British Journal of Haematology

We show that clonal hematopoiesis is associated with an increased incidence of autoimmune hemolytic anemia. The hazard ratios of autoimmune hemolytic anemia and immune thrombocytopenia associated with clonal hematopoiesis were similar.

Fetal hemoglobin (HbF) prevents the polymerization of sickle hemoglobin (HbS). HbF, measured usually as a percent of total hemoglobin (%HbF), is inversely associated with the severity of sickle cell disease (SCD) but fails to capture the distribution of HbF concentrations within red blood cells (RBCs). The relative proportion of HbF and HbS within a RBC is reflected by the HbF:HbS ratio whereas HbF/F-cell quantifies the absolute amount of HbF/RBC. While correlated, HbF:HbS ratio and HbF/F-cell are not interchangeable. In the context of mean corpuscular hemoglobin (MCH), HbF/F-cell approximates whether sufficient HbF is present to inhibit HbS polymerization. We examined the association of mean HbF/F-cell with sub-phenotypes of sickle cell disease in three independent cohorts. Both %HbF and HbF/F-cell were significantly associated with multiple clinical and laboratory features of SCD; however, HbF/F-cell demonstrated stronger associations with clinical severity measures across cohorts. Higher HbF/F-cell was associated with fewer clinical events, reduced hemolysis, and mortality. Changes in HbF/F-cell after hydroxyurea treatment were associated with ~11-13% reduction in acute events in patients with <1 pg increase and >60% reduction with a >5 pg increase in HbF/F-cell. For each pg increase in HbF/F-cell there was ~6% reduction in the rate of acute events. As a surrogate for the distribution of HbF concentrations among F-cells, HbF/F-cell adds physiologically relevant insights that could guide prognosis and treatment

Background: Large language models (LLMs) perform well on standardized medical exam questions, but their reliability for complex hematology decision making is uncertain. We compared four general-purpose LLMs (GPT-4o, GPT-o3, Claude Sonnet 4, and DeepSeek-V3) with a Virtual MDS Panel (VMP), a coordinated multi-agent AI system in which domain-specialized, rule-bound software agents (WHO/ICC guidelines; IPSS-R/IPSS-M; NCCN) collaborate to generate tumor-board-level recommendations. Methods: Each model generated diagnostic, prognostic, and treatment recommendations for 30 myelodysplastic syndrome cases. Nine international MDS experts from five institutions, blinded to model identity, completed 3,000 structured ratings using 5-point Likert scales for diagnosis, prognosis, and therapy and classified errors by severity. Results: General-purpose LLMs achieved modest expert ratings (overall mean scores: 3.7 for GPT-o3, 3.2 for GPT-4o, 3.1 for DeepSeek, and 3.0 for Claude) and contained major factual errors in at least 24% of responses. The VMP increased the proportion of outputs rated 4 or higher to 87% (vs. 34-66% for general-purpose models), improved mean scores to 4.3 overall (4.3 for diagnosis, 4.4 for prognosis, and 4.1 for therapy), and reduced major errors to 8%. Conclusions: In this blinded evaluation of 30 complex MDS cases, general-purpose LLMs produced clinically important errors at rates that raise safety concerns for autonomous hematology decision making. The VMP, a rule-bound, multi-agent architecture, approached expert-level accuracy supporting its potential role as an effective decision-support tool for MDS in the future.

Waldenstrom macroglobulinemia (WM) is a rare indolent neoplasm characterized by presence of [&ge;] 10% lymphoid cells in BM that exhibit plasmacytoid or plasma cell differentiation that secretes an IgM monoclonal protein. This is a retrospective analysis of 89 patients of WM that describes the clinical and laboratory characteristics, treatment patterns and outcome of patients of WM. The median age of the entire cophort was 66 years with male predominance (67.4%). Most common presentations were symptoms pertaining to anemia (77.5%) and constitutional symptoms (33.7%). Median bone marrow lymphoplasmacytic cells were 41%. Positivity for MYD88 and CXCR4 mutations were seen in 81.8% and 2.4% cases. BR was the most common regimen used (52.8%). Overall response rates were seen at 87.8%. Median overall survival, progression free survival and time to next treatment is 8.49 years, 2.15 years and 3.88 years. BR regimen was associated with highest event free survival.

