TCRαβ/CD19 cell-depleted HLA-haploidentical transplantation to treat pediatric acute leukemia: updated final analysis

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.

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.

Short-term effects of stored homologous red blood cell transfusion on cardiorespiratory function and inflammation: an experimental study in a hypovolemia model

The pathophysiological mechanisms associated with the effects of red blood cell (RBC) transfusion on cardiopulmonary function and inflammation are unclear. We developed an experimental model of homologous 14-days stored RBC transfusion in hypovolemic swine to evaluate the short-term effects of transfusion on cardiopulmonary system and inflammation. Sixteen healthy male anesthetized swine (68±3.3 kg) were submitted to controlled hemorrhage (25% of blood volume). Two units of non-filtered RBC from each animal were stored under blood bank conditions for 14 days. After 30 min of hypovolemia, the control group (n=8) received an infusion of lactated Ringer's solution (three times the removed volume). The transfusion group (n=8) received two units of homologous 14-days stored RBC and lactated Ringer's solution in a volume that was three times the difference between blood removed and blood transfusion infused. Both groups were followed up for 6 h after resuscitation with collection of hemodynamic and respiratory data. Cytokines and RNA expression were measured in plasma and lung tissue. Stored RBC transfusion significantly increased mixed oxygen venous saturation and arterial oxygen content. Transfusion was not associated with alterations on pulmonary function. Pulmonary concentrations of cytokines were not different between groups. Gene expression for lung cytokines demonstrated a 2-fold increase in mRNA level for inducible nitric oxide synthase and a 0.5-fold decrease in mRNA content for IL-21 in the transfused group. Thus, stored homologous RBC transfusion in a hypovolemia model improved cardiovascular parameters but did not induce significant effects on microcirculation, pulmonary inflammation and respiratory function up to 6 h after transfusion.

Preservation of Antigen-Specific Functions of αβ T Cells and B Cells Removed from Hematopoietic Stem Cell Transplants Suggests Their Use As an Alternative Cell Source for Advanced Manipulation and Adoptive Immunotherapy

Hematopoietic stem cell transplantation is standard therapy for numerous hematological diseases. The use of haploidentical donors, sharing half of the HLA alleles with the recipient, has facilitated the use of this procedure as patients can rely on availability of a haploidentical donor within their family. Since HLA disparity increases the risk of graft-versus-host disease, T-cell depletion has been used to remove alloreactive lymphocytes from the graft. Selective removal of αβ T cells, which encompass the alloreactive repertoire, combined with removal of B cells to prevent EBV-related lymphoproliferative disease, proved safe and effective in clinical studies. Depleted αβ T cells and B cells are generally discarded as by-products. Considering the possible use of donor T cells for donor lymphocyte infusions or for generation of pathogen-specific T cells as mediators of graft-versus-infection effect, we tested whether cells in the discarded fractions were functionally intact. Response to alloantigens and to viral antigens comparable to that of unmanipulated cells indicated a functional integrity of αβ T cells, in spite of the manipulation used for their depletion. Furthermore, B cells proved to be efficient antigen-presenting cells, indicating that antigen uptake, processing, and presentation were fully preserved. Therefore, we propose that separated αβ T lymphocytes could be employed for obtaining pathogen-specific T cells, applying available methods for positive selection, which eventually leads to indirect allodepletion. In addition, these functional T cells could undergo additional manipulation, such as direct allodepletion or genetic modification.

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.

