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Bruns Cirrhosis Lab · RWTH Aachen University

Immunity, inflammation and infection in cirrhosis

Our mission

The Bruns Cirrhosis Lab studies infection and immunity in patients with chronic liver disease and ascites. We focus on the gut–liver axis, peritoneal immunity, spontaneous bacterial peritonitis, acute-on-chronic liver failure and cirrhosis-related immune dysfunction. By bringing hepatology and immunology together in translational research, we aim to improve the care of patients with cirrhosis.

Our research Join us

Photo: University Hospital Aachen

Portrait of Tony Bruns, a man with short blond hair, beard and dark-framed glasses, wearing a white coat and tie against a light blue background

Welcome

The Bruns Cirrhosis Lab, led by Professor Tony Bruns (Research and Teaching Area Hepatology, RWTH Aachen University, and Department of Internal Medicine III, University Hospital Aachen), studies how inflammation, infection and immune dysfunction arise in patients with cirrhosis and ascites, and which findings can help to diagnose and treat complications such as spontaneous bacterial peritonitis (SBP) earlier. Our work combines patient cohorts, clinical trials and laboratory experiments, in collaboration with partners in Aachen, Germany and Europe.

We welcome enquiries from colleagues, collaborators and early-career scientists who would like to work on these questions. Medical students who are looking for a doctoral thesis are very welcome to get in touch: you will find everything you need under Join us below. We look forward to hearing from you.

Univ.-Prof. Dr. med. Tony Bruns
Head of the Research and Teaching Area Hepatology
Department of Internal Medicine III, University Hospital Aachen
RWTH Aachen University

Our research

Patients with decompensated cirrhosis are at high risk of bacterial infection, sepsis and organ failure. We investigate why the immune system fails, and how it drives tissue injury, when the liver is damaged. We follow clinical questions across compartments, from the gut barrier and the peritoneal cavity to the blood, and across innate and adaptive immunity.

  1. Infections and spontaneous bacterial peritonitis

    Bacterial infections are the most frequent trigger of decompensation and organ failure in cirrhosis. Ascites is both a site of infection and a window into the immune response of the peritoneal cavity. We study how bacterial products and live bacteria activate peritoneal immunity, which soluble markers in ascitic fluid indicate infection and outcome, and how infections, including those with resistant pathogens, are best treated.

  2. Gut–liver axis and barriers

    In cirrhosis, the intestinal and gut–vascular barriers fail, and bacteria and their products reach the liver, the circulation and the ascites. We measure barrier failure in patients with circulating and ascitic biomarkers, and we test whether restoring the gut microbiota, for example by encapsulated faecal microbiota transfer in the TransImmune trial, can reduce immune activation.

  3. Sepsis and organ failure

    Systemic inflammation links infection with failure of the kidneys, the circulation and other organs. We study how innate and adaptive immune cells, inflammasome activation and released danger signals contribute to sepsis, acute kidney injury and organ dysfunction in cirrhosis, and how immune dysfunction can be recognised early.

  4. Cirrhosis, ACLF and liver transplantation

    Acute-on-chronic liver failure (ACLF) is the most severe course of decompensated cirrhosis, and infections are its most important precipitant. We study the immune and clinical features that mark the transition from acute decompensation to ACLF. We also investigate the impact of inflammation and organ failure on outcomes after liver transplantation.

How we work

We use biological samples, including immune cells, from patients with decompensated cirrhosis and ACLF, and combine them with in vitro models to study cellular crosstalk, the response to infection and cell migration.

Cirrhosis & ACLF IN THE LAB IN PATIENTS Immunecells Cell culture &bacterial co-culture Flow & masscytometry RNA & single-cellsequencing Proteins &biomarkers Dataanalysis Asciticfluid Infections& SBP Gut–liveraxis Sepsis & organfailure Acute kidneyinjury Patient data& outcomes

In patients

  • Investigator-initiated clinical trials and observational studies
  • Ascitic fluid, blood and immune cells from prospective cohorts
  • Clinical data and long-term outcomes
  • Functional assessment of barriers and organs

In the lab

  • Isolation of primary cells
  • Co-culture, infection and inflammation models
  • Flow and mass cytometry
  • Single-cell and bulk RNA sequencing
  • Protein and cytokine profiling
  • Data analysis and machine learning

