# Diagnostic and therapeutic journey of infantile endobronchial tuberculosis: a case report

## TL;DR

A rare case of infantile endobronchial tuberculosis with immunodeficiency and coinfection was successfully treated with a combination of therapies and bronchoscopic interventions.

## Contribution

This case report highlights the first documented coexistence of infantile EBTB, IKZF1-related immunodeficiency, and P. jirovecii coinfection.

## Key findings

- Serial bronchoscopies confirmed necrotizing endobronchial tuberculosis with airway stenosis.
- The patient achieved clinical and radiological remission with no airway sequelae after 18 months.
- Repeated intraluminal bronchoscopic therapy combined with systemic treatment prevented irreversible airway damage.

## Abstract

Endobronchial tuberculosis (EBTB) in infants is rare and is often overlooked because of nonspecific clinical manifestations. Coexisting primary immunodeficiency and opportunistic infections further increased diagnostic and therapeutic complexity.

We reported a male infant aged 40 days who presented with fever and mild cough. Chest imaging showed progressive bilateral nodular and granulomatous lesions despite broad-spectrum antibacterial therapy. Microbiological evaluation revealed positive T-SPOT.TB and GeneXpert MTB/RIF results from bronchoalveolar lavage fluid (BALF), while metagenomic next-generation sequencing identified Pneumocystis jirovecii. Genetic testing demonstrated a heterozygous IKZF1 mutation, consistent with underlying immunodeficiency. Serial bronchoscopies confirmed necrotizing endobronchial tuberculosis with airway stenosis. The patient received standard anti-tuberculosis therapy, systemic corticosteroids, trimethoprim–sulfamethoxazole, intravenous immunoglobulin, and repeated bronchoscopic intraluminal drug delivery. Clinical and radiological remission was achieved, with no airway sequelae during 18-month follow-up.

This case highlighted the unique coexistence of infantile EBTB, IKZF1-related immunodeficiency, and P. jirovecii coinfection. Early bronchoscopy played a pivotal diagnostic and therapeutic role. Repeated intraluminal bronchoscopic therapy combined with systemic treatment might prevent irreversible airway damage in severe pediatric EBTB.