Inhibition of B-cell proliferation and antibody production by mesenchymal stromal cells is mediated by T cells

Bone marrow (BM)-derived mesenchymal stromal cells (MSCs), endowed with immunosuppressive and anti-inflammatory properties, represent a promising tool in immunoregulatory and regenerative cell therapy. Clarifying the interactions between MSCs and B-lymphocytes may be crucial for designing innovative MSC-based strategies in conditions in which B cells play a role, including systemic lupus erythematosus (SLE) and rejection of kidney transplantation. In this study, we show that, both in healthy subjects and in patients, in vitro B-cell proliferation, plasma-cell differentiation, and antibody production are inhibited by BM-derived MSCs when peripheral blood lymphocytes are stimulated with CpG, but not when sorted B cells are cultured with MSCs+CpG. Inhibition is restored in CpG+MSC cocultures when sorted T cells are added to sorted B cells, suggesting that this effect is mediated by T cells, with both CD4(+) and CD8(+) cells playing a role. Moreover, cell-cell contact between MSCs and T cells, but not between MSCs and B cells, is necessary to inhibit B-cell proliferation. Thus, the presence of functional T cells, as well as cell-cell contact between MSCs and T cells, are crucial for B-cell inhibition. This information can be relevant for implementing MSC-based therapeutic immune modulation in patients in whom T-cell function is impaired.

Comprehensive characterization of mesenchymal stromal cells from patients with Fanconi anaemia

Fanconi anaemia (FA) is an inherited disorder characterized by pancytopenia, congenital malformations and a predisposition to develop malignancies. Alterations in the haematopoietic microenvironment of FA patients have been reported, but little is known regarding the components of their bone marrow (BM) stroma. We characterized mesenchymal stromal cells (MSCs) isolated from BM of 18 FA patients both before and after allogeneic haematopoietic stem cell transplantation (HSCT). Morphology, fibroblast colony-forming unit (CFU-F) ability, proliferative capacity, immunophenotype, differentiation potential, ability to support long-term haematopoiesis and immunomodulatory properties of FA-MSCs were analysed and compared with those of MSCs expanded from 15 age-matched healthy donors (HD-MSCs). FA-MSCs were genetically characterized through conventional karyotyping, diepoxybutane-test and array-comparative genomic hybridization. FA-MSCs generated before and after HSCT were compared. Morphology, immunophenotype, differentiation potential, ability in vitro to inhibit mitogen-induced T-cell proliferation and to support long-term haematopoiesis did not differ between FA-MSCs and HD-MSCs. CFU-F ability and proliferative capacity of FA-MSCs isolated after HSCT were significantly lower than those of HD-MSCs. FA-MSCs reached senescence significantly earlier than HD-MSCs and showed spontaneous chromosome fragility. Our findings indicate that FA-MSCs are defective in their ability to survive in vitro and display spontaneous chromosome breakages; whether these defects are involved in pathophysiology of BM failure syndromes deserves further investigation.

Cysteamine treatment restores the in vitro ability to differentiate along the osteoblastic lineage of mesenchymal stromal cells isolated from bone marrow of a cystinotic patient

Background

Cystinosis is a rare autosomal recessive disease caused by mutations of the CTNS gene, which encodes for a lysosomal cystine/H⁺ symporter. In mice, inactivation of the CTNS gene causes intralysosomal cystine accumulation and progressive organ damage that can be reversed, at least in part, by infusion of mesenchymal stromal cells (MSCs). Little is known on the mesenchymal compartment of cystinotic patients. The aim of the study was to test the phenotypical and functional properties of cystinotic MSCs (Cys-MSCs) isolated from bone marrow (BM) aspirate of a patient with nephropathic cystinosis.

Methods

Morphology, proliferative capacity (measured as population doublings), immunophenotype (by flow-cytometry) and immunomodulatory properties (as phytohemagglutinin-induced peripheral blood mononuclear cell proliferation) were analyzed. The osteogenic differentiation potential of Cys-MSCs was evaluated by histological staining (alkaline phosphatase activity, Alzarin Red and von Kossa staining) spectrophotometry and Quantitative Reverse Transcriptase Polymerase Chain Reaction for osteigenic markers in the presence and in the absence of cysteamine. Cys-MSCs were compared with those isolated and expanded ex vivo from three healthy donors (HD-MSCs).

