-19 vaccines (type, schedule); who and when to vaccinate; contraindications and risk of serious adverse events; rare adverse events; third dose and vaccination after COVID-19; and other general prevention measures. Using the Delphi methodology for Consensus, 21 statements and their corresponding rationale were elaborated and discussed with the representatives of 31 centers, followed by voting. A high grade of Consensus was obtained on topics such as the potential risk of severe COVID-19 outcome in pediatric oncohematological patients, the need for vaccination as a preventative measure, the type, schedule and booster dose of vaccine, the eligibility of the patients for vaccination, and the timing, definition, and management of contraindications and serious adverse events, and other general prevention measures. All 21 of the statements were approved. This consensus document highlights that children and adolescents affected by hematological and oncological diseases are a fragile category. Vaccination plays an important role to prevent COVID-19, to permit the regular administration of chemotherapy or other treatments, to perform control visits and hospital admissions, and to prevent treatment delays.

Several nonmalignant disorders (NMDs), either inherited or acquired, can be cured by allogeneic hematopoietic stem cell transplantation (HSCT). Between January 2012 and April 2020, 70 consecutive children affected by primary immunodeficiencies, inherited/acquired bone marrow failure syndromes, red blood cell disorders, or metabolic diseases, lacking a fully matched donor or requiring urgent transplantation underwent TCRαβ/CD19-depleted haploidentical HSCT from an HLA-partially matched relative as part of a prospective study. The median age at transplant was 3.5 years (range 0.3-16.1); the median time from diagnosis to transplant was 10.5 months (2.7 for SCID patients). Primary engraftment was obtained in 51 patients, while 19 and 2 patients experienced either primary or secondary graft failure (GF), the overall incidence of this complication being 30.4%. Most GFs were observed in children with disease at risk for this complication (eg, aplastic anemia, thalassemia). All but 5 patients experiencing GF were successfully retransplanted. Six patients died of infectious complications (4 had active/recent infections at the time of HSCT), the cumulative incidence of transplant-related mortality (TRM) being 8.5%. Cumulative incidence of grade 1-2 acute GVHD was 14.4% (no patient developed grade 3-4 acute GVHD). Only one patient at risk developed mild chronic GVHD. With a median follow-up of 3.5 years, the 5-year probability of overall and disease-free survival was 91.4% and 86.8%, respectively. In conclusion, TCRαβ/CD19-depleted haploidentical HSCT from an HLA-partially matched relative is confirmed to be an effective treatment of children with NMDs. Prompt donor availability, low incidence of GVHD, and TRM make this strategy an attractive option in NMDs patients. The study is registered at ClinicalTrial.gov as NCT01810120., (© 2022 by The American Society of Hematology. Licensed under Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International (CC BY-NC-ND 4.0), permitting only noncommercial, nonderivative use with attribution. All other rights reserved.)

We studied pretransplant minimal residual disease (MRD) in 224 patients (median age 44 years; range 17-65) with acute myeloid leukemia (AML) undergoing allogeneic stem cell transplant (HSCT) in complete remission. MRD was evaluated on marrow samples using multicolor flow cytometry and assessment of WT1 gene expression. Both methods showed a strong prognostic value and their combination allowed the identification of three groups of patients with different risk of relapse. In multivariate analysis, combined MRD was the only predictor of cumulative incidence of relapse, regardless of donor type, conditioning regimen, first or second CR at HSCT, HSCT year, and ELN risk group. Multivariate regression model showed that only negative combined MRD status (P < .001) and myeloablative conditioning (P = .004) were independently associated with better OS. Among MRD-positive patients, a reduced incidence of relapse was observed in patients receiving haplo transplant (P < .05) and in patients who showed grade II-IV aGVHD (P < .03). In patients with negative combined MRD, the intensity of conditioning regimen did not affect the overall favorable outcome. We suggest that pretransplant MRD evaluation combined with transplant-related factors can identify AML patients at higher risk for relapse and might help in defining the overall transplant strategy., (© 2021 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

