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Luspatercept has been demonstrated to reduce the need for blood transfusion with manageable side effects in clinical trials, thus receiving the approval for the treatment of anemia associated with transfusion dependent beta thalassemia in adults. However, very little data on its safety and efficacy in real life have been hitherto published. Special warnings and precautions for use refer to the possibility of occurrence of thromboembolic events, extramedullary hemopoiesis masses and increased blood pressure. Ten Italian Specialized Centres for the treatment of Hemoglobinopathies, with the patronage of the “Società Italiana Talassemie ed Emoglobinopatie” (SITE), evaluated the effects of luspatercept in terms of safety and blood transfusion reduction in 116 patients (Table 1) who received the first dose of the drug after its marketing. The median duration of treatment was 158 days (min-max: 15-442). β globin genotype was β 0/β 0in 42 subjects (36.2%), β 0/ β +in 33 (28.4%), β +/ β +in 23 (19.8%), β 0/β wtplus α gene triplication in 4 (3.4%) and unknown in 14 (12%). Sixty-four patients (55.2%) were splenectomized. At the time of data collection, 32 patients (27.6%) had already discontinued the drug. Discontinuation had occurred after a median time of 132 days of treatment (min-max: 15-338) due to insufficient efficacy in the judgement of the physician (10) or patient (3), side effects attributed to luspatercept (16) that were detrimental to the continuation of therapy in the judgement of the physician (6) or patient (10), pregnancy (1) and other causes (2).

Background: CD19 direct chimeric antigen receptor (CAR) T-cell therapy is an efficacious therapy for patients (pts) affected by relapsed/refractory (R/R) large B-cell lymphomas (LBCL). The role of early evaluation by Positron emission tomography/computed tomography (PET/CT) is still undefined. The study's objective was to analyze the role of early PET/CT according to histology and CAR T-cell product administered.

The mechanisms mediating hematopoietic stem and progenitor cell (HSPC) mobilization by G-CSF are complex. We have found previously that G-CSF–enforced mobilization is controlled by peripheral sympathetic nerves via norepinephrine (NE) signaling. In the present study, we show that G-CSF likely alters sympathetic tone directly and that methods to increase adrenergic activity in the BM microenvironment enhance progenitor mobilization. Peripheral sympathetic nerve neurons express the G-CSF receptor and ex vivo stimulation of peripheral sympathetic nerve neurons with G-CSF reduced NE reuptake significantly, suggesting that G-CSF potentiates the sympathetic tone by increasing NE availability. Based on these data, we investigated the NE reuptake inhibitor desipramine in HSPC mobilization. Whereas desipramine did not by itself elicit circulating HSPCs, it increased G-CSF–triggered mobilization efficiency significantly and rescued mobilization in a model mimicking “poor mobilizers.” Therefore, these data suggest that blockade of NE reuptake may be a novel therapeutic target to increase stem cell yield in patients.

The mechanisms mediating hematopoietic stem and progenitor cell (HSPC) mobilization by G-CSF are complex. We have found previously that G-CSF–enforced mobilization is controlled by peripheral sympathetic nerves via norepinephrine (NE) signaling. In the present study, we show that G-CSF likely alters sympathetic tone directly and that methods to increase adrenergic activity in the BM microenvironment enhance progenitor mobilization. Peripheral sympathetic nerve neurons express the G-CSF receptor and ex vivo stimulation of peripheral sympathetic nerve neurons with G-CSF reduced NE reuptake significantly, suggesting that G-CSF potentiates the sympathetic tone by increasing NE availability. Based on these data, we investigated the NE reuptake inhibitor desipramine in HSPC mobilization. Whereas desipramine did not by itself elicit circulating HSPCs, it increased G-CSF–triggered mobilization efficiency significantly and rescued mobilization in a model mimicking “poor mobilizers.” Therefore, these data suggest that blockade of NE reuptake may be a novel therapeutic target to increase stem cell yield in patients.

This prospective study investigated the efficacy, safety, and response duration of low-dose rituximab (100 mg fixed dose for 4 weekly infusions) together with a short course of steroids as first- or second-line therapy in 23 patients with primary autoimmune hemolytic anemia (AIHA). The overall response was 82.6% at month +2, and subsequently stabilized to ∼ 90% at months +6 and +12; the response was better in warm autoimmune hemolytic anemia (WAIHA; overall response, 100% at all time points) than in cold hemagglutinin disease (CHD; average, 60%); the relapse-free survival was 100% for WAIHA at +6 and +12 months versus 89% and 59% in CHD, respectively, and the estimated relapse-free survival at 2 years was 81% and 40% for the warm and cold forms, respectively. The risk of relapse was higher in CHD and in patients with a longer interval between diagnosis and enrollment. Steroid administration was reduced both as cumulative dose (∼ 50%) and duration compared with the patient's past history. Treatment was well tolerated and no adverse events or infections were recorded; retreatment was also effective. The clinical response was correlated with amelioration biologic markers such as cytokine production (IFN-γ, IL-12, TNF-α, and IL-17), suggesting that low-dose rituximab exerts an immunomodulating activity. This study is registered at www.clinicaltrials.govas NCT01345708.