Results

Despite a slightly lower proliferative capacity, Cys-MSCs displayed a characteristic spindle-shaped morphology and similar immunephenotype as HD-MSCs. Cys-MSCs and HD-MSCs prevented proliferation of PHA-stimulated allogeneic peripheral blood mononuclear cells to the same extent. After in vitro induction into osteoblasts, Cys-MSCs showed reduced alkaline phosphatase (ALP) activity, calcium depositions and expression of ALP and collagen type 1. When Cys-MSCs were treated in vitro with increasing doses of cysteamine (50-100-200 μM/L) during the differentiation assay, recovery of Cys-MSCs differentiation capacity into osteoblasts was observed. No difference in adipogenic differentiation was found between Cys-MSCs and HD-MSCs.

Conclusions

Our results indicate that, as compared to HD-MSCs, Cys-MSCs show reduced ability to differentiate into osteoblasts, which can be reverted after cysteamine treatment.

Microvescicles derived from mesenchymal stromal cells are not as effective as their cellular counterpart in the ability to modulate immune responses in vitro

Mesenchymal stromal cells (MSCs) are multipotent cells that possess broad immunomodulatory properties; the mechanisms underlying these properties have not been completely clarified. Aim of this study was to compare in vitro immunomodulatory effects of MSCs with those of microvesicles (MVs) released in supernatants from the same MSCs. MSCs were generated from bone marrow of 12 healthy donors (HDs) and MVs were isolated from their supernatant by serial ultracentrifugation according to two different procedures. Both MSCs and MVs were characterized by flow cytometry and incubated in vitro with peripheral blood mononuclear cells (PBMCs) of 12 HDs after stimulation with PHA and CpG. Growth factors and cytokines were quantified by ELISA. MVs were identified as 0.1-1 μm particles positive for CMFDA, CD107, and CD13. MSCs were significantly more capable to inhibit in vitro PHA-induced T-cell proliferation as compared with the corresponding MVs (P<0.01 and P<0.05 for MSC:PBMC ratio 1:2 and 1:10, respectively). While MVs displayed similar inhibitory activity on B-cell proliferation (P=0.43 as compared with PBMCs/CpG/MSCs; MSC:PBMC ratio 1:10) they induced lower inhibitory effect on plasmacell differentiation and antibody secretion (P<0.05 as compared with PBMCs/CpG/MSCs). For both T and B cells, MSC co-colture induced a statistically significant increase in IL-10 and TGFβ and decrease of GM-CSF and IFNγ, as compared with MV incubation. Our data indicate a lower in vitro immunomodulatory effect of MVs on T-cell proliferation and antibody formation, as compared with their cellular counterpart. The relative clinical benefit of either MSCs or MVs needs to be compared in proper prospective studies.

Biological, functional and genetic characterization of bone marrow-derived mesenchymal stromal cells from pediatric patients affected by acute lymphoblastic leukemia

Alterations in hematopoietic microenvironment of acute lymphoblastic leukemia patients have been claimed to occur, but little is known about the components of marrow stroma in these patients. In this study, we characterized mesenchymal stromal cells (MSCs) isolated from bone marrow (BM) of 45 pediatric patients with acute lymphoblastic leukemia (ALL-MSCs) at diagnosis (day+0) and during chemotherapy treatment (days: +15; +33; +78), the time points being chosen according to the schedule of BM aspirates required by the AIEOP-BFM ALL 2009 treatment protocol. Morphology, proliferative capacity, immunophenotype, differentiation potential, immunomodulatory properties and ability to support long-term hematopoiesis of ALL-MSCs were analysed and compared with those from 41 healthy donors (HD-MSCs). ALL-MSCs were also genetically characterized through array-CGH, conventional karyotyping and FISH analysis. Moreover, we compared ALL-MSCs generated at day+0 with those isolated during chemotherapy. Morphology, immunophenotype, differentiation potential and in vitro life-span did not differ between ALL-MSCs and HD-MSCs. ALL-MSCs showed significantly lower proliferative capacity (p<0.001) and ability to support in vitro hematopoiesis (p = 0.04) as compared with HD-MSCs, while they had similar capacity to inhibit in vitro mitogen-induced T-cell proliferation (p = N.S.). ALL-MSCs showed neither the typical translocations carried by the leukemic clone (when present), nor other genetic abnormalities acquired during ex vivo culture. Our findings indicate that ALL-MSCs display reduced ability to proliferate and to support long-term hematopoiesis in vitro. ALL-MSCs isolated at diagnosis do not differ from those obtained during treatment.

