# Lung function trajectories in children with pulmonary TB and non-TB lower respiratory tract infections

## TL;DR

The study found that children with TB or non-TB lung infections had similar declines in lung function over a year compared to healthy children.

## Contribution

This is the first study to compare lung function trajectories in children with TB and non-TB lower respiratory tract infections using longitudinal spirometry data.

## Key findings

- Children with TB had significantly lower FVC compared to healthy controls after one year.
- Both TB and non-TB LRTI groups showed decreased FEV1 and FVC compared to controls.
- Restrictive spirometry patterns were common in both symptomatic groups at follow-up.

## Abstract

This longitudinal study compared lung function in children with pulmonary TB (PTB), children with non-TB lower respiratory tract infections (LRTIs) and healthy controls.

Children aged 4–13 years presenting with presumed PTB and their healthy siblings who could perform spirometry were included. Children were classified as having TB, non-TB LRTIs after careful evaluation and during follow-up. Spirometry measurements were completed at baseline and at subsequent study visits during 52 weeks of follow-up. Measurements included forced expiratory volume in 1 second (FEV1), forced vital capacity (FVC), and FEV1/FVC using 2022 race-neutral Global Lung Initiative reference ranges.

Of 143 children, 46 had TB, 64 had non-TB LRTIs, and 33 were healthy controls. The median age was 6 years (IQR 5–9) and 10 (7%) were living with HIV. Restrictive spirometry patterns were common in both symptomatic groups at the end of follow-up, with a significantly lower FVC in children with TB compared to controls. In multivariable analysis adjusted for time and study group, FEV1 and FVC decreased for both the TB and non-TB LRTI groups, compared to healthy controls.

Lung-function trajectories were similar between children with TB and non-TB LRTI, with low FVC one-year after diagnosis.