Desmopressin is often administered to correct factor VIII (FVIII) levels in female hemophilia A carriers (HAC). However, the post-desmopressin FVIII pharmacokinetic profiles have been reported only in small case series in this population. Therefore, this study analyzed the post-desmopressin FVIII and von Willebrand factor response in 361 HAC included at 14 French hemophilia treatment centers. A population pharmacokinetic/pharmacodynamic model was developed to analyze the VWF and FVIII levels by taking into account the F8 gene variants (n=143, 39.6%, with null, and n=218, 60.4%, with non-null variants), demographic and laboratory covariates. The prior/after desmopressin mean basal, peak and recovery FVIII:C levels were 0.34 IU.mL-1 (0.08-0.65), 1.13 IU.mL-1 (0.19-2.69), and 2.85 (1.06-7.13), respectively. Peak FVIII:C was ≥0.5 IU.mL-1 in 95.6% (345/361) and ≥0.8IU.mL-1 in 78.7% (284/361) of patients. The covariate analysis showed a poorer desmopressin FVIII response for null than non-null F8 variants: lower mean peak (1.04 vs 1.23 IU.mL-1, p<5.10-5) and lower percentage of patients with normalized FVIII:C (91.6% vs 98.1%, p=0.0068), higher mean clearance (5898.83 vs 2704.06 IU.h-1, p=1.58.10-15), lower mean AUC0-12h (7.73 vs 9.06 IU.mL-1.h, p<5.10-6), and shorter mean time with FVIII:C ≥0.8 IU.mL-1 (1.9 vs 4.1h, p<6.10-6). HAC with body weight <35 kg had lower peak FVIII:C, higher FVIII clearance, lower AUC0-12h, and shorter time with FVIII:C ≥0.8 IU.mL-1 than HAC with body weight 35-70 kg. The ABO blood type did not influence the response to desmopressin. In HAC, the post-desmopressin FVIII response is strongly influenced by the F8 genotype and body weight.

Transfusion-related acute lung injury (TRALI) is a leading cause of transfusion-related mortality. Though the precise mechanism is not fully understood, a two-hit model is widely accepted, involving both a predisposing patient condition and the transfusion itself. Mitochondrial damage-associated molecular patterns (mtDAMPs), such as mitochondrial DNA (mtDNA) and N-formylated peptides (NFPs), are elevated in trauma patients and stored blood products, and have been implicated in adverse transfusion outcomes, prompting us to investigated whether mtDAMPs could serve as a priming "first-hit" in TRALI. Using a murine model, we found that injection of purified mitochondria followed by a monoclonal anti-major histocompatibility complex class I (MHC class I) antibody (34-1-2s) induced significantly greater lung injury compared to the isotype control. This was evidenced by increased pulmonary edema, elevated plasma macrophage inflammatory protein-2 (MIP-2), enhanced neutrophil lung infiltration, hypothermia, and respiratory distress. Similar effects were observed using a Toll-Like Receptor 9 agonist (ODN 2395), purified mtDNA, and a synthetic NFP (WKYMVm), agonist of Formyl Peptide Receptor (FPR). Notably, a TLR9 antagonist blocked the mtDAMP-induced TRALI response, whereas two FPR antagonists did not, underscoring a key role for mtDNA and TLR9 signaling in disease priming. These findings suggest that mtDAMPs, particularly mtDNA, present in both transfusion products and recipient plasma may predispose patients to antibody-mediated TRALI. Targeting mtDAMPs or their receptors may offer a novel therapeutic strategy to mitigate TRALI risk.

Until recently, the JAK1/2 inhibitor, ruxolitinib (Jakafi), was the only therapy for steroid-refractory acute graft-versus-host disease (SR-aGVHD) approved by the U.S. Food and Drug Administration (FDA) for use in patients older than 12 years. Now the FDA has approved a potent mesenchymal stromal cell product (MSC), remestemcel-L-rknd (Ryoncil), for children 18 and younger, showing 70% response rates and nearly 70% six-month survival. In this Spotlight, we highlight this important advance in the field.

