Functional impact of sequelae in drug-susceptible and multidrug-resistant tuberculosis

Abstract

<b>BACKGROUND:</b> Evidence on the impact of tuberculosis (TB) treatment on lung function is scarce. The aim of this study was to evaluate post-treatment sequelae in drug-susceptible and drug-resistant-TB (DR-TB) cases in Mexico and Italy.<b>METHODS:</b> At the end of TB treatment the patients underwent complete clinical assessment, functional evaluation of respiratory mechanics, gas exchange and a 6-minute walking test. Treatment regimens (and definitions) recommended by the World Health Organization were used throughout.<b>RESULTS:</b> Of 61 patients, 65.6% had functional impairment, with obstruction in 24/61 patients (39.4%), and 78% with no bronchodilator response. These effects were more prevalent among DR-TB cases (forced expiratory volume in 1 s/forced vital capacity [FEV₁/FVC] < lower limit of normality, 14/24 vs. 10/34; <i>P</i> = 0.075). DR-TB patients showed moderately severe (FEV₁ < 60%) and severe obstruction (FEV₁ < 50%) (<i>P</i> = 0.008). Pre- and post-bronchodilator FEV₁ and FEV₁/FVC (% of predicted) were significantly lower among DR-TB cases. Plethysmography abnormalities (restriction, hyperinflation and/or air trapping) were more frequent among DR-TB cases (<i>P</i> = 0.001), along with abnormal carbon monoxide diffusing capacity (DLCO) (<i>P</i> = 0.003).<b>CONCLUSION:</b> The majority of TB patients suffer the consequences of post-treatment sequelae (of differing levels), which compromise quality of life, exercise tolerance and long-term prognosis. It is therefore important that lung function is comprehensively evaluated post-treatment to identify patient needs for future medication and pulmonary rehabilitation.