HLA-haploidentical hematopoietic stem cells transplantation with regulatory and conventional T-cell adoptive immunotherapy in pediatric patients with very high-risk acute leukemia.

Allogeneic hematopoietic stem cell transplantation (HSCT) is still needed for many children with very high-risk acute leukemia. An HLA-haploidentical family donor is a suitable option for those without an HLA-matched donor. Here we present outcomes of a novel HLA-haploidentical HSCT (haplo-HSCT) strategy with adoptive immunotherapy with thymic-derived CD4+CD25+ FoxP3+ regulatory T cells (Tregs) and conventional T cells (Tcons) performed between January 2017 and July 2021 in 20 children with high-risk leukemia. Median age was 14.5 years (range, 4-21), 15 had acute lymphoblastic leukemia, 5 acute myeloid leukemia. The conditioning regimen included total body irradiation (TBI), thiotepa, fludarabine, cyclophosphamide. Grafts contained a megadose of CD34+ cells (mean 12.4 × 106/Kg), Tregs (2 × 106/Kg) and Tcons (0.5-1 × 106/Kg). All patients achieved primary, sustained full-donor engraftment. Only one patient relapsed (5%). The incidence of non-relapse mortality was 15% (3/20 patients). Five/20 patients developed ≥ grade 2 acute Graft versus Host Disease (aGvHD). It resolved in 4 who are alive and disease-free; 1 patient developed chronic GvHD (cGvHD). The probability of GRFS was 60 ± 0.5% (95% CI: 2.1-4.2) (Fig. 6), CRFS was 79 ± 0.9% (95% CI: 3.2-4.9) as 16/20 patients are alive and leukemia-free. The median follow-up was 2.1 years (range 0.5 months-5.1 years). This innovative approach was associated with very promising outcomes of HSCT strategy in pediatric patients.

Long-term assessment of clinical outcomes and disease progression in patients with corrected Tetralogy of Fallot.

OBJECTIVE: Understanding changes of right ventricular (RV) geometry and function in repaired Tetralogy of Fallot (rToF) patients can improve decision-making for pulmonary valve replacement. Therefore, we aimed to assess the magnitude and clinical correlations of RV changes in rToF patients. PATIENTS AND METHODS: Clinical and MRI data of rToF patients who underwent repeated cardiac magnetic resonance imaging (MRI) at two centers between December 2003 and September 2020 were analyzed together with anatomical factors, including RV outflow tract obstruction, pulmonary artery branch stenosis, and tricuspid regurgitation. Adverse cardiac events and/or NYHA class worsening were documented and correlated with MRI changes. QRS length was reported at each MRI. RESULTS: Two-hundred-and-nineteen rToF patients (53% males, aged 20.2 ± 10.1 years) were enrolled. An increase of ventricular dimensions, except LVEDVi, and worsening of right and left ejection fractions were found over an average period of 5 years of follow-up. These changes were statistically significant but within 10% of the initial value. No significant changes were reported on a year-to-year basis, except in a small group of patients (6%) in whom no predictive factors were identified. Despite similar RV dimensions at the first examination, younger patients had a higher RV ejection fraction and a different annual rate of change of ventricular dimensions compared to older ones. Patients with arrhythmias (20%) were more frequently older and had larger RV dimensions but showed no significant correlations with MRI changes/years. CONCLUSIONS:  Changes in RV dimensions and function occur rarely and very slowly in rToF patients. A small percentage of patients experience a significant worsening in a short time interval without any recognized risk factors. Arrhythmias appear to occur in a small percentage of cases in the late follow-up.

The role of 3D imaging in the follow-up of patients with repaired tetralogy of Fallot.

OBJECTIVE: The patients with repaired Tetralogy of Fallot (rToF) are a growing population due to the improvement of surgical management in neonatal age. However, the significant pulmonary regurgitation, consequent to the repair, is the most frequent sequelae and leads to a progressive right ventricle dilation over time. The latter, in turn, is responsible for the possible dysfunction of right and/or left ventricle and an increased risk of dangerous ventricular arrhythmias. Therefore, right ventricle monitoring is necessary for rToF patients and a 3D method is required due to its three anatomical and functional subunits. Magnetic resonance imaging (MRI) has become the 3D modality of choice in the evaluation of both cardiac anatomy and ventricular volumes in rToF patients since it is able to evaluate both the pathophysiology and anatomy, it is free of radiation and, when strictly necessary, it uses a non-iodinated contrast agent. Cardiac CT should be considered in the evaluation of the sequelae in rToF only in selected cases, given that it implies a radiation dose and iodinated contrast, in addition to not evaluating the pathophysiology as MRI.

