ActivinA modulates B-acute lymphoblastic leukaemia cell communication and survival by inducing extracellular vesicles production.

Extracellular vesicles (EVs) are a new mechanism of cellular communication, by delivering their cargo into target cells to modulate molecular pathways. EV-mediated crosstalk contributes to tumor survival and resistance to cellular stress. However, the role of EVs in B-cell Acute Lymphoblastic Leukaemia (B-ALL) awaits to be thoroughly investigated. We recently published that ActivinA increases intracellular calcium levels and promotes actin polymerization in B-ALL cells. These biological processes guide cytoskeleton reorganization, which is a crucial event for EV secretion and internalization. Hence, we investigated the role of EVs in the context of B-ALL and the impact of ActivinA on this phenomenon. We demonstrated that leukemic cells release a higher number of EVs in response to ActivinA treatment, and they can actively uptake EVs released by other B-ALL cells. Under culture-induced stress conditions, EVs coculture promoted cell survival in B-ALL cells in a dose-dependent manner. Direct stimulation of B-ALL cells with ActivinA or with EVs isolated from ActivinA-stimulated cells was even more effective in preventing cell death. This effect can be possibly ascribed to the increase of vesiculation and modifications of EV-associated microRNAs induced by ActivinA. These data demonstrate that ActivinA boosts EV-mediated B-ALL crosstalk, improving leukemia survival in stress conditions.

Safety profile of first-line targeted therapies in elderly and/or comorbid chronic lymphocytic leukaemia patients (unfit subpopulation). A systematic review and network meta-analysis.

This systematic literature review (CRD42023393903) and a Bayesian network meta-analysis (NMA) aimed to assess the relative safety profile of first-line targeted therapies (acalabrutinib, ibrutinib, obinutuzumab, ofatumumab, pirtobrutinib, ublituximab, umbralisib, venetoclax, zanubrutinib) in chronic lymphocytic leukaemia (CLL) patients with advanced age and/or comorbidities. The NMA revealed that zanubrutinib was the safest treatment option in terms of the overall safety profile (e.g., serious adverse events [AEs] grade 1-5), followed by venetoclax-obinutuzumab, which showed an advantage in terms of AEs grade 1-5. The use of Bruton's tyrosine kinase inhibitor (BTKi) monotherapy was more favourable in terms of the risk of haematological AEs, but chemoimmunotherapy showed advantages in terms of cardiovascular, gastrointestinal, and infectious AEs. The risk of secondary cancers was similar between treatments. In conclusion, targeted therapies are associated with variable and clinically relevant AEs. The therapies appear to be safer when used as monotherapy rather than in combination with immunological agents in naïve CLL patients with advanced age and/or comorbidities.

89Zr-immunoPET-guided selection of a CD33xIL15 fusion protein optimized for antitumor immune cell activation and in vivo tumour retention in acute myeloid leukaemia.

PURPOSE: Immune cells are capable of eliminating leukemic cells, as evidenced by outcomes in hematopoietic cell transplantation (HCT). However, patients who fail induction therapy will not benefit from HCT due to their minimal residual disease (MRD) status. Thus, we aimed to develop an immunomodulatory agent to reduce MRD by activating immune effector cells in the presence of leukaemia cells via a novel fusion protein that chimerises two clinically tolerated biologics: a CD33 antibody and the IL15Ra/IL15 complex (CD33xIL15). METHODS: We generated a set of CD33xIL15 fusion protein constructs with varying configurations and identified those with the best in vitro AML-binding, T cell activation, and NK cell potentiation. Using 89Zr-immunoPET imaging we then evaluated the biodistribution and in vivo tumour retention of the most favourable CD33xIL15 constructs in an AML xenograft model. Ex vivo biodistribution studies were used to confirm the pharmacokinetics of the constructs. RESULTS: Two of the generated fusion proteins, CD33xIL15 (N72D) and CD33xIL15wt, demonstrated optimal in vitro behaviour and were further evaluated in vivo. These studies revealed that the CD33xIL15wt candidate was capable of being retained in the tumour for as long as its parental CD33 antibody, Lintuzumab (13.9 ± 3.1%ID/g vs 18.6 ± 1.1%ID/g at 120 h). CONCLUSION: This work demonstrates that CD33xIL15 fusion proteins are capable of targeting leukemic cells and stimulating local T cells in vitro and of concentrating in the tumour in AML xenografts. It also highlights the importance of 89Zr-immunoPET to guide the development and selection of tumour-targeted antibody-cytokine fusion proteins.