This prospective study investigated the efficacy, safety, and response duration of low-dose rituximab (100 mg fixed dose for 4 weekly infusions) together with a short course of steroids as first- or second-line therapy in 23 patients with primary autoimmune hemolytic anemia (AIHA). The overall response was 82.6% at month +2, and subsequently stabilized to ∼ 90% at months +6 and +12; the response was better in warm autoimmune hemolytic anemia (WAIHA; overall response, 100% at all time points) than in cold hemagglutinin disease (CHD; average, 60%); the relapse-free survival was 100% for WAIHA at +6 and +12 months versus 89% and 59% in CHD, respectively, and the estimated relapse-free survival at 2 years was 81% and 40% for the warm and cold forms, respectively. The risk of relapse was higher in CHD and in patients with a longer interval between diagnosis and enrollment. Steroid administration was reduced both as cumulative dose (∼ 50%) and duration compared with the patient's past history. Treatment was well tolerated and no adverse events or infections were recorded; retreatment was also effective. The clinical response was correlated with amelioration biologic markers such as cytokine production (IFN-γ, IL-12, TNF-α, and IL-17), suggesting that low-dose rituximab exerts an immunomodulating activity. This study is registered at www.clinicaltrials.gov as NCT01345708.

To assess whether antithrombotic prophylaxis with low-molecular-weight heparin effectively prevents recurrence of late pregnancy complications, 135 women with previous history of preeclampsia, hemolytic anemia, elevated liver enzymes and low platelet count syndrome, intrauterine fetal death, fetal growth restriction, or placental abruption who had been referred within the 12th gestational week were randomized to medical surveillance alone (n = 68) or combined to open-label nadroparin (3800 IU daily subcutaneous injections) treatment (n = 67) in the setting of a randomized, parallel-group, superiority trial, run in Italy from April 2007 to April 2010. Primary outcome was a composite end point of late-pregnancy complications. Analysis was by intention to treat. The study was stopped for futility at the time of the first planned interim analysis. Among the 128 women eventually available for final analyses, 13 of the 63 (21%) randomized to nadroparin compared with 12 of the 65 (18%) on medical surveillance alone progressed to the primary end point. The absolute event risk difference between treatment arms (2.2; −1.6 to 16.0) was not statistically significant (P= .76). Thus, nadroparin did not prevent late-pregnancy complications in women at risk of recurrence. This finding challenges the role of antithrombotic prophylaxis with low-molecular-weight heparin in the prevention of recurrent late pregnancy complications The trial was registered at http://ricerca-clinica.agenziafarmaco.itas EudraCT 2006-004205-26.

To assess whether antithrombotic prophylaxis with low-molecular-weight heparin effectively prevents recurrence of late pregnancy complications, 135 women with previous history of preeclampsia, hemolytic anemia, elevated liver enzymes and low platelet count syndrome, intrauterine fetal death, fetal growth restriction, or placental abruption who had been referred within the 12th gestational week were randomized to medical surveillance alone (n = 68) or combined to open-label nadroparin (3800 IU daily subcutaneous injections) treatment (n = 67) in the setting of a randomized, parallel-group, superiority trial, run in Italy from April 2007 to April 2010. Primary outcome was a composite end point of late-pregnancy complications. Analysis was by intention to treat. The study was stopped for futility at the time of the first planned interim analysis. Among the 128 women eventually available for final analyses, 13 of the 63 (21%) randomized to nadroparin compared with 12 of the 65 (18%) on medical surveillance alone progressed to the primary end point. The absolute event risk difference between treatment arms (2.2; −1.6 to 16.0) was not statistically significant (P = .76). Thus, nadroparin did not prevent late-pregnancy complications in women at risk of recurrence. This finding challenges the role of antithrombotic prophylaxis with low-molecular-weight heparin in the prevention of recurrent late pregnancy complications The trial was registered at http://ricerca-clinica.agenziafarmaco.it as EudraCT 2006-004205-26.

Previous observational studies suggest that rituximab may be useful in the treatment of primary immune thrombocytopenia (ITP). This randomized trial investigated rituximab efficacy in previously untreated adult ITP patients with a platelet count of 20 × 109/L or less. One hundred three patients were randomly assigned to receive 40 mg/d dexamethasone for 4 days with or without 375 mg/m2 rituximab weekly for 4 weeks. Patients who were refractory to dexamethasone alone received salvage therapy with dexamethasone plus rituximab. Sustained response (ie, platelet count ≥ 50 × 109/L at month 6 after treatment initiation), evaluable in 101 patients, was greater in patients treated with dexamethasone plus rituximab (n = 49) than in those treated with dexamethasone alone (n = 52; 63% vs 36%, P = .004, 95% confidence interval [95% CI], 0.079-0.455). Patients in the experimental arm showed increased incidences of grade 3 to 4 adverse events (10% vs 2%, P = .082, 95% CI, −0.010 to 0.175), but incidences of serious adverse events were similar in both arms (6% vs 2%, P = .284, 95% CI, −0.035 to 0.119). Dexamethasone plus rituximab was an effective salvage therapy in 56% of patients refractory to dexamethasone. The combination of dexamethasone and rituximab improved platelet counts compared with dexamethasone alone. Thus, combination therapy may represent an effective treatment option before splenectomy. This study is registered at http://clinicaltrials.gov as NCT00770562.

