---
title: "ADAMTS13 as a thromboinflammatory brake at the vascular–immune interface — article content not pre"
id: "frontiers-in-immunology-18-adamts13-as-a-thromboinflammatory-brake-at-the-vascular-immune-interface-from"
canonical_url: "https://medichelpline.com/clinical-feed/frontiers-in-immunology-18-adamts13-as-a-thromboinflammatory-brake-at-the-vascular-immune-interface-from"
content_type: "clinical_feed_article"
specialty: "Infectious Disease"
source_name: "Frontiers in Immunology"
source_url: "https://www.frontiersin.org/articles/10.3389/fimmu.2026.1922929"
published_at: "2026-09-18T00:00:00.000Z"
evidence_level: "Journal Feed"
license: "CC-BY-NC-4.0 / Informational Use"
---
# ADAMTS13 as a thromboinflammatory brake at the vascular–immune interface — article content not pre
## Provenance & Clinical Metadata
- **Canonical URL:** https://medichelpline.com/clinical-feed/frontiers-in-immunology-18-adamts13-as-a-thromboinflammatory-brake-at-the-vascular-immune-interface-from
- **Specialty:** [Infectious Disease](https://medichelpline.com/clinical-feed/infectious-disease.md)
- **Primary Source:** Frontiers in Immunology
- **Source URL:** [Original Journal Publication](https://www.frontiersin.org/articles/10.3389/fimmu.2026.1922929)
- **Published At:** 2026-09-18T00:00:00.000Z
- **Evidence Rating:** Journal Feed
## Executive GIST (TL;DR)
- The provided source page lacked the article text for the Frontiers in Immunology piece titled “ADAMTS13 as a thromboinflammatory brake at the vascular-immune interface: from viral immunothrombosis to the tumor microenvironment.” - The page consisted primarily of site navigation, journal section listings, and links; no abstract, figures, methods, results, discussion, author names, or references were included in the retrieved content. - Because the full article content was not available in the supplied source, specific clinical or mechanistic details about **ADAMTS13**, its role at the vascular–immune interface, or its relevance to viral immunothrombosis and the tumor microenvironment cannot be summarized or paraphrased from this input. - Key bibliographic elements needed for clinical summarization (authors, publication date, DOI, abstract, conclusions, data, and cited evidence) were not present in the retrieved text. - To obtain accurate clinical or translational insights, the full article should be retrieved from the journal website, DOI resolver, institutional access, or the corresponding author. Secondary sources (reviews or guidelines) may help but must be cited directly from their texts. - Any clinical interpretation, mechanistic summary, or recommendations would require accessing the original article; such content cannot be inferred or invented from the available navigation-only source. - Recommended next steps: use the DOI or journal search, access Frontiers in Immunology article landing page, or contact the journal editorial office for the complete article and supporting materials before producing a clinical rewrite or guidance.