Extracellular vesicles in cattle infected with bovine leukaemia virus: isolation and molecular analysis.

Introduction: Exosomes are nanosized lipid bilayer membranous microvesicles, extracellularly released from a variety of mammalian cells. They mediate intercellular signalling by transporting several types of RNA, lipids and proteins and participate in the intercellular exchange of DNA, RNA, micro RNA, proteins and other components. These microvesicles are present in all body fluids in physiological and pathological conditions and reflect the state of the host organism. The aim of the study was the isolation and molecular determination of exosomes in blood and supernatant fluids of bovine dendritic cell cultures infected with bovine leukaemia virus (BLV). Material and Methods: Exosomes were isolated by ultracentrifugation from the blood sera, plasma and supernatant of bovine BLV-infected and uninfected control dendritic cell cultures and their presence was confirmed with scanning electron and transmission electron microscopy. Western blot analysis of the structural BLV glycoprotein 51 (Env) and protein 24 (Gag) and of the tetraspanin exosomal markers CD9, CD63 and flotillin-1 was undertaken in BLV+ and control BLV- cattle. Results: In exosomes of leukaemic cattle both BLV proteins and exosomal markers were detected. In healthy control animals only exosomal markers were determined. Conclusion: Proteins of BLV were released with exosomes and could be transferred into recipient cells as an alternative propagation route not requiring virus infection.

Reactivation of cytomegalovirus and bloodstream infection and its impact on early survival after allogeneic haematopoietic stem cell transplantation: a multicentre retrospective study.

Cytomegalovirus reactivation (CMVr) and bloodstream infections (BSI) are the most common infectious complications in patients after allogeneic haematopoietic stem cell transplantation (allo-HSCT). Both are associated with great high morbidity whilst the BSI is the leading cause of mortality. This retrospective study evaluated the incidence of CMVr and BSI, identified associated risk factors, assessed their impact on survival in allo-HSCT recipients during the first 100 days after transplantation. The study comprised 500 allo-HSCT recipients who were CMV DNA-negative and CMV IgG-positive before allo-HSCT. Amongst them, 400 developed CMVr and 75 experienced BSI within 100 days after allo-HSCT. Multivariate regression revealed that graft failure and acute graft-versus-host disease were significant risk factors for poor prognosis, whereas CMVr or BSI alone were not. Amongst all 500 patients, 56 (14%) developed both CMVr and BSI in the 100 days after HSCT, showing significantly reduced 6-month overall survival (p = 0.003) and long-term survival (p = 0.002). Specifically, in the initial post-transplant phase (within 60 days), BSI significantly elevate mortality risk, However, patients who survive BSI during this critical period subsequently experience a lower mortality risk. Nevertheless, the presence of CMVr in patients with BSI considerably diminishes their long-term survival prospects. This study provides real-world data on the impact of CMVr and BSI following transplantation on survival, particularly in regions such as China, where the prevalence of CMV IgG-positivity is high. The findings underscore the necessity for devising and executing focused prevention and early management strategies for CMVr and BSI to enhance outcomes for allo-HSCT recipients.

Mutations in Genes Producing Nitric Oxide and Hydrogen Sulfide and Their Connection With Apoptotic Genes in Chronic Myeloid Leukemia.