Previous observational studies suggest that rituximab may be useful in the treatment of primary immune thrombocytopenia (ITP). This randomized trial investigated rituximab efficacy in previously untreated adult ITP patients with a platelet count of 20 × 109/L or less. One hundred three patients were randomly assigned to receive 40 mg/d dexamethasone for 4 days with or without 375 mg/m2rituximab weekly for 4 weeks. Patients who were refractory to dexamethasone alone received salvage therapy with dexamethasone plus rituximab. Sustained response (ie, platelet count ≥ 50 × 109/L at month 6 after treatment initiation), evaluable in 101 patients, was greater in patients treated with dexamethasone plus rituximab (n = 49) than in those treated with dexamethasone alone (n = 52; 63% vs 36%, P= .004, 95% confidence interval [95% CI], 0.079-0.455). Patients in the experimental arm showed increased incidences of grade 3 to 4 adverse events (10% vs 2%, P= .082, 95% CI, −0.010 to 0.175), but incidences of serious adverse events were similar in both arms (6% vs 2%, P= .284, 95% CI, −0.035 to 0.119). Dexamethasone plus rituximab was an effective salvage therapy in 56% of patients refractory to dexamethasone. The combination of dexamethasone and rituximab improved platelet counts compared with dexamethasone alone. Thus, combination therapy may represent an effective treatment option before splenectomy. This study is registered at http://clinicaltrials.govas NCT00770562.

Angiopoietin-1 (Ang-1), ligand for the endothelial cell–specific Tie-2 receptors, promotes migration and proliferation of endothelial cells, however, whether these effects are promoted through the release of a secondary mediator remains unclear. In this study, we assessed whether Ang-1 promotes endothelial cell migration and proliferation through the release of interleukin-8 (IL-8). Ang-1 elicited in human umbilical vein endothelial cells (HUVECs) a dose- and time-dependent increase in IL-8 production as a result of induction of mRNA and enhanced mRNA stability of IL-8 transcripts. IL-8 production is also elevated in HUVECs transduced with retroviruses expressing Ang-1. Neutralization of IL-8 in these cells with a specific antibody significantly attenuated proliferation and migration and induced caspase-3 activation. Exposure to Ang-1 triggered a significant increase in DNA binding of activator protein-1 (AP-1) to a relatively short fragment of IL-8 promoter. Upstream from the AP-1 complex, up-regulation of IL-8 transcription by Ang-1 was mediated through the Erk1/2, SAPK/JNK, and PI-3 kinase pathways, which triggered c-Jun phosphorylation on Ser63 and Ser73. These results suggest that promotion of endothelial migration and proliferation by Ang-1 is mediated, in part, through the production of IL-8, which acts in an autocrine fashion to suppress apoptosis and facilitate cell proliferation and migration.

Angiopoietin-1 (Ang-1), ligand for the endothelial cell–specific Tie-2 receptors, promotes migration and proliferation of endothelial cells, however, whether these effects are promoted through the release of a secondary mediator remains unclear. In this study, we assessed whether Ang-1 promotes endothelial cell migration and proliferation through the release of interleukin-8 (IL-8). Ang-1 elicited in human umbilical vein endothelial cells (HUVECs) a dose- and time-dependent increase in IL-8 production as a result of induction of mRNA and enhanced mRNA stability of IL-8 transcripts. IL-8 production is also elevated in HUVECs transduced with retroviruses expressing Ang-1. Neutralization of IL-8 in these cells with a specific antibody significantly attenuated proliferation and migration and induced caspase-3 activation. Exposure to Ang-1 triggered a significant increase in DNA binding of activator protein-1 (AP-1) to a relatively short fragment of IL-8 promoter. Upstream from the AP-1 complex, up-regulation of IL-8 transcription by Ang-1 was mediated through the Erk1/2, SAPK/JNK, and PI-3 kinase pathways, which triggered c-Jun phosphorylation on Ser63 and Ser73. These results suggest that promotion of endothelial migration and proliferation by Ang-1 is mediated, in part, through the production of IL-8, which acts in an autocrine fashion to suppress apoptosis and facilitate cell proliferation and migration.

Background.Cardiovascular magnetic resonance (CMR) is the only available technique for the non-invasive quantification of MIO. The native T1 mapping has recently been proposed as an alternative to the universally adopted T2* technique, due to the higher sensitivity for detection of changes associated with mild or early iron overload.

Pepe: Chiesi Farmaceutici S.p.A.:Other: no profit support and speakers' honoraria;Bayer:Other: no profit support;ApoPharma Inc.:Other: no profit support.Pistoia:Chiesi Farmaceutici S.p.A.:Other: speakers' honoraria.Meloni:Chiesi Farmaceutici S.p.A.:Other: speakers' honoraria.

