Non-cystic fibrosis bronchiectasis and calcifications: are IGRAs of any use?

Abstract

Introduction: Tuberculosis (TB) is known as a leading cause of non-CF bronchiectasis in high burden TB settings. However, the finding of pulmonary sequelae suggestive for past-TB is not always associated with a positive history for tuberculosis episode. QFT-TB GOLD could reflect the past history of pulmonary TB. Aim: To evaluate the prevalence of IGRAs positive test among patients with non-CF bronchiectasis patients, calcifications and no history of TB treatment. Material and methods: 34 enrolled patients (mean age 56.6 years, 53% females) with non-CF bronchiectasis and calcifications were tested with QFT-TB Gold (results were reported as positive, negative, indeterminate). High-resolution computed tomography images (HRCT) were analyzed to appreciate the type and extent of bronchiectasis and the presence of calcifications in chest and abdominal organs. Results: Severe bronchiectasis was identified in 20 patients with a BSI score ≥9 points, 68% (23 cases) demonstrating cystic bronchiectasis at least in one lobe. The modified Reiff score was 7.9±4.1 (1-14), and the more detailed Bhalla score was 12.8±4 (5-19). The most frequent localization of the calcifications was in the lung parenchyma 27 cases (76%) and bronchial wall 25 cases (74%), followed by calcification of lymph nodes 50% and pleural calcifications 32%. Eight patients (24%) had positive QFT-TB Gold test result at study enrollment. After a one year follow up, only one of the QFT positive patients developed active smear positive pulmonary TB (by the 6th month). Conclusions: Presence of calcification on HRCT in patients with non-CF bronchiectasis has a poor correlation with positive latent tuberculosis infection status.