Evidence map›Paper›PMID 42209889›Full record

ArticleIntensive care medicine experimental2026

Evaluation of plasma calprotectin as a marker for infection in various clinical settings: a prospective observational study.

Tobias Zimmermann, Timothy Arthur Chandos Snow, Pedro Lopez-Ayala, Ahmed Al-Hindawi, Samer Elkhodair, Nishkantha Arulkumaran, Martin Siegemund, Mervyn Singer, David Brealey

Abstract read
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Article in Intensive care medicine experimental, 2026. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Not yet cited in PubMed.

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1 · What the graph read from it

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2 · The registry

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3 · Its place in the literature

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4 · The record

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5 · Who and what money

Authors and funding

9 authors.

Tobias ZimmermannBloomsbury Institute of Intensive Care Medicine, Centre for Respiratory Medicine, University College London, Gower St, London, WC1E 6BT, UK.
Timothy Arthur Chandos SnowBloomsbury Institute of Intensive Care Medicine, Centre for Respiratory Medicine, University College London, Gower St, London, WC1E 6BT, UK.
Pedro Lopez-AyalaCardiovascular Research Institute Basel, University Hospital Basel, University of Basel, Basel, Switzerland.
Ahmed Al-HindawiBloomsbury Institute of Intensive Care Medicine, Centre for Respiratory Medicine, University College London, Gower St, London, WC1E 6BT, UK.
Samer ElkhodairEmergency Department, University College London Hospital, London, UK.
Nishkantha ArulkumaranBloomsbury Institute of Intensive Care Medicine, Centre for Respiratory Medicine, University College London, Gower St, London, WC1E 6BT, UK.
Martin SiegemundIntensive Care Unit, Department of Acute Medicine, University Hospital Basel, University of Basel, Basel, Switzerland.
Mervyn Singer *Bloomsbury Institute of Intensive Care Medicine, Centre for Respiratory Medicine, University College London, Gower St, London, WC1E 6BT, UK. m.singer@ucl.ac.uk.ORCID http://orcid.org/0000-0002-1042-6350
David Brealey *Bloomsbury Institute of Intensive Care Medicine, Centre for Respiratory Medicine, University College London, Gower St, London, WC1E 6BT, UK.

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

backgroundReliably distinguishing infection from sterile inflammation is a major clinical challenge. Uncertainty can lead to unnecessary courses of antibiotics, fueling antimicrobial resistance and adverse effects. Calprotectin, a biomarker released by activated immune cells, may inform decision-making.

methodsThis prospective, observational, single-centre study recruited patients with suspected infection who provided blood samples on enrolment from the Emergency Department (ED) and Intensive Care Unit (ICU) of a central London university hospital. A separate longitudinal study with five days' blood sampling was performed in patients undergoing elective major non-cardiac surgery, in whom infection was adjudicated according to the Standardised Endpoints in Perioperative Medicine (StEP) initiative. Diagnostic adjudication was performed blinded to calprotectin. The primary outcome was the ability of calprotectin to diagnose infection. Secondary outcomes included a comparison to C-reactive protein (CRP).

results427 patients were included, of whom 186 (44%) were female. Of 245 ED patients, 71 (29%) had active cancer and 56 (23%) were on immunosuppressants. The median calprotectin level in the no-infection group was 1.97 mg/L (IQR 1.02-3.39), compared to 2.76 (IQR 1.65-5.08) mg/L in low-probability infection, 2.63 mg/L (IQR 1.83-5.23) in high-probability infection, and 2.64 mg/L (IQR 1.49-4.45) in patients with confirmed infection. Ordinal regression analysis found no meaningful association between calprotectin levels and infection, or bacterial infection. Logistic regression showed an unadjusted AUC of 0.53 (95%-CI 0.45-0.62) for calprotectin and a binary outcome of infection compared to an AUC of 0.63 (95%-CI 0.55-0.71) for CRP. Similar results were seen in a sensitivity analysis excluding patients with cancer or immunosuppression. In 98 ICU patients, neither calprotectin nor CRP showed a meaningful association with an adjudicated diagnosis of infection or ICU death. In the peri-operative cohort, calprotectin levels remained elevated over 5 days, but with no difference between patients developing or not developing infection.

conclusionCalprotectin showed only limited ability to differentiate infection from inflammation across ED, ICU, and elective surgery patients. Excluding patients with cancer or immunosuppression did not alter the overall findings.

Indexed as

BiomarkerCalprotectinDiagnosisInfectionInflammationSepsis

Identifiers

PMID42209889
PMCPMC13219622

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Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.