Circulating miR-19a-3p Distinguishes Severe Pediatric Pneumonia by Regulating Cellular MXD1

Circulating levels of miR-19a-3p were significantly elevated in pediatric patients with severe pneumonia and effectively distinguished severe from non-severe cases with a receiver operating characteristic area under the curve of 0.894. In the clinical cohort, researchers quantified circulating miR-19a-3p expression using reverse transcription-quantitative polymerase chain reaction across 108 children with severe pneumonia and 96 children with non-severe pneumonia. Multivariate regression analysis identified both elevated miR-19a-3p levels and D-dimer as independent risk factors associated with severe pneumonia in pediatric patients.

Dual-luciferase reporter assays validated the MXD1 gene as a direct downstream binding target of miR-19a-3p. Analysis of patient blood samples demonstrated that MXD1 expression correlated negatively with miR-19a-3p levels, with a correlation coefficient of r = -0.685. To investigate the underlying cellular mechanism, investigators evaluated the effects of manipulating miR-19a-3p expression in lipopolysaccharide-stimulated BEAS-2B human airway epithelial cells.

In the cell culture experiments, blocking miR-19a-3p alleviated inflammatory responses, reduced malondialdehyde content, increased superoxide dismutase activity, and improved cell viability following lipopolysaccharide exposure. Co-transfection experiments with small interfering RNA targeting MXD1 partially offset these protective cellular effects, indicating that miR-19a-3p drives inflammatory responses and oxidative injury in airway epithelial cells largely through the suppression of MXD1.

The study authors concluded that upregulated miR-19a-3p demonstrates strong discrimination between severe and non-severe pneumonia in children, supporting its potential value as a non-invasive biomarker for disease severity. Because mechanistic investigations were conducted in cultured airway epithelial cell models, the findings identify the miR-19a-3p and MXD1 regulatory axis as a candidate for therapeutic targeting rather than an established clinical treatment.

Subject of Research: Circulating miR-19a-3p and MXD1 as severity biomarkers and cellular mediators in pediatric pneumonia

Article Title: miR-19a-3p as a biomarker for distinguishing severe pneumonia in children by targeting MXD1

Article References: Dang, S., Hou, Y., Ji, L., Gao, J., & Xu, J. (2026). miR-19a-3p as a biomarker for distinguishing severe pneumonia in children by targeting MXD1. BMC Immunology. https://doi.org/10.1186/s12865-026-00931-8

Image Credits: AI Generated

DOI: 10.1186/s12865-026-00931-8

Keywords: pediatric pneumonia, severe pneumonia, miR-19a-3p, MXD1, biomarkers, BEAS-2B cells, airway epithelial cells, oxidative stress, biomarker, distinguishing, severe, pneumonia