## Clinical Analysis & Structured Key Points
Frontiers | ADAMTS13 as a thromboinflammatory brake at the vascular-immune interface: from viral immunothrombosis to the tumor microenvironment HYPOTHESIS AND THEORY article Front. Immunol. , 18 September 2026 Sec. Inflammation Volume 17 - 2026 | https://doi.org/10.3389/fimmu.2026.1922929 Published in Frontiers in Immunology Inflammation 7 impact factor 11.3 citescore Editor & Reviewers Edited by B E Beate E. Kehrel Reviewed by K H Konstantine Halkidis M D Maribel Diaz-Ricart Outline Figures and Tables Figure 1 View in article Table 1 Operational distinction among categorical ADAMTS13 failure, relative VWF-processing imbalance, and complement-dominant thrombotic microangiopathy. View in article HYPOTHESIS AND THEORY article Front. Immunol. , 18 September 2026 Sec. Inflammation Volume 17 - 2026 | https://doi.org/10.3389/fimmu.2026.1922929 ADAMTS13 as a thromboinflammatory brake at the vascular-immune interface: from viral immunothrombosis to the tumor microenvironment P H Peng Huang 1 X S Xiaoyu Sun 2 J P Jie Peng 2 W T Wei Tian 3 * 1. Department of Interventional Oncology, Zibo Central Hospital, Zibo, Shandong, China 2. Department of Pathology, Zibo Central Hospital, Zibo, Shandong, China 3. Department of Oncology, Zibo Central Hospital, Zibo, Shandong, China See more Article metrics View details Abstract ADAMTS13 is conventionally regarded as the protease whose severe deficiency causes thrombotic thrombocytopenic purpura (TTP). By cleaving shear-unfolded ultra-large and high-molecular-weight von Willebrand factor (VWF), ADAMTS13 limits a platelet- and leukocyte-adhesive vascular scaffold. We propose a narrower and testable extension of this biology to cancer: an imbalance between VWF burden and ADAMTS13 processing capacity may act as a context-dependent modifier or amplifier of thromboinflammation in selected VWF-rich, shear-exposed tumor vascular niches, but is not established as an initiating or universally rate-limiting cause of cancer-associated thrombosis. We define “relative ADAMTS13 insufficiency” as a research phenotype rather than a diagnosis or evidence of causality. It refers to ADAMTS13 activity outside the severe-deficiency range, typically ≥10%, together with increased VWF burden and a disproportionately low ADAMTS13 activity/VWF antigen ratio (ADAMTS13:Act/VWF: Ag). This phenotype is mechanistically nonspecific and may reflect increased VWF release, impaired whole-molecule VWF clearance, reduced ADAMTS13 production, stability, or availability, functional inhibition of proteolysis, reduced VWF susceptibility to cleavage, or shared upstream inflammation. Human evidence from COVID-19 and cancer remains predominantly associative, whereas tumor-relevant perturbation studies provide preclinical causal support in defined models. The causal importance of the VWF–ADAMTS13 axis in human tumors nevertheless remains unproven. We therefore position this module within a broader thromboinflammatory network that includes complement activation, neutrophil extracellular traps, platelet activation, and tissue factor–thrombin–fibrin pathways. ICI-associated endothelial phenotypes are distinguished from rare ICI-associated immune TTP with categorical severe ADAMTS13 deficiency. Candidate interventions are accordingly presented as mechanistic research nodes requiring staged validation rather than as established oncology therapies. 1 Introduction ADAMTS13 (a disintegrin and metalloproteinase with thrombospondin type 1 motifs, member 13) is best known as the enzyme whose severe deficiency causes thrombotic thrombocytopenic purpura (TTP) ( 1 – 3 ). By cleaving von Willebrand factor (VWF) under shear stress, ADAMTS13 limits the persistence and accumulation of ultra-large VWF (UL-VWF) multimers that drive platelet aggregation; severe loss of this activity defines TTP ( 1 – 3 ). This diagnostic framing, in which ADAMTS13 is viewed as either sufficient or severely deficient, has dominated clinical and research attention for two decades ( 1 ) and remains central to the differential diagnosis of thrombotic microangiopathies ( 4 ). A broader functional role has emerged from studies of viral and inflammatory immunothrombosis, in which thrombus formation can serve as an effector arm of innate immunity ( 5 ). In severe COVID-19, sepsis, and