C-X-C motif chemokine ligand 8 (CXCL8)

Overview

Serum interleukin-8 (IL-8), also known as CXCL8, is a circulating chemokine measured in blood to assess systemic inflammatory activity. It is produced by a wide range of cells, including epithelial cells, endothelial cells, macrophages, and other immune-competent cells, and functions primarily as a chemoattractant and activator of neutrophils. In clinical and translational research, serum IL-8 is commonly used as a biomarker of inflammation, immune activation, tissue injury, infection, and tumor-associated inflammatory signaling.

Biologically, IL-8 is relevant because it reflects both local and systemic inflammatory states. Elevated serum IL-8 can accompany acute inflammatory syndromes, chronic inflammatory disease, cancer-associated inflammation, and treatment-related immune responses. Conversely, reduced or controlled IL-8 levels may indicate attenuation of inflammatory signaling or a favorable immunomodulatory effect. In recent studies, serum IL-8 has been used alongside other cytokines such as IL-6, TNF-α, IL-10, IFN-γ, and MCP-1 to characterize immune responses in respiratory models, cancer, cardiovascular-like hemocompatibility systems, and clinical cohorts.

Recent Publications Summary

Recent publications have continued to position C-X-C motif chemokine ligand 8 (CXCL8/IL-8) as a marker and mediator of inflammatory activation across diverse disease settings. In dry eye disease, tear proteomics identified IL-8 among inflammatory proteins altered in both aqueous-deficient and evaporative disease, and follow-up validation linked IL-8 and IL-18 expression with histone-associated NETosis-related features in tear fluid and corneal epithelial cell assays 42549839Aug. In severe community-acquired pneumonia, admission IL-8 was evaluated with sST2 for early risk stratification of guideline-consistent myocardial injury, with the combined model showing good discrimination in a prospective cohort 42532052Jul. In pediatric Mycoplasma pneumoniae pneumonia and severe traumatic brain injury, IL-8 was reported alongside other inflammatory mediators as part of broader cytokine surges associated with disease severity and early clinical dynamics 42417864Jul42360398Jun.

CXCL8 also emerged in several studies as part of inflammatory networks tied to chronic disease progression and tissue remodeling. In diabetic foot ulcer, single-cell and bulk transcriptomic integration identified senescent macrophages with a pro-inflammatory SASP and highlighted enhanced CXCL8–ACKR1 signaling as a notable intercellular communication axis toward endothelial cells 42399485Jul. In glioma radiogenomics, CXCL8 was one of seven hub genes associated with extracellular matrix remodeling and MRI-derived Rad-scores 42127900May. In Alzheimer’s disease-related network pharmacology analysis, CXCL8 was identified as a central hub gene within immune-inflammatory pathways linked to gut microbiota-derived metabolites 42406869Jul. CXCL8 was also one of the pro-inflammatory cytokines assessed in cervical cancer progression across weight categories and in diabetic retinopathy screening studies, where IL-8 rose with increasing disease severity 42049436Apr42019754Apr.

Therapeutic and mechanistic studies further implicated CXCL8-related biology in treatment response and immune cell recruitment. In pancreatic cancer models, KRAS-driven upregulation of IL-8 was described as part of an inflammatory tumor microenvironment that contributed to resistance, while blockade of CXCR2, the IL-8 receptor, helped overcome NETosis-associated resistance when combined with MEK inhibition and anti-PD-1 therapy 41855192Mar. In COVID-associated Guillain-Barré syndrome, IL-8 was confirmed as a key cytokine in cerebrospinal fluid and serum profiling, with transcriptomic data suggesting myeloid cells as potential sources 42399536Jul. In breast cancer, a single-cell multi-omics study emphasized chemokine-driven inflammatory fibroblast programs in the tumor microenvironment, providing additional context for CXCL8-linked inflammatory signaling, while other studies of breast cancer and related conditions measured IL-8 as part of systemic cytokine panels during chemotherapy or inflammation-focused profiling 42436124Jul42350900Jun.

What Changes, What Holds

1. IL-8 now looks useful as a cross-disease inflammatory readout rather than only a generic cytokine marker
NEW DIRECTION Dry-eye, pneumonia, traumatic brain injury, and pediatric infection studies extend CXCL8/IL-8 beyond the Overview’s broad inflammatory-biomarker role by tying it to tear-film NETosis features and early risk stratification in acute illness. That does not overturn its established status as a circulating inflammation marker, but it suggests greater context-specific utility and mechanistic linkage than a simple blood biomarker alone 42549839Aug42532052Jul.

2. CXCL8 is emerging as a mediator of remodeling and cell–cell signaling in chronic disease, not just a marker of inflammation
NEW DIRECTION The new work keeps the Overview intact on inflammatory activity but broadens CXCL8’s meaning by placing it in senescent macrophage signaling in diabetic foot ulcer, matrix-remodeling hub networks in glioma, and immune-inflammatory pathway analysis in Alzheimer-related models. The most substantive addition is that CXCL8 may participate in tissue remodeling and intercellular communication, not merely reflect them 42399485Jul42127900May.

3. CXCL8-linked signaling is now being used to explain treatment resistance and immune-cell trafficking, but the biomarker role still stands
NEW DIRECTION Pancreatic cancer models and COVID-associated Guillain-Barré profiling suggest CXCL8 biology may be mechanistically upstream of resistance and myeloid recruitment, while breast-cancer multi-omics continues to situate it within inflammatory stromal programs. None of this displaces the Overview’s inflammatory biomarker account; instead, it adds a more causal, therapeutic framing that remains preclinical or associative and still needs prospective validation 41855192Mar42399536Jul.

Overview update candidates: CXCL8’s role in NETosis-linked tear inflammation; its participation in senescent macrophage/intercellular signaling and tissue remodeling; and its possible mechanistic involvement in treatment resistance and myeloid recruitment.