Pathogenesis of Post-Tuberculosis Lung Disease: Defining Knowledge Gaps and Research Priorities at the 2nd International Post-Tuberculosis Symposium

Post-tuberculosis (TB) lung disease (PTLD) is increasingly recognized as a major contributor to the global burden of chronic lung disease, with recent estimates indicating that over half of TB survivors have impaired lung function after successful completion of TB treatment. However, the pathologic mechanisms that contribute to PTLD are not well understood, thus limiting the development of therapeutic interventions to improve long-term outcomes after TB. This report summarizes the work of the "Pathogenesis and Risk Factors Committee" for the Second International Post-Tuberculosis Symposium, which took place in Stellenbosch, South Africa in April 2023. The committee first identified six areas with high translational potential: (1) tissue matrix destruction, including the role of matrix metalloproteinase dysregulation and neutrophil activity, (2) fibroblasts and profibrotic activity, (3) granuloma fate and cell death pathways, (4) mycobacterial factors including pathogen burden, (5) animal models, and (6) the impact of key clinical risk factors including HIV, diabetes, smoking, malnutrition, and alcohol. We share here the key findings from a literature review of those areas, highlighting knowledge gaps and areas where further research is needed.