chronic HIV infection, VWF antigen commonly rises while ADAMTS13 activity is normal or modestly reduced, and a low ADAMTS13/VWF ratio is associated with organ dysfunction or adverse outcomes ( 6 – 11 ). We use “relative ADAMTS13 insufficiency” as a proposed research phenotype for this load-to-capacity mismatch: ADAMTS13 activity remains outside the severe-deficiency range used for TTP, typically ≥10%, but is disproportionately low relative to the concurrent VWF burden. This phenotype does not, by itself, identify the underlying mechanism and should not be conflated with TTP or interpreted as evidence that ADAMTS13 is necessarily causal or rate limiting. In some vascular niches, it may reflect insufficient VWF-processing capacity relative to substrate burden, whereas in others it may primarily accompany endothelial activation and systemic inflammation. Whether this proposed modifier has a causal role in human cancer remains unresolved. Many tumor microenvironments exhibit endothelial activation, complement dysregulation, platelet engagement, NET formation, and coagulation activation ( 12 – 15 ), yet evidence linking ADAMTS13 to malignancy remains fragmented across case reports, cohort associations, tissue-level observations, and a limited number of animal perturbation studies ( 16 – 21 ). Several alternative or complementary processes may contribute to the observed VWF–ADAMTS13 imbalance, including increased VWF secretion, impaired hepatic or splenic cellular clearance, altered ADAMTS13 synthesis, stability, or endocytosis, and parallel activation of inflammatory and coagulation pathways. These processes have rarely been assessed together in tumor settings. The purpose of this Hypothesis and Theory article is therefore to organize the available evidence into a bounded and falsifiable model, rather than to assume that ADAMTS13 insufficiency is the sole or dominant cause of cancer-associated thrombosis. Here, we propose that the VWF–ADAMTS13 axis may function as a context-dependent thromboinflammatory modifier in selected tumor vascular niches. First, we define the molecular conditions under which this axis operates and distinguish ADAMTS13-mediated control of VWF multimer size from whole-molecule VWF clearance. Second, we examine evidence from viral and inflammatory settings while distinguishing human associations from perturbation-based evidence and considering alternative common-cause explanations. Third, we position the axis within the broader complement–NET–platelet–coagulation network and evaluate tumor- and ICI-related findings according to explicit evidence tiers. Finally, we define a measurable research phenotype, formulate falsifiable predictions, and outline the studies required before biomarker-guided intervention can be considered. Figure 1 summarizes this framework. Figure 1 ADAMTS13 as a context-dependent thromboinflammatory brake across viral/inflammatory and tumor contexts. Both panels depict endothelial Weibel–Palade body exocytosis, endothelial-anchored UL-VWF strings, platelet recruitment, and proteolytic processing by ADAMTS13. The left panel summarizes viral and inflammatory evidence, whereas the right panel extends the model to tumor-associated vascular inflammation. Local force can expose the VWF A2 region; in heterogeneous tumor flow, A2 exposure is context dependent. The schematic emphasizes endothelial-anchored UL-VWF, while circulating and collagen-bound VWF and hepatic, splenic, and sinusoidal cellular clearance are discussed in Section 2.1. The boundary band indicates that cellular clearance also contributes and that ADAMTS13 need not be rate limiting. Solid lines denote direct or experimental support, dashed lines association or inference, and the outlined band a conditional boundary. The candidate complement–VWF interface is supported mainly by non-cancer evidence and remains untested in tumor vessels. The ICI box presents two distinct observations in the tumor-treatment context: an unresolved endothelial association and rare anti-ADAMTS13 immune TTP with severe categorical deficiency. The lower rows identify candidate mechanistic probes or research nodes; the evidence and clinical applicability vary by disease context, and none is established for cancer-associated relative insufficiency. 