Tuberculosis (TB) is a formidable global health issue, claiming 1.6 million lives annually. While the burden is most pronounced in sub-Saharan Africa and South East Asia, even countries with low TB incidence, such as the UK, are witnessing an uptick in diagnoses. In 2023, England reported 4,850 new TB diagnoses, representing a 10% increase from the previous year, according to provisional data from the UK Health Security Agency.
Although treatment for drug-susceptible pulmonary tuberculosis is highly effective, a concerning aspect is emerging: up to 94% of cured patients develop permanent lung damage and scarring, known as fibrosis. To delve deeper into this issue, Dr Sharenja Ratnakumar led a systematic review and meta-analysis focused on post-tuberculosis lung impairment. The study analysed data from 75,631 individuals across 15 studies conducted in 17 countries with varying tuberculosis incidence rates and income levels. Supported by Breathing Matters, the findings revealed that participants with prior TB had significantly lower lung function results compared to healthy controls.
Specifically, TB survivors exhibited:
- Smaller lungs (restrictive disease).
- Narrower airways with slower airflow (obstructive disease).
These physiological changes translate to smaller breaths that take longer to exhale, rendering breathing less efficient. Consequently, tuberculosis survivors may experience breathlessness, impacting their ability to work and carry out daily activities, ultimately diminishing their quality of life.
Being presented at this year’s ESCMID Global Congress in Barcelona, Spain, this research underscores the under-recognised global challenge posed by post-TB lung disease. With approximately 155 million people alive today due to successful TB treatment, addressing this issue becomes paramount.
When someone contracts tuberculosis, their immune system activates to fight the infection. Dr Ratnakumar is researching the underlying mechanisms of this fibrotic lung damage. She is focussing on a cellular network involving immune and lung cells. Specifically, she is interested in an enzyme called Phosphodiesterase-4 (PDE4), which plays a role in regulating immune responses during TB infection. By understanding these pathways, her work aims to find potential therapies that could reduce the risk of lung fibrosis (scarring) in TB survivors.
[Posted April 2024]