# Clinical features of Tropheryma Whipplei in pediatric pneumonia: an mNGS and tNGS-based case-control study

## TL;DR

This study explores how Tropheryma whipplei affects children with pneumonia, finding that it may not be a main cause of the disease.

## Contribution

The study identifies TW-positive pediatric pneumonia as having milder symptoms, suggesting TW may act as a colonizer rather than a primary pathogen.

## Key findings

- TW-positive patients were younger, had lower BMIs, and showed milder inflammation compared to controls.
- Severe TW-positive cases had localized right-lung lesions and more bronchial involvement.
- TW-positive pediatric pneumonia was frequently associated with co-detections of Mycoplasma pneumoniae and other pathogens.

## Abstract

Tropheryma whipplei (TW), which causes Whipple disease, has recently been associated with respiratory diseases, particularly pneumonia. To understand its role in pediatric pneumonia, this study analyzed the clinical and pathogenetic characteristics of TW in pediatric pneumonia patients.

We utilized metagenomic and targeted next-generation sequencing (mNGS/tNGS) data from 3,759 pediatric bronchoalveolar lavage fluid (BALF) samples (2023-2024). This case-control study included 103 TW-positive pediatric pneumonia patients (59 with severe pneumonia, SPTW+; 44 with mild pneumonia, MPTW+), along with 206 TW-negative pneumonia patients as controls (118 with severe pneumonia, SPTW-; 88 with mild pneumonia, MPTW-).

Through inter-group comparisons, the results showed that TW-positive patients were younger and had lower BMIs than controls, with shorter hospital stays and milder inflammation. Severe TW-positive cases showed more localized right-lung lesions, less pleural effusion, and more bronchial involvement. Mycoplasma pneumoniae co-detection was frequent (86.4%), along with Moraxella catarrhalis, human bocavirus type 1, and rhinovirus A.

TW-positive pediatric pneumonia presents with milder symptoms, suggesting that TW may act as a colonizer rather than a primary pathogen. Consequently, antimicrobial treatment specifically targeting TW may not be immediately warranted at detection. These results provide important insight for the individualized treatment of pediatric pneumonia with TW positive.