Background Despite advances in chronic myeloid leukemia (CML) genetics, the role of nitric oxide (NO) and hydrogen sulfide (H2S) gene mutations and their relationship to apoptotic genes is unclear. Therefore, this study investigated NO- and H2S-producing genes' mutations and their interactions with apoptotic genes using Sanger sequencing and next-generation sequencing (NGS). Methodology A complete blood count (CBC) was carried out to measure the total number of white blood cells, while IL-6 levels were assessed in both control and CML patients using an ELISA technique. Sanger sequencing was used to analyze mutations in the CTH and NOS3 genes, whereas NGS was applied to examine mutations on all chromosomes. Results White blood cell (WBC) and granulocyte counts were significantly higher in CML patients compared to controls (p<0.0001), and monocyte counts were similarly higher (p<0.05). Interleukin-6 (IL-6) levels were significantly elevated in CML patients than controls (p<0.0001), indicating a possible link to CML etiology or progression. Multiple mutations have been identified in both genes, notably in CTH exon 12 and the NOS3 genes VNTR, T786C, and G894T. This study also measured IL-6 concentrations using IL-6 assays, identifying its potential as a CML prognostic diagnostic. WBC counts, granulocyte counts, and mid-range absolute counts, or MID counts, were significantly higher in CML patients than in normal control individuals. NGS identified 1643 somatic and sex chromosomal abnormalities and 439 actively expressed genes in CML patients. The findings imply a genomic landscape beyond the BCR-ABL1 mutation in CML development compared to other databases. Conclusion In conclusion, this study advances the understanding of the genetic characteristics of CML by identifying mutations in the NO- and H2S-producing genes and their complex connections with genes involved in apoptosis. The comprehensive genetic profile obtained by Sanger sequencing and NGS provides possibilities for identifying novel targets for therapy and personalized treatments for CML, therefore contributing to developments in hematological diseases.

A retrospective observational study of ibrutinib in chronic lymphocytic leukaemia in a real-life setting in France using the national claims database (OSIRIS).

BACKGROUND: Ibrutinib is a Bruton's tyrosine kinase inhibitor indicated for the first-line treatment and relapse of chronic lymphocytic leukaemia (CLL), Waldenström's macroglobulinemia (WM) and mantle cell lymphoma (MCL). This study aimed to describe the characteristics of CLL patients treated with ibrutinib and its effectiveness, safety, and treatment pattern in real life. METHODS: All patients covered by the general health scheme (approximately 80% of the French population) with a first ibrutinib dispensation from August 1, 2017 (date of reimbursement in France) to December 31, 2020, were identified in the French National Health Insurance database (SNDS). An algorithm was developed to identify the disease (CLL, MCL or WM) for which ibrutinib was prescribed. This article focused on CLL patients. The time to next treatment (TTNT) was plotted using Kaplan‒Meier curves. RESULTS: During this period, 6,083 patients initiated ibrutinib, among whom 2,771 (45.6%) patients had CLL (mean age of 74 years; 61% of men). At ibrutinib initiation, 46.6% of patients had a cardiovascular comorbidity. Most patients (91.7%) were not hospitalized during the exposure period for one of the cardiovascular or bleeding events studied. Hospitalizations were more frequent in patients with a cardiovascular comorbidity (5.9% versus 11.0%, p-value < 0.0001) and aged over 70 (5.9% versus 9.4%, p-value < 0.0001). The median TTNT was not reached. CONCLUSION: This is one of the largest cohorts of ibrutinib-treated patients in the world. The profile of CLL patients treated with ibrutinib was in accordance with the marketing authorization and reimbursement. This study confirmed effectiveness and safety data.

Multiple small-dose infusions of G-CSF-mobilized haploidentical lymphocytes after autologous haematopoietic stem cell transplantation for acute myeloid leukaemia.