Letermovir (LMV) is licensed for prophylaxis of CMV infection in allogeneic hematopoietic cell transplant adult CMV-seropositive patients. Due to its favorable safety profile, LMV brings potential for use in other clinical situations, outside the approved indication. The objective of the study was to analyze the efficacy and safety of the use of LMV in off-label indications in EBMT centers. A total of 49 patients were reported including 44 adults and 5 children. LMV was administered for: secondary prophylaxis (37 adults, 3 children), primary prophylaxis (2 children), pre-emptive treatment (5 adults), and therapy of CMV disease (2 adults; pneumonia, colitis). Cyclosporine was concomitantly used in 26 patients. Overall, LMV was used for a median 112 days (range: 10-473). Cumulative incidence of breakthrough infections during secondary prophylaxis was 10.1% (95% CI = 3.1-21.9). Prophylactic treatment with LMV resulted in 94.9% (95% CI = 81.0-98.7), and 81.9% (95% CI = 65.7-90.9) probability of, respectively, 60 and 120-day survival without CMV infection in patients receiving secondary prophylaxis. During therapy of CMV infection/disease, probability of 60 and 120-day overall survival was 100% and 71.4% (95% CI = 25.8-92.0), respectively. No breakthrough infection occurred in children on LMV prophylaxis. Adverse events were reported in 15/49 (30.4%) patients: the most common being nausea/vomiting (22.4%). In conclusion, the efficacy of the use of LMV as secondary prophylaxis was high, and the preliminary experience with the use of LMV for the treatment of patients with refractory CMV infection/disease was positive. Our data showed that higher dose or prolonged therapy did not result in increased rate of adverse events.

Prophylaxis of Pneumocystis jiroveci pneumonia (PJP) with trimethoprim/sulfamethoxazole is a standard of care for children with hematologic malignancies, while its use in solid tumor patients is still debated. A retrospective study focusing on the use of PJP prophylaxis in patients with solid tumors was performed among 16 AIEOP centers: 1046/2863 patients did not receive prophylaxis and no cases of PJP were reported., Competing Interests: The authors have no funding and conflicts of interest to disclose., (Copyright © 2021 Wolters Kluwer Health, Inc. All rights reserved.)

Background: Little is known as yet about the outcome of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection in children being treated for cancer., Methods: We collected information on the clinical characteristics and outcomes of a cohort of 29 children (16 female and 13 male; median age, 7 years [range, 0-16 years]) diagnosed with SARS-CoV-2 infection while on chemotherapy/immunotherapy (n = 26), or after stem cell transplantation (n = 3) during the peak of the epidemic in Italy. These patients suffered from leukemia (n = 16), lymphoma (n = 3), solid tumors (n = 10), and Langerhans cell histiocytosis (n = 1)., Results: The course of the disease was mild in all cases, with only 12 children developing symptoms (pneumonia in 3 cases), and none needing intensive care. Fifteen patients were hospitalized, including 7 asymptomatic patients. Nine patients (including 5 with no symptoms) were given hydroxychloroquine, and 3 of them were also given lopinavir/ritonavir. Among the 26 patients on chemotherapy/immunotherapy, the treatment was suspended in 16 cases for a median of 26 days (range, 15-68 days), whereas 8 patients continued their chemotherapy and 2 had minor modifications to their treatment regimen., Conclusions: SARS-CoV-2 infection seems to take a milder clinical course in children than in adults with cancer. Specific SARS-CoV-2 treatment seems unnecessary for most children. In light of our findings, and albeit with the necessary caution, we suggest avoiding major changes to planned anticancer treatments in pediatric patients acquiring COVID-19., (© The Author(s) 2020. Published by Oxford University Press on behalf of The Journal of the Pediatric Infectious Diseases Society. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

NK cells can exert remarkable graft-versus-leukemia (GvL) effect in HLA-haploidentical hematopoietic stem cell transplantation (haplo-HSCT). Here, we dissected the NK-cell repertoire of 80 pediatric acute leukemia patients previously reported to have an excellent clinical outcome after αβT/B-depleted haplo-HSCT. This graft manipulation strategy allows the co-infusion of mature immune cells, mainly NK and γδT cells, and hematopoietic stem cells (HSCs). To promote NK-cell based antileukemia activity, 36/80 patients were transplanted with an NK alloreactive donor, defined according to the KIR/KIR-Ligand mismatch in the graft-versus-host direction. The analysis of the reconstituted NK-cell repertoire in these patients showed relatively high proportions of mature and functional KIR + NKG2A - CD57 + NK cells, including the alloreactive NK cell subset, one month after HSCT. Thus, the NK cells adoptively transfused with the graft persist as a mature source of effector cells while new NK cells differentiate from the donor HSCs. Notably, the alloreactive NK cell subset was endowed with the highest anti-leukemia activity and its size in the reconstituted repertoire could be influenced by human cytomegalovirus (HCMV) reactivation. While the phenotypic pattern of donor NK cells did not impact on post-transplant HCMV reactivation, in the recipients, HCMV infection/reactivation fostered a more differentiated NK-cell phenotype. In this cohort, no significant correlation between differentiated NK cells and relapse-free survival was observed.