Cb2, the gene encoding the peripheral cannabinoid receptor, is located in a common virus integration site and is overex-pressed in retrovirally induced murine myeloid leukemias. Here we show that this G protein-coupled receptor (GPCR) is also aberrantly expressed in a high percentage of human acute myeloid leukemias. We investigated the mechanism of transformation by Cb2 and demonstrate that aberrant expression of this receptor on hematopoietic precursor cells results in distinct effects depending on the ligand used. Cb2-expressing myeloid precursors migrate upon stimulation by the endocannabinoid 2-arachidonoylglycerol and are blocked in neutrophilic differentiation upon exposure to another ligand, CP55940. Both effects depend on the activation of Gαi proteins and require the mitogen-induced extracellular kinase/extracellular signal-regulated kinase (MEK/ERK) pathway. Down-regulation of cyclic adenosine monophosphate (cAMP) levels upon Gαi activation is important for migration induction but is irrelevant for the maturation arrest. Moreover, the highly conserved G protein-interacting DRY motif, present in the second intracellular loop of GPCRs, is critical for migration but unimportant for the differentiation block. This suggests that the Cb2-mediated differentiation block requires interaction of Gαi proteins with other currently unknown motifs. This indicates a unique mechanism by which a transforming GPCR, in a ligand-dependent manner, causes 2 distinct oncogenic effects: altered migration and block of neutrophilic development. (Blood. 2004;104:526-534)

Cb2,the gene encoding the peripheral cannabinoid receptor, is located in a common virus integration site and is overex-pressed in retrovirally induced murine myeloid leukemias. Here we show that this G protein-coupled receptor (GPCR) is also aberrantly expressed in a high percentage of human acute myeloid leukemias. We investigated the mechanism of transformation by Cb2 and demonstrate that aberrant expression of this receptor on hematopoietic precursor cells results in distinct effects depending on the ligand used. Cb2-expressing myeloid precursors migrate upon stimulation by the endocannabinoid 2-arachidonoylglycerol and are blocked in neutrophilic differentiation upon exposure to another ligand, CP55940. Both effects depend on the activation of Gαiproteins and require the mitogen-induced extracellular kinase/extracellular signal-regulated kinase (MEK/ERK) pathway. Down-regulation of cyclic adenosine monophosphate (cAMP) levels upon Gαiactivation is important for migration induction but is irrelevant for the maturation arrest. Moreover, the highly conserved G protein-interacting DRY motif, present in the second intracellular loop of GPCRs, is critical for migration but unimportant for the differentiation block. This suggests that the Cb2-mediated differentiation block requires interaction of Gαiproteins with other currently unknown motifs. This indicates a unique mechanism by which a transforming GPCR, in a ligand-dependent manner, causes 2 distinct oncogenic effects: altered migration and block of neutrophilic development. (Blood. 2004;104:526-534)

The importance of HLA-DPB1 matching for the outcome of allogeneic hematologic stem cell (HSC) transplantation is controversial. We have previously identified HLA-DPB1*0901 as a target of cytotoxic T cells mediating in vivo rejection of an HSC allograft. Here we show that HLA-DPB1*0901 encodes a T-cell epitope shared by a subset of DPB1 alleles that determines nonpermissive mismatches for HSC transplantation. Several T-cell clones obtained from the patient at the time of rejection showed HLA-DP restricted recognition of allogeneic targets expressing HLA-DPB1*0901, *1001, *1701, *0301, *1401, and *4501, but not other alleles. Based on these findings, we developed an algorithm for prediction of nonpermissive HLA-DPB1 mismatches. Retrospective evaluation of 118 transplantations showed that the presence of nonpermissive HLA-DPB1 mismatches was correlated with significantly increased hazards of acute grade II to IV graft-versus-host disease (HR = 1.87, P = .046) and transplantation-related mortality (HR = 2.69, P = .027) but not relapse (HR = 0.98, P = .939), as compared with the permissive group. There was also a marked but statistically not significant increase in the hazards of overall mortality (HR = 1.64, P = .1). These data suggest that biologic characterization of in vivo alloreactivity can be a tool for definition of clinically relevant nonpermissive HLA mismatches for unrelated HSC transplantation.

The importance of HLA-DPB1 matching for the outcome of allogeneic hematologic stem cell (HSC) transplantation is controversial. We have previously identified HLA-DPB1*0901 as a target of cytotoxic T cells mediating in vivo rejection of an HSC allograft. Here we show that HLA-DPB1*0901 encodes a T-cell epitope shared by a subset of DPB1 alleles that determines nonpermissive mismatches for HSC transplantation. Several T-cell clones obtained from the patient at the time of rejection showed HLA-DP restricted recognition of allogeneic targets expressing HLA-DPB1*0901, *1001, *1701, *0301, *1401, and *4501, but not other alleles. Based on these findings, we developed an algorithm for prediction of nonpermissive HLA-DPB1 mismatches. Retrospective evaluation of 118 transplantations showed that the presence of nonpermissive HLA-DPB1 mismatches was correlated with significantly increased hazards of acute grade II to IV graft-versus-host disease (HR = 1.87, P= .046) and transplantation-related mortality (HR = 2.69, P= .027) but not relapse (HR = 0.98, P= .939), as compared with the permissive group. There was also a marked but statistically not significant increase in the hazards of overall mortality (HR = 1.64, P= .1). These data suggest that biologic characterization of in vivo alloreactivity can be a tool for definition of clinically relevant nonpermissive HLA mismatches for unrelated HSC transplantation.

