Testing one hypothesis multiple times

In applied settings, tests of hypothesis where a nuisance parameter is only identifiable under the alternative often reduces into one of Testing One Hypothesis Multiple times (TOHM). Specifically, a fine discretization of the space of the non-identifiable parameter is specified, and the null hypothesis is tested against a set of sub-alternative hypothesis, one for each point of the discretization. The resulting sub-test statistics are then combined to obtain a global p-value. In this paper, we discuss a computationally efficient inferential tool to perform TOHM under stringent significance requirements, such as those typically required in the physical sciences, (e.g., p-value < 10−7 ). The resulting procedure leads to a generalized approach to perform inference under non-standard conditions, including non-nested models comparisons

Novel therapeutic approaches to familial HLH (emapalumab in FHL)

Primary Hemophagocytic lymphohistiocytosis (pHLH) is a rare, life-threatening, hyperinflammatory disorder, characterized by uncontrolled activation of the immune system. Mutations affecting several genes coding for proteins involved in the cytotoxicity machinery of both natural killer (NK) and T cells have been found to be responsible for the development of pHLH. So far, front-line treatment, established on the results of large international trials, is based on the use of glucocorticoids, etoposide ± cyclosporine, followed by allogeneic hematopoietic stem cell transplantation (HSCT), the sole curative treatment for the genetic forms of the disease. However, despite major efforts to improve the outcome of pHLH, many patients still experience unfavorable outcomes, as well as severe toxicities; moreover, treatment-refractory or relapsing disease is a major challenge for pediatricians/hematologists. In this article, we review the epidemiology, etiology and pathophysiology of pHLH, with a particular focus on different cytokines at the origin of the disease. The central role of interferon-γ (IFNγ) in the development and maintenance of hyperinflammation is analyzed. The value of emapalumab, a novel IFNγ-neutralizing monoclonal antibody is discussed. Available data support the use of emapalumab for treatment of pHLH patients with refractory, recurrent or progressive disease, or intolerance to conventional therapy, recently, leading to FDA approval of the drug for these indications. Additional data are needed to define the role of emapalumab in front-line treatment or in combination with other drugs

T-cell depleted HLA-haploidentical HSCT in a child with neuromyelitis optica

Neuromyelitis optica is an immune-mediated disease characterized by a relapsing course, resulting in progressive disability. In children, given the long life expectancy, a disease-modifying treatment could be particularly desirable. Unfortunately, the currently available treatment strategies with this potential are scarce. Very limited data are available about the use of allogeneic hematopoietic stem cell transplantation (HSCT) for autoimmune neurological diseases. In this report, we present a pediatric case successfully treated with allogeneic HSCT from an HLA-haploidentical donor, after ex vivo TCR/CD19-depletion of the graft. To the best of our knowledge, this is the first case of a pediatric patient to benefit from such a treatment

Resistance to neoplastic transformation of ex-vivo expanded human mesenchymal stromal cells after exposure to supramaximal physical and chemical stress

The risk of malignant transformation of ex-vivo expanded human mesenchymal stromal cells (huMSCs) has been debated in the last years; however, the biosafety of these cells after exposure to supramaximal physical and chemical stress has never been systematically investigated. We established an experimental in vitro model to induce supramaximal physical (ionizing radiation, IR) and chemical (starvation) stress on ex-vivo expanded bone marrow (BM)-derived huMSCs and investigated their propensity to undergo malignant transformation. To this aim, we examined MSC morphology, proliferative capacity, immune-phenotype, differentiation potential, immunomodulatory properties and genetic profile before and after stressor exposure. Furthermore, we investigated the cellular mechanisms underlying MSC response to stress. MSCs were isolated from 20 healthy BM donors and expanded in culture medium supplemented with 5% platelet lysate (PL) up to passage 2 (P2). At this stage, MSCs were exposed first to escalating doses of IR (30, 100, 200 Gy) and then to starvation culture conditions (1% PL). With escalating doses of radiation, MSCs lost their typical spindle-shaped morphology, their growth rate markedly decreased and eventually stopped (at P4-P6) by reaching early senescence. Irradiated and starved MSCs maintained their typical immune-phenotype, ability to differentiate into adipocytes/osteoblasts and to inhibit mitogen-induced T-cell proliferation. The study of the genetic profile of irradiated/ starved MSCs did not show any alteration. While the induction of supramaximal stress triggered production of ROS and activation of DNA damage response pathway via multiple mechanisms, our data indicate that irradiated/starved MSCs, although presenting altered morphology/growth rate, do not display increased propensity for malignant transformation

Immune modulation properties of zoledronic acid on TcRγδ T-lymphocytes after TcRαβ/CD19-depleted haploidentical stem cell transplantation: an analysis on 46 pediatric patients affected by acute leukemia

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

Engineered mucoperiosteal scaffold for cleft palate regeneration towards the non-immunogenic transplantation

