Although some respiratory virus infections are known to contribute to the development and exacerbation of asthma, commensal virome in airway have not been extensively studied due to technical challenges.
We investigated the characteristics of the virome in asthmatic airways.
Both the bacteriome and virome profiles in sputum from 12 healthy individuals, 15 patients with non-severe asthma, and 15 patients with severe asthma were analyzed and assessed for the association with clinical characteristics such as severity, exacerbation, Asthma Control Test (ACT), and lung function.
While analysis of the 16S rRNA bacteriome in the airway showed no differences, clear contrasts in the diversity and composition of airway virome were observed between healthy controls and patients with asthma. Herpesviruses were the most abundant type of virus in the asthma group (44.6% ± 4.6%), mainly with cytomegalovirus (CMV) and Epstein-Barr virus (EBV) accounting for 24.5% ± 3.3% and 16.9% ± 3.5% respectively in contrast to those in the healthy controls (5.4% ± 2.5% and 7.1% ± 3.0%, respectively). CMV and EBV were more abundant in asthmatics who experienced exacerbation and their abundance showed correlation with more severe asthma, lower ACT score, and lower lung function. On the contrary, bacteriophage abundant in healthy controls was severely reduced in asthma patients in the order of non-severe and severe asthma and presented significant positive correlation with ACT and FEV1/FVC.
Lung virome, especially, CMV, EBV, and bacteriophage may be potential biomarkers of asthma severity and exacerbation.