Background Blood pressure (BP) regulation in individuals with sickle cell disease (SCD) is influenced by a complex interplay of genetic and physiological factors. While SCD has traditionally been associated with lower BP, there is an increased risk of hypertension. Emerging BP research suggests significant heterogeneity across genotypes, age groups, and sex. Objectives: This study investigated the longitudinal effects of population-level characteristics and continuous clinical and laboratory predictors on systolic (SBP) and diastolic blood pressure (DBP) in individuals with SCD, with emphasis on the interactions between baseline and predicted blood pressure slopes over time. Methods We retrospectively analyzed longitudinal data from a cohort of 2,739 patients with diverse SCD genotypes. Descriptive statistics were documented across sex, age range, genotype, health status and relative systemic hypertension risk categories (rHTN-risk). Linear mixed-effects models provided estimates of fixed- and random-effects of baseline BP and of time-related BP effects, respectively. Post-estimation margins provided contrasts of baseline-adjusted BP means and of pre-specified time effects on BP patterns. Results Males had significantly higher baseline SBP ({beta} = 6.64, p < 0.001) but lower baseline DBP ({beta} = -2.61, p < 0.001) compared with age-matched HbSS females. Baseline SBP was more unstable compared with baseline DBP and baseline DBP was more predictive of future BP trends than baseline SBP. Genotype was a consistent predictor of DBP (p < 0.05), but not of SBP. Similarly, we observed increased risks of relative diastolic hypertension across most genotypes, while the prevalence and magnitude of systolic hypertension was lower across all genotype compared with HbSS. Conclusions Blood pressure trajectories in SCD patients are not uniform and are significantly related to genotype, age group and sex over time. Baseline diastolic levels were less heterogenous and exhibited clear upward trajectories over time. These findings support the need for patient-specific BP surveillance in the care and management of SCD.

PURPOSEBispecific antibodies (BsAbs) represent a major advancement in the management of relapsed/refractory multiple myeloma (RRMM), offering high response rates even in heavily pretreated patients. However, their use presents operational, safety, and supportive care complexities that require coordinated care teams, and evolving infrastructure. This manuscript summarizes best practice recommendations for adverse event (AE) management, outpatient operational models, referral pathways, and emerging strategies to optimize long-term tolerability. METHODSMedlive--A PlatformQ Health Brand conducted qualitative interviews of academic and community-based clinicians. Discussions focused on BsAb implementation, patient selection and counseling, and AE management. Experts provided recommendations on team-based protocols, transitions of care, and inpatient versus outpatient considerations. RESULTSTen hematologists/oncologists (academic n=4; community n=6) described practice patterns, barriers, and perspectives on BsAb use. BsAbs were consistently regarded as highly effective across multiple lines of therapy, particularly for patients without alternatives. Cytokine release syndrome (CRS) was the most common acute toxicity, generally low grade and managed effectively with early tocilizumab, including prophylactic use in outpatient settings. Immune effector cell-associated neurotoxicity syndrome (ICANS) was rare, mild, and best mitigated through early recognition and caregiver support. Infections, largely from BCMA-associated hypogammaglobulinemia, frequently interrupted therapy, necessitating antiviral prophylaxis, pneumocystis jirovecii pneumonia (PJP) prophylaxis, and intravenous immunoglobulin (IVIG). Outpatient step-up dosing is expanding, supported by prophylactic strategies and academic-community collaboration. Timely referral was emphasized to preserving eligibility. Major outpatient challenges included sequencing, infrastructure readiness, and standardized caregiver and staff education. CONCLUSIONEffective community implementation of BsAbs requires multidisciplinary coordination, standardized AE protocols, infection prevention, and infrastructure to support monitoring, referrals, and equitable access. These measures are critical to ensure safe, sustainable integration of bispecific therapies and to optimize patient outcomes.

