Systematic Review and Meta-Analysis Suggested That Neutrophils Predominated the Airways of Children With the Respiratory Syncytial Virus.

AIM: The respiratory syncytial virus (RSV) is a predominant aetiology of early-life respiratory infections. This systematic review and meta-analysis compared the cell types involved in airways inflammation in children with and without RSV, noting that immune responses can influence long-term complications and may involve different inflammatory cells. METHOD: We searched for relevant studies published in English on PubMed, Embase, Google Scholar and Web of Science until 31 August 2025. Bias assessment was performed using the Joanna Briggs Institute Critical Appraisal Checklist. Heatmaps were generated and forest plots were created, with I2 values over 40% indicating heterogeneity. RESULTS: The search identified 126 studies and a quantitative meta-analysis was conducted on six studies that comprised 202 with RSV and 97 unaffected controls. Compared to the controls, children with RSV showed increased percentages of neutrophils and decreased macrophages in their bronchoalveolar lavage fluid. Forest plots revealed that the pooled standard mean differences and 95% confidence intervals for neutrophil and macrophage percentages were 2.12 (1.74 to 2.50) and -3.14 (-4.16 to -2.12), respectively. CONCLUSION: Overall, this systematic review and meta-analysis suggested that neutrophils predominated in the airways of children with RSV. This highlights the value of investigating these in future studies.