TcRαβ/CD19-cell depleted HLA-haploidentical hematopoietic stem cell transplantation (haplo-HSCT) represents a promising new platform for children affected by acute leukemia in need of an allograft and lacking a matched donor, disease recurrence being the main cause of treatment failure. The use of zoledronic acid to enhance TcRγδ+ lymphocyte function after TcRαβ/CD19-cell depleted haplo-HSCT was tested in an open-label, feasibility, proof-of-principle study. Forty-six children affected by high-risk acute leukemia underwent haplo-HSCT after removal of TcRαβ+ and CD19+ B lymphocytes. No post-transplant pharmacological graft-versus-host disease (GvHD) prophylaxis was given. Zoledronic acid was administered monthly at a dose of 0.05 mg/kg/dose (maximum dose 4 mg), starting from day +20 after transplantation. A total of 139 infusions were administered, with a mean of 3 infusions per patient. No severe adverse event was observed. Common side effects were represented by asymptomatic hypocalcemia and acute phase reactions (including fever, chills, malaise, and/or arthralgia) within 24-48 h from zoledronic acid infusion. The cumulative incidence of acute and chronic GvHD was 17.3% (all grade I-II) and 4.8% (all limited), respectively. Patients given 3 or more infusions of zoledronic acid had a lower incidence of both acute GvHD (8.8 vs. 41.6%, p = 0.015) and chronic GvHD (0 vs. 22.2%, p = 0.006). Transplant-related mortality (TRM) and relapse incidence at 3 years were 4.3 and 30.4%, respectively. Patients receiving repeated infusions of zoledronic acid had a lower TRM as compared to those receiving 1 or 2 administration of the drug (0 vs. 16.7%, p = 0.01). Five-year overall survival (OS) and disease-free survival (DFS) for the whole cohort were 67.2 and 65.2%, respectively, with a trend toward a better OS for patients receiving 3 or more infusions (73.1 vs. 50.0%, p = 0.05). The probability of GvHD/relapse-free survival was significantly worse in patients receiving 1-2 infusions of zoledonic acid than in those given ≥3 infusions (33.3 vs. 70.6%, respectively, p = 0.006). Multivariable analysis showed an independent positive effect on outcome given by repeated infusions of zoledronic acid (HR 0.27, p = 0.03). These data indicate that the use of zoledronic acid after TcRαβ/CD19-cell depleted haploHSCT is safe and may result in a lower incidence of acute GvHD, chronic GvHD, and TRM., (Copyright © 2020 Merli, Algeri, Galaverna, Milano, Bertaina, Biagini, Girolami, Palumbo, Sinibaldi, Becilli, Leone, Boccieri, Grapulin, Gaspari, Airoldi, Strocchio, Pagliara and Locatelli.)

Pathophysiology of graft failure (GF) occurring after allogeneic hematopoietic stem cell transplantation (HSCT) still remains elusive. We measured serum levels of several different cytokines/chemokines in 15 children experiencing GF, comparing their values with those of 15 controls who had sustained donor cell engraftment. Already at day +3 after transplantation, patients developing GF had serum levels of interferon (IFN)-γ and CXCL9 (a chemokine specifically induced by IFNγ) significantly higher than those of controls (8859±7502 vs. 0 pg/mL, P =0.03, and 1514.0±773 vs. 233.6±50.1 pg/mlL, P =0.0006, respectively). The role played by IFNγ in HSCT-related GF was further supported by the observation that a rat anti-mouse IFNγ-neutralizing monoclonal antibody promotes donor cell engraftment in Ifngr1 -/- mice receiving an allograft. In comparison to controls, analysis of bone marrow-infiltrating T lymphocytes in patients experiencing GF documented a predominance of effector memory CD8 + cells, which showed markers of activation (overexpression of CD95 and downregulation of CD127) and exhaustion (CD57, CD279, CD223 and CD366). Finally, we obtained successful donor engraftment in 2 out of 3 children with primary hemophagocytic lymphohistiocytosis who, after experiencing GF, were re-transplanted from the same HLA-haploidentical donor under the compassionate use coverage of emapalumab, an anti-IFNγ monoclonal antibody recently approved by the US Food and Drug Administration for treatment of patients with primary hemophagocytic lymphohistiocytosis. Altogether, these results suggest that the IFNγ pathway plays a major role in GF occurring after HSCT. Increased serum levels of IFNγ and CXCL9 represent potential biomarkers useful for early diagnosis of GF and provide the rationale for exploring the therapeutic/preventive role of targeted neutralization of IFNγ., (Copyright© 2019 Ferrata Storti Foundation.)