IntroductionSolitary plasmacytomas (SP) are rare neoplasm of localised proliferation of clonal plasma cells. It can be classified based on site of involvement and bone marrow involvement. It is an indolent disease in the majority of patients. Primary modality of treatment is radiotherapy and surgical excision. Materials and methodsThis was a retrospective audit of SP who were treated and followed up at a tertiary care center in eastern India from January 2012 to December 2025. Patients who has solitary plasma cytoma with more than 10% plasma cells, POEMS syndrome, have been excluded from analysis. ResultsWe identified 46 patients of SP. The median age of the studied population was 53 years (23-75 years). Males were more commonly affected than females (M:F=2.2:1). Most common chief complaints were bony pain (67.4%). SBP was seen in 39 (84.8%) cases whereas SEP was seen in 7 (15.2%) cases. Vertebra was the most common site of involvement (61.4%). Median M band concentration 0.24 g/dL (0.1 to 1.95 gm/dL). IgG was the most common isotype accounting for 60.6% cases. Six cases (13%) had minimal bone marrow involvement. The majority of the patients received local radiotherapy (89.1%). With a median follow up of 5.4 years (95% CI: 1.8 - 9.0), median OS was not reached, median PFS was 9.22 years (95% CI: 5.8-12.6), median time to next treatment (TTNT) was 9.86 years (95% CI: 6.8 - 12.9). ConclusionSolitary plasmacytoma commonly affects young males. Bones are more commonly affected than extramedullary sites. SP has a lower rate of progression and excellent prognosis when treated with local radiotherapy.

Richter transformation of Chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL) into classic Hodgkin lymphoma (CHL-RT) is rare and remains incompletely understood. Two histologic subtypes are recognized: type 1 (CLL/SLL with scattered Hodgkin/Reed-Sternberg (HRS) cells) and type 2 (HRS cells within a polymorphous inflammatory background). In this multi institutional study of 77 patients with CHL-RT (27 type 1 and 50 type 2), we characterized immune evasion markers, PD-L1/PD-L2 copy number alterations, tumor microenvironment, and performed targeted next-generation sequencing on 37 CLL/SLL samples. HRS cells in CHL-RT displayed immune evasion phenotypes similar to de novo CHL, though PD-L1 expression was lower in type 1 cases. PD-L1/PD-L2 gain/polysomy were frequent (83.3%). CLL/SLL with CHL-RT harbored increased mutations in XPO1, FBXW7, BIRC3, TRAF3, and HLA-A versus reference CLL/SLL. Similar mutational profiles, demographics, and survival outcomes support a biological continuum between type 1 and type 2 CHL-RT, with distinct genetic features in CLL/SLL predisposing to CHL transformation.

ObjectiveHereditary hemorrhagic telangiectasia (HHT) is a vascular genetic disorder caused by endothelial cell dysfunction and characterized by telangiectasias and arteriovenous malformations (AVMs). HHT results primarily from loss-of-function mutations affecting components of the BMP9-ALK1-ENG-SMAD signaling cascade, a pathway essential for endothelial quiescence and vascular homeostasis, and currently lacks a cure. Here, we investigated whether nitazoxanide, an orally bioavailable drug with extensive clinical use, can modulate endothelial signaling relevant to HHT. Approach and ResultsNitazoxanide treatment activated SMAD1/5/8 signaling and increased expression of the downstream target ID1 in endothelial cells, while concurrently inhibiting mTOR signaling, indicating a dual modulatory effect on pathways implicated in HHT pathogenesis. In vivo, nitazoxanide activated SMAD signaling in BMP9/10-immunoblocked mice and significantly reduced AVM formation and hypervascularization. Importantly, nitazoxanide restored SMAD1/5/8 activation and ID1 expression in patient-derived blood outgrowth endothelial cells harboring loss-of-function mutations in ALK1 or SMAD4, which exhibit impaired BMP signaling. ConclusionThese findings identify nitazoxanide as a pharmacological modulator capable of activating BMP-SMAD signaling while restraining mTOR activity, thereby overcoming key signaling defects in HHT endothelial cells. Collectively, our results highlight nitazoxanide as a promising therapeutic candidate to target endothelial dysfunction in HHT.