Selected publications

All publications PubMed

  1. Macrophage-derived IL-15 imprints peritoneal TRM-like CD8 T cells in cirrhosis and spontaneous bacterial peritonitis

    Ibidapo-Obe O, Stengel S, Frissen M, Reißing J, Große K, Rooney M, Quickert S, Nguyen TH, Baumgart S, Leal-Lassalle H, Benedé-Ubieto R, Nevzorova YA, Bruns T

    JHEP Rep (2025) PubMedDOIPMC

  2. Peritoneal immunity in decompensated cirrhosis

    Ibidapo-Obe O, Rooney MD, Bruns T

    Expert Rev Clin Immunol (2025) PubMedDOI

  3. Surrogate Markers of Intestinal Permeability, Bacterial Translocation and Gut-Vascular Barrier Damage Across Stages of Cirrhosis

    Haedge F, Reuken PA, Reißing J, Große K, Frissen M, El-Hassani M, Aschenbach R, Teichgräber U, Stallmach A, Bruns T

    Liver Int (2025) PubMedDOIPMC

  4. Type-I interferon shapes peritoneal immunity in cirrhosis and drives caspase-5-mediated progranulin release upon infection

    Rooney M*, Duduskar SN*, Ghait M, Reißing J, Stengel S, Reuken PA, Quickert S, Zipprich A, Bauer M, Russo AJ, Rathinam VA, Stallmach A, Rubio I, Bruns T

    J Hepatol (2024) PubMedDOI

  5. Th2 Cell Activation in Chronic Liver Disease Is Driven by Local IL33 and Contributes to IL13-Dependent Fibrogenesis

    Reißing J, Berres M, Strnad P, Wree A, Inzaugarat ME, Trautwein C, Bruns T*, Zimmermann HW*

    Cell Mol Gastroenterol Hepatol (2024) PubMedDOIPMC

  6. Gut-liver axis: barriers and functional circuits

    Pabst O, Hornef MW, Schaap FG, Cerovic V, Clavel T, Bruns T

    Nat Rev Gastroenterol Hepatol (2023) PubMedDOI

  7. Peritoneal Level of CD206 Associates With Mortality and an Inflammatory Macrophage Phenotype in Patients With Decompensated Cirrhosis and Spontaneous Bacterial Peritonitis

    Stengel S*, Quickert S*, Lutz P, Ibidapo-Obe O, Steube A, Köse-Vogel N, Yarbakht M, Reuken PA, Busch M, Brandt A, Bergheim I, Deshmukh SD, Stallmach A, Bruns T

    Gastroenterology (2020) PubMedDOI

  8. Mucosal-Associated Invariant T Cells Redistribute to the Peritoneal Cavity During Spontaneous Bacterial Peritonitis and Contribute to Peritoneal Inflammation

    Ibidapo-Obe O, Stengel S, Köse-Vogel N, Quickert S, Reuken PA, Busch M, Bauer M, Stallmach A, Bruns T

    Cell Mol Gastroenterol Hepatol (2020) PubMedDOIPMC

  9. CMV infection of human sinusoidal endothelium regulates hepatic T cell recruitment and activation

    Bruns T, Zimmermann HW, Pachnio A, Li KK, Trivedi PJ, Reynolds G, Hubscher S, Stamataki Z, Badenhorst PW, Weston CJ, Moss PA, Adams DH

    J Hepatol (2015) PubMedDOI

  10. Soluble urokinase plasminogen activator receptor is compartmentally regulated in decompensated cirrhosis and indicates immune activation and short-term mortality

    Zimmermann HW, Reuken PA, Koch A, Bartneck M, Adams DH, Trautwein C, Stallmach A, Tacke F, Bruns T

    J Intern Med (2013) PubMedDOI

  11. Recruitment mechanisms of primary and malignant B cells to the human liver

    Shetty S*, Bruns T*, Weston CJ, Stamataki Z, Oo YH, Long HM, Reynolds GM, Pratt G, Moss P, Jalkanen S, Hubscher SG, Lalor PF, Adams DH