2 ADAMTS13 as a thromboinflammatory brake: molecular model and evidence from viral and inflammatory immunothrombosis ADAMTS13 was identified as the protease deficient in TTP, and the dominant clinical paradigm has focused on its severe deficiency in acute TTP presentations. Recent work in viral immunothrombosis and severe inflammatory states, however, reveals a broader functional role that operates at activity levels well above the TTP diagnostic threshold. Here, we first describe the molecular operating model of ADAMTS13 as a thromboinflammatory brake at the vascular-immune interface, and then synthesize the multi-layered evidence from viral and inflammatory contexts that provides the empirical basis for this brake function. 2.1 Operating model at the vascular-immune interface The core VWF–ADAMTS13 proteolytic circuit comprises four interacting elements. First, VWF is synthesized by endothelial cells and stored with P-selectin and other mediators in Weibel–Palade bodies as ultra-large multimers ( 22 ). Second, endothelial activation triggers luminal UL-VWF strings, while circulating plasma VWF provides a second substrate pool. Following endothelial disruption, exposed subendothelial collagen immobilizes circulating VWF, allowing it to bridge the damaged vessel wall to platelet GPIbα; surface anchorage and local hydrodynamic forces can extend VWF and increase platelet capture ( 23 ). Third, shear and tensile force act primarily on tethered VWF, unfolding its A2 domain and exposing the Tyr1605–Met1606 bond. VWF engagement through ADAMTS13 exosites promotes productive proteolysis, so VWF functions as both substrate and activating cofactor ( 24 – 28 ). Fourth, ADAMTS13 cleavage shortens platelet-reactive VWF multimers and reduces the VWF-dependent scaffold for platelet and leukocyte recruitment. ADAMTS13-mediated proteolysis should be distinguished from whole-molecule clearance of VWF. Intact VWF and VWF–FVIII complexes are also removed by hepatic and splenic macrophages and sinusoidal endothelial cells, with contributions from receptors including CLEC4M, stabilin-2, and SCARA5 ( 29 – 31 ). Conversely, ADAMTS13 itself can undergo receptor-mediated uptake, including through Siglec-5/14 ( 32 ). Recent work further indicates that hepatic macrophage removal of ADAMTS13-cleaved VWF can be required for full protection in vivo , emphasizing complementarity rather than competition between cleavage and clearance ( 33 ). Tumor-associated myeloid and endothelial remodeling could alter VWF burden, ADAMTS13 availability, or both, but direct evidence in tumor-bearing hosts is lacking. The model therefore does not assume that ADAMTS13 is invariably rate limiting. Within this framework, ADAMTS13 is positioned as a context-dependent modifier of VWF-dependent thromboinflammation. It acts downstream of cytokine release and endothelial activation by proteolytically reducing the multimeric size and platelet-adhesive potential of shear-exposed VWF ( 24 – 28 ). It does not suppress upstream inflammation, neutralize tissue factor or thrombin, dismantle NETs, or inhibit the entire complement cascade. We therefore use “thromboinflammatory brake” as a positional metaphor for this selective VWF-processing function, rather than to imply that ADAMTS13 is a master regulator or a universally rate-limiting determinant of thrombosis. Relative ADAMTS13 insufficiency is used here as a proposed research phenotype, not as a clinical diagnosis, and should not be conflated with TTP. Operationally, it denotes ADAMTS13 activity outside the severe-deficiency range used for TTP, typically ≥10% of normal, together with increased VWF burden and a disproportionately low ADAMTS13:Act/VWF: Ag ratio ( 1 – 4 , 34 ). ADAMTS13 activity, VWF: Ag, and the ratio should be reported separately, using a consistent ratio direction and values normalized to comparable reference-plasma standards ( 34 ). Activity below 10%, particularly in a compatible clinical syndrome, should instead prompt evaluation for categorical severe ADAMTS13 deficiency and immune-mediated or congenital TTP ( 1 – 4 , 34 ). No universal threshold has been validated for relative ADAMTS13 insufficiency across inflammatory diseases or cancer types. The ratio should therefore be analyzed primarily as a continuous variable and supplemented by serial change from a pretreatment baseline. If