Background: Modern therapy for childhood and adolescent leukemia requires accurate risk classification of genomic subtype. Although short-read next-generation sequencing (NGS)- based approaches provide comprehensive clinical diagnostics in limited, highly resourced settings, they remain expensive, slow, and inaccessible to most children worldwide. Transformative approaches are needed to improve diagnostic classification for leukemia globally. Methods: We simultaneously continued to develop an analytical pipeline NASVar (Nanopore variant calling for adaptive sampling), and conducted a multicenter, type-two hybrid clinical validation study of an Oxford Nanopore Technologies (ONT) adaptive-sampling whole-genome sequencing (asWGS) assay across hospitals with varying diagnostic resources. In preparation for implementation, a global panel developed a leukemia-based standardized gene set and consensus laboratory-developed test (LDT) validation guidelines. Measures of assay effectiveness compared to both conventional and orthogonal NGS methods, where available, were simultaneously collected with data to measure the implementation outcomes of feasibility, fidelity, appropriateness, and cost. Results: All four centers successfully completed the LDT validation, with minimal adaptations required for regulatory compliance. A total of 457 specimens were sequenced (331 B-ALL, 83 AML, 43 T-ALL). For the 210 B-ALL cases with locally resolved genomic subtypes defined by DNA alterations, asWGS was 100% concordant (210/210). Cases locally defined as B-other were resolved via asWGS with disease-defining DNA alterations in 47% (49/105) of cases. An additional 41% (43/105) of locally defined B-other cases were classified by incorporation of DNA methylation, and all 16 B-ALL patient-derived xenograft controls were correct, for a total of 96% (318/331) of all B-ALL cases in the cohort resolved with single assay asWGS. For AML, 97% (56/58) of cases with locally resolved genomic subtypes were identified by automated asWGS analysis, while an additional two cases were identified after targeted manual review. At Indus Hospital in Pakistan, the B-ALL and AML diagnostic genomic subtype yield increased from 28% with local standard of care diagnostic testing, to 84% with asWGS. The cost of reagents and consumables in the United States, assuming pooled three-plexing, was $343/sample. Based on the combined hybrid validation results, all centers are independently preparing for clinical return of results. Conclusions: ONT asWGS was successfully validated as a clinical assay in four diverse hospital settings. As a single, multi-omic platform that delivers value across the continuum of high-resource to resource-limited contexts, the approach offers a disruptive solution to address the global equity gap in cancer diagnostics.

BACKGROUNDHereditary hemorrhagic telangiectasia (HHT) is a genetic disorder caused by pathogenic variants in the endothelial TGF{beta}/BMP pathway, crucial for the vascular arterial-venous differentiation. Vascular defects result in fragile and malformed vessels. The precise mechanisms driving vascular network failure remain incompletely understood, complicating the design of targeted therapies. METHODSNasal telangiectasias from HHT patients carrying variants in ACVRL1 or ENG were used to perform scRNA-seq (2 ACVRL1- and 1 ENG-patient) and spatial transcriptomics (1 ACVRL1 and 1 ENG) to uncover endothelial cells (EC) populations. Vascular characteristics within biopsies were evaluated using transmission electron microscopy (TEM) (1 ACVRL1 and 1 ENG) and histological analyses (23 ACVRL1 and 7 ENG), with particular attention to regions exhibiting varying degrees of damage. RESULTSComparing our HHT tissues with healthy donor from the literature, we identified cellular heterogeneity within EC populations, revealing two distinct venous clusters: a stable, quiescent population (Mature Vein) and an activated, pro-inflammatory population (HHT Vein). The coexistence of these two clusters suggests cellular diversity within the biopsy, further validated by TEM and histology, revealing a juxtaposition of well-organized collagen and cellular architecture with severely disrupted, fibrotic regions. Moreover, cellular crosstalk analyses allowed us to identify critical ligands in ECs that interact with fibroblasts and mural cells. In particular, we found Midkine (MDK) lost in HHT Vein ECs with further validation in vitro, suggesting its potential role in cellular stability. Furthermore, spatial transcriptomics allowed to further uncover pathologic phenotypes in cells neighboring HHT Vein ECs. CONCLUSIONSHHT biopsies exhibit localized inflamed and fibrotic vascular areas with the presence of different transcriptional sub-populations of EC. Within the same tissue, stable and activated ECs can be distinguished. The pathologic-like EC cluster, present exclusively in the HHT samples, may contribute to vascular leakage through the loss of important ligands involved in cellular communication.

