Risk Factors and Biomarkers for Post-tuberculosis Lung Damage

Risk Factors and Biomarkers for Post-tuberculosis Lung Damage in a Chinese Cohort: Protocol for a Prospective Observational Study

This prospective study aims to determine the incidence of Post-tuberculosis lung damage (PTLD), examine trends in the changes in lung function, and investigate the impact of smoking and other factors on respiratory symptoms, lung function, and chest CT findings, which will aid in the development of prognostic and therapeutic strategies for PTLD.

Introduction: Post-tuberculosis lung damage (PTLD) refers to residual pulmonary impairment following the completion of tuberculosis (TB) treatment, characterized by persistent respiratory symptoms and abnormal pulmonary function. The risk factors and biomarkers for PTLD have been scarcely investigated. Additionally, it remains unclear whether and to what extent cigarette smoking affects PTLD in patients with TB.

Methods and analysis: This prospective observational study will enroll 400 adult male ever-smoker or never-smoker patients aged 25-60 years, with newly confirmed active TB between 2022 and 2024 from the Department of Respiratory and Critical Care Medicine at Peking University Third Hospital and the Tuberculosis Department at Beijing Geriatric Hospital. Baseline data (age, smoking history, and smoking pack-years), clinical symptoms, lung functions, and chest CT (computed tomography) findings will be prospectively collected. Respiratory questionnaires, lung function measurements, and chest CT examinations will be completed during follow-up visits at 6 months after the initiation of TB treatment, immediately at the completion of TB treatment, and at 1 year, 2 years, and 3 years after the completion of TB treatment. Peripheral blood samples will be obtained at baseline to measure inflammatory mediators and cytokines in serum. The collected data will be analyzed to determine the incidence of and factors/biomarkers for PTLD after TB treatment.

Inclusion Criteria:

Male patients aged 25-60 years newly diagnosed with active pulmonary TB.

Exclusion Criteria:

1. patients with positive sputum smear or TB culture results;
2. human immunodeficiency virus-positive patients;
3. patients infected with multidrug-resistant TB;
4. patients with malignant neoplasms (e.g., lung cancer) or severe cardiovascular and cerebrovascular diseases;
5. non-compliant patients who were unable to complete the lung function tests;
6. patients without lung parenchymal destruction (such as tuberculous pleurisy). -