The expression of cytotoxic T-lymphocyte antigen–4 (CTLA-4) molecule in human normal and neoplastic hematopoietic cells, both on the cell membrane and in the intracellular compartment, was evaluated. Flow cytometric analysis carried out with a panel of anti–CTLA-4 human single-chain fragment of variable domain (scFv) antibodies revealed that CTLA-4 was not expressed on the surface, whereas it was highly expressed within the cytoplasm, in freshly isolated peripheral blood mononuclear cells (PBMCs), T cells, B cells, CD34+stem cells, and granulocytes. Various treatments with agents able to specifically activate each cell type induced CTLA-4 expression on the surface of these cells. Similarly, increased CTLA-4 expression was observed in different hematopoietic cell lines although they also expressed surface CTLA-4, at different degrees of intensity, before activation. Surprisingly, CTLA-4 RNA transcripts were detectable in such cell lines only after nested polymerase chain reaction (PCR) specific for CTLA-4 extracellular domain, suggesting a very fast CTLA-4 RNA processing accompanied by prolonged CTLA-4 protein accumulation. We further demonstrated surface expression of CTLA-4 in a variety of acute and chronic myeloid leukemias (AMLs and CMLs) and B- and T-lymphoid leukemias, either adult or pediatric. CTLA-4 was expressed in 25% to 85% of AMLs and CMLs depending on the leukemia subtype and the epitope analyzed, whereas in acute B- and T-leukemias CTLA-4 expression was mainly cytoplasmic. Chronic B leukemias appeared to express CTLA-4, both on the surface and in cytoplasm, whereas few cases tested of chronic T leukemias were negative. Two anti–CTLA-4 immunotoxins (scFvs-saporin) induced in vitro apoptosis of neoplastic cells from a representative AML, suggesting a novel immunotherapeutic approach to AML based on CTLA-4 targeting.

The expression of cytotoxic T-lymphocyte antigen–4 (CTLA-4) molecule in human normal and neoplastic hematopoietic cells, both on the cell membrane and in the intracellular compartment, was evaluated. Flow cytometric analysis carried out with a panel of anti–CTLA-4 human single-chain fragment of variable domain (scFv) antibodies revealed that CTLA-4 was not expressed on the surface, whereas it was highly expressed within the cytoplasm, in freshly isolated peripheral blood mononuclear cells (PBMCs), T cells, B cells, CD34+ stem cells, and granulocytes. Various treatments with agents able to specifically activate each cell type induced CTLA-4 expression on the surface of these cells. Similarly, increased CTLA-4 expression was observed in different hematopoietic cell lines although they also expressed surface CTLA-4, at different degrees of intensity, before activation. Surprisingly, CTLA-4 RNA transcripts were detectable in such cell lines only after nested polymerase chain reaction (PCR) specific for CTLA-4 extracellular domain, suggesting a very fast CTLA-4 RNA processing accompanied by prolonged CTLA-4 protein accumulation. We further demonstrated surface expression of CTLA-4 in a variety of acute and chronic myeloid leukemias (AMLs and CMLs) and B- and T-lymphoid leukemias, either adult or pediatric. CTLA-4 was expressed in 25% to 85% of AMLs and CMLs depending on the leukemia subtype and the epitope analyzed, whereas in acute B- and T-leukemias CTLA-4 expression was mainly cytoplasmic. Chronic B leukemias appeared to express CTLA-4, both on the surface and in cytoplasm, whereas few cases tested of chronic T leukemias were negative. Two anti–CTLA-4 immunotoxins (scFvs-saporin) induced in vitro apoptosis of neoplastic cells from a representative AML, suggesting a novel immunotherapeutic approach to AML based on CTLA-4 targeting.

Estrogen replacement therapy has been associated with reduction of cardiovascular events in postmenopausal women, though the mechanism for this benefit remains unclear. Here we show that at physiological concentrations estrogen activates the anandamide membrane transporter of human endothelial cells and leads to rapid elevation of calcium (apparent within 5 minutes) and release of nitric oxide (within 15 minutes). These effects are mediated by estrogen binding to a surface receptor, which shows an apparent dissociation constant (Kd) of 9.4 ± 1.4 nM, a maximum binding (Bmax) of 356 ± 12 fmol × mg protein−1, and an apparent molecular mass of approximately 60 kDa. We also show that estrogen binding to surface receptors leads to stimulation of the anandamide-synthesizing enzyme phospholipase D and to inhibition of the anandamide-hydrolyzing enzyme fatty acid amide hydrolase, the latter effect mediated by 15-lipoxygenase activity. Because the endothelial transporter is shown to move anandamide across the cell membranes bidirectionally, taken together these data suggest that the physiological activity of estrogen is to stimulate the release, rather than the uptake, of anandamide from endothelial cells. Moreover, we show that anandamide released from estrogen-stimulated endothelial cells, unlike estrogen itself, inhibits the secretion of serotonin from adenosine diphosphate (ADP)–stimulated platelets. Therefore, it is suggested that the peripheral actions of anandamide could be part of the molecular events responsible for the beneficial effects of estrogen.

