Pathophysiological role of nerve growth factor (NGF) in asthma: insights into airway inflammation, remodeling, and neural regulation in intensive care settings

Background & objective: Nerve Growth Factor (NGF) plays a key role in the pathophysiology of bronchial asthma through contributing to inflammation of airway, remodeling of airway and neural regulation. This systematic review aimed for the evaluation of mechanisms that contributed to asthma and its relevance to ICU settings. Methodology: The PRISMA 2020 guidelines were followed in this review. Studies that explored NGF expression, regulation and therapeutic targeting in asthma were sought using a comprehensive search of PubMed, Scopus and Google Scholar. Study design, population, NGF measure methods, key findings, and ICU relevance were focused on data extraction. The assessment of risk of any bias was done using Evident Project Risk of Bias Tool. GRADE assessment was used for certainty of evidence. Results: Of the 10 studies included, 6 were based on animal models, 3 were based on human observational studies and the remaining one was a systematic review. Asthma patients exhibited markedly higher NGF levels than control subjects (mean: 3.45 ± 0.76 pg/mL). Eosinophilic counts (r = 0.74, P < 0.01) and inflammatory cytokines correlated in positive with NGF. Airway inflammation decreased by 45.2% (P = 0.002), and airway remodeling by 32% (P = 0.004) via anti-NGF therapy. Similar results were observed by vitamin D supplementation that caused NGF downregulation by 41% (P = 0.003) via the Nrf2/HO-1 pathway. Risk of bias assessment showed that four studies were classified as low risk, five as moderate, and one as high. Conclusion: NGF was significantly stimulated in asthma and contributed to inflammation, reformation and neuroimmune interactions. The correlation of NGF with severe exacerbations and ICU outcomes suggested its potential as a biomarker for therapeutic target. However large scale and long-term evaluation of NGF against asthma was required. Future studies should validate the role of NGF in asthma management particularly in ICU settings. Abbreviations: NGF: Nerve Growth Factor, ICU: Intensive Care Unit, BALF: Bronchoalveolar Lavage Fluid, AHR: Airway Hyperresponsiveness, IL-6: Interleukin-6, IL-1β: Interleukin-1 Beta, CRP: C-Reactive Protein, TRPV1: Transient Receptor Potential Vanilloid 1, Nrf2: Nuclear factor erythroid 2-related factor 2, HO-1: Heme Oxygenase-1, ELISA: Enzyme-Linked Immunosorbent Assay, RT-qPCR: Reverse Transcription Quantitative Polymerase Chain Reaction, GRADE: Grading of Recommendations, Assessment, Development, and Evaluations, PRISMA Preferred Reporting Items for Systematic Reviews and Meta-Analyses, RSV: Respiratory Syncytial Virus, OVA: Ovalbumin, RhoA: Ras homolog family member A, PM: Particulate Matter Keywords: Nerve Growth Factor; Asthma; Airway Remodeling; Inflammation; Neuroimmunomodulation; Intensive Care Units; Critical Care; Biomarkers Citation: Bukhari AAS, Shaikh ARK, Salman W, Bhatti FA, Malik W, Minhas M, Muddasser A, Khaliq H. Pathophysiological role of nerve growth factor (NGF) in asthma: insights into airway inflammation, remodeling, and neural regulation in intensive care settings. Anaesth. pain intensive care 2025;29(3):681-689. DOI: 10.35975/apic.v29i3.2778 Received: February 03, 2025; Revised: February 28, 2025; Accepted: March 05, 2025