ORIGINAL RESEARCH article

Front. Immunol.

Sec. Inflammation

Volume 16 - 2025 | doi: 10.3389/fimmu.2025.1589959

Changes in immune cell signatures during early infection reflect decoupling of capillary perfusion and glycocalyx dimensions

Provisionally accepted
  • University Hospital Münster, Münster, Germany

The final, formatted version of the article will be published soon.

Microvascular injury is central to the pathophysiology of sepsis, but its interaction with the immune system in early infection is unclear. This study aimed to phenotype peripheral blood mononuclear cells (PBMC) from emergency department (ED) patients with suspected bacterial infection and correlate the results with microvascular changes. This prospective observational study included 49 adult ED patients with suspected infection and 17 healthy controls. Capillary density and glycocalyx dimensions were measured by sublingual microscopy, while peripheral blood immune cell subsets were analyzed by deep flow cytometry. Network visualization of 72 differentially regulated parameters revealed specific changes in different immune cell subsets. Innate immune changes included a functional diversion of monocytes towards pathogen defense and tissue repair, whereas adaptive immune changes included the development of CD4+ T cells with Th2-profile and cytotoxic CD8+ T cells. Unsupervised clustering revealed two distinct immune endotypes: E1 with a suppressed immune response and higher disease severity, and E2 with an enhanced immune response and lower disease severity. Patients showed significant reductions in capillary density and glycocalyx dimensions, which were neither correlated in magnitude nor associated with endotypes. There was a strong association between damaged glycocalyx and several monocyte and T-cell subsets. This association was not observed for capillary density. We demonstrate that glycocalyx damage is associated with a unique immunological signature, distinct from functional capillary density. These findings provide a strong basis for future studies of immune dysregulation and microvascular dysfunction in infection.

Keywords: Sepsis, Microcirculation, Sublingual microscopy, endothelial glycocalyx, Immune phenotypes, Flow Cytometry

Received: 08 Mar 2025; Accepted: 22 Apr 2025.

Copyright: © 2025 Hunkemöller, Wirth, Rovas, Pavenstädt, Klotz and Kümpers. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.

* Correspondence: Philipp Kümpers, University Hospital Münster, Münster, Germany

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