Next generation HLA-haploidentical HSCT.

Relapse is still the major cause of failure of allogeneic stem cell transplantation in high-risk acute leukemia patients. Indeed, whoever the donor and whatever the transplantation strategy, post-transplant relapse rates are ~30%, which is hardly satisfactory. The present phase 2 study analyzed the impact of adoptive immunotherapy with naturally occurring FoxP3+ T-regulatory cells (2 × 10(6) per kg) and conventional T lymphocytes (1 × 10(6) per kg) on prevention of GvHD and leukemia relapse in 43 high-risk adults undergoing full-haplotype mismatched transplantation without any post-transplant immunosuppression. Ninety-five percent of patients achieved full-donor type engraftment. Only 6/41 patients (15%) developed ⩾ grade II acute GvHD. Specific CD4(+) and CD8(+) for opportunistic pathogens emerged significantly earlier than after standard T-cell-depleted haplo-transplantation. The probability of disease-free survival was 0.56. At a median follow-up of 46 months (range 18-65 months), only 2/41 evaluable patients have relapsed. The cumulative incidence of relapse was significantly lower than in historical controls (0.05 vs 0.21; P = 0.03). These results demonstrate that the immunosuppressive potential of Tregs can be used to suppress GvHD without loss of the benefits of GvL activity. Humanized murine models provided insights into the mechanisms underlying separation of GvL from GvHD.

Ventricular assist devices as a bridge to heart transplantation or as destination therapy in pediatric patients.

PURPOSE: Despite the remarkable advances with the use of ventricular assist devices (VAD) in adults, pneumatic pulsatile support in children is still limited. We report on our experience in the pediatric population. METHODS: Retrospective review of 27 consecutive children offered mechanical support with Berlin Heart as a bridge to heart transplant, and Jarvik 2000 as a destination therapy from February 2002 to October 2011. RESULTS: The median patient age was 4.8 years (range = 75 days to 20.5 years). The median patient weight was 18.6 kg (range = 2.9-63 kg). We divided the patients in two groups, including in group I patients assisted for bridging to heart transplantation and in group II patients with Duchenne's dystrophy assisted as destination therapy. In the group I, 11 patients required biventricular mechanical support (BVAD), but in all other cases, a single left VAD proved sufficient (56%). The median duration of VAD support was 48 days (1 to 192 days). The median pre-VAD pulmonary vascular resistance index (Rpi) was 5.7 WU/m(2) (3.5 to 14.4 WU/m(2)). Twelve patients (48%) were successfully bridged to heart transplantation after a median duration of mechanical support of 63 days (range = 2-168 days). Ten deaths occurred (40%), three for neurological complications, two for sepsis, two for multiorgan failure, and three other for device malfunctioning. Since 2007, the survival rate of our patients has increased from 33% to 75%, and the need for BVAD has decreased from 89% to 23%. In the group II, two patients with mean age of 15.3 years were assisted with Jarvik 2000, and both of them are alive in a follow-up of 10.4 months. In two patients with Rpi > 10 WU/m(2), unresponsive to pulmonary vasodilatator therapy, Rpi dropped to 2.2 and 2 WU/m(2) after 40 and 23 days of BVAD support, respectively. Six patients (32%) required at least one pump change. Of 12 patients undergoing heart transplantation, five developed an extremely elevated (>60%) panel-reactive antibody by enzyme-linked immunosorbent assay, confirmed by Luminex. All of them experienced at least one acute episode of rejection in the first month after heart transplant, needing plasmapheresis. The survival rate after heart transplantation was 100% with a median follow-up of 34.4 months (45 days to 8.7 years). CONCLUSIONS: Mechanical support in children with end-stage heart failure is an effective strategy as a bridge to heart transplantation with a reasonable morbidity and mortality. BVAD support may offer an additional means to reverse extremely elevated pulmonary vascular resistance. The total implantable system opens a future scenarios for patients not eligible for heart transplantation.