Introduction: The clinical application of immunotherapy has resulted into a significant improvement in the outcome of children with relapsed/refractory B-cell precursor acute lymphoblastic leukemia (r/r BCP-ALL). In this setting, the use of bispecific T-cell-engager antibodies (BiTEs), such as blinatumomab, which harness the cytotoxic activity of T cells against CD19-positive lymphoblasts, has emerged as a most promising and impactful strategy. Areas covered: This review discusses the main structural and functional features of BiTEs, as well as the current status of their clinical application in childhood ALL. Moreover, future prospects to increase the efficacy of BiTEs are addressed. Expert commentary: The promising results obtained in patients with advanced BCP-ALL pave the way for further improvement in the context of less resistant/advanced disease. Future research is rapidly progressing on several aspects, including the use of blinatumomab in first-line protocols, identification of factors predicting response, use of combinatorial approaches and bioengineering of new molecules with dual specificity or increased potency, stability and half-life. The results of these studies, expected to be available in the next future, will provide further advancement in the development of effective, impactful, targeted immunotherapy for treatment of childhood BCP-ALL, with the concrete potential to revolutionize the clinical practice.

Purpose of Review: Myelodysplastic syndromes (MDSs) are rare disorders in children, showing peculiar clinical manifestations and biological features. This review will summarize biological, genetic and clinical features of childhood MDS and will provide an update of the algorithm of treatment of the different disease variants., Recent Findings: The most recent classification of MDS includes refractory cytopenia of childhood (RCC), advanced and therapy-related MDS. Importantly, in children, these clonal hematopoietic disorders may be often associated with inherited bone marrow failure syndromes, this representing a challenge for diagnostic work-up and treatment. Moreover, germline syndromes predisposing to develop MDS/acute myeloid leukemia have been recently identified, such as those caused by mutations in GATA2, ETV6, SRP72 and SAMD9/SAMD9-L., Summary: Treatment of childhood MDS varies according to specific disease features; allogeneic hematopoietic stem cell transplantation (HSCT) using a Human Leukocyte antigen (HLA)-identical donor, whenever available, represents the treatment of choice for most of these children. HSCT is indicated in MDS with excess of blasts, or in therapy-related MDS. For RCC patients, HSCT is recommended for RCC associated with monosomy 7, or complex karyotype and for patients showing severe neutropenia or transfusion dependence. Novel approaches of HSCT from an HLA-haploidentical relative after selective graft manipulation allow reducing transplant-related complications.

To investigate rates and outcomes of antibiotic de-escalation during pre-engraftment neutropenia in allogeneic hematopoietic stem cell transplantation (HSCT) recipients. 110 consecutive HSCTs performed between January 2013 and March 2014 were analyzed. De-escalation was defined as narrowing the spectrum of antibiotic treatment either within (early) or after 96 hours (late) from starting antibiotics. Discontinuation, considered a form of de-escalation, was defined as stopping antibiotics before engraftment. De-escalation failure was defined as restarting/escalating antibiotics within 96 hours after de-escalation. Predictors of de-escalation were analyzed. Among 102 patients who started antibiotics and were included, 68 (67%) received monotherapy (mainly piperacillin-tazobactam, n = 58), whereas 34 (33%) received combination therapy (mainly meropenem plus glycopeptide, n = 24). Median duration of neutropenia was 17 days. Bloodstream infections (BSIs) were diagnosed in 28 patients (20%). Early de-escalation rate was 25.5% (n = 26) and mostly consisted of reducing the spectrum of β-lactams (n = 11, 42%). In comparison with theoretical scenario of continuing therapy until engraftment, the median savings in terms of antibiotic days were 10 for meropenem, 8 for piperacillin-tazobactam, and 7 for vancomycin. Failure rate of early de-escalation was 15% (4/26). Late de-escalation rate was 30.4% (n = 31) and failure rate 19% (6/31). The rate of de-escalation any time before engraftment was 55.9% (n = 57), including discontinuation in 33 patients (32%). Death at day 60 after HSCT occurred in 3 patients who never underwent de-escalation. Acute myeloid disease and BSIs were independent predictors of early de-escalation. De-escalation, including discontinuation, is feasible and safe in pre-engraftment neutropenia after allogeneic HSCT., (Copyright © 2018 The American Society for Blood and Marrow Transplantation. Published by Elsevier Inc. All rights reserved.)