Estrogen replacement therapy has been associated with reduction of cardiovascular events in postmenopausal women, though the mechanism for this benefit remains unclear. Here we show that at physiological concentrations estrogen activates the anandamide membrane transporter of human endothelial cells and leads to rapid elevation of calcium (apparent within 5 minutes) and release of nitric oxide (within 15 minutes). These effects are mediated by estrogen binding to a surface receptor, which shows an apparent dissociation constant (Kd) of 9.4 ± 1.4 nM, a maximum binding (Bmax) of 356 ± 12 fmol × mg protein−1, and an apparent molecular mass of approximately 60 kDa. We also show that estrogen binding to surface receptors leads to stimulation of the anandamide-synthesizing enzyme phospholipase D and to inhibition of the anandamide-hydrolyzing enzyme fatty acid amide hydrolase, the latter effect mediated by 15-lipoxygenase activity. Because the endothelial transporter is shown to move anandamide across the cell membranes bidirectionally, taken together these data suggest that the physiological activity of estrogen is to stimulate the release, rather than the uptake, of anandamide from endothelial cells. Moreover, we show that anandamide released from estrogen-stimulated endothelial cells, unlike estrogen itself, inhibits the secretion of serotonin from adenosine diphosphate (ADP)–stimulated platelets. Therefore, it is suggested that the peripheral actions of anandamide could be part of the molecular events responsible for the beneficial effects of estrogen.

Introduction: Ineffective erythropoiesis (IE) is a crucial hallmark of β-Thalassemia (β-Thal) and sets the goal for treatment of both Transfusion-Dependent (TDT) and Non Transfusion-Dependent Thalassemia (NTDT) patients. The Growth Differentiation Factor (GDF) group has a relevant role in the molecular regulation of IE. Specifically, GDF11 contributes to the inhibition of RBC maturation and it is targeted by activin traps, such as luspatercept. However, its role is still debated; i.e., in a mouse model of β-Thal, the absence of GDF11 alone is not sufficient to mitigate IE (Guerra A et al., Blood, 2019). GDF15 increases from early until late phases of erythroid differentiation and negatively regulates erythroid cell development in-vitro, modulating maturation and apoptosis. (Ranjbaran R et a.l, Exp Cell Res, 2020). A few clinical studies found elevated serum GDF15 levels in β-Thal (Tanno T et al., Nat Med, 2007; Huang Y et al., Int J Med Sci, 2019), but data are sparse and a clear correlation with the severity of the pathology is still missing.

Recipients of allogeneic hematopoietic stem cell transplant (HSCT) have been excluded from clinical trials of SARS-CoV-2 messenger RNA (mRNA) vaccines; however, since these patients are at higher risk of severe complications following infection, they have been given high priority in vaccination campaigns worldwide. In this prospective observational study, we evaluated the immunogenicity of two BNT162b2 (Pfizer-BioNTech) vaccine doses in allogeneic HSCT recipients compared to healthy controls. IgG antibodies to the receptor-binding domain (RBD) of the S1 subunit of the spike protein of SARS-CoV-2 were analyzed by SARS-CoV-2 IgG II Quant (Abbott, Ireland). The cutoff value of the test used in this study is 7.1 BAU/mL (Binding Antibody Unit/mL) and the results greater than 7.1 indicate that seroconversion has occurred, as recommended by the manufacturer. Peripheral blood samples were collected for immunological analysis at three timepoints: pre-vaccine baseline (w0, before the first BNT162b2 dose), week 3 (w3, before the second vaccine dose) and week 5 (w5, 2 weeks following the second dose). Patients older than 18 years who received BNT162b2 vaccine following an HSCT at seven Italian centers were included in the study. Enrolled patients received two successive doses (at 3-week interval) at a median of 15 months (range 2-141) after HSCT. Twenty-nine age-matched health care workers who were vaccinated with BNT162b2 were recruited as the control group. Among the 34 patients evaluable for serological response, three patients were excluded from the analysis as the baseline serology demonstrated previous natural SARS-CoV-2 infection. On w3, after the first vaccine dose 7/31 (23%) patients developed anti-S IgG antibodies as compared to 28/29 (97%) controls (p<0.01). HSCT recipients showed lower antibody titers (median 1.8 BAU, range 0-481) as compared to healthy controls (median 118 BAU, range 6-1172, p<0.01). In univariate analysis, transplant-to-vaccination interval (>12 months, p<0.01), baseline CD4+ T cell count (>200/mm3, p=0.01), and CD4+CD45RA+ T naive cell count (>100/ mm3, p<0.01) were significantly associated with antibody response after the first vaccine dose. On w5, after the second vaccine dose, 24/31 (77%) of the patients showed antibody response, as compared to 99% of healthy controls (p<0.01); in fact, 71% of non-responders to the first dose developed IgG antibodies after vaccine boost (Figure 1). Median antibody titer after second dose was 350 BAU/ml (0-21.731). In univariate analysis, no significant association was found between patient characteristics and immunogenicity after vaccine boost. Adverse events were rare and modest. Nine percent of the patients reported mild local reactions after vaccine administration, including pain at the injection site and less commonly local erythema, local lymphadenopathy, or swelling; 35% of patients reported systemic adverse events, and all were mild. The most frequently reported systemic reactions included weakness (15%), headache (9%), and diarrhea (3%). In conclusion, in recipients of HSCT, a single dose of the BNT162b2 SARS-CoV-2 vaccine yielded poor efficacy, while immunogenicity increased significantly after vaccine boost at day 21 after the first dose. Patients who received vaccines beyond one year after transplant were more likely to mount anti-S IgG antibodies, which could be due to a broader immune reconstitution, as we observed an enhanced response to single BNT162b2 vaccine dose in patients with higher CD4+ T cell and particularly CD4+CD45RA+ naïve T cell counts.