Estimation of the binding free energy by Linear Interaction Energy models.

Since Hansch's extra thermodynamic multi-parameter approach, originally coined as Linear Free Energy Relationship, great efforts in medicinal chemistry have been made to properly estimate the binding free energy. Despite the often small amount, its value is however very critical in determining a successful binding. As a result, its correct estimation may provide a guide for a prospective rational drug design. The calculation of the absolute binding free energies is however a very challenging task as it requires a rigorous treatment of a number of physical terms that are both very time demanding and to some extent not immediately interpretable. In view of this, the introduction of some numerical approximations has permitted to develop the so called Linear Interaction Energy method that, at present, constitutes the best compromise among accuracy, speed of computation and easy interpretation. The initially developed Linear Interaction Energy method was subsequently revisited and several important improvements have been made. Significant examples are the Extended Linear Response, the surface generalized Born LIE, the molecular mechanics generalized Born surface area, the linear interaction energy in continuum electrostatics as well as its quantum mechanics variant. Principles and selected applications of these methods will be herein reviewed.

New strategies in the chemotherapy of leukemia: eradicating cancer stem cells in chronic myeloid leukemia.

Chronic myeloid leukemia (CML) is a myeloproliferative disorder caused by the Philadelphia-positive chromosome deriving from a translocation between chromosomes 22 and 9. The oncogenic product of this aberrant chromosome is the constitutively active tyrosine kinase BCR-ABL that is responsible for leukemic cell growth, proliferation and survival driven by the dysregulation of a large array of signal transduction pathways. Inhibition of BCR-ABL with tyrosine kinase inhibitors proved to be an efficient therapy of CML in the chronic phase. Unfortunately, the impressive success of BCR-ABL inhibitors as front-line therapy in CML has been tempered by problems of disease persistence or relapse arising from different mechanisms, including mutations in the kinase domain of the enzyme BCRABL and mechanisms independent from BCR-ABL activity. Growing evidence has also suggested a pivotal role of persistent leukemic cancer stem cells, characterized by high self-renewal and pluripotency, in CML maintenance and/or relapse. The present review deals with the most recent advances in this challenging field and focuses on the development of new drugs and therapeutic approaches to eradicate the subtle and dangerous leukemic stem cells responsible for maintaining and sustaining tumor growth.

Optimizing a photoallodepletion protocol for adoptive immunotherapy after haploidentical SCT.

In adults, one-haplotype-mismatched haematopoietic SCT (haploidentical HSCT) is associated with slow immune recovery due to decaying thymic function and extensive T-cell depletion of the graft. Although essential for preventing GVHD, T-cell depletion underlies the major reasons for transplant failure: leukemia relapse and infections, with infection-related mortality accounting for about 40% of non-leukemic deaths. Adoptive T-cell therapy would be helpful for these patients but to administer it without causing GVHD, alloreactive T cells need to be eliminated from donor T lymphocytes before infusion. In a preclinical study, to address this problem, we determined the efficacy of photodynamic purging of alloreactive T cells, by investigating combinations of parameters in order to achieve maximum allodepletion, preservation of T-regulatory cells and of pathogen and leukemia-specific T-cell responses in donor-vs-recipient MLR. We also needed to identify an optimal method to quantify the Ag-specific T-cell repertoires. Optimal procedures were identified. In particular, we compared limiting-dilution analyses (LDA) of proliferating T cells with H(3)-thymidine incorporation by bulk T cells and with flow cytometry CD25 expression, which is accepted as a T-cell activation marker. This study demonstrated that LDA is a reliable, predictable and sensitive method for measuring alloreactive, pathogen- and leukemia-specific T-cell frequencies.

D184E mutation in aquaporin-4 gene impairs water permeability and links to deafness.