Prior use of antithrombotic agents and neurological functional outcome at discharge in patients with ischemic stroke

BACKGROUND

Studies in experimental animals have suggested that antithrombotic agents may have a neuroprotective effect after an ischemic injury. The aim of this study was to analyze the effect of prior use of antithrombotic agents (antiplatelets or anticoagulants) on neurological functional outcome in patients with acute ischemic stroke.

SUBJECTS AND METHODS

Consecutive patients included in the Perugia Stroke Registry were considered for this analysis. Neurological functional outcome was evaluated at discharge using the modified Rankin Scale (mRS >or= 3 disabling stroke).

RESULTS

Of the 1921 patients included in the analysis (mean age 76.3 +/- 12.5 years; 53% males), 662 (34.5%) were on antithrombotic treatment (581 antiplatelets, 71 anticoagulants and 10 antiplatelets associated with anticoagulants). One hundred and twenty-two patients (6.4%) died in hospital; at discharge 712 patients (37.1%) were disabled and 1,087 patients (56.6%) were non-disabled. Fifty-four (44.3%) of the deceased patients and 270 (37.9%) of disabled patients were on antithrombotic treatment, while 338 (31.1%) non-disabled patients were taking antithrombotic agents. From multivariate analysis, age and stroke severity were associated with an adverse outcome. Male gender, dyslipidemia, stroke due to small vessel disease and no history of previous stroke were associated with an improved outcome, while no correlation was found between prior use of antithrombotic agents and outcome (mortality odds ratio; OR = 1.32, 95% confidence interval; CI 0.85-2.04; P = 0.20, mortality or disability OR = 0.95, 95% CI 0.72-1.25; P = 0.80).

CONCLUSION

Prior use of antithrombotic agents does not improve the functional outcome in patients with acute ischemic stroke.

Atrial fibrillation in patients with first-ever stroke: frequency, antithrombotic treatment before the event and effect on clinical outcome

BACKGROUND AND PURPOSES

Atrial fibrillation (AF) is an independent risk factor for stroke. The aims of this study were to assess: (i) the frequency of known or unknown AF in patients admitted to the hospital for a first-ever ischemic stroke and whether AF is associated with an adverse outcome at discharge (death or disability); (ii) the rates and determinants for the use of antithrombotic agents before stroke in patients with known AF and the adherence to the current treatment guidelines; and (iii) whether the lack of adherence to the current guidelines is associated with adverse outcome at discharge.

METHODS

Consecutive patients with acute first-ever stroke admitted to an individual Stroke Unit between January 2000 to December 2003, were included in the study. Twelve-lead electrocardiogram (ECG) was performed in all patients on admission. Functional outcome was measured at discharge according to modified Rankin Score.

RESULTS

A total of 1549 patients were included in the study: 238 patients (15.4%) were known to have AF and 76 (4.9%) were diagnosed with AF (unknown) on ECG performed on admission. At discharge 91 patients (5.9%) had died and 605 patients (39.0%) had died or were functionally dependent. Multivariate analysis showed that AF on admission was correlated with mortality or disability (OR = 1.58, 95% CI 1.09-2.30, P = 0.015). Before stroke, 124 out of 238 patients with known AF (52.1%) were not on antithrombotic therapy, 83 (34.9%) were receiving antiplatelet and 31 (13.0%) anticoagulant treatment. Previous transient ischemic attack, history of ischemic heart disease and hyperlipidemia were associated with the use of antithrombotic therapy. Only 24 out of 114 patients on antithrombotic treatment on admission were adequately treated according to the current guidelines. Of the adequately treated patients, 41.7% died or were disabled at discharge respect to 52.3% of the patients non-adequately treated (RR = 0.80, 95% CI 0.48-1.30).

