Effects of ICS in patients with COPD on the clinical presentation of pulmonary tuberculosis

<bold>Background:</bold> Concerns have arisen regarding the adverse effects of inhaled corticosteroids (ICS) on pulmonary infections, including an increased risk of pneumonia and pulmonary tuberculosis (TB). It has been shown that ICS usage in chronic obstructive pulmonary disease (COPD) patients is associated with severe pneumonia. However, limited evidence exists on how ICS usage affects the severity of pulmonary TB. <bold>Objective:</bold> To determine if ICS usage in COPD patients is associated with severe pulmonary TB in terms of smear positivity and cavitation. <bold>Methods:</bold> We reviewed COPD patients diagnosed with pulmonary TB in two tertiary centres in Hong Kong from 2008 to 2021 in this retrospective cohort study. ICS users and non-users were compared in terms of clinical, radiological, and microbiological presentations. Potential risk factors for positive smear and cavitary TB were analyzed. The characteristics of ICS usage were compared between subjects with different smear and cavity statuses. <bold>Results:</bold> Two hundred and sixty six hospital admissions of pulmonary TB with underlying COPD were included. ICS usage was independently associated with smear-positive TB (AOR = 1.94, p=0.023), and a trend was observed for cavitary TB. Hypoalbuminemia was independently associated with smear positivity (AOR = 0.94 per 1 g/L drop, p<0.006) and cavitary TB (AOR = 0.94 per 1 g/L drop, p=0.018). No significant difference in mortality was found between ICS users and non-users. Subjects with cavitary TB had a longer mean duration of ICS use (63.5 months vs. 40.5 months, p<0.001). <bold>Conclusion:</bold> ICS usage adversely affected the microbiological presentation of pulmonary TB in COPD patients, specifically smear positivity.