Cleft lip and palate (CL/P) is the most prevalent craniofacial birth defect in humans. None of the surgical procedures currently used for CL/P repair lead to definitive correction of hard palate bone interruption. Advances in tissue engineering and regenerative medicine aim to develop new strategies to restore palatal bone interruption by using tissue or organ-decellularized bioscaffolds seeded with host cells. Aim of this study was to set up a new natural scaffold deriving from a decellularized porcine mucoperiosteum, engineered by an innovative micro-perforation procedure based on Quantum Molecular Resonance (QMR) and then subjected to in vitro recellularization with human bone marrow-derived mesenchymal stem cells (hBM-MSCs). Our results demonstrated the efficiency of decellularization treatment gaining a natural, non-immunogenic scaffold with preserved collagen microenvironment that displays a favorable support to hMSC engraftment, spreading and differentiation. Ultrastructural analysis showed that the micro-perforation procedure preserved the collagen mesh, increasing the osteoinductive potential for mesenchymal precursor cells. In conclusion, we developed a novel tissue engineering protocol to obtain a non-immunogenic mucoperiosteal scaffold suitable for allogenic transplantation and CL/P repair. The innovative micro-perforation procedure improving hMSC osteogenic differentiation potentially impacts for enhanced palatal bone regeneration leading to future clinical applications in humans

Outcomes of children with hemophagocytic lymphohistiocytosis given allogeneic hematopoietic stem cell transplantation in Italy

We report on 109 patients with hemophagocytic lymphohistiocytosis (HLH) undergoing 126 procedures of allogeneic hematopoietic stem cell transplantation (HSCT) between 2000 and 2014 in centers associated with the Italian Pediatric Hematology Oncology Association. Genetic diagnosis was FHL2 (32%), FHL3 (33%), or other defined disorders known to cause HLH (15%); in the remaining patients no genetic abnormality was found. Donor for first transplant was an HLA-matched sibling for 25 patients (23%), an unrelated donor for 73 (67%), and an HLA-partially matched family donor for 11 children (10%). Conditioning regimen was busulfan-based for 61 patients (56%), treosulfan-based for 21 (20%), and fludarabine-based for 26 children (24%). The 5-year probabilities of overall survival (OS) and event-free survival (EFS) were 71% and 60%, respectively. Twenty-six patients (24%) died due to transplant-related causes, whereas 14 (13%) and 10 (9%) patients experienced graft rejection and/or relapse, respectively. Twelve of 14 children given a second HSCT after graft failure/relapse are alive and disease-free. Use of HLA-partially matched family donors was associated with higher risk of graft failure and thus with lower EFS (but not with lower OS) in multivariable analysis. Active disease at transplantation did not significantly affect prognosis. These data confirm that HSCT can cure most HLH patients, active disease not precluding successful transplantation. Because in HLH patients HLA-haploidentical HSCT performed through CD34 + cell positive selection was found to be associated with poor sustained engraftment of donor cells, innovative approaches able to guarantee a more robust engraftment are warranted in patients given this type of allograft

Unrelated donor vs HLA-haploidentical a/b T-cell- and B-cell-depleted HSCT in children with acute leukemia

Traditionally, hematopoietic stem cell transplantation (HSCT) from both HLA-matched related and unrelated donors (UD) has been used for treating children with acute leukemia (AL) in need of an allograft. Recently, HLA-haploidentical HSCT after ab T-cell/B-cell depletion (abhaplo-HSCT) was shown to be effective in single-center studies. Here, we report the first multicenter retrospective analysis of 127 matched UD (MUD), 118 mismatched UD (MMUD), and 98 abhaplo-HSCT recipients, transplanted between 2010 and 2015, in 13 Italian centers. All these AL children were transplanted in morphological remission after a myeloablative conditioning regimen. Graft failure occurred in 2% each of UD-HSCT and abhaplo-HSCT groups. In MUD vs MMUD-HSCT recipients, the cumulative incidence of grade II to IV and grade III to IV acute graft-versus-host disease (GVHD) was 35% vs 44% and 6% vs 18%, respectively, compared with 16% and 0% in abhaplo-HSCT recipients (P &lt; .001). Children treated with abhaplo-HSCT also had a significantly lower incidence of overall and extensive chronic GVHD (P &lt; .01). Eight (6%) MUD, 32 (28%) MMUD, and 9 (9%) abhaplo-HSCT patients died of transplant-related complications. With a median follow-up of 3.3 years, the 5-year probability of leukemia-free survival in the 3 groups was 67%, 55%, and 62%, respectively. In the 3 groups, chronic GVHD-free/relapse-free (GRFS) probability of survival was 61%, 34%, and 58%, respectively (P &lt; .001). When compared with patients given MMUD-HSCT, abhaplo-HSCT recipients had a lower cumulative incidence of nonrelapse mortality and a better GRFS (P &lt; .001). These data indicate that abhaplo-HSCT is a suitable therapeutic option for children with AL in need of transplantation, especially when an allele-matched UD is not available