Aquaporins (AQPs) play a physiological role in several organs and tissues, and their alteration is associated with disorders of water regulation. The identification of molecular interactions, which are crucial in determining the rate of water flux through the channel, is of pivotal role for the discovery of molecules able to target those interactions and therefore to be used for pathologies ascribable to an altered AQP-dependent water balance. In the present study, a mutational screening of human aquaporin-4 (AQP4) gene was performed on subjects with variable degrees of hearing loss. One heterozygous missense mutation was identified in a Spanish sporadic case, leading to an Asp/Glu amino acid substitution at position 184 (D184E). A BLAST analysis revealed that the amino acid D184 is conserved across species, consistently with a crucial role in the structure/function of AQP4 water channels. The mutation induces a significant reduction in water permeability as measured by the Xenopus laevis oocytes swelling assay and by the use of mammalian cells by total internal reflection microscopy. By Western blot, immunofluorescence and 2D Blue Native/SDS-PAGE we show that the reduction in water permeability is not ascribable to a reduced expression of AQP4 mutant protein or to its incorrect plasma membrane targeting and aggregation into orthogonal arrays of particles. Molecular dynamics simulation provided a molecular explanation of the mechanism whereby the mutation induces a loss of function of the channel. Substituting glutamate for aspartate affects the mobility of the D loop, which acquires a higher propensity to equilibrate in a "closed conformation", thus affecting the rate of water flux. We speculate that this mutation, combined with other genetic defects or concurrently with certain environmental stimuli, could confer a higher susceptibility to deafness.

Targeting monoamine oxidases with multipotent ligands: an emerging strategy in the search of new drugs against neurodegenerative diseases.

The socioeconomic burden of multi-factorial pathologies, such as neurodegenerative diseases (NDs), is enormous worldwide. Unfortunately, no proven disease-modifying therapy is available yet and in most cases (e.g., Alzheimer's and Parkinson's disease) the approved drugs exert only palliative and symptomatic effects. Nowadays, an emerging strategy for the discovery of disease-modifying drugs is based on the multi-target directed ligand (MTDL) design, an innovative shift from the traditional approach one-drug-one-target to the more ambitious one-drug-more-targets goal. Herein, we review the discovery strategy, the mechanism of action and the biopharmacological evaluation of multipotent ligands exhibiting monoamine oxidase (MAO) inhibition as the core activity with a potential for the treatment of NDs. In particular, MAO inhibitors exhibiting additional acetylcholinesterase (AChE) or nitric oxide synthase (NOS) inhibition, or ion chelation/antioxidant-radical scavenging/anti-inflammatory/A2A receptor antagonist/APP processing modulating activities have been thoroughly examined.

BCR-ABL inhibitors in chronic myeloid leukemia: process chemistry and biochemical profile.

Chronic myeloid leukemia (CML) is a myeloproliferative disease originating from a constitutively active tyrosine kinase, called BCR-ABL, expressed by an oncogene resulting from a reciprocal translocation between chromosome 9 and chromosome 22, coded as (t[9,22][q34;q11]). Inhibition of BCR-ABL with tyrosine kinase inhibitors (TKI) proved to be an efficient targeted therapy of Philadelphia-positive (Ph+) CML in the chronic phase. This review mainly addresses the synthetic pathways and process chemistry leading to the large scale preparation for pre-clinical demands and clinical supply of the three TKIs approved for Ph+ CML, i.e., imatinib, dasatinib and nilotinib and three more investigational drugs, i.e., bosutinib, ponatinib and bafetinib. Recent progress on the biochemical profiling of the six examined TKIs has been also reported.

Quinolizidinyl derivatives of bi- and tricyclic systems as potent inhibitors of acetyl- and butyrylcholinesterase with potential in Alzheimer's disease.

On the pattern of the potent and selective butyrylcholinesterase (BChE) inhibitors ethopropazine and Astra1397, sets of quinolizidinyl derivatives of bi- and tricyclic (hetero)aromatic systems were studied as dual, or BChE-selective inhibitors. All compounds exhibited activity against both cholinesterases, but inhibition of BChE was generally stronger, with submicromolar IC50 values for most of them (e.g. 15: IC50 versus BChE=0.15 µM; SI=47). However, in a subset of quinolizidinyl derivatives of 6-hydroxycoumarin an inverted selectivity for acetylcholinesterase (AChE) was observed (e.g. 46: IC50 versus AChE=0.35 µM; SI=0.06). Docking studies furnished a sound interpretation of the observed different enzyme activity. Several of the studied compounds have shown, in the past, additional pharmacological properties (as antagonism on presynaptic muscarinic autoreceptor; inhibition of enkephaline aminopeptidase and antipsychotic activity) of some relevance in Alzheimer's disease, and may, therefore, represent hits for the development of interesting single-entity multi-target drugs.