Piga: Celgene: Membership on an entity's Board of Directors or advisory committees, Research Funding; Acceleron: Research Funding. Longo: Bristol Myers Squibb: Honoraria; BlueBird Bio: Honoraria.

Kordasti: Alexion: Honoraria; Celgene: Research Funding; Beckman Coulter: Honoraria; Novartis: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding. Pane: AbbVie; Amgen; Novartis: Other: Travel, accommodation, expenses; AbbVie; Amgen; Novartis, GSK, Incyte: Speakers Bureau; Novartis Pharma SAS;: Research Funding; AbbVie; Amgen; Novartis, GSK , Incyte: Consultancy.

We investigated the molecular basis for a mild phenotype in a group of patients with beta + thalassemia originating from Northern Sardinia by definition of the beta-thalassemia mutation, alpha-globin mapping and beta-globin haplotype determination. In nine patients, we detected the compound heterozygous state for the -87 promoter mutation and the codon 39 nonsense mutation; in one patient, we detected the combination of the codon 39 nonsense mutation and beta + IVS-1 nt 6 mutation. These patients were either nontransfusion dependent for survival or became transfusion dependent later. We did not detect the -87 promoter mutation in any of 115 thalassemia major patients originating from the same part of Sardinia, investigated as controls. Heterozygotes for the - 87 promoter mutation showed statistically higher hemoglobin (Hb) levels and larger and better hemoglobinized RBCs as compared with heterozygotes for the codon 39 nonsense mutation. From these data, we conclude that the -87 promoter mutation is a mild thalassemia allele, able to produce a phenotype of intermediate severity even in combination with a beta degree-thalassemia mutant. The coinheritance of alpha-thalassemia or the -++-- 5' subhaplotype in several cases may have contributed to development of the mild clinical picture. Characterization of the beta-thalassemia mutation in combination with alpha-globin mapping and haplotype analysis may allow a better estimate of the probability of a given clinical phenotype, thus permitting more accurate counseling.

The effect of succinylacetone (SA), a highly specific inhibitor of ALA-dehydratase and heme synthesis, on hemoglobin (Hb) production, transferrin receptor (TfR), and ferritin expression was analyzed in differentiating Friend leukemia cells (FLC). This compound exerted a pronounced inhibitory effect not only on heme and Hb synthesis, but also on all the remaining above-mentioned parameters. In particular, SA induced: (1) a reduction of the level of α-globin mRNA; (2) a decreased number of exposed TfR molecules, without modification of their affinity for the ligand; (3) a reduced level of TfR RNA, without significant change of TfR gene transcription rate; and (4) a lower ferritin content. The addition of exogenous hemin to differentiating FLC exerted opposite effects, and particularly induced an increase of both the number of TfRs and ferritin content. These findings suggest that in erythroid cells optimal heme synthesis is required to coordinately sustain globin chains synthesis and TfR/ferritin production; thus, the intracellular heme level may represent a key regulatory factor in the Hb synthesis pathway.

The chromosomal breakpoints of t(4;11) translocation of acute lymphoblastic leukemia (ALL) have been recently identified at molecular level and shown to involve the AF4 (FEL) gene on chromosome 4 and the ALL-1 (MLL, Hrx) gene on chromosome 11. The ALL-1/AF4 fusion gene is transcribed into a chimeric mRNA. Using primer sets derived from ALL-1 and AF4 cDNAs by reverse transcription-polymerase chain reaction (RT- PCR), we were able to amplify the breakpoint sites of the fusion transcript of all 15 ALL cases with karyotypic or molecular evidence of the t(4;11). DNA fragments of different size were obtained as the consequence of different breakpoints on chromosome 11 and the presence of alternative splicing of ALL-1 exon 8. The feasibility of monitoring the residual cells carrying the t(4;11) in 2 ALL patients with different clinical outcome was evaluated. Overall, the presented results provide evidence that RT-PCR can be used as a rapid method for detecting this chromosomal abnormality and following the patient's response to therapy.

