Exhaled Breath Condensate and Pulmonary Sequela in Children Post COVID-19

Introduction: SARS-CoV-2 presents as an acute respiratory illness. A substantial proportion of adults experience persistent respiratory symptoms, while there is a lack of data on pulmonary sequela in children after acute COVID-19. Exhaled Breath Condensate (EBC) is a noninvasive tool allowing collection of condensate originating in airway epithelial lining fluid, contains substances from small-and medium-sized airways, which can be assessed for inflammatory and oxidative stress biomarkers.

Aim: To evaluate EBC parameters and lung function in children post COVID-19 infection.

Methods: We contacted 612 COVID-19 PCR positive cases, age 5-18 years between 07/2020-04/2021 using data from Clalit Health services, offering a pulmonary assessment. 60 children arrived 1-6 months post positive COVID-19 PCR, and were categorized retrospectively into 3 disease severity classes. The evaluation included medical history, mental and physical activity questioners as well as spirometry, 6MWD, and EBC sampling (pH and IL-6 levels).

Results: 58 children were grouped to asymptomatic, mild, and moderate disease (n=14;37;7, respectively). Notably, the asymptomatic group was younger than the other groups (p=0.001). There was a trend towards increased disease severity classification in children with a history of exertional dyspnea [asymptomatic 0, mild 5%, moderate 29%] and past ICS use [asymptomatic 0, mild 22%, moderate 29%]. We found no difference between the 3 groups regarding EBC (pH, IL-6), 6MWD, PFT, and total activity score.

Conclusions: COVID-19 is mostly asymptomatic-mild in children. No significant pulmonary sequela was noticed by EBC markers, spirometry, 6MWD, and physical activity score. This data is of importance for post-COVID-19 pulmonology surveillