HemaSphere最新文献

Hepcidin is an essential regulator of systemic iron availability mediating both iron uptake from the diet and its release from body stores. Abnormally high hepcidin levels resulting from inflammation in chronic diseases cause iron restriction with the onset of anemia. Restoring physiological levels of hepcidin could contribute to ameliorating anemia in these patients. Heparin derivatives are known to suppress hepcidin expression acting on the BMP/SMAD pathway. The novel heparin derivative sevuparin, modified to markedly reduce its anticoagulant activity, is proposed as a promising hepcidin antagonizing strategy. Sevuparin was tested for its anti-hepcidin properties in vitro in HepG2 cells, in vivo in mice, and in healthy volunteers. Sevuparin strongly suppressed basal, BMP6-, and IL6-dependent hepcidin expression in HepG2 cells in a dose- and time-dependent manner, modulating the essential BMP6/SMAD cascade. These effects were evident in C57BL/6J mice after intravenous injection of a single dose of sevuparin (20 mg/kg) with a 70% reduction of hepcidin mRNA. Remarkably, similar effects were observed in healthy volunteers following single subcutaneous doses at 3, 6, and 9 mg/kg with 40%–50% suppression at 3 and 6 mg/kg and 72% at 9 mg/kg. Moreover, sevuparin was able to reduce hepcidin upregulation in a mouse model of acute inflammation induced by LPS, also showing an amelioration of the inflammatory markers. Combined with its excellent safety profile, these data suggest a role for sevuparin in treating high-hepcidin disorders.

Sickle cell disease (SCD) is a monogenic disease, resulting from a single-point mutation, that presents a complex pathophysiology and high clinical heterogeneity. Inflammation stands as a prominent characteristic of SCD. Over the past few decades, the role of different cells and molecules in the regulation of the inflammatory process has been elucidated. In conjunction with the polymerization of hemoglobin S (HbS), intravascular hemolysis, which releases free heme, HbS, and hemoglobin-related damage-associated molecular patterns, initiates multiple inflammatory pathways that are not yet fully comprehended. These complex phenomena lead to a vicious cycle that perpetuates vaso-occlusion, hemolysis, and inflammation. To date, few inflammatory biomarkers can predict disease complications; conversely, there is a plethora of therapies that reduce inflammation in SCD, although clinical outcomes vary widely. Importantly, whether the clinical heterogeneity and complications are related to the degree of inflammation is not known. This review aims to further our understanding of the roles of main immune cells, and other inflammatory factors, as potential prognostic biomarkers for predicting clinical outcomes or identifying novel treatments for SCD.

The emergence of abnormal protein bands (APBs), also known as oligoclonal protein bands, has been documented in patients with multiple myeloma (MM) post hematopoietic stem cell transplantation. However, the incidence rate and clinical significance of APBs remain contentious. Few studies have explored the occurrence and prognostic implications of APBs in patients with MM treated with B-cell maturation antigen (BCMA)–specific chimeric antigen receptor (CAR)-T therapy. In this retrospective study, we examined the frequency, isotypes, and duration of APBs, as well as their correlation with MM disease characteristics, treatment response, clinical outcomes, and immune signature in patients with relapsed/refractory MM who had received LCAR-B38M therapy at the Xi'an site of the phase 1 LEGEND-2 trial. Among 47 patients assessed, 23 (48.9%) developed APBs following CAR-T therapy, with IgG being the most common isotype. The median onset and duration of APBs post-CAR-T infusion were 3.6 and 5.8 months, respectively. Patients with APBs demonstrated significantly improved response to LCAR-B38M therapy, along with longer overall and progression-free survival. Furthermore, those with APBs exhibited enhanced recovery rates of immunoglobulins and higher absolute counts of white blood cells, neutrophils, and lymphocytes post-CAR-T treatment compared to those without APBs. However, no significant differences were observed between the two groups in the percentages of various T-cell subsets and natural killer cells. Overall, the presence of APBs in patients with MM following CAR-T treatment was associated with deeper remission and a more favorable prognosis, suggesting a robust humoral response and subsequent immune reconstitution.