Bloodstream infections (BSIs) are frequent and important infectious complications after hematopoietic cell transplantation (HCT). The aim of this study was to analyze the incidence, risk factors, and outcome of pre-engraftment BSIs after allogeneic HCT. We retrospectively analyzed data from 553 consecutive patients who underwent HCT between 2010 and 2016. Sixty percent of the patients received T cell-replete unmanipulated haploidentical bone marrow with high-dose post-transplantation cyclophosphamide. The BSI rate was 30%; among isolated 213 pathogens, 54% were Gram-positive, 43% were Gram-negative, and 3% were fungi. Independent risk factors for pre-engraftment BSI were transplantation from a haploidentical donor or from cord blood (P < .001), active disease (P = .002), age (P = .04), and myeloproliferative disorders or aplastic anemia (P < .001). Transplantation from a haploidentical donor was an independent risk factor for both Gram-positive and Gram-negative BSI. The 7-day mortality after any BSI was 5% (9 of 178), and in multivariate analysis, BSI etiology was the sole risk factor, with increased mortality in carbapenem-resistant Gram-negative BSI (P < .001). Nonrelapse mortality at day +60 after HCT was 3.8% (21 of 553); independent predictors were active disease (P = .045), year of HCT (P = .027), nonengraftment (P = .001), and pre-engraftment BSI (P < .001), with significantly higher risk in BSI due to Gram-negative pathogens compared with Gram-positive pathogens, and BSI due to carbapenem-resistant Gram-negative pathogens compared with susceptible pathogens. Pre-engraftment BSI is a frequent complication after HCT from a haploidentical donor or cord blood. Because the negative impact of pre-engraftment BSI on 60-day nonrelapse mortality was caused mainly by carbapenem-resistant Gram-negative pathogens, particular attention should be given to appropriate empiric therapy and management of patients at high risk for Gram-negative BSI., (Copyright © 2018. Published by Elsevier Inc.)

Cardiovascular complications are included among the systemic effects of tyrosine kinase inhibitor (TKI)-based therapeutic strategies. To test the hypothesis that inhibition of Kit tyrosine kinase that promotes cardiac progenitor cell (CPC) survival and function may be one of the triggering mechanisms of imatinib mesylate (IM)-related cardiovascular effects, the anatomical, structural and ultrastructural changes in the heart of IM-treated rats were evaluated. Cardiac anatomy in IM-exposed rats showed a dose-dependent, restrictive type of remodeling and depressed hemodynamic performance in the absence of remarkable myocardial fibrosis. The effects of IM on rat and human CPCs were also assessed. IM induced rat CPC depletion, reduced growth and increased cell death. Similar effects were observed in CPCs isolated from human hearts. These results extend the notion that cardiovascular side effects are driven by multiple actions of IM. The identification of cellular mechanisms responsible for cardiovascular complications due to TKIs will enable future strategies aimed at preserving concomitantly cardiac integrity and anti-tumor activity of advanced cancer treatment., (Copyright © 2017 Elsevier Ltd. All rights reserved.)

The advantage of using a Human Leukocyte Antigen (HLA)-mismatched related donor is that almost every patient who does not have an HLA-identical donor or who urgently needs hematopoietic stem cell transplantation (HSCT) has at least one family member with whom shares one haplotype (haploidentical) and who is promptly available as a donor. The major challenge of haplo-HSCT is intense bi-directional alloreactivity leading to high incidences of graft rejection and graft-versus-host disease (GVHD). Advances in graft processing and pharmacologic prophylaxis of GVHD have reduced these risks and have made haplo-HSCT a viable alternative for patients lacking a matched donor. Indeed, the haplo-HSCT has spread to centers worldwide even though some centers have preferred an approach based on T cell depletion of G-CSF-mobilized peripheral blood progenitor cells (PBPCs), others have focused on new strategies for GvHD prevention, such as G-CSF priming of bone marrow and robust post-transplant immune suppression or post-transplant cyclophosphamide (PTCY). Today, the graft can be a megadose of T-cell depleted PBPCs or a standard dose of unmanipulated bone marrow and/or PBPCs. Although haplo-HSCT modalities are based mainly on high intensity conditioning regimens, recently introduced reduced intensity regimens (RIC) showed promise in decreasing early transplant-related mortality (TRM), and extending the opportunity of HSCT to an elderly population with more comorbidities. Infections are still mostly responsible for toxicity and non-relapse mortality due to prolonged immunosuppression related, or not, to GVHD. Future challenges lie in determining the safest preparative conditioning regimen, minimizing GvHD and promoting rapid and more robust immune reconstitution.

