Association of tuberculosis infection with asthma in a european multinational cohort

Abstract

<b>Background:</b> Tuberculosis (TB) infection induces profound systemic immunological and inflammatory changes that could increase the risk of respiratory morbidity and mortality. The association with asthma is only partly understood. <b>Objective:</b> To study the association of TB with asthma in Nordic population samples. <b>Methods:</b> This is a preliminary analyses of the first data from the fourth follow-up of the Respiratory Health in Northern Europe (RHINE) IV, from five centers (Bergen, Reykjavik, Umea, Uppsala and Gothenburg). Data was obtained by using a standardized questionnaire where participants provided information on whether they have or ever had TB, asthma and asthma-like symptoms. Asthma symptoms score was defined from 0 to 8, based on 8 self-reported symptoms. In addition, allergic asthma was defined as a positive answer to a question on nasal allergy (including hay fever) in addition to having asthma. Similarly,&nbsp;non-allergic asthma was defined as having asthma but not nasal allergy. The associations were analyzed using logistic regression models adjusted for age, sex and BMI. <b>Results:</b> Out of 3,675 participants, 3,224 had full information on TB, asthma and asthma-like symptoms. Of these 24 had TB and among them 13 had either asthma or asthma symptoms score of ≥ 3. There was a significant association between asthma and TB (OR 3.71, 95%CI 1.61-8.55). This was mainly due to an association with non-allergic asthma (OR=4.96, 95%CI 2.1-11.4). We did not observe a significant association between allergic asthma and TB. <b>Conclusion:</b> Our study showed that TB infection was associated with asthma, in particular non-allergic asthma. Longitudinal analyses are needed to further explore these results.