We investigated the molecular basis for a mild phenotype in a group of patients with β+thalassemia originating from Northern Sardinia by definition of the β-thalassemia mutation, a-globin mapping and β-globin haplotype determination. In nine patients, we detected the compound heterozygous state for the —87 promoter mutation and the codon 39 nonsense mutation; in one patient, we detected the combination of the codon 39 nonsense mutation and β+IVS-1 nt 6 mutation. These patients were either nontrans-fusion dependent for survival or became transfusion dependent later. We did not detect the —87 promoter mutation in any of 115 thalassemia major patients originating from the same part of Sardinia, investigated as controls. Heterozygotes for the —87 promoter mutation showed statistically higher hemoglobin (Hb) levels and larger and better hemoglobinized RBCs as compared with heterozygotes for the codon 39 nonsense mutation. From these data, we conclude that the —87 promoter mutation is a mild thalassemia allele, able to produce a phenotype of intermediate severity even in combination with a β°-thalas-semia mutant. The coinheritance of a-thalassemia or the — + + - -5’ subhaplotype in several cases may have contributed to development of the mild clinical picture. Characterization of the β-thalassemia mutation in combination with a-globin mapping and haplotype analysis may allow a better estimate of the probability of a given clinical phenotype, thus permitting more accurate counseling.

Background

Lucchesi: Novartis: Honoraria; Pfizer: Honoraria; Incyte: Honoraria.

Paroxysmal nocturnal hemoglobinuria (PNH) and the stable phase of chronic myelogenous leukemia (CML) are the two hematological conditions known to be associated with low levels of leukocyte alkaline phosphatase (LAP) activity in peripheral blood polymorphonuclear cells (PMN). LAP mRNA levels were determined in PMN from PNH and CML patients by RNA blotting analysis. In CML, LAP mRNA is undetectable, suggesting either decreased transcription or rapid degradation of the message. Contrarily, in PNH normal or high levels of LAP mRNA are present. This latter finding supports the concept of a deficit in the anchorage of the protein to the plasma membrane through the glycolipid pathway, even though other post-transcriptional mechanisms could be involved.

Paroxysmal nocturnal hemoglobinuria (PNH) and the stable phase of chronic myelogenous leukemia (CML) are the two hematological conditions known to be associated with low levels of leukocyte alkaline phosphatase (LAP) activity in peripheral blood polymorphonuclear cells (PMN). LAP mRNA levels were determined in PMN from PNH and CML patients by RNA blotting analysis. In CML, LAP mRNA is undetectable, suggesting either decreased transcription or rapid degradation of the message. Contrarily, in PNH normal or high levels of LAP mRNA are present. This latter finding supports the concept of a deficit in the anchorage of the protein to the plasma membrane through the glycolipid pathway, even though other post-transcriptional mechanisms could be involved.

Severe hepatic VOD/SOS is a potentially life-threatening complication of HCT conditioning that may also develop after high-dose chemotherapy. The most severe form of VOD/SOS is often accompanied by multi-organ failure (MOF) and is associated with a mortality rate of >80% when managed with supportive care alone. As part of the marketing authorization in Europe, there was an obligation to set up a disease registry of patients with severe VOD/SOS post-HCT who were treated with defibrotide. The goal of this registry was to collect safety and outcome data and assess patterns of defibrotide utilization in the post-approval setting.

Mohty: Jazz Pharmaceuticals: Honoraria, Research Funding. Blaise:Sanofi: Honoraria; Molmed: Consultancy, Honoraria; Jazz Pharmaceuticals: Honoraria; Pierre Fabre medicaments: Honoraria. Labopin:Jazz Pharmaceuticals: Honoraria. Hanvesakul:Jazz Pharmaceuticals: Employment, Equity Ownership. Ryan:Jazz Pharmaceuticals: Employment, Equity Ownership. Lawson:Jazz Pharmaceuticals: Consultancy, Honoraria.

Taher: Novartis: Honoraria, Research Funding; Celgene: Research Funding. Origa:Novartis: Honoraria; Apopharma: Honoraria. Kouraklis:Novartis: Honoraria; Amgen: Honoraria; Janssen: Honoraria; Gilead: Consultancy; Roche: Consultancy; Celegene: Consultancy. Kattamis:Novartis: Honoraria, Research Funding; ApoPharma: Honoraria. Cortoos:Novartis: Employment. Huang:Novartis: Employment. Weill:Novartis: Employment. Herranz:Novartis: Employment. Porter:Bluebird Bio: Consultancy; Agios Pharmaceuticals: Consultancy, Honoraria; Celegene: Consultancy; Novartis: Consultancy, Honoraria, Research Funding.

Taher: Novartis: Honoraria, Research Funding; Celgene: Research Funding. Origa:Novartis: Honoraria; Apopharma: Honoraria. Kouraklis:Gilead: Consultancy; Janssen: Honoraria; Novartis: Honoraria; Amgen: Honoraria; Roche: Consultancy; Celegene: Consultancy. Kattamis:Novartis: Honoraria, Research Funding; ApoPharma: Honoraria. Cortoos:Novartis: Employment. Huang:Novartis: Employment. Weill:Novartis: Employment. Herranz:Novartis: Employment. Porter:Novartis: Consultancy, Honoraria, Research Funding; Celegene: Consultancy; Agios Pharmaceuticals: Consultancy, Honoraria; Bluebird Bio: Consultancy.