Late Breaking Abstract - The high prevalence and load of Epstein-Barr virus in adults with bronchiectasis: A prospective cohort study

<b>Background:</b> Epstein-Barr virus (EBV) is prevalent and has been implicated in chronic obstructive pulmonary disease and idiopathic pulmonary fibrosis. However, the roles of EBV in adults with bronchiectasis are unclear. We aimed to delineate the association between EBV infection and bronchiectasis. <b>Methods:</b> We recruited 108 bronchiectasis patients and 18 healthy controls. We collected sputum for EBV detection during follow-up, with an interval of every 3 to 6 months, and at bronchiectasis exacerbation. <b>Results:</b> We collected 442 sputum specimens from 108 patients. The Bronchiectasis patients yielded significantly higher detection rate of EBV when remaining clinically stable (48.1% vs. 22.2%, P=0.040), but not the load (mean Log10load: 4.47 vs. 5.00, P=0.270), compared with controls. EBV was consistently detected in bronchiectasis, with 71.5% of patients having identical detection status in two consecutive stable visits. There was no substantial difference in detection rate (40.8% vs. 48.1%, P=0.393) and load (mean Log10load: 4.34 vs. 4.47, P=0.270) at exacerbation compared with stable visits. Both EBV detection rate and load varied slightly at different time points throughout the course of exacerbation. Neither the infection status nor the viral load correlated with bronchiectasis severity. EBV load correlated negatively with sputum inflammatory biomarker levels (all P&lt;0·05). Patients tested positive to, or colonized with, EBV had faster lung function decline and shorter time to next exacerbation (both P&lt;0·05) than those without. EBV infection was unrelated to other pathogens. <b>Conclusion:</b> EBV might have partially contributed to the progression of bronchiectasis.