Functional high-risk (FHR) multiple myeloma (MM) is defined as an unexpected, early relapse (ER) of disease in the absence of baseline molecular or clinical risk factors (RF), making FHR MM inherently dependent on which RFs were assessed at diagnosis, but also on what treatment patients received. To establish the true incidence of FHR, we analysed uniformly treated, transplant-eligible (TE) patients from the UK NCRI Myeloma-XI trial that had been profiled for IMS/IMWG defined high-risk cytogenetic aberrations (HRCA) and the SKY92 gene expression HR signature (GEP-HR). 135 TE MyXI patients meeting these criteria were studied, with a median follow-up of 88 months. 25 patients (18.5%) experienced ER, defined as relapse <18 months from maintenance randomization post-autologous stem-cell transplantation. Hereof, 15 (60%) were classified as IMS/IMWG-HR at diagnosis, of whom 8 were also GEP-HR. Another 6 patients were GEP-HR only and would have been missed by IMS/IMWG-HR. Among 4 patients with both IMS/IMWG- & GEP-standard risk (SR), 2 had isolated HR markers at diagnosis, leaving only 2 patients (8% of ER; 1.5% of all) truly meeting all FHR criteria. The combination of IMS/IMWG-HR and GEP-HR profiling identified 84% of ER, and differentiated long-term outcome across all 135 patients: co-occurring IMS/IMWG-HR and GEP-HR was associated with very short overall survival compared to the absence of both (HR=13.1, 95%-CI: 6.5-26.1, P<0.0001), followed by GEP-HR only (HR=5.1, 95%-CI: 2.4-11.1, P<0.0001) and IMS/IMWG-HR only (HR=3.2, 95%-CI: 1.6-6.2, P=0.0007). Our results support more comprehensive baseline diagnostic profiling to identify those at risk of ER upfront. ISRCTN49407852, NCT01554852.

Two gene therapy products have been FDA approved for sickle cell disease. Nearly all patients in the clinical trials that led to approval were either sickle hemoglobin gene homozygotes (sickle cell anemia) or had HbS-β0 thalassemia. HbSC disease, caused by compound heterozygosity for HbS and HbC genes, is the second most common genotype of sickle cell disease. Gene therapy has not been tested in HbSC disease patients who are severely symptomatic. We discuss the pathophysiology and clinical features of HbSC disease, and how gene therapy is likely to provide a curative option for some individuals. We also discuss the mechanism through which HbF and HbF-like HbA (HbAT87Q) might mitigate adverse clinical outcomes and end-organ damage in HbSC disease and other compound heterozygous sickle hemoglobinopathies.

Repeated bleeding into joints in hemophilia leads to chronic inflammation that plays a central role in the pathogenesis of hemophilic arthropathy (HA). Our recent studies revealed that factor VIIa (FVIIa) treatment releases extracellular vesicles from the endothelium (eEVs) and FVIIa-released eEVs exhibit anti-inflammatory and barrier protective functions. The present study was undertaken to investigate the effect of FVIIa-released eEVs on HA and the mechanism of their protective effect. Joint bleeding in hemophilia (F8-/- ) mice was induced by a needle puncture injury. Injured mice were treated with saline, control eEVs, or FVIIa-released eEVs, and the changes in the knee joints were analyzed by gross examination of knees as well as histological and immunohistochemical analysis. Joint tissues were examined for evidence of synovial hyperplasia, macrophage infiltration, neoangiogenesis, cartilage degeneration, and chondrocyte apoptosis. The data showed that treatment of mice with control eEVs had no significant effect on the development of HA whereas treatment with FVIIa-released eEVs markedly reduced all pathological features of joint bleed-induced HA. Incorporation of microRNA10a (miR10a) inhibitor into FVIIa-released eEVs abrogated the protective effect of FVIIa-released eEVs on HA. More importantly, loading miR10a mimic into control eEVs conferred a protective effect. Administration of miR10a containing FVIIa-released eEVs or control eEVs loaded with miR10a mimic were found to abrogate joint bleed-induced IL-6 production in the synovium. miR10a in eEVs had no effect on hemostasis. Cumulatively, our data indicates that EVs containing miR10a that effectively suppress synovial inflammation would have immense therapeutic value in treating HA.