This retrospective study analysed 106 acute myeloid leukaemia (AML) patients undergoing autologous haematopoietic stem cell transplantation (ASCT) to assess the impact of multiple small-dose infusions of granulocyte-colony-stimulating factor (G-CSF)-mobilized haploidentical lymphocytes as post-ASCT maintenance therapy. Among them, 50 patients received lymphocyte maintenance therapy, 21 received alternative maintenance therapy, and 35 received no maintenance therapy. Patients receiving lymphocyte maintenance therapy demonstrated significantly higher overall survival (OS) and disease-free survival (DFS) compared to those without maintenance therapy, with 4-year OS and DFS rates notably elevated. While there were no significant differences in recurrence rates among the three groups, lymphocyte maintenance therapy showcased particular benefits for intermediate-risk AML patients, yielding significantly higher OS and DFS rates and lower relapse rates compared to alternative maintenance therapy and no maintenance therapy. The study suggests that multiple small-dose infusions of G-CSF-mobilized haploidentical lymphocytes may offer promising outcomes for AML patients after ASCT, particularly for those classified as intermediate-risk. These findings underscore the potential efficacy of lymphocyte maintenance therapy in reducing disease relapse and improving long-term prognosis in this patient population.

Australians with chronic lymphocytic leukaemia continue to have high rates of second primary malignancies in the modern era.

Population-based studies have demonstrated a high risk of second cancers, especially of the skin, among patients with chronic lymphocytic leukaemia (CLL). We describe age-standardised incidence ratios (SIRs) of second primary malignancies (SPM) in Australian patients with relapsed/refractory CLL treated with at least two lines of therapy, including ibrutinib. From December 2014 to November 2017, 156 patients were identified from 13 sites enrolled in the Australasian Lymphoma and Related Diseases Registry, and 111 had follow-up data on rates of SPM. At 38.4 months from ibrutinib therapy commencement, 25% experienced any SPM. SIR for melanoma and all cancers (excluding nonmelanomatous skin cancers) were 15.8 (95% confidence interval (CI): 7.0-35.3) and 4.6 (95% CI: 3.1-6.9) respectively. These data highlight the importance of primary preventive interventions and surveillance, particularly as survival from CLL continues to improve.

Atraumatic splenic rupture as first presentation of hairy cell leukaemia-a case report.

Atraumatic splenic rupture is a complex surgical pathology owing to its rarity, non-specificity of symptoms and gravity of possible outcomes. This case outlines the investigation and management of a patient with atraumatic splenic rupture secondary to undiagnosed hairy cell leukaemia. While the patient was initially managed conservatively, they went on to have a splenectomy owing to ongoing transfusion requirements. A review of the literature has also been performed and presented to highlight the potential causes of atraumatic splenic rupture and the various options for confirming diagnosis and definitive management.

Cancer incidence in Swedish oil refinery workers exposed to benzene.

BACKGROUND: Oil refinery workers are exposed to benzene, which is a well-known cause of leukaemia, but results on leukaemia in oil refinery workers have been mixed, and the data on workers' exposure is limited. Oil refinery workers are also exposed to asbestos and several studies have shown increased risk of mesothelioma. AIM: The objective was to investigate cancer incidence, especially leukaemia, at low to moderate exposure to benzene in an update of a previous study of employees at three Swedish oil refineries. METHODS: Cancer incidence was followed up in 2264 men (1548 refinery operators) employed at three oil refineries in Sweden for at least one year. Job types and employment times were collected from complete company files. A retrospective assessment of the benzene exposure was performed by occupational hygienists in collaboration with the refineries using historic measurements as well as detailed information on changes in the industrial hygiene and technological developments. Cases of cancer were retrieved by a linkage with the Swedish Cancer Register through 35-47 years of follow-up and standardized incidence ratios (SIR) with 95% confidence intervals (CI) were calculated. RESULTS: In total, 258 tumors had occurred versus 240 expected (SIR 1.07; 95% CI 0.95-1.21). There were 10 cases of leukaemia, all in refinery operators (SIR 2.4; 95% CI 1.18-4.51). There were three cases of pleural mesothelioma, two of which in refinery operators. The mean estimated cumulative benzene exposure for the cases of leukaemia was 7.9 ppm-years (median 4.9, range 0.1-31.1). DISCUSSION: The study suggests that low to moderate average cumulative benzene exposure increases the risk of leukaemia. Limitations include the modest number of cases and potential misclassification of exposure. CONCLUSION: The present study indicated an increased risk of leukaemia in male oil refinery workers with low to moderate exposure to benzene.