Chimeric antigen receptor T-cell (CAR-T) therapy targeting CD19 has transformed outcomes for children with relapsed or refractory (R/R) B-cell acute lymphoblastic leukemia (B-ALL), yet the influence of molecular subtype on outcomes remains unclear. We evaluated the impact of cytogenetic and molecular signatures on complete response (CR), overall survival (OS), and leukemia-free survival (LFS) after CD19 CAR-T therapy in eighty-six pediatric patients with R/R B-ALL treated with tisagenlecleucel. CR was assessed 30 days after infusion. Cytogenetic data were available for 84 patients and molecular profiling for 62. Survival analyses included 72 patients who received CD19 CAR-T as the sole cellular therapy. Seventy-seven patients achieved CR (89.5%). Pre-infusion bone marrow blasts of [&ge;]20% were associated with lower CR rates (53.8% vs 95.9%, p<0.0001) and significantly reduced OS and LFS (both p<0.0001). Among molecular markers, RAS mutations correlated with inferior OS (p=0.0222) and LFS (0.0402). In multivariate analysis, bone marrow blasts >20% and RAS mutations independently predicted inferior OS. Post CAR-T, CD19 negative relapses showed almost twice higher prevalence of RAS mutations (66% vs 37.5%). These findings highlight RAS mutations as a key molecular predictor of outcome after CD19 CAR-T therapy and suggest emergence of unique risk stratification for patients receiving CD19-targeting therapy. Key PointsO_LIRAS mutations independently predict unfavorable survival after CAR-T CD19 in pediatric B-ALL. C_LIO_LIRAS mutations increase risk of CD19 negative relapse after CAR-T CD19 therapy in pediatric B-ALL. C_LI

BackgroundVenous thromboembolism is a major cause of morbidity and mortality. Despite identification of risk factors, not all individuals with thrombophilia develop thrombosis. Understanding the multigenic factors modifying this incomplete penetrance would help guide patient care. MethodsThe zebrafish has a conserved hemostatic system and is amenable to large genetic studies. Loss of antithrombin III (At3) in zebrafish leads to an early consumptive coagulopathy and lethality in adulthood. Using this genetic background as a sensitized model we performed a dominant unbiased genome-wide N-ethyl-N-nitrosourea (ENU) mutagenesis screen followed by whole genome sequencing (WGS). We used survival studies, laser-mediated endothelial injury, and ex vivo protein assays to validate hits. ResultsENU-treated at3+/- males were crossed with at3+/- females to produce 4,030 total offspring (1.5x genome coverage). Four permanent lines transmitting a survival benefit beyond 7 months were identified and sequenced. A candidate screen of 63 known coagulation-related loci revealed a missense mutation, C504F, in a highly conserved residue of the prothrombin (F2) heavy chain, which was validated through genetic and biochemical studies. Evaluation of UK Biobank electronic health record (EHR) data was underpowered to detect interactions between F2 and AT3 due to minmal deleterious mutations. Mutations produced through genome editing revealed that heterozygosity for factor X and plasminogen also modified at3-/-, resulting in reduced lethality. The three remaining lines had no coagulation-related variants segregating with survival, suggesting the presence of novel modifier loci. ConclusionsUnbiased genome-wide screening identified a modifier of thrombosis. This demonstrated that re-balancing of hemostasis to mitigate thrombosis is conserved in zebrafish, including an unexpected role for fibrinolysis. This interaction was not detected even in a large human dataset, establishing the continued benefit of the zebrafish model. Finally, we found evidence for novel loci outside of the canonical coagulation cascade that may be new targets for diagnosis or treatment.