Acute myeloid leukemia (AML) is a highly heterogeneous hematological malignancy that increasingly affects the elderly population, with its post-transcriptional landscape remaining largely elusive. Establishing a stable proteomics-based classification system and systematically screening age-related proteins and regulatory networks are crucial for understanding the pathogenesis and outcomes of AML. In this study, we leveraged a multi-omics cohort of 374 newly diagnosed AML patients, integrating proteome, phosphoproteome, genome, transcriptome, and drug screening data. Through similarity network fusion clustering, we established eight proteomic subtypes with distinct clinical and molecular properties, including S1 (CEBPA mutations), S3 (myelodysplasia-related AML), S4 (PML::RARA), S5 (NPM1 mutations), S6 (PML::RARA and RUNX1::RUNX1T1), S8 (CBFB::MYH11), S2 and S7 (mixed), aligning well with and adding actionable value to the latest World Health Organization nomenclature of AML. Hematopoietic lineage profiling of proteins indicated that megakaryocyte/platelet- and immune-related networks characterized distinct aging patterns in AML, which were consistent with our recent findings at the RNA level. Phosphosites also demonstrated distinct age-related features. The high protein abundance of megakaryocytic signatures was observed in S2, S3, and S7 subtypes, which were associated with advanced age and dismal prognosis of patients. A hematopoietic aging score with an independent prognostic value was established based on proteomic data, where higher scores correlated with myelodysplasia-related AML, NPM1 mutations, and clonal hematopoiesis-related gene mutations. Collectively, this study provides an overview of the molecular circuits and regulatory networks of AML during the aging process, advancing current classification systems and offering a comprehensive perspective on the disease.

Immunotherapy has transformed the treatment landscape of multiple myeloma (MM), a hematological cancer predominantly affecting older individuals. Yet, whether immune aging, shaped by intrinsic aging processes, genetics and external factors, impacts treatment efficacy remains unclear. To address this, we investigated the influence of age on the immune system in MM patients and explored whether immune aging associates with clinical outcomes in older patients. Using flow cytometry, we conducted high-dimensional profiling of T-cells and NK-cells in peripheral blood and bone marrow samples from 124 older (>65 years) and 145 younger (£65 years) newly diagnosed MM (NDMM) patients (ages 34-92 years) enrolled in the HOVON-143 and CASSIOPEIA/HOVON-131 trials. On average, older patients exhibited a more activated, differentiated, and senescent T-cell compartment than younger patients. Nonetheless, substantial inter-individual variation in T-cell subset frequencies within both age groups indicated that calendar age inadequately reflects an individual's immune status. We therefore developed an immune clock on high-dimensional phenotypic T-cell data to quantify each patient's 'immune age', revealing substantial variation in immune ages among patients of similar calendar age. Importantly, immune age appeared a stronger predictor of clinical outcomes than calendar age in older, non-fit NDMM patients receiving daratumumab-ixazomib-dexamethasone, even after adjusting for frailty and other established risk factors. Overall, these findings highlight immune age as a clinically relevant composite metric that better reflects a patient's immune status than their calendar age. Validating this methodology in other immunotherapy settings may improve our ability to predict immunotherapy efficacy in older patients with MM or other hematological cancers.