Minimal residual disease (MRD) was monitored by Wilms tumor 1 (WT1) expression in 207 patients with acute myeloid leukemia (AML) after an allogeneic hemopoietic stem cell transplantation (HSCT) as a trigger to initiate pre-emptive immunotherapy (IT) with cyclosporin discontinuation and/or donor lymphocyte infusion. The trigger for IT was WT1 ≥ 180 copies/10(4) Abelson cells in marrow cells in the first group of 122 patients (WT1-180) and ≥ 100 copies in a subsequent group of 85 patients (WT1-100). Forty patients received IT. The cumulative incidence (CI) of relapse was 76% in WT1-180 (n = 17) versus 29% in WT1-100 patients (n = 23) receiving IT (P = .006); the leukemia-free survival from MRD positivity was 23% versus 74%, respectively (P = .003). We then looked at the entire AML patient population (n = 207). WT1-180 and WT1-100 patients were comparable for disease phase and age. The overall 4-year CI of transplantation-related mortality was 13% in both groups; the CI of leukemia relapse was 38% in the WT1-180 and 28% in the WT1-100 patients (P = .05) and leukemia-free survival was 56% versus 48%, respectively (P = .07). In conclusion, we suggests that WT1-based pre-emptive immunotherapy is feasible in patients with undergoing an allogeneic HSCT. The protective effect on relapse is greater when IT is triggered at lower levels of WT1., (Copyright © 2016 American Society for Blood and Marrow Transplantation. Published by Elsevier Inc. All rights reserved.)

This is a retrospective analysis of 95 patients with myelofibrosis who were allografted between 2001 and 2014. The aims of the study were to assess whether the outcome of alternative donor grafts has improved with time and how this compares with the outcome of identical sibling grafts. Patients were studied in 2 time intervals: 2000 to 2010 (n = 58) and 2011 to 2014 (n = 37). The Dynamic International Prognostic Scoring System score was comparable in the 2 time periods, but differences in the most recent group included older age (58 versus 53 years, P = .004), more family haploidentical donors (54% versus 5%, P < .0001), and the introduction of the thiotepa-fludarabine-busulfan conditioning regimen (70% of patients versus 2%, P < .0001). Acute and chronic graft-versus-host disease were comparable in the 2 time periods. The 3-year transplantation-related mortality (TRM) in the 2011 to 2014 period versus the 2000 to 2010 period is 16% versus 32% (P = .10), the relapse rate 16% versus 40% (P = .06), and actuarial survival 70% versus 39% (P = .08). Improved survival was most pronounced in alternative donor grafts (69% versus 21%, P = .02), compared with matched sibling grafts (72% versus 45%, P = .40). In conclusion, the outcome of allografts in patients with myelofibrosis has improved in recent years because of a reduction of both TRM and relapse. Improvement is most significant in alternative donor transplantations, with modifications in donor type and conditioning regimen., (Copyright © 2016 American Society for Blood and Marrow Transplantation. Published by Elsevier Inc. All rights reserved.)

