Identification of IL-8 in CSF as a potential biomarker in sepsis-associated encephalopathy

Yingying Mao; Amin Zhang; Haitao Yang; Chen Zhang

doi:10.1016/j.cyto.2023.156390

Identification of IL-8 in CSF as a potential biomarker in sepsis-associated encephalopathy

Cytokine. 2023 Dec:172:156390. doi: 10.1016/j.cyto.2023.156390. Epub 2023 Oct 7.

Authors

Yingying Mao¹, Amin Zhang², Haitao Yang¹, Chen Zhang³

Affiliations

¹ Department of General Practice, Liaocheng People's Hospital, No.67 West Dongchang Road, Liaocheng 252000, Shandong Province, China.
² Department of Pediatrics, Qilu Hospital of Shandong University, No.107 West Wenhua Road, Jinan 250012, Shandong Province, China.
³ Department of Pediatrics, Qilu Hospital of Shandong University, No.107 West Wenhua Road, Jinan 250012, Shandong Province, China. Electronic address: zczc_8888@163.Com.

PMID: 37812997
DOI: 10.1016/j.cyto.2023.156390

Abstract

Background: Sepsis-associated encephalopathy (SAE) is frequently present at the acute and chronic phase of sepsis, which is characterized by delirium, coma, and cognitive dysfunction. Despite the increased morbidity and mortality of SAE, the pathogenesis of SAE remains unclear. This study aims to discover the potential biomarkers, so as to clear the pathogenesis potentially contributing to the development of SAE and provide new therapeutic strategies for the treatment of SAE.

Methods: The GSE135838 dataset was obtained from the Gene Expression Omnibus (GEO) database and utilized for analysis the differentially expressed genes (DEGs). The DEGs were analyzed by limma package of R language and the extracellular protein-differentially expressed genes (EP-DEGs) were screened by the Human Protein Atlas (HPA) and UniProt database. Gene Ontology (GO) analysis and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis were carried out to analyze the function and pathway of EP-DEGs. STRING, Cytoscape, MCODE and Cytohubba were used to construct a protein-protein interaction (PPI) network and screen key EP-DEGs. Key EP-DEGs levels were detected in the cerebrospinal fluid (CSF) of SAE patients and non-sepsis patients with critical illness. ROC curve was used to evaluate the diagnostic of SAE.

Results: We screened 82 EP-DEGs from DEGs. EP-DEGs were enriched in cytokine-cytokine receptor interaction, IL-17 signaling pathway and NOD-like receptor signaling pathway. We identified 2 key extracellular proteins IL-1B and IL-8. We clinically verified that IL-6 and IL-8 levels were increased in CSF of SAE patients and CSF IL-8 (AUC = 0.882, 95 % CI = 0.775-0.988) had a higher accuracy in the diagnosis of SAE than CSF IL-6 (AUC = 0.824, 95 % CI = 0.686-0.961). Furthermore, we found that the IL-8 levels in CSF might not associated with Glasgow Coma Scale (GCS) scores of SAE patients.

Conclusion: IL-8 may be the key extracellular cytokine in the pathogenesis of SAE. Bioinformatics methods were used to explore the biomarkers of SAE and validated the results in clinical samples. Our findings indicate that the IL-8 in CSF might be the potential diagnostic biomarker and therapeutic target in SAE.

Keywords: Bioinformatics analysis; Biomarkers; Cytokines; IL-8; Sepsis-associated encephalopathy.

MeSH terms

Biomarkers
Computational Biology / methods
Gene Expression Profiling / methods
Humans
Interleukin-6
Interleukin-8
Sepsis* / complications
Sepsis-Associated Encephalopathy*

Substances

Interleukin-8
Interleukin-6
Biomarkers