Key PointsO_ST_ABSQuestionC_ST_ABSDoes the circadian timing of stem cell infusion influence the risk of aGVHD after allo-PBSCT? FindingsIn this randomized prospective clinical trial that included 198 patients, infusion stem cell at 12:00 pm at noon was associated with a significantly lower incidence and less severity of aGVHD compared with infusion at 6:00 pm, without influencing engraftment or relapse. MeaningScheduling stem cell infusion at an earlier time-of-day may reduce aGVHD risk after allo-PBSCT. IMPORTANCEAcute graft-versus-host disease (aGVHD) remains a major complication following allogeneic peripheral blood stem cell transplantation (allo-PBSCT), compromising patient survival and quality of life. OBJECTIVETo evaluate the effect of stem cell infusion time-of-day on aGVHD after allo-PBSCT. DESIGNA multicenter, randomized, open-label, phase 3 clinical trial was conducted from March 18, 2024, through June 11, 2025, with follow-up through December 31, 2025 (median, 462 days among survivors). SETTINGSix transplantation centers in China. PARTICIPANTSPatients aged 12 to 60 years with malignant hematologic diseases undergoing first allo-PBSCT were screened; 198 eligible patients were randomized. INTERVENTIONSPatients were randomly assigned in a 1:1 ratio to receive stem cell infusion at either 12:00 pm at noon ({+/-} 0.5 hour) or 6:00 pm ({+/-} 0.5 hour). MAIN OUTCOMES AND MEASURESThe primary end point was the cumulative incidence of grade II-IV aGVHD within 100 days after transplantation. Secondary end points included grade III-IV aGVHD, hematopoietic recovery, transplant-related mortality (TRM), relapse, and survival outcomes. RESULTSAmong 198 randomized patients (median age, 38 years; 119 [60.1%] male), grade II-IV aGVHD within 100 days occurred in 11 of 99 patients (11.1%) in the 12:00 pm group and 22 of 99 patients (23.2%) in the 6:00 pm group. The cumulative incidences of grade II-IV and III-IV aGVHD were significantly lower in the 12:00 pm group (II-IV: 11.1% [95% CI, 5.9%-18.2%] vs 23.2% [95% CI, 15.4%-32.0%], P = 0.029, hazard ratio, 2.18 [95% CI, 1.06-4.48]; III-IV: 2.0% [95% CI, 0.4%-6.5%] vs 12.2% [95% CI, 6.7%-19.5%], P = 0.006, hazard ratio, 6.25 [95% CI, 1.39-28.15]). There were no significant differences in hematopoietic recovery, TRM, or relapse between groups. The estimated probability of GVHD-free, relapse-free survival (GRFS) at 360 days favored the 12:00 pm group (66.7% [95% CI, 56.2%-75.2%] vs 56.5% [95% CI, 46.1%-65.5%]). CONCLUSIONS AND RELEVANCEStem cell infusion at 12:00 pm was associated with a lower incidence and severity of aGVHD compared with infusion at 6:00 pm, without influencing engraftment or relapse. Optimization of infusion timing may represent a simple strategy to reduce aGVHD risk. TRIAL REGISTRATIONClinicalTrials.gov Identifier: NCT06294678.

iii.Background and ObjectivesThe "Pan-European Transfusion Research InfrAstructure" (PETRA) project was established to advance the use of donor, blood product, and patient datasets in Europe, aiming to benefit both patient and donor health. Here, the initial PETRA objective was to describe the landscape of existing donor and blood establishment (BE) databases. Materials and MethodsAn online survey was circulated to the European Blood Alliances BE members. The survey collected information on the feasibility of accessing donor data, and challenges and possibilities for linking these datasets with information on the associated blood products and transfusion recipients, and donors own health records. ResultsSeventeen BEs across 16 countries completed the survey. The majority could, in principle, link their donor data to product data (13 BEs (76%)) and recipient data (10 BEs (59%)), for research purposes. However, capabilities were limited and in only 29% of the BEs was the donor to recipients linkage an automated process. BEs reported significant challenges to achieve full vein-to-vein linkage, including legal constraints and lack of consent (11 BEs) and resources (10-14 BEs). IT and data issues as well as lack of knowledge and training were cited as obstacles by a minority of BEs. ConclusionWhilst the survey results suggest considerable interest in developing linkages between blood donors, their products, and recipients, many challenges remain due to a variety of obstacles. First steps in working towards a PETRA may be assistance to navigate legal frameworks as well as investing in resources and quality and harmonisation of data collections. iv. HighlightsO_LI17 blood establishments (BEs) in 16 countries responded to a survey on obstacles and opportunities for achieving vein-to-vein datasets. C_LIO_LIIn 59% of the BEs donor-to-recipient links can be established for research improving transfusion outcomes, but only in 29% this is an automated process. C_LIO_LIIn order to work towards a "Pan-European Transfusion Research InfrAstructure" (PETRA), legal frameworks, adequate donor consent and (financial and human) resources are the most common obstacles that require addressing. C_LI