Impact of additional cytogenetic aberrations at diagnosis on prognosis of adults patients with Philadelphia chromosome positive acute lymphoblastic leukemia undergoing allogeneic hematopoietic cell transplantation: a retrospective analysis.

Additional chromosomal abnormalities(ACAs) at diagnosis are associated with inferior prognosis in chronic myeloid leukemia. However, the prognostic significance of ACAs in adult patients with Philadelphia Chromosome Positive acute lymphoblastic leukemia (Ph + ALL) receiving TKI-targeted drugs and allogeneic hematopoietic stem cell transplantation(HSCT) is unknown. One hundred thirty-six adult patients with Ph + ALL were included in the study and retrospectively analysed, evaluating the effect of ACAs on outcomes of transplantation. ACAs are observed in 60 cases (44%). ACAs detected in more than 5% of cases were defined as major-route and encompass: +der(22), +der(9), + 8, -7 and complex karyotype. The median follow-up was 26.4 months. In the subgroup analyses of major route ACAs, three-year cumulative incidence of relapse (CIR) and progression-free survival(PFS) are statistically significant in + 8[66.7% vs.23.7%, P = 0.024; 77.8% vs. 23.7%, P = 0.0087], -7[53.8% vs. 23.7%, P = 0.035%; 61.5% vs. 32.9%, P = 0.033], and complex karyotypes[42.9% vs. 23.7%, P = 0.027; 47.6% vs. 23.7%] compared with t(9;22) sole. Additionally, the 3-year CIR for Ph + ALL with + der(22) is 44% vs. 23.7% for t(9;22) sole(P = 0.045). The 3-year overall survival (OS) in the - 7 group is 46.5%, which is statistically significant compared with the other groups(P = 0.001). In multivariate analyses, three years CIR and PFS are statistically significant in + der(22), + 8, -7 and complex karyotype compared with t(9;22) sole(P < 0.05). More importantly, Ph + ALL with - 7 was negatively associated with the rate of 3-year OS(P = 0.012). Thus, ACAs at diagnosis appear to have a significant prognostic impact on transplantation outcomes in patients with Ph + ALL.

GATA2 deficiency syndrome: A compensatory mechanism gone awry?

In their paper, using zebrafish models, Gioacchino et al. have demonstrated the GATA2 haploinsufficiency, the genetic hallmark of GATA2 deficiency syndrome, promotes erythroid and myeloid cytopenia, and have discovered a self-regulatory mechanism to compensate GATA2 levels and protein function. Commentary on: Gioacchino et al. GATA2 heterozygosity causes an epigenetic feedback mechanism resulting in myeloid and erythroid dysplasia. Br J Haematol 2024 (Online ahead of print). doi: 10.1111/bjh.19585.

CREST-UK: Real-world effectiveness, safety and outpatient delivery of CPX-351 for first-line treatment of newly diagnosed therapy-related AML and AML with myelodysplasia-related changes in the UK.

Favourable outcomes with CPX-351 versus conventional 7 + 3 were demonstrated in the pivotal phase III trial in adults aged 60-75 years with newly diagnosed, highrisk/secondary acute myeloid leukaemia (AML). As a complement to the clinical trial and to address important data gaps, the CPX-351 Real-World Effectiveness and SafeTy (CREST-UK; NCT05169307) study evaluated the use of CPX-351 in routine clinical practice in the UK, in 147 patients with newly diagnosed therapy-related AML or AML with myelodysplasia-related changes. Best response of complete remission or complete remission with incomplete platelet or neutrophil recovery was achieved by 53% of evaluable patients. Kaplan-Meier median overall survival (OS) was 12.8 months (95% confidence interval 9.2-15.3). Fifty (34%) patients proceeded to haematopoietic cell transplantation (HCT); median OS landmarked from the HCT date was not reached. There were no new safety concerns with CPX-351 identified in CREST-UK. Patients treated with CPX-351 in the outpatient setting spent an average of 24.4, 16.7, 28.2, and 27.7 fewer days on the ward compared with inpatients during first induction, second induction, first consolidation, and second consolidation, respectively. The results from CREST-UK provide valuable insights into the effectiveness, safety, and outpatient delivery of CPX-351 in routine clinical practice in the UK.