dichotomization is used, the cut-point should be prespecified, assay-specific, and externally validated; the CATS lower-quartile value of <0.31 should be regarded as an exploratory cohort benchmark rather than a clinical threshold ( 18 ). For discovery studies, one possible operational approach would be to combine VWF: Ag above a laboratory-specific upper reference limit, or a substantial rise from baseline, with a prespecified low ratio while retaining each component separately. The ratio should be regarded as a pragmatic load-to-capacity index rather than a direct kinetic measurement. VWF: Ag primarily reflects circulating VWF protein abundance and does not directly characterize its multimeric distribution or platelet-binding function; platelet-dependent VWF activity, collagen-binding activity, or multimer analysis should therefore be added when feasible ( 35 ). Most clinical ADAMTS13 activity assays use peptide substrates under static conditions and may not reproduce the processing of native or anchored VWF under disease-relevant flow and shear conditions ( 34 ).Serial samples should ideally be analyzed on the same platform, and unexpected results should be confirmed with an alternative assay where feasible. Interpretation should also account for ABO blood group, age, acute-phase activity, liver dysfunction, hemolysis or hyperbilirubinemia, and recent plasma-containing therapy. Unexpectedly low ADAMTS13 activity should prompt measurement of ADAMTS13 antigen and inhibitor/IgG testing. 2.2 Evidence for a context-dependent ADAMTS13 brake in viral and inflammatory immunothrombosis Evidence supporting ADAMTS13 as a thromboinflammatory modifier beyond its established role in TTP can be organized into five evidence domains: observational evidence of an inflammation-associated VWF–ADAMTS13 imbalance, clinical endpoint associations in viral immunothrombosis, candidate molecular mechanisms, upstream pharmacological observations, and genetic evidence in non-viral immunothrombosis. These domains differ substantially in causal strength and should therefore be interpreted separately. Observational basis for inflammation-associated relative insufficiency. Bockmeyer et al. reported a prospective longitudinal cohort encompassing systemic inflammation after extracorporeal cardiopulmonary circulation and severe sepsis. ADAMTS13 activity declined stepwise with the severity of the inflammatory response, accompanied by the appearance of plasma UL-VWF multimers, and these changes were associated with organ dysfunction and lethality ( 6 ). These observations provide an empirical basis for considering a relative VWF–ADAMTS13 imbalance in inflammatory states, but do not establish that inflammation directly causes the decline in ADAMTS13 activity or that ADAMTS13 becomes rate limiting. Sepsis-focused reviews describe a similar pattern across heterogeneous etiologies, with increased VWF burden and relatively reduced ADAMTS13 activity during inflammatory endothelial activation ( 7 ). Clinical endpoint associations in COVID-19. In hospitalized patients with COVID-19, a combined pattern of elevated VWF antigen, lower ADAMTS13 activity, and complement activation was associated with mortality ( 10 ). This concurrence identifies a prognostic thromboinflammatory signature but does not establish a causal sequence among VWF, ADAMTS13, and complement. These abnormalities may instead arise in parallel from common upstream processes, including endothelial injury and systemic inflammation. Similarly, reduced ADAMTS13/VWF ratios together with markers of endothelial injury in severe disease are consistent with a load-to-capacity imbalance, but human observational data cannot determine whether ADAMTS13 dysfunction is a driver, an amplifier, or predominantly a biomarker. Potential mechanisms of reduced effective VWF-processing capacity. Why measured ADAMTS13 activity or effective VWF-processing capacity decreases during inflammation remains unresolved and is likely context dependent. Several non-mutually exclusive mechanisms may contribute. Inflammatory cytokines may alter ADAMTS13 expression ( 36 ), while IL-6 can inhibit cleavage of endothelial UL-VWF strings under flow ( 37 ). Neutrophil-derived oxidants can directly impair ADAMTS13 proteolytic activity ( 38 ), whereas oxidative modification of the VWF