Background: SARS-CoV-2 infection is an established prothrombotic trigger, yet the population-level temporal relationship between circulating viral activity and pulmonary embolism (PE) remains poorly characterized. We aimed to evaluate the short-term association between respiratory viral activity and PE hospitalizations, accounting for specific temporal lags. Methods: We conducted a population-level time-series analysis of incident PE hospitalizations in Ontario, Canada, from 2011 to 2024. Using distributed lag non-linear models, we assessed the association between standardized weekly activity levels of SARS-CoV-2, influenza A/B, and respiratory syncytial virus (RSV) and PE risk over a 5-week lag period. Relative risks (RR) per standard deviation (SD) increase in viral activity were estimated via negative binomial regression using cross-basis terms to account for both exposure-response and lag-response non-linearities. Models were adjusted for Fourier seasonal terms and secular trends. Findings: Among 70,670 incident PE cases identified between 2011 and 2024, SARS-CoV-2 activity demonstrated a significant temporal association with PE. A cumulative RR increase of 20% per SD in SARS-CoV-2 activity was observed over the five weeks following exposure (RR 1.20; 95% CI 1.05-1.37). The risk followed a distinct delay trajectory: weekly cumulative RRs peaked at week 3 (RR 1.21; 95% CI 1.01-1.45). For the 2020-2024 period, influenza A also showed an association peaking at week 3 without statistical significance (RR 1.17; 95% CI 0.95-1.45). Interpretation: Increased population-level SARS-CoV-2 activity is associated with a heightened risk of PE, peaking at approximately the third week. This delayed peak suggests a protracted thrombo-inflammatory window, likely driven by sustained endothelial injury. These findings highlight the vascular burden of COVID-19 and suggest that infection prevention measures, including vaccination, may provide significant downstream protection against thromboembolic disease.

BackgroundCompanion canines need advances in therapeutic options for solid tumor malignancies. Prior studies established feasibility of autologous natural killer (NK) cell infusions in canines with solid tumors; however, autologous products are limited by dysfunctional immunity and a manufacturing process that delays care. Allogeneic NK cells offer the possibility of "off-the-shelf" therapy to be administered from healthy donors. MethodsPeripheral blood mononuclear cells (PBMCs) were isolated from healthy canine donors via density gradient separation. NK cells were expanded with recombinant human IL-2 and canine IL-21 with the addition of K562 feeder cells transfected with CD137 ligand and membrane bound human IL-15. Additional experiments included IL-12 in the expansions. In vitro potency was assessed via co-culture with the D17-mKate2 canine osteosarcoma cell line. Three canines were enrolled in a phase 1 trial infusing ex vivo expanded allogeneic NK cells after lymphodepletion. ResultsFlow cytometric analysis confirmed successful expansion of canine NK cells with up to 50% of cells demonstrating NKp46+ after 14 days of expansion. Residual T cell numbers varied based on donor. The addition of IL-12 led to increased NK cell expansion. Incucyte demonstrated potency with increasing osteosarcoma cell death at higher effector to target ratios. Three canines with metastatic/refractory solid tumors were successfully lymphodepleted and infused with allogeneic NK cell products. The canines tolerated the infusions well. ConclusionsCanine allogeneic NK cells were successfully expanded and activated ex vivo, demonstrated potency in vitro, and safety in vivo. Further studies will optimize the NK cell product and escalate dosing to reach the maximal tolerable dose.

Background: Multiple myeloma (MM) remains incurable despite therapeutic advances, reflecting limited understanding of the molecular mechanisms underlying disease initiation and progression. MM develops through asymptomatic precursor stages, monoclonal gammopathy of undetermined significance (MGUS) and smouldering multiple myeloma (SMM). This study aimed to investigate protein changes associated with disease progression and, through a further integrative approach, to highlight molecular changes of potential predictive and/or therapeutic value. Methods: We performed a comparative proteomic analysis of 94 bone marrow-derived CD138+-selected plasma cell samples (29 MGUS, 20 SMM, and 45 MM) using LC-MS/MS. Differential protein abundance was assessed using pairwise Mann-Whitney U tests between groups, with Benjamini-Hochberg correction. Pathway enrichment, protein-protein interaction, and co-expression network analyses were also conducted. Selected proteins were further evaluated using public transcriptomic datasets and experimentally validated in independent samples by flow cytometry and enzyme-linked immunosorbent assay (ELISA). Results: Following data processing, proteomic analysis identified 6,203 proteins. Pairwise comparisons revealed significant proteomic differences across disease stages, with 370 differentially abundant proteins exhibiting monotonic changes during disease progression. Pathway analysis showed that monotonically upregulated proteins were mainly associated with gene expression and cell proliferation, whereas downregulated proteins were linked to immune-related processes. Further co-expression network analysis, combined with criteria including detection frequency, biological relevance, and translational potential, highlighted a group of prioritised proteins. Representative examples include nucleolin (NCL) and U3 small nucleolar ribonucleoprotein IMP3 (IMP3), involved in nucleolar organisation, ribosome biogenesis and rRNA processing, as well as the immune-associated lactotransferrin (LTF) and serine protease cathepsin G (CTSG). Transcriptomic support and independent experimental validation by flow cytometry and ELISA confirmed the relevance of selected candidates. Conclusions: Taken together, our findings highlight coordinated changes in immune regulation, RNA processing and ribosome biogenesis during MM progression and identify candidate proteins and their networks, including the emerging pharmacologically tractable target NCL and the underexplored IMP3 of potential therapeutic relevance, opening new avenues for further investigation.