Expression, Function, and Significance of Non B Cell-Derived Immunoglobulin in Haematological System.

Acute myeloid leukaemia (AML) is a collection of genetically diverse diseases characterised by abnormal proliferation of immature haematopoietic cells and disruption of normal haematopoiesis. Myeloid cells and lymphocytes originate from different haematopoietic precursors within the bone marrow. It has been traditionally assumed that myeloid cells cannot produce immunoglobulin (Ig), a marker of B cells and plasma cells. However, in recent years, all five Ig classes have been detected in CD34+ haematopoietic stem cells, mature monocytes and neutrophils, differentiated macrophages and tumour-associated macrophages, acute myeloid leukaemia cell lines, as well as myeloblasts of AML. The rearranged V(D)J sequences exhibit unique restricted or biased V gene usage and evidence of somatic mutation. Furthermore, AML-derived Igs could promote cell proliferation, induce apoptosis, and enhance migration. Elevated levels of Ig expression predict inferior clinical outcomes. These findings indicate that AML-derived Ig plays a role in AML pathogenesis and progression, and could serve as a novel biomarker for risk stratification, disease monitoring, and targeted therapy. In this chapter, we provide a comprehensive review of recent literature on the expression, function, and significance of non B cell-derived Ig in the haematological system, with a focus on AML.

Clinical outcomes of chronic myeloid leukaemia patients taking asciminib through a Managed Access Programme (MAP) in Australia.

Asciminib is a novel allosteric STAMP (specifically targets the ABL myristoyl pocket) inhibitor of the BCR::ABL1 oncogene. Real-world clinical outcomes of patients with tyrosine kinase inhibitor (TKI)-resistant/intolerant chronic myeloid leukaemia (CML) in Australia on the Managed Access Programme for asciminib showed higher molecular responses for those with intolerance versus resistance ± intolerance to their last TKI. There remains a clinical need to improve outcomes in patients with CML who have resistance to multiple TKIs, especially in the ponatinib-pretreated cohort.

Dasatinib induces endothelial dysfunction leading to impaired recovery from ischaemia.

Chronic myeloid leukaemia (CML) management is complicated by treatment-emergent vascular adverse events seen with tyrosine kinase inhibitors (TKIs) such as nilotinib, dasatinib and ponatinib. Pleural effusion and pulmonary arterial hypertension (PAH) have been associated with dasatinib treatment. Endothelial dysfunction and impaired angiogenesis are hallmarks of PAH. In this study, we explored, at cellular and whole animal levels, the connection between dasatinib exposure and disruption of endothelial barrier integrity and function, leading to impaired angiogenesis. Understanding the mechanisms whereby dasatinib initiates PAH will provide opportunities for intervention and prevention of such adverse effects, and for future development of safer TKIs, thereby improving CML management.

Secondary primary malignancies after CD-19 directed CAR-T-cell therapy in lymphomas: A report from the Italian CART-SIE study.

Secondary primary malignancies (SPM) have been reported after anti-BCMA or anti-CD19 chimeric antigen receptor (CAR)-T-cell therapies. While the cytotoxic effect of antecedent therapies, including chemotherapy and radiotherapy, has been well established, few data are available on risk related to CAR-T immunotherapies. The study aimed to analyse the incidence of SPM in 651 patients enrolled in the Italian prospective observational CART-SIE study. SPMs were documented in 4.3% (28/651), and the most frequent SPMs were haematological malignancies. In conclusion, the frequency of SPMs in our cohort of heavily pretreated patients receiving CAR-T was relatively low and consistent with previous studies.