Jose Javier Fuster

Background: Plasma levels of haptoglobin and IgA2 (immunoglobulin A2) have recently been associated with subclinical atherosclerosis in European cohorts. We sought to validate these findings in an American population and to determine whether these biomarkers predict all‐cause mortality or major cardiovascular adverse events beyond traditional risk scales (Framingham Risk Score) or vascular imaging. Methods: We analyzed 5328 asymptomatic US adults (mean age 69 years, 56.9% women) from the BioImage study (A Clinical Study of Burden of Atherosclerotic Disease in an At‐Risk Population; NCT00738725). Subjects underwent carotid plaque burden assessment by ultrasound, coronary artery calcium by computed tomography, and baseline plasma haptoglobin and IgA2 levels measurement by immunoturbidimetry. The end point was a composite of major cardiovascular adverse events and all‐cause death during follow‐up. Results: Haptoglobin and IgA2 correlated significantly with carotid plaque burden and coronary artery calcium, independent of Framingham Risk Score. After a median follow‐up of 4.6 years, 466 participants (8.8%) experienced the composite outcome. Haptoglobin and IgA2 independently predicted the outcome, and associations remained significant after further adjustment for carotid plaque burden or coronary artery calcium. Similar results were observed for predictive capacity of high‐sensitivity C‐reactive protein. Individuals with high levels of all biomarkers (above the median) had a 2‐fold higher event rate compared with those with low levels. Combined biomarker assessment, albeit modestly, significantly improved risk prediction beyond Framingham Risk Score and imaging. Conclusions: Haptoglobin and IgA2 predict the composite outcome of major cardiovascular adverse events and all‐cause death, independently to Framingham Risk Score, in asymptomatic American adults. Their measurement, alone or in combination with imaging, may enhance cardiovascular risk stratification in primary prevention.

BACKGROUND: Clonal hematopoiesis driven by somatic mutations is an emerging cardiovascular risk factor, and the DNA damage response gene PPM1D is among the most frequently mutated genes. Mutations in PPM1D are enriched in cancer patients and survivors, where cytotoxic therapies promote the expansion of mutant clones, a condition termed therapy-related clonal hematopoiesis. Although PPM1D -mutant clonal hematopoiesis has been associated with increased risk and poorer prognosis of atherosclerotic cardiovascular disease in humans, it remains unclear whether these mutations, or their expansion under cytotoxic stress, causally contribute to atherosclerosis. METHODS: We modeled PPM1D -mutant clonal hematopoiesis in Ldlr ^−/− mice through bone marrow transplantation strategies. Conventional transplantation approaches were used to generate mice with complete or partial hematopoietic reconstitution by cells carrying monoallelic or biallelic gain-of-function Ppm1d ^R451X mutations. To mimic therapy-related clonal hematopoiesis, we used a nonconditioned adoptive transfer model in which a small fraction of mutant hematopoietic cells was introduced into recipients, followed by fractionated low-dose γ-radiation to promote clonal expansion. All mice were fed a Western diet to induce atherosclerosis. Clonal dynamics, plaque size and characteristics, and macrophage functions were evaluated using flow cytometry, histopathology, and in vitro assays. RESULTS: Ppm1d -mutant cells expanded in blood and bone marrow after low-dose radiation, but not in nonirradiated mice. Across all transplantation strategies, Ppm1d mutations did not affect plasma cholesterol, atherosclerotic plaque size, or composition. In vitro, mutant macrophages showed no alterations in proliferation, cytokine expression, or cholesterol handling, although apoptosis in response to genotoxic stress was modestly reduced (≈20%). CONCLUSIONS: Ppm1d -mutant hematopoietic cells expand predominantly under genotoxic stress and do not promote atherosclerosis in mice under the conditions tested. These findings raise the possibility that the association of PPM1D mutations with atherosclerotic cardiovascular disease may, at least in part, reflect exposure to DNA damage response–activating stressors that independently promote clonal expansion and atherosclerosis, rather than direct causality.

Subclinical atherosclerosis (SA) burden and progression are independently associated with all-cause mortality. However, monitoring SA progression requires reliable and cost-effective biomarkers. While leukocyte telomere length (LTL) attrition has been linked to cardiovascular disease and mortality, it remains uncertain whether changes in LTL over time can predict SA progression. In this study, we conducted a longitudinal study to assess whether accelerated LTL attrition is associated with SA progression over a 6-year period in healthy middle-aged individuals. LTL was measured by high-throughput quantitative fluorescence in-situ hybridization in peripheral-blood leukocyte samples obtained 6 years apart from a sub-cohort of 1068 Progression of Early Subclinical Atherosclerosis (PESA)-study participants. SA was assessed by 3D vascular ultrasound in the carotid and femoral territories. Associations were evaluated using linear and logistic regression models. LTL parameters at baseline and after 6 years showed a positive correlation, but no significant associations were found between changes in LTL and changes in plaque volume over 6 years, either in the total sample or when stratified by sex. Likewise, no significant associations were found between LTL changes and the odds of SA progression over a 6-year period. Similar results were found when considering short telomere load changes. These findings suggest limited utility of LTL dynamics as an early biomarker for SA progression in healthy middle-aged individuals.