TP53 mutations represent one of the strongest adverse prognostic factors in myelodysplastic neoplasms (MDS). While multi-hit TP53 (TP53multiHit) alterations uniformly lead to very poor outcomes, the prognostic relevance of monoallelic TP53 (TP53mono) mutations remains controversial. TP53 variants can cause loss-of-function, dominant-negative, or gain-of-function effects. We hypothesized that functional heterogeneity among TP53 variants contributes to the variable clinical behavior observed in monoallelic TP53-mutated MDS. Therefore, we analyzed pretreatment samples from 4,505 patients with MDS from two independent cohorts (IWG, n=3,173; J-MDS, n=1,332), including 271 patients with TP53mono and 499 with TP53multiHit. Functional annotation of TP53 variants was performed using a previously published phenotype score (PS) derived from saturation mutagenesis screens, capturing dominant-negative and loss-of-function effects. Median overall survival (OS) differed significantly by TP53 allelic state (TP53 wild-type (TP53wt) 42.4 months; TP53mono 22.9 months; TP53multiHit 9.2 months; p < 0.001). Within the TP53mono subgroup, functional annotation identified marked heterogeneity. Patients with high PS ([&ge;]7) showed significantly inferior OS compared with those with low PS (median OS: 13.8 vs. 39.2 months; HR 1.68, 95% CI 1.16-2.42; p = 0.006), particularly for IPSS-R and IPSS-M low-risk cases. Combining PS and variant allele frequency (VAF) further improved risk stratification. TP53mono patients with PS [&ge;]7 and VAF [&ge;]22% had outcomes comparable to TP53multiHit (median OS: 8.8, p = 0.2), whereas those with PS <7 and VAF <22% exhibited survival similar to TP53wt (median OS: 49.7, p = 0.9). Overall, functional annotation of TP53 variants refines prognostication in TP53mono-mutated MDS and may enhance individualized risk assessment.

Terminal erythroid differentiation involves dramatic cellular remodeling that culminates in the expulsion of the nucleus, a process known as enucleation. While enucleation is conserved across mammals and is crucial for the generation of fully functional erythrocytes, the mechanisms governing this process have remained largely unknown, in part because the absence of genetic material in mature, enucleated red blood cells hinders genetic experimentation. Here, we performed a pooled, forward-genetic CRISPR-Cas9 screen in enucleated red blood cells derived from primary human hematopoietic stem cells to identify genes required for enucleation. We found that Chloride Intracellular Channel 3 (CLIC3) and Vesicle-associated membrane protein 8 (VAMP8) are both necessary for terminal erythroid differentiation, yet likely act through different mechanisms. Knockdown of CLIC3 led to a delay in erythroblast differentiation, culminating in impaired enucleation. We found that the knockdown cells had increased p53 and p21 and exhibited cell cycle alterations, suggesting CLIC3 plays a crucial role in coordinating cell cycle progression during erythropoiesis. In comparison, VAMP8-depleted cells initially appear to undergo accelerated differentiation but then display a specific defect in enucleation. Transcriptional analysis of the VAMP8-knockdown cells suggested dysregulation of pathways for vesicle trafficking and actin binding, and imaging of late-stage erythroblasts revealed impaired nuclear polarization and disorganized actin. This work provides a new approach for functional genomics in enucleated cells and reveals novel factors important for terminal erythroid differentiation and enucleation. Key pointsO_LIA CROPseq-based CRISPR-Cas9 screen enables functional genomics in enucleated primary human red blood cells. C_LIO_LIChloride Intracellular Channel 3 (CLIC3) and Vesicle Associated Membrane Protein 8 (VAMP8) were identified as critical for terminal erythroid differentiation and enucleation, likely acting through two distinct mechanisms. C_LI