    Hepatology (2012) PubMedDOI

* Equal contribution

Our working model

Schematic of the gut–liver–peritoneum axis in decompensated cirrhosis: the cirrhotic liver with more portosystemic shunting and portal hypertension and less bile flow; the gut with lower microbial diversity, more facultative anaerobes and oral microbiota, intestinal inflammation, gut–vascular barrier dysfunction and translocation to mesenteric lymph nodes; and the peritoneal cavity with more bacterial products and viable bacteria, inflammatory priming, T cell activation and inflammatory cytokines. The three compartments are linked by systemic inflammation, the acute phase response and tissue damage.
The gut–liver–peritoneum axis in decompensated cirrhosis. Ibidapo-Obe O, Rooney MD, Bruns T, Expert Rev Clin Immunol 2025. Licence CC BY-NC-ND 4.0, BioRender.

Team

Physicians and scientists working together to study immunity, infection and organ failure in liver disease.

Members of the research group in white coats standing in front of a hedge.

Head of the group

Portrait of Tony Bruns, a man with short blond hair, beard and dark-framed glasses, wearing a white coat and tie against a light blue background

Univ.-Prof. Dr. med. Tony Bruns

Head of the Research and Teaching Area Hepatology
Department of Internal Medicine III, University Hospital Aachen
RWTH Aachen University

Tony Bruns is a hepatologist and clinician scientist at University Hospital Aachen. His group investigates why patients with cirrhosis develop infections and organ failure, with a focus on ascites, peritoneal immunity and the gut–liver axis. He is a principal investigator in the DFG Collaborative Research Centre (CRC) 1382 “Gut-Liver Axis” and the coordinating investigator of the TransImmune trial of faecal microbiota transfer in cirrhosis.

Full profile · tbruns@ukaachen.de

Current members

Dr. rer. nat. Oluwatomi Ibidapo-Obe

Postdoctoral researcher

Dr. Oluwatomi Ibidapo-Obe is a postdoctoral immunologist in the Bruns lab. She obtained her PhD on unconventional T-cell subsets in patients with decompensated cirrhosis and bacterial infection. She is first author of studies on MAIT cells in spontaneous bacterial peritonitis (CMGH 2020) and on macrophage-derived IL-15 imprinting tissue-resident-memory-like CD8 T cells in the peritoneal cavity (JHEP Reports 2025). Her current work addresses peritoneal CD4 and CD8 T cells in liver disease within CRC 1382 project B07, and she will focus on immunometabolism. She received the Rising Star award of CRC 1382.

Dr. rer. nat. Johanna Reißing

Scientist

Dr. Johanna Reißing is a postdoctoral biologist and scientist in the Bruns lab. She works on T-helper cells and macrophage biology in patients with cirrhosis and is first author of studies on IL-33-driven Th2 cell activation in chronic liver disease (CMGH 2024) and on the macrophage receptor VSIG4 in spontaneous bacterial peritonitis (JHEP Reports 2022). She is investigating the prognostic significance of a panel of biomarkers of immune activation in chronic liver disease.

Mick Frissen, M.Sc.

Doctoral researcher

Mick Frissen is a PhD student in the Bruns lab. He holds a Master's degree in Molecular Life Science from Maastricht University and investigates microRNAs and neutrophil–macrophage crosstalk in chronic liver disease, including patients with decompensated cirrhosis and spontaneous bacterial peritonitis.

Majda El Hassani, M.Sc.

Doctoral researcher

Majda El Hassani is a PhD student in the Bruns lab. She investigates how sterile injury-driven and bacterial infection-driven phase transitions differ in alcohol-related cirrhosis, a project within the research focus “Phase transition in disease” of the Medical Faculty at RWTH Aachen University. She holds a Master's degree in molecular and cellular biology from the University of Cagliari, where she studied the neuropeptide VGF in the mesencephalon.

Dr. med. Frederic Haedge

Physician, clinician scientist

Dr. Frederic Haedge is a physician and clinician scientist at the Department of Internal Medicine III, University Hospital Aachen. He received his medical degree with a thesis on gasotransmitters in kidney disease. His current research addresses intestinal barrier function in cirrhosis. He is first author of a study validating circulating surrogate markers of intestinal permeability, bacterial translocation and gut-vascular barrier damage across stages of cirrhosis (Liver International 2025) and works on prognostic biomarkers of the gut–liver axis in decompensated cirrhosis. He also holds a Gerok rotation position in CRC 1382.