Prognostic significance of genetic variants in the IL-23/Th17 pathway for the outcome of T cell-depleted allogeneic stem cell transplantation.

T helper (Th) 17 cells have emerged as important mediators in infectious and inflammatory diseases and, recently, in transplant rejection. We analyzed the associations between five common genetic variants in the IL-23/Th17 signaling pathway, namely in IL17A, IL17F and IL23R genes, and clinical outcome in T cell-depleted allogeneic SCT (allo-SCT). In the multivariate analysis, variants in IL23R and IL17A genes were the most important prognostic factors. Thus, patient GA genotype at rs11209026 in IL23R was associated with improved overall survival (hazard ratio (HR)=0.48; P=0.028) and, in donor, with decreased risk of fungal infections (P=0.05). In contrast, patient TC and CC genotypes at rs8193036 in IL17A gene were associated with increased risk of CMV infection (HR=3.68; P=0.011) and patient acute GVHD (HR=7.08; P=0.008), respectively. These results suggest that genetic variants in the IL-23/Th17 inflammatory pathway are important prognostic factors for the clinical outcome of allo-SCT. Although validation studies are ultimately required, our results would suggest the potential usefulness of IL-23/Th17 genotyping in donor selection and patient evaluation.

Folding in lipid membranes (FILM): a novel method for the prediction of small membrane protein 3D structures.

We present the results of applying a novel knowledge-based method (FILM) to the prediction of small membrane protein structures. The basis of the method is the addition of a membrane potential to the energy terms (pairwise, solvation, steric, and hydrogen bonding) of a previously developed ab initio technique for the prediction of tertiary structure of globular proteins (FRAGFOLD). The method is based on the assembly of supersecondary structural fragments taken from a library of highly resolved protein structures using a standard simulated annealing algorithm. The membrane potential has been derived by the statistical analysis of a data set made of 640 transmembrane helices with experimentally defined topology and belonging to 133 proteins extracted from the SWISS-PROT database. Results obtained by applying the method to small membrane proteins of known 3D structure show that the method is able to predict, at a reasonable accuracy level, both the helix topology and the conformations of these proteins.

Haploidentical stem cell transplantation for acute leukemia.

PREMISE: Since March 1993, 133 patients with high-risk acute leukemia (66 AML, 67 ALL) have received a megadose of T-cell depleted hematopoietic stem cells. The 1993-95 conditioning protocol included TBI, thiotepa, ATG and CY for 36 patients who received an inoculum made up of lectin-separated bone marrow and PBPCs. After 1995, to minimise the extra-hematological toxicity of the conditioning and eliminate GvHD, we substituted fludarabine for CY in the conditioning and PBPCs were depleted of T-cells by a positive selection of the CD34+ cells using CellPro (n=44 patients) or, since January 1999, CliniMacs (n = 53 patients). A later modification to the protocol in January 1999 was the suspension of post transplant G-CSF. WORK IN PROGRESS: We report here the results in the last 53 acute leukemia patients all of whom were transplanted under our modified protocol. Ages ranged from 9 to 62 years with a median of 38 years for the 33 patients with AML and 23 for the 20 with ALL. All were at high risk because 25 were actually in relapse at transplant, 16 were in second or later CR and even the 12 patients in CR1 were at high risk because of the unfavourable prognostic features. Overall 52/53 patients (98%) engrafted. The TBI-Fludarabine-based conditioning was well tolerated even in the 14 patients between 45 and 62 years of age. There was no veno-occlusive disease of the liver and the incidence of severe mucositis was low. Even though no post-transplant immunosuppressive therapy was given, acute GvHD grade > or = II occurred in only 4 cases and only one progressed to chronic GvHD. Overall, 16 patients (30%) have died of non-leukemic causes. Relapses occurred mainly in patients who were already in relapse at transplant (12/25). Only 3 of the 28 who were in any CR at transplant have so far relapsed. As our group has already shown, donor-vs-recipient NK cell alloreactivity exerts a specific graft-vs-AML effect in the absence of GvHD. In fact, leukemia relapse was largely controlled in AML recipients whose donor was NK alloreactive, with only 2 out of 16 relapsing. To date, 13 of 18 AML (72%) and 5 of 10 ALL (50%) who were in any CR at transplant, survive disease-free while 4 of the 15 patients (16%) in relapse at transplant survive. The probability of event-free survival for patients transplanted in CR is 60% in the 18 AML patients and 38% in the 10 ALL. The probability of EFS was significantly better in the 16 AML patients whose transplant included donor vs recipient NK cell alloreactivity than in those whose transplant did not (70% vs 7%). In conclusion, given our current results, the most suitable candidate for the full haplotype mismatched transplant should be in early stage disease and selection of an NK alloreactive donor is recommended.