The adult heart has the capacity to generate new myocytes that are markedly enhanced in acute and chronic heart failure of ischemic and non-ischemic origin. In addition, a pool of blood trafficking progenitor cells able to sense myocardial damage may home to the sites of injury participating to cardiac repair. This new view of myocardial biology leads to an expanding long-term research and therapeutic goals for cardioprotection. A fundamental concept to be analyzed is whether cardiac diseases are influenced by changes in the properties of tissue specific and circulating progenitors. Loss of self-renewal capacity, impaired growth or increased susceptibility to death may lead to a reduction of progenitors and leave myocardial damage unrepaired. Cardiac progenitors generate all myocardial cell lineages, thus impairment in their growth is expected to be critically involved in the structural and functional modifications of the heart. The fact that, in addition to well known effects of anthracyclines, also new drugs that target molecular pathways implicated in cell death and growth can be cardiotoxic further supports our hypothesis. Understanding the role of resident and extracardiac progenitors in the pathogenesis of cardiomyopathies of different etiology will provide not only a better comprehension of cardiac homeostasis but will also open new avenues for therapeutic interventions. The progress toward effective myocardial regeneration based on exploiting the self-renewal potential of the myocardium and the systemic pool of cardiogenic cells should advance the likelihood of efficient cardioprotection and restoration of cardiac function.

Forty-two patients relapsing after an unmanipulated haploidentical BM transplant and post-transplant CY (PT-CY), were given 108 DLI, with median interval from transplant of 266 days (range, 67-1372). DLI were given at escalating doses, expressed as CD3+ cells/kg, without GVHD prophylaxis, and ranged from 1 × 10(3) to 1 × 10(7) cells/kg (median 5 × 10(5) cells/kg). The average number of DLI per patient was 2.6 (range, 1-6). The diagnosis was leukemias (n=32) grafted with a myeloablative regimen and Hodgkin's disease (n=10), grafted with a nonmyeloablative regimen. Leukemic patients with molecular relapse (n=20), received DLI alone (n=17) or in association with azacytidine (n=3); leukemic patients with hematologic relapse (n=12) received chemotherapy followed by DLI (n=11) or DLI alone (n=1); Hodgkin patients received DLI following 1-3 courses of chemotherapy. In these three groups the incidence of acute GVHD II-III was 15%, 17% and 10%; response rate was 45%, 33% and 70%; 2-year actuarial survival was 43%, 19% and 80% respectively. This study confirms that escalating doses of DLI can be given in the haploidentical setting with PT-CY, with a relatively low risk of acute GVHD. Response rates and survival are dependent on the underlying disease.

Therapeutic options for patients with relapsed or refractory acute leukemia are still undefined and often unsatisfactory. We report the outcome of 79 patients with relapsed-refractory acute leukemia treated with fludarabine, cytarabine, and liposomal daunorubicin (FLAD regimen) followed by hematopoietic stem cell transplantation (HSCT), when clinically indicated, between May 2000 and January 2013. Forty-one patients had acute myeloid leukemia (AML), and 38 had acute lymphoblastic leukemia (ALL). Two patients with myeloid blast crises of CML and three with lymphoid blast crises were included in the AML and ALL subgroups, respectively. Median age was 48 years (range 13-77). FLAD was well tolerated with negligible, nonhematological toxicity. Six patients (7.5 %) died before response evaluation. Forty-seven patients achieved hematologic complete response (CR). Complete remission rate was 53 and 65 % among AML and ALL patients, respectively. No CR was recorded among 11 refractory AML patients. Twenty-four patients (30 %) underwent HSCT. Nine patients received stem cells from an HLA identical sibling, and 15 from an alternative donor (3 unrelated matched, 12 haploidentical sibling). Median overall survival in AML and ALL patients receiving FLAD therapy was 9 and 8 months, respectively. A 5-year projected OS for patients receiving the whole program (FLAD + HSCT) was 24 % for AML patients (median survival 43 months), 28 % for ALL patients treated in relapse (median survival 15 months), and 0 % for ALL patients treated for refractory disease. In this paper, we show that FLAD seems to be an effective bridge therapy to HSCT for a part of poor prognosis acute leukemia patients. However, prospective studies are needed to confirm our results.