Dr. med. Karsten Große

Physician, clinician scientist

Dr. Karsten Große is an internist and intensive care physician at the Department of Internal Medicine III, University Hospital Aachen, and a member of the Bruns lab. He is a clinical expert in critical illness, ACLF, infections and liver transplantation. He has published on the prognostic implications of enterococci in liver abscesses (Scientific Reports 2021) and is first author of the protocol of the TransImmune trial of encapsulated faecal microbiota transfer in cirrhosis (BMJ Open 2026). His MD thesis addressed genetic risk factors for spontaneous bacterial peritonitis.

Dr. med. Mohamad Murad

Physician, clinician scientist

Dr. Mohamad Murad is an internist at the University Hospital Aachen with a particular interest in hepatobiliary cancer. His research focuses on prognostic biomarkers in decompensated liver disease and outcomes after liver transplantation. He is first author of a study on HDL-associated apolipoproteins in ascitic fluid (Scientific Reports 2025) and investigates the impact of bacterial bloodstream infection after liver transplantation.

Pia Burmeister

MD student

Pia Burmeister is a medical student and doctoral candidate in the Bruns lab. Her thesis project compares biomarker profiles of acute and chronic kidney dysfunction in patients with decompensated cirrhosis.

Simon Hauck

MD student

Simon Hauck is a medical student and doctoral candidate in the Bruns lab. His thesis project addresses risk factors and prognostic implications of bloodstream infection in patients with cirrhosis and acute-on-chronic liver failure.

Ekaterini Kourouklari

Physician, MD candidate

Ekaterini Kourouklari is a physician and doctoral candidate in the Bruns lab. Her thesis project addresses liver stiffness measured by elastography and the clinical course after liver transplantation.

Amelie Meurer

MD student

Amelie Meurer is a medical student and doctoral candidate in the Bruns lab. Her thesis project analyses how critical illness and infection affect organ allocation and waiting-list mortality in patients listed for liver transplantation.

Lilly Müller

MD student

Lilly Müller is a medical student and doctoral candidate in the Bruns lab. Her thesis project is a retrospective study on species-dependent differences in the course and outcome of spontaneous bacterial peritonitis.

Anna Theresa Rickel

MD student

Anna Theresa Rickel is a medical student and doctoral candidate in the Bruns lab. Her thesis project addresses risk factors for renal dysfunction after liver transplantation.

Ayten Camur

MD student

Ayten Camur is a medical student and doctoral candidate in the Bruns lab. Her thesis project examines encephalopathy before and after liver transplantation, using blood biomarkers of neurodegeneration and neuropsychological tests.

Former lab members and alumni (in alphabetical order)

  • Prof. Dr. rer. nat. Eihab Al-Herwi
  • Dr. med. Clemens Kittler
  • Dr. rer. nat. Nilay Köse-Vogel
  • Dr. rer. nat. Martina Mai
  • Dr. med. Alexander Olkus
  • Dr. med. Jack Peter
  • Dr. med. Stefanie Quickert
  • Prof. Dr. med. Philipp A. Reuken
  • Dr. rer. nat. Michael Rooney
  • Dr. rer. nat. Sven Stengel
  • Dr. med. Anika Vogt
  • Dr. rer. nat. Melina Yarbakht

Why do patients with advanced liver disease develop infections and organ failure?

Join our research team and help us find out.

We supervise medical students (MD thesis), Master's students and PhD students. Interested in a PhD or postdoc position? Please get in touch as well.

Why work with us?

  • You will learn how to do research and to think scientifically.
  • You work with biological samples from patients.
  • You learn methods such as flow cytometry, single-cell RNA sequencing or cell culture models.
  • You are embedded in collaborative research networks.

What we expect

Interest in immunology or clinical research, critical thinking, an open mind, reliability and the willingness to take a research semester (MD students). Lab experience is not required.

How to apply

Send a short email to tbruns@ukaachen.de with your CV, your current stage of study, a brief motivation and your preferred start date. Selected candidates are invited to meet the team.

Introductory reviews in German (for medical students)

Networks, funding and partners