Redefining pneumonia and sepsis care

Posted on: 31 October 2025

Irish-led studies published in The Lancet and Nature Medicine are a major milestone for Trinity College Dublin and for Irish critical care

Professor Martin-Loeches, who this year became the first Academic Professor of Intensive Care Medicine at Trinity College Dublin after being a Clinical Professor for some years, is also a clinician scientist, leading major research programmes that bridge bedside care and advanced science to improve outcomes for critically ill patients.

Pneumonia: a true medical emergency

The Lancet paper ‘Community Acquired Pneumonia’ reframes community-acquired pneumonia (CAP) as a medical emergency, not a routine infection.
CAP is among the world’s leading causes of hospitalisation and death, responsible for around 2 million deaths every year. In Ireland, it is one of the most common reasons for emergency admission — especially among older adults and those with existing health problems.

“Every winter, our emergency departments are flooded with pneumonia cases,” said lead author Professor Martin-Loeches . “Many patients need high-level monitoring or ventilation, but our hospitals are chronically overcrowded, and ICU capacity is extremely limited. That delay in getting to the right level of care can cost lives.”

Ireland has about 6 ICU beds per 100000 people, compared with 30 in Germanyand 10–12 in the UK — among the lowest rates in Europe.
This shortage means Irish ICUs often run at full capacity, forcing hospitals to care for some critically ill patients in emergency rooms or general wards.

The Lancet paper calls for faster recognition, better diagnostics, and personalised treatment pathways. It also highlights that pneumonia survivors remain at risk of heart attacks, strokes, and prolonged fatigue well after discharge.

Supporting GPs and tackling antibiotic overuse

The study also addresses the escalating problem of antibiotic overuse in the community, which is fuelling antimicrobial resistance.

“GPs are under enormous pressure,” said Professor Martin-Loeches. “Patients often come in expecting an antibiotic, especially in winter. But many infections are viral, and antibiotics simply won’t help.

“We have to support, not criticise, our GPs. They’re working under intense time pressure and with limited diagnostic resources. Giving them access to rapid molecular or biomarker-based tests would make a huge difference — it would help them confirm bacterial infections and prescribe confidently while protecting antibiotic effectiveness.”

Martin-Loeches also cautioned the public against self-diagnosis:

“We should never rely on chatbots or AI tools like ChatGPT to decide whether we need antibiotics. These tools can share general information, but they can’t replace the experience, training, and clinical judgment of a GP. Medicine is about context — and that’s something only a doctor can provide.”

The immune code of sepsis: findings from the study in Nature Medicine

In the companion Nature Medicine study, Professor Martin-Loeches and an international team uncovered how the immune system breaks down in sepsis and critical illness.
Analysing over 7 000 blood samples from patients with sepsis, COVID-19, trauma, and burns, they identified two key immune failure patterns — myeloid overactivation and lymphoid suppression.

Their new model, called Hi-DEF, functions like an “immune ECG” — showing whether a patient’s immune system is overactive or exhausted.

“For decades, we’ve treated sepsis as one disease,” said Professor Martin-Loeches. “In reality, each patient’s immune system behaves differently. Understanding these patterns helps us choose the right therapy at the right time.”

The study also revealed that certain immune profiles respond better to anti-inflammatory drugs like anakinra, while others may be harmed by steroids — a breakthrough that could guide more precise, safer treatments in the future.

Key findings from this study

1  Large-scale integration:
The SUBSPACE consortium analysed over 7,000 transcriptomic samples from 37 independent sepsis cohorts, enabling a robust cross-cohort comparison of immune endotypes in critical illness.

2  Cell-type-specific framework:
Researchers developed gene expression signatures specific to myeloid and lymphoid cells, allowing quantification of immune compartment dysregulation in sepsis and other syndromes.

3  Consistent associations with outcomes:
Myeloid and lymphoid dysregulation correlated strongly with disease severity and mortality across all cohorts, highlighting their prognostic value.

4  Cross-syndrome relevance:
The same immune dysregulation patterns were observed in patients with ARDS, trauma, and burns, indicating a shared or conserved immune mechanism across diverse critical care syndromes.

5.Therapeutic implications:

In randomized controlled trials (SAVE-MORE, VICTAS, VANISH), myeloid and lymphoid dysregulation predicted differential mortality responses to treatments such as anakinra and corticosteroids, suggesting potential for precision immunotherapy in critical illness.

Why this research matters for Ireland

“Having two Irish-led studies published in The Lancet and Nature Medicine is a major milestone for Trinity and for Irish critical care,” said Professor Martin-Loeches.
“But it’s also a reminder of the challenges we face — overcrowded hospitals, limited ICU capacity, and the enormous daily pressure on GPs and emergency staff. Pneumonia and sepsis are time-critical emergencies, and we need to make sure patients in Ireland can access the level of care they deserve.”

Both studies share a clear message: early recognition, better diagnostic tools, and smarter, more personalised treatment can save lives — while easing the strain on an already overburdened healthcare system.

Next steps

The Trinity team is now developing projects that combine immune profiling, AI-assisted data analysis, and bedside diagnostic innovation to improve infection management and critical care pathways in Irish hospitals.

Work is underway at St James’s Hospital and Tallaght University Hospital, within wider European collaborations on digital health and sepsis innovation.

Professor Martin-Loeches, concluded by saying:  “Our goal is to bring science directly to the bedside — giving every critically ill patient in Ireland a faster diagnosis, a tailored treatment, and a better chance to recover.”

 Professor Martin-Loeches has published over 700 manuscript and included among the Stanford/Elsevier Top 2% Scientists List 2024.

Read the papers

The Lancet: The full seminar: ‘Community Acquired Pneumonia’ can be read at this link:https://www.thelancet.com/journals/lancet/article/PIIS0140-6736(25)01493-X/abstract

Nature Medicine: The full paper: ‘A consensus immune dysregulation framework for sepsis and critical illnesses’ can be read at this link: https://www.nature.com/articles/s41591-025-03956-5

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