We studied 459 consecutive patients with hematologic malignancies, median age 44 years (range, 15 to 71 years), who underwent transplantation with grafts from identical sibling donors (SIB; n = 176), matched unrelated donors (MUD; n = 43), mismatched unrelated donors (mmUD; n = 43), unrelated cord blood (UCB; n = 105) or HLA-haploidentical family donors (HAPLO; n = 92). Graft-versus-host disease (GVHD) prophylaxis consisted of cyclosporine and methotrexate in the SIB recipients; antithymocyte globulin for the MUD, mmUD, and UCB recipients; and post-transplantation cyclophosphamide, cyclosporine, and mycophenolate in the HAPLO recipients. Conditioning regimens were mostly myeloablative (69%). Advanced disease phase was more frequent, but not significantly so, in the HAPLO and mmUD groups (P = .08). Acute GVHD grade II-IV was significantly less frequent in the HAPLO, UCB, and MUD groups (14% to 21%) compared with the SIB (31%) and mmUD (42%) groups (P < .001), and there was a trend toward less moderate-severe chronic GVHD in the HAPLO and UCB groups (P = .053). The proportion of patients off cyclosporine at 1 year ranged from 55% for the SIB group to 81% for the HAPLO group (P < .001). Transplantation-related mortality at 2 years was lower in the HAPLO and SIB groups (18% to 24%) compared with the MUD, mmUD, and UCB groups (33% to 35%; P = .10). Relapse rate was comparable in the 5 groups (P = .80). The 4-year actuarial survival was 45% in the SIB group, 43% in the MUD group, 40% in the mmUD group, 34% in the UCB group, and 52% in the HAPLO group (P = .10). In multivariate analysis, advanced disease was a negative predictor of survival (hazard ratio [HR], 2.4; P < .0001), together with a diagnosis of acute leukemia (HR, 1.8; P = .0001); HAPLO grafts were comparable to SIB (P = .80), whereas UCB had inferior survival (P = .03). In conclusion, unmanipulated haploidentical family donor transplants are an additional option for patients lacking a matched sibling donor., (Copyright © 2014 American Society for Blood and Marrow Transplantation. Published by Elsevier Inc. All rights reserved.)

Poor graft function (PGF) is characterized by pancytopenia and a hypoplastic marrow, with complete donor chimerism, usually without severe graft-versus-host disease (GVHD). We report 41 patients with PGF, treated with granulocyte colony-stimulating factor-mobilized CD34 selected cells, at a median interval from transplant of 140 days, without conditioning and without GVHD prophylaxis. Donors were HLA matched siblings (n = 12), unrelated donors (n = 18), or mismatched family members (n = 11). The median number of infused CD34(+) cells was 3.4 × 10(6)/kg. The rate of trilineage recovery was 75%: 83% for HLA matched siblings and 72% for unrelated and mismatched family members (P = .3). The cumulative incidence of acute grade II GVHD was 15%, and no patient developed de novo chronic GVHD. The actuarial 3-year survival is 63%: 76% and 25% for patients with or without trilineage recovery. These data confirm the role of CD34(+) selected cells from the same donor in the treatment of PGF and warrant the request for a second donation also when the donor is unrelated., (Copyright © 2014 American Society for Blood and Marrow Transplantation. Published by Elsevier Inc. All rights reserved.)

Twenty-six patients with advanced Hodgkin's disease received a related HLA haploidentical unmanipulated BMT, following a non-myeloablative conditioning with low-dose TBI, proposed by the Baltimore group; GvHD prophylaxis consisted of high-dose post-transplantation CY (PT-CY), mycophenolate and a calcineurin inhibitor. All patients had received a previous autograft, and 65% had active disease at the time of BMT. Sustained engraftment of donor cells occurred in 25 patients (96%), with a median time to neutrophil recovery (>0.5 × 10(9)/L) and platelet recovery (>20 × 10(9)/L) of +18 and +23 days from BMT. The incidence of grade II-IV acute GVHD and of chronic GVHD was 24% and 8%, respectively. With a median follow-up of 24 months (range 18-44) 21 patients are alive, 20 disease free. The cumulative incidence of TRM and relapse was 4% and 31%, respectively. The actuarial 3-year survival is 77%, the actuarial 3-year PFS is 63%. In conclusion, we confirm that high-dose PT-CY is effective as prophylaxis of GVHD after HLA haploidentical BMT, can prevent rejection and does not appear to eliminate the allogeneic graft versus lymphoma effect.

Tyrosin kinase inhibitors (TKI), have dramatically changed the natural history of chronic myeloid leukemia (CML) leading to an impressive increase in overall survival rates and allowing many CML patients to achieve a close-to-normal life expectancy. Unfortunately, there is growing evidence that these drugs are not curative, about 30-35% of the patients who receive imatinib become resistant or discontinue the drug because of side effects; moreover, 15% of all patients become resistant to all TKIs, a condition which represents the biggest challenge in CML treatment. Recent progresses in CML stem cell biology have identified new agents and therapeutic strategies that can be used to target the CML stem cell compartment. These studies have opened new perspectives and have highlighted key strategies for treating, and possibly curing, CML in the upcoming years.