cleavage region may reduce substrate susceptibility to ADAMTS13 ( 39 ). Receptor-mediated endocytosis, including uptake through Siglec-5/14, may further reduce circulating ADAMTS13 availability ( 32 ). In addition, a large acute release of VWF may generate a kinetic substrate–protease mismatch even without a marked absolute reduction in ADAMTS13. S-protein-associated NLRP3/IL-1β activation accompanied by increased VWF without compensatory ADAMTS13 upregulation, together with CFH-variant effects on the VWF–ADAMTS13 axis, illustrate possible regulatory inputs ( 40 , 41 ), but neither explains why ADAMTS13 activity is reduced in tumor microenvironments. Most of these candidate mechanisms have been demonstrated in vitro , ex vivo, or outside cancer and therefore require direct testing in tumor-bearing systems. Upstream pharmacological observation. In severe COVID-19, anti-C5a therapy was associated with attenuation of the decline in ADAMTS13 activity relative to standard care ( 42 ). This finding is compatible with an effect of upstream complement or endothelial regulation on the measured VWF–ADAMTS13 axis, but the biomarker change does not establish that complement directly caused ADAMTS13 loss or that restored VWF processing mediated clinical benefit. It therefore supports mechanistic plausibility and experimental prioritization rather than a completed causal pathway. Genetic and leukocyte-anchored evidence beyond acute viral immunothrombosis. Stronger perturbational evidence comes from non-viral inflammatory models. In a Staphylococcus aureus sepsis model, Peetermans et al. showed that vwf -deficient mice had reduced mortality and enhanced bacterial clearance, whereas adamts13 -deficient mice had increased mortality, with these differences largely attributable to differences in organ microthrombus burden ( 43 ). This genetic contrast provides preclinical evidence that altering the VWF–ADAMTS13 circuit can modify thromboinflammatory outcomes in a defined inflammatory context. Conceptually, it parallels the zebrafish tumor model discussed later, in which loss of ADAMTS13 worsens outcome whereas removal of the VWF substrate is protective. Consistent with the involvement of a broader leukocyte–vascular network, virally suppressed HIV infection is accompanied by persistent complement dysregulation, altered VWF–ADAMTS13 dynamics, increased neutrophil extracellular trap (NET) formation, and platelet activation, while C5a receptor antagonism reduces NET formation ( 11 ). NETs themselves provide a scaffold for VWF-dependent thrombosis and contribute causally to deep-vein thrombosis in mouse models ( 44 , 45 ). These observations support
## Related Clinical Research

- [Non-Anticoagulant Heparins: Immune Modulation and Therapeutic Advances](https://medichelpline.com/clinical-feed/frontiers-in-immunology-18-non-anticoagulant-heparins-glycan-mediated-immune-modulation-and-therapeutic.md)
- [Sepsis and HIV: framing a globally relevant agenda](https://medichelpline.com/clinical-feed/pubmed-42561970.md) (DOI: 10.1016/S0140-6736(26)01064-0)
- [COVID-19 mortality among people with HIV in Florida before and after COVID-19 vaccine availability](https://medichelpline.com/clinical-feed/plos-one-13-covid-19-mortality-risk-among-people-with-hiv-in-florida-before-and-after-the.md)
- [Steatotic Liver Disease Subtypes in People Living with HIV: Mortality and Cardiovascular Risks in](https://medichelpline.com/clinical-feed/pubmed-42670693.md) (DOI: 10.5009/gnl250555)
- [Increased risk of acute gastroenteritis after COVID-19 hospitalisation: a retrospective England an](https://medichelpline.com/clinical-feed/medrxiv-3-risk-of-acute-gastroenteritis-following-covid-19-exposure-a-retrospective.md)

## Navigation
- [← Back to Infectious Disease Feed](https://medichelpline.com/clinical-feed/infectious-disease.md)
- [← All Clinical Specialties](https://medichelpline.com/clinical-feed.md)
## Medical & Regulatory Disclaimer

> [!CAUTION]
> MedicHelpline content is structured for research, educational, and professional discovery purposes. It does not constitute individual medical advice, clinical diagnosis, or treatment recommendations.
> Always verify dosing, contraindications, and regulatory alerts against official product labeling and primary regulatory sources before clinical decision-making.