The challenge of post-tuberculosis lung disease

About half of microbiologically cured TB patients experience TB-related persistent respiratory health problems or residual lung pathology, which are summarised under the term post-TB lung disease (PTLD). The development of PTLD is complex and moderated by a multitude of host, pathogen and environmental risk factors. With regards to pathogenesis, two processes are likely to be important: 1) Mycobacterium tuberculosis infection-driven tissue damage, and 2) pathological tissue remodelling following active disease. The PTLD phenotype that is currently best described in the data is obstructive airways disease in adults. Other patterns of PTLD including bronchiectasis, other (non-obstructive) lung function abnormalities, such as low forced vital capacity or impaired diffusion capacity, and patterns of secondary morbidity, such as chronic pulmonary aspergillosis and pulmonary arterial hypertension, are less well described. In the absence of robust, evidence-based management guidelines for PTLD, clinical statements suggest a set of diagnostic and therapeutic “toolboxes” which must be adapted to the local and clinical context of PTLD patients.