CONCLUSIONS

AF (on history or new diagnosis) was present in 20.3% of the patients with first-ever stroke admitted to a Stroke Unit and it was associated with increased mortality or disability. Only 10% of patients with known AF were previously receiving an adequate antithrombotic treatment according to current guidelines.

[Estimating the grade of patient satisfaction at the bone marrow transplantation department in Florence hospitals]

The satisfaction of the patients admitted to the bone marrow transplant unit of Careggi Hospital was evaluated by the nursing team. The aim of the evaluation was to measure the level of satisfaction for the nursing care and services and the areas of improvement. The questionnaire, with 23 questions referring to 5 areas (hotel care, Nurses' reliability, Ability to reassure, to answer to patients' needs and Empathy) derived from the conceptual model of Servqual. Ninety patients were given (or mailed) the questionnaire during a follow-up visit. Patients were asked to answer the questions evaluating each aspect on a scale from 1 (falls short of expectation) to 10 (exceeds all expectations). The answers show a very high satisfaction (> 8) for all the areas except for the food that reported a medium score of 5.2. Further analysis will allow a better understanding of the causes of dissatisfaction.

Absence of serological surrogate markers for Trypanosoma-cruzi-infected blood donors

Specific serological screening tests for Trypanosoma-cruzi-infected donors are not yet available and thus not routinely performed in North America. With the recent increase of Latin-American immigration to North America and Europe, there is a risk of transmission by blood products. In this study, we evaluated the possibility whether any of the serological screening tests currently recommended by the AABB could be used as a surrogate marker for this protozoarium. A group of 26,365 blood donors (male = 21,053 and female = 5,312) was analysed for the correlation of T. cruzi antibodies (TcAb) with other serological markers (HIV, HBsAg, ALT, HTLV-I/II, HCV, Anti-HBc, syphilis and unexpected hemoglobins other than A1, A2 and F). Association could be demonstrated only between syphilis and TcAb in the female group (p = 0.005), but the low number of donors found with this association (n = 4) renders the effect of this correlation very small. A higher prevalence of TcAb was found in older age groups, with even gender distribution (p < 0.05), however, donors aged more than 54 years also represent a minority of the donor pool (4.83%) and the detection of positive donors in this age group also has a minor preventive effect on transfusion-transmitted Chagas disease. We conclude that when infected blood donors must be detected, specific serological screening for TcAb is essential and that currently no surrogate marker can be considered for detecting T. cruzi-infected blood donors.

Electrophysiological and neuropsychological functions in patients treated with interferon-beta

The neurotoxicity of interferon-beta (IFN-beta) was assessed by performing electrophysiological examinations and neuropsychological tests on 22 patients with malignant hematological diseases before, during, and after IFN-beta treatment. IFN-beta (6 x 10(6) IU/m2) was infused i.v. for 6 h daily for 7 days on alternate weeks for a total of three cycles (induction therapy) and was then continued at the same dose, twice a week, for an additional 24 weeks (maintenance therapy). Twenty-one of the 22 patients were evaluable. There were no significant changes in EEGs, visual evoked potentials, sensory conduction central time or motor nerve conduction velocity of two long nerves in the 15-19 patients studied before and after induction therapy, nor in the 6-8 patients investigated at the end of maintenance therapy. Neuropsychological monitoring failed to disclose any IFN-induced deterioration in 21 patients tested before and at the end of induction therapy or in the 10 patients who were also studied at the end of maintenance therapy. Despite certain limitations in the patient follow-up, the results underline the good general tolerance of IFN-beta.