Fredrik Kahn

Our research

We investigate how infections trigger and reshape the innate immune system and how a response that begins as protective can tip into harmful immune dysregulation. Sepsis is our flagship model: each year it affects about 50 000 Swedes and causes roughly 10 000 deaths, exceeding the burden of the ten most common cancers combined. Behind every number is a patient whose recovery and long-term quality of life, depends on managing the dysregulated immune response. 

Unfortunately, sepsis survivors have a high risk of developing severe complications, such as cardiovascular and neurological disease, but our knowledge of the prognosis and why this occurs is limited. Precision medicine principles that have revolutionised oncology and rheumatology, where therapies target well defined molecular or cellular pathways, now need to reach the infectious disease area, and our group is working to lay that foundation.

We also explore immune dysregulation in primary and secondary immunodeficiencies, investigating how IgG replacement therapy reshapes the local airway milieu, both immunoglobulin levels and resident immune cells. Despite systemic IgG supplementation, a subset of patients continues to face recurrent respiratory infections, underscoring persistent gaps in mucosal immunity.

Our research spans four interconnected themes:

| Sepsis & acute immune dysregulation – we aim to profile neutrophil and monocyte subtypes, map their signalling networks and quantify soluble biomarkers that drive organ failure.

| Long term sequelae – survivors will be followed 1) prospectively in a dedicated sepsis out-patient clinic and 2) retrospectively through biobanks, national registers and EHRs to learn why they develop excess cardiovascular and cognitive disease and to discover markers for personalised follow up.

| Immunodeficiency – studies of inborn and secondary immunodeficiencies map local airway immunity and uncover cellular mechanisms behind recurrent infections despite IgG replacement.

| Vaccination – a 3 500 participant COVID 19 cohort and population wide registries in Skåne let us quantify vaccine effectiveness and safety in real time and understand how pre-existing immunity shapes subsequent infection outcomes.

We combine bedside blood and airway sampling with single cell transcriptomics, proteomics, data driven microscopy and advanced statistics. Our ultimate goal is to translate these mechanistic insights into precision immunomodulation for infectious diseases.

Aims

• Characterise early immune dysregulation – map neutrophil and monocyte heterogeneity alongside pathogen specific and host genetic factors within the first hours of infection.
• Rapid diagnostics – develop point of care multi marker panels that use this information to stratify patients and guide immediate therapy.
• Targeted therapies – identify immune pathways suitable for precision intervention and test them in mechanism driven clinical trials.
• Predict and prevent long term complications – discover biomarkers that forecast cardiovascular and cognitive sequelae, enabling tailored follow up and secondary prevention.
• Airway immunity in IgG deficiency – map local immunoglobulin levels, immune cell profiles and activation states in patients on IgG substitution to guide next generation therapies.

Strengths of the group

• Triple competence leadership – the combination of knowledge in infectious disease practice, hands on laboratory expertise and advanced epidemiology/biostatistics, allowing questions to be framed and answered end to end.
• GCP trained leadership – The group has experience in multicentre biomarker trials and vaccine effectiveness studies.
• Bench to bedside platform – ICU recruitment, on site sample processing and integrated laboratory  and bioinformatic analysis let us follow patients from the first blood draw to long term registry outcomes.
• Prospective sepsis out-patient clinic – A unique cohort that allows us to investigate biomarkers and long term sequalae to answer some of the most pressing questions.
• Interdisciplinary expertise – Our group contains a mixture of clinicians, immunologists and statisticians, which collaborate on shared datasets in one group environment.
• Broad networks – active partnerships with rheumatology, neurology and proteomics ensure rapid translation of our findings and access to necessary methodologies. But also, collaboration with researchers in AI.

Impact

• Precision medicine roadmap – building on successes in oncology and rheumatology, we adapt targeted precision concepts to infectious diseases, a shift poised to reduce sepsis mortality and long-term morbidity worldwide.
• Diagnostics pipeline – As an example of our previous and current research, the neutrophil derived biomarker HBP is progressing toward clinical use as an early sepsis test; pragmatic trials evaluate real world impact on triage, treatment and length of stay.
• Long term health – new biomarkers and risk models aim to cut post sepsis cardiovascular and cognitive morbidity by enabling targeted follow up and early intervention.
• Policy influence – real time vaccine effectiveness analyses supported Sweden’s COVID 19 strategy and continue to inform booster recommendations.

| Research Output

Affiliations

• Wallenberg Center for Molecular Medicine Lund
• Department of Infectious Diseases, Skåne University Hospital & Lund University

Social Media 

• LinkedIn
• ORCID: 0000 0001 5566 6350