Monoclonal gammopathy of undetermined significance (MGUS) is the precursor of multiple myeloma (MM) and related disorders. MGUS is characterized by asymptomatic paraproteinemia. In some cases, multiple paraproteins can be identified but the clinical implications of this phenomenon are poorly understood. In this study, we aim to inform the approach to this challenging MGUS subgroup by utilizing data from iStopMM, a population-based screening study and randomized trial of follow-up strategies. In total, 75,422 Icelanders over the age of 40 were screened for MGUS with 3389 (4.4%) having at least one paraprotein of whom 303 (9%) had multiple paraproteins. IgM paraproteins were more common in those with multiple paraproteins (49% vs. 27% of paraproteins, p < 0.001), and IgM and non-IgM paraproteins frequently co-occurred (60% of cases). Two-thirds of these participants were randomized to active follow-up where only 31% of multiple paraproteins were persistent. Paraprotein concentrations were mostly independent, and although progression events were few, the progression rate was similar between those with multiple paraproteins and a single paraprotein. In a next-generation flow cytometry (NGF) sub-study, two phenotypically distinct aberrant plasma cell populations could be identified in some with multiple paraproteins. The findings suggest that multiple paraproteins often reflect independent ongoing disease processes that should be monitored independently but otherwise treated similarly to other MGUS cases. Specifically, the findings highlight the need for independent monitoring of IgM and non-IgM paraproteins in these individuals. The study provides novel insights into the management of this understudied MGUS subset.

Acute myeloid leukemia (AML) derives from hematopoietic stem and progenitor cells (HSPCs). To date, no AML-exclusive, non-HSPC-expressed cell-surface target molecules for AML selective immunotherapy have been identified. Therefore, to still apply surface-directed immunotherapy in this disease setting, time-limited combined immune-targeting of AML cells and healthy HSPCs, followed by hematopoietic stem cell transplantation (HSCT), might be a viable therapeutic approach. To explore this, we generated a recombinant single-chain variable fragment-based bispecific T-cell engaging and activating antibody directed against CD3 on T-cells and CD117, the surface receptor for stem cell factor, expressed by both AML cells and healthy HSPCs. Bispecific CD117xCD3 targeting induced lysis of CD117-positive healthy human HSPCs, AML cell lines and patient-derived AML blasts in the presence of T-cells at subnanomolar concentrations in vitro. Furthermore, in immunocompromised mice, engrafted with human CD117-expressing leukemia cells and human T-cells, the bispecific molecule efficiently prevented leukemia growth in vivo. Additionally, in immunodeficient mice transplanted with healthy human HSPCs, the molecule decreased the number of CD117-positive cells in vivo. Therefore, bispecific CD117xCD3 targeting might be developed clinically in order to reduce CD117-expressing leukemia cells and HSPCs prior to HSCT.

Despite significant progress in the treatment of multiple myeloma (MM), relapsed/refractory patients urgently require more effective therapies. We here describe the discovery, mechanism of action, and preclinical anti-MM activity of engineered toxin body MT-0169, a next-generation immunotoxin comprising a CD38-specific antibody fragment linked to a de-immunized Shiga-like toxin A subunit (SLTA) payload. We show that specific binding of MT-0169 to CD38 on MM cell lines triggers rapid internalization of SLTA, causing cell death via irreversible ribosome inhibition, protein synthesis blockade, and caspase 3/7 activation. In co-culture experiments, bone marrow mesenchymal stromal cells did not induce drug resistance against MT-0169. In the preclinical setting, MT-0169 effectively lysed primary MM cells from newly diagnosed and heavily pretreated MM patients, including those refractory to daratumumab, with minimal toxicity against nonmalignant hematopoietic cells. MM cell lysis showed a significant correlation with their CD38 expression levels but not with cytogenetic risk, tumor load, or number of prior lines of therapy. Finally, MT-0169 showed efficient in vivo anti-MM activity in various mouse xenograft models, including one in which MM cells are grown in a humanized bone marrow-like niche. These findings support clinical investigation of MT-0169 in relapsed/refractory MM patients, including those refractory to CD38-targeting immunotherapies.