# Plasma nontargeted metabolomics study of H1N1 and H3N2 influenza in children

## TL;DR

This study identifies specific metabolites in children's blood that could help detect and monitor H1N1 and H3N2 influenza early.

## Contribution

The study reveals distinct glycerophospholipid metabolomic profiles associated with H1N1 and H3N2 influenza in children.

## Key findings

- H1N1 influenza is linked to 14 altered glycerophospholipid metabolites, 11 of which are downregulated and correlate with inflammatory markers.
- H3N2 influenza shows 12 altered glycerophospholipid metabolites, with some correlating to liver function and inflammatory markers.
- Distinct metabolomic profiles in H1N1 and H3N2 suggest potential biomarkers for early diagnosis and disease monitoring.

## Abstract

This study used a nontargeted metabolomic approach to investigate small molecular metabolites in the peripheral blood of pediatric patients with influenza. By comparing these metabolites with those in healthy children, potential biomarkers for the early detection and diagnosis of influenza were explored.

Plasma samples were collected from 47 children with H1N1 influenza, 40 with H3N2 influenza, and 40 healthy controls at Xi’an Children’s Hospital, Xi’an Jiaotong University Second Affiliated Hospital, and Xi’an Central Hospital between May and September 2023. Nontargeted metabolomic detection and analysis were performed.

In the H1N1 group, 14 glycerophospholipid metabolites were significantly altered compared to controls, with 11 (78.5%) markedly downregulated. These downregulated metabolites showed negative correlations with inflammatory markers, including white blood cell (WBC) count, neutrophils, C-reactive protein (CRP), and Procalcitonin (PCT), whereas the upregulated metabolite PC(P-18:1(9Z)/16:0) showed positive correlations with validation markers. In the H3N2 group, 12 glycerophospholipid metabolites were significantly altered, with 9 being downregulated. The downregulated LysoPC(20:0/0:0) showed a positive correlation with alanine aminotransferase (ALT) but a negative correlation with WBC count, while the upregulated metabolite LysoPA(18:1(9Z)0:0) correlated positively with ALT, aspartate aminotransferase (AST), and lactate dehydrogenase (LDH).

Distinct metabolomic profiles were identified in pediatric H1N1 and H3N2 influenza cases compared to healthy controls. Specific glycerophospholipid metabolites were closely associated with inflammatory and liver function markers, highlighting their potential as biomarkers for disease monitoring and early diagnosis.