Initial airflow obstruction in new cases of pulmonary tuberculosis: Complication, comorbidity or missed?

Abstract

Tuberculosis (TB) may have a similar spirometry findings as a chronic obstructive pulmonary disease but the prevalence of TB-induced airflow obstruction (AO) is still unknown. Objectives: To measure frequency of AO in new TB cases at the beginning of treatment and to evaluate factors associated with obstructive abnormalities following TB diagnosis. Materials and Methods: 317 patients that have no history of prior AO were recruited into the study with a median age of 39.0 years (IQR, 30.0–49.0). AO was defined using the FEV1/F(VC) < LLN. Results: AO was detected in 29.97% (95/317) new TB cases. These patients had a more severe clinical manifestation of TB with a greater likelihood of cough, OR = 5.47 (95%CI 1.90–15.70) and wheezing, OR = 10.51 (95%CI 5.72–19.27), p < 0.001. The frequency of AO was positively associated with bronchoscopic evidence of narrowing of the main airways. Furthermore, from multiple logistic regression analysis we would assume that higher FEV1 value in TB patients with AO was related to greater BMI and inversely associated with older age, female sex and radiographic extent (p < 0.05). Conclusions: Obstructive pattern on spirometry frequently occurs in new TB cases without previously detected AO. This category of patients should be targeted for detailed follow-up, particularly, in high TB burden countries