Sex differences influence cancer incidence, treatment response, and susceptibility to cardiovascular toxicity. Males exhibit higher rates and poorer outcomes in most non-sex-specific cancers, while females more frequently experience treatment-related adverse events, including cancer therapy-related cardiac dysfunction. Biological factors such as hormonal status, genetic polymorphisms, immune responses, and pharmacokinetics contribute to these disparities. In cardio-oncology, women—particularly premenopausal or with specific genotypes—may be at increased risk for cardiotoxicity after treatment with anthracyclines, immune checkpoint inhibitors or radiotherapy. Clonal hematopoiesis and certain germline genetic variants such as single nucleotide polymorphisms (e.g., RARG rs2229774, HAS3 rs2232228) are emerging as potential sex-informed biomarkers for predicting cardiotoxicity risk. Despite growing evidence, sex remains insufficiently integrated into clinical trials and guideline development in cardio-oncology. This review highlights the importance of sex-specific surveillance, prevention, and multi-omic risk stratification to advance precision cardio-oncology and support better outcomes for patients across the cancer care continuum.

Activation-induced cytidine deaminase (AID) is essential for B cell affinity maturation. We investigated why AID deficiency gives rise to giant germinal centers (GCs) using the AIDR112H mouse model that is devoid of AID activity. The increased GC response was associated with accumulation of GC B cells in the light zone in immunized AIDR112H mice. AIDR112H GC B cells had reduced capacity to upregulate IRF4 to initiate plasma cell differentiation, leading to accumulation of a transitional GC population with reduced GL7 expression. Genetic introduction of a high-affinity B cell receptor was unable to restore plasma cell differentiation of AIDR112H B cells, while ectopic expression of catalytically active AID rescued plasma cell generation. AID and ten-eleven translocation 2 (TET2) synergistically facilitated demethylation of the Irf4 promoter/enhancer, and this was impeded in AIDR112H cells. These data reveal a B cell–intrinsic mechanism that governs the plasma cell fate decision through epigenetic remodeling mediated by AID in cooperation with TET2.

Neutrophils exhibit remarkable phenotypic and functional diversity across tissues and diseases^1,2, yet the lack of understanding of how this immune compartment is globally organized challenges translation to the clinic. Here we performed single-cell transcriptional profiling of neutrophils spanning 47 anatomical, physiological and pathological scenarios to generate an integrated map of the global neutrophil compartment in mice, which we refer to as NeuMap. NeuMap integrates and expands existing models^3,4 to generate fundamental new insights; it reveals that neutrophils organize in a finite number of functional hubs that distribute sequentially during maturation to then branch out into interferon-responsive and immunosuppressive states, as well as a functionally silent state that dominates in the healthy circulation. Computational modelling and timestamp analyses identify prototypical trajectories that connect these hubs, and reveal that the dynamics and preferred paths vary during health, inflammation and cancer. We show that TGFβ, IFNβ and GM-CSF push neutrophils along the different trajectories, and projection of chromatin accessibility sites onto NeuMap reveals that the transcription factor JUNB controls angiogenic and immunosuppressive states and promotes tissue revascularization. The architecture of NeuMap appears to be conserved across sex, environmental and genetic backgrounds, as well as in humans. Finally, we show that NeuMap enables inference of the pathophysiological state of the host by profiling blood neutrophils. Our study delineates the global architecture of the neutrophil compartment and establishes a framework for exploration and exploitation of neutrophil biology.

Clonal hematopoiesis (CH) due to Tet methylcytosine dioxygenase 2 ( TET2) driver mutations is associated with coronary heart disease and a worse prognosis for patients with aortic valve stenosis (AVS). However, it is unknown what role CH plays in the pathogenesis of AVS. In a meta-analysis of All of Us, BioVU, and the UK Biobank, patients with clonal hematopoiesis of indeterminate potential (CHIP) had an increased risk of AVS, with a higher risk among patients with TET2 or ASXL1 mutations. Single-cell RNA-Seq of immune cells from patients with AVS harboring TET2 CH driver mutations revealed monocytes with heightened proinflammatory signatures and increased expression of procalcific paracrine signaling factors, most notably oncostatin M (OSM). Secreted factors from TET2 -silenced macrophages increased in vitro calcium deposition by mesenchymal cells, which was ablated by OSM silencing. Atherosclerosis-prone low-density lipoprotein receptor–deficient ( Ldlr ^–/– ) mice receiving CH-mimicking Tet2 ^−/− bone marrow transplants displayed greater calcium deposition in aortic valves. Together, these results demonstrate that monocytes with CH promote aortic valve calcification and that patients with CH are at increased risk of AVS.