Asthma and atopy prevalence are not reduced among former tuberculosis patients compared with controls in Lima, Peru.

BACKGROUND: Although there are theoretical reasons for believing that asthma and atopy may be negatively correlated with tuberculosis, epidemiological studies have had conflicting findings. OBJECTIVE: To determine if people with confirmed tuberculosis were less likely to be atopic and less likely to have atopic disease including asthma compared to those with no previous tuberculosis. METHODS: Patients in Lima, Peru with a prior history of tuberculosis were identified from clinic records in this cohort study. A representative sample of individuals without a prior tuberculosis diagnosis was recruited from the same community. Allergen skin prick testing was performed to classify atopic status. Allergic rhinitis was identified by history. Asthma was defined by symptoms and spirometry. Eosinophilic airway inflammation was measured using exhaled nitric oxide levels. RESULTS: We evaluated 177 patients with, and 161 individuals without, previous tuberculosis. There was a lower prevalence of atopy among people with prior tuberculosis on univariate analysis (odds ratio 0.57; 95% confidence interval 0.37-0.88) but, after adjustment for potential confounders, this was no longer statistically significant (aOR 0.64, 95% CI 0.41-1.01). The prevalence of allergic rhinitis (aOR 0.76, 95% CI 0.47 to 1.24 and asthma (aOR 1.18, 95% CI 0.69 to 2.00) did not differ significantly between the two groups. We also found no significant difference in the prevalence of elevated exhaled nitric oxide (aOR 1.30, 95% CI 0.78 to 2.17) or a combined index of atopic disease (aOR 0.86, 95% CI 0.54 to 1.36). CONCLUSION: In this urban environment in a middle-income country, prior tuberculosis may be associated with a reduced risk of atopy but does not protect against asthma and atopic disease.

Chronic airflow obstruction after successful treatment of multidrug-resistant tuberculosis.

Cross-sectional studies reveal an association between tuberculosis (TB) and chronic airflow obstruction, but cannot adequately address confounding. We hypothesised that treated pulmonary TB is an independent risk factor for chronic airflow obstruction. The Pulmones Post TB cohort study enrolled participants from Lima, Peru, aged 10-70 years with a history of drug-susceptible (DS)- or multidrug-resistant (MDR)-TB who had completed treatment and were clinically cured. Unexposed participants without TB were randomly selected from the same districts. We assessed respiratory symptoms, relevant environmental exposures, and spirometric lung function pre- and post-bronchodilator. In total, 144 participants with DS-TB, 33 with MDR-TB and 161 unexposed participants were fully evaluated. Compared with unexposed participants, MDR-TB patients had lower lung volumes (adjusted mean difference in forced vital capacity -370 mL, 95% CI -644- -97) and post-bronchodilator airflow obstruction (adjusted OR 4.89, 95% CI 1.27-18.78). Participants who had recovered from DS-TB did not have lower lung volumes than unexposed participants, but were more likely to have a reduced forced expiratory volume in 1 s/forced vital capacity ratio <0.70 (adjusted OR 2.47, 95% CI 1.01-6.03). Individuals successfully treated for TB may experience long-lasting sequelae. Interventions facilitating earlier TB treatment and management of chronic respiratory disease should be explored.