Platelets are specialized cells for hemostasis that circulate in close contact to the glycocalyx, an extracellular layer of interwoven glycoproteins, proteoglycans, and glycosaminoglycans that maintain vascular homeostasis. Platelets survey their circulating environment, balancing inhibitory signals that prevent inappropriate activation with activating signals that initiate thrombus formation. Disease can disrupt this delicate balance of endogenous inhibitory signaling, leading to an increased risk of thrombosis as in patients with inflammatory bowel disease (IBD). In this study, we demonstrate that physiological concentrations of hyaluronan (HA), an essential component of the glycocalyx, acts as an inhibitor of activation and aggregation in human platelets. Using a combination of affinity chromatography, and functional assays of platelets from humans and genetically modified mice, we identify layilin as the receptor for HA and an endogenous inhibitor of platelet activation. LAYN KO platelets display agonist-induced hyperactivation of αiiBβ3 and increased adhesion to fibrinogen under venous shear. Loss of layilin results in dysregulation of Rho GTPase family members-RAC1, Cdc42, RhoA, and Ras-like Rap1,- via layilin's binding partner, merlin, and downstream PAK1. Furthermore, IBD patient platelets contain reduced layilin protein levels correlating with heightened basal Rac1-GTP levels and increased reactivity. Finally, although IBD platelets show enhanced sensitivity to activation, pharmacological inhibition of RAC1 effectively reduces platelet hyperactivity in IBD patient platelets. These findings highlight a novel role for layilin and HA in the maintenance of platelet homeostasis that becomes disrupted in patients with IBD.

Older patients with diffuse large B cell lymphoma (DLBCL) present unfavorable genetic and microenvironmental alterations. In this phase 2 trial, we assessed the efficacy and safety of zanubrutinib in combination with rituximab and lenalidomide (ZR2) in patients with de novo DLBCL aged ≥75 years (NCT04460248). Forty patients were enrolled, and the primary endpoint was complete response rate, which was 65.0% (95% confidence interval [CI]: 48.3-78.9) at the end of induction treatment. The 2-year progression-free and overall survival rates were 67.1% (95% CI: 50.1-79.4) and 82.4% (95% CI: 66.5-91.2). The most common grades 3 and 4 hematologic adverse event (AE) was neutropenia (n = 14; 35.0%). The most common grades 3 and 4 non-hematologic AEs were increased alanine transaminase (n = 5; 12.5%) and aspartate transaminase level (n = 5; 12.5%), and pulmonary infection (n = 5; 12.5%). No events of atrial fibrillation were observed. Importantly, the efficacy of ZR2 was more dependent on tumor microenvironmental than genetic alterations, in association with up-regulation of Class I and II human leukocyte antigen, increased number and function of conventional type 1 dendritic cells. Pre-existing expansion of intra-tumoral CD8+T cells and treatment-induced clonal T-cell receptor (TCR) repertoire contributed to better clinical outcome. TCR sequencing of the peripheral blood mononuclear cell samples from patients with durable remission detected the expanded T cell clones 3 years post-treatment. These findings thus provided better understanding of T-cell immunological memory effect on immunotherapy as ZR2, and a paradigm shift in the era of mechanism-based targeted therapy of aggressive lymphoma.

The EZH2 histone methyltransferase inhibitors tazemetostat and valemetostat have recently received approval for clinical use in follicular lymphoma and adult T-cell leukemia/lymphoma, respectively. In follicular lymphoma, the expression of AID is responsible for increased mutational signatures and genomic instability. Because EZH2 inhibitors induce epigenetic and transcriptional changes in normal and lymphoma B cells, we studied whether these inhibitors could alter the pattern of AID-mediated chromosomal translocations. Here we show that treatment with EZH2 inhibitors did not significantly change AID expression or AID-dependent chromosomal translocation frequency when used as monotherapyin either CH12F3 mouse B cells or MEC-1 human B cells. In contrast, when combined with PI3Kδ inhibition, which enhances AID expression, EZH2 inhibition significantly increased the frequency of chromosomal translocations compared to either EZH2 or PI3Kδ inhibition alone both in mouse CH12F3 cells and human MEC-1 cells. EZH2 inhibition also further enhanced translocation formation in mouse B cells that were Ligase4 deficient. Mechanistically, EZH2 inhibition in B cells depletes the repressive histone modification H3K27me3 while concurrently enhancing the active histone modification H3K27ac, thereby selectively increasing transcriptional activity and facilitating chromosomal translocation formation in the presence of high AID activity or Ligase4 deficiency. These findings highlight the impact of drugs that induce epigenetic changes to influence chromosomal translocations and demonstrate the genetic safety of EZH2 inhibitors as monotherapy while highlighting the increased risk of genomic instability when used in cells prone to translocations, such as B cells with high AID levels or DNA-repair deficiency.