Cytisine derivatives as high affinity nAChR ligands: synthesis and comparative molecular field analysis.

A number of new N-substituted cytisine derivatives were prepared and tested, along with similar compounds already described by us and others, as high affinity neuronal acetylcholine receptor ligands. Structure-affinity relationships were discussed in the light of our recently proposed pharmacophore model for nicotinic receptor agonists. The most significant physicochemical interactions modulating the receptor-ligand binding were detected at the three dimensional (3D) level by means of comparative molecular field analysis (CoMFA). The best predictive PLS model was a single-field steric model showing good statistical figures: n = 17, Q2 = 0.717, s(ev) = 0.566, r2 = 0.942, s = 0.275.

Cataracts in patients receiving stem cell transplantation after conditioning with total body irradiation.

One hundred and ninety-three patients with hematological malignancies and a follow-up > or =1 year, treated with stem cell transplantation (45 autologous, 99 allogeneic T cell-depleted matched, 49 allogeneic T cell-depleted mismatched) from July 1985 to May 1998, were considered evaluable for the development of cataracts. Total body irradiation (TBI), administered either according to a hyperfractionated scheme (HTBI) or in a single dose (STBI), was employed in the conditioning regimens. HTBI was prescribed in 94% of patients undergoing allogeneic matched transplant, while STBI was used in 71% of patients receiving allogeneic mismatched and in all patients undergoing autologous transplant. The median follow-up was 7.56 years in the HTBI and 3.02 years in the STBI group. Among the different risk factors analyzed by univariate analysis only the TBI scheme and type of transplant reached statistical significance (P < 0.0001 and P < 0.001, respectively). By multivariate analysis only the TBI scheme was an independent factor for cataract development (STBI vs HTBI RR 7.2; P < 0.01). Our results showed that STBI is more cataractogenic than HTBI. The incidence of cataract we observed was among the lowest described in the literature. T cell depletion, because it prevents graft-versus-host disease and reduces the protracted use of post-transplant steroids, explains the results we obtained.

Ligands of neuronal nicotinic acetylcholine receptor (nAChR): inferences from the Hansch and 3-D quantitative structure-activity relationship (QSAR) Models.

Neuronal acetylcholine ion channel receptors (nAChRs), that exist in several subtypes resulting from a different organisation of various subunits around the central ion channel, are involved in a variety of functions and disorders of the central nervous system. There is evidence to implicate a deficit of nAChRs in the symptomatology of severe neurologic pathologies, such as Alzheimer s and Parkinson s diseases. Reliable three-dimensional structures of nAChRs are not available yet, and this hampers adopting structure-based approaches in designing new ligands. Also pharmacophore models are not reliable enough to be used in ligand-based approaches to drug design and little structure-activity work has been reported so far. This paper deals with structure-activity relationships of a wide series of nicotinic ligands. It provides results from a study of the quantitative structure activity relationships (QSARs) based on literature data of about 270 nicotinic agonists, belonging to various chemical classes. The QSAR study was carried out by using either a classical Hansch approach or a Comparative Molecular Field Analysis (CoMFA). Within each congeneric series, Hansch-type equations revealed detrimental steric effects as the factors mainly modulating the receptor affinity, whereas CoMFA allowed us to merge progressively models obtained for each class of congeners into a more general one that showed good cross-validation statistics. The CoMFA coefficient isocontour maps illustrated, at the 3-D level, the most relevant interactions responsible for a high receptor affinity, whereas the robustness of the global three-dimensional QSAR/CoMFA (n = 206, q(2) = 0.749, r(2) = 0.847, s= 0.600) model was supported by the high value of the prediction statistics (r(2)pred = 0.961) and confirmed by the satisfactory predictions of the affinity data of an external set of 18 recently published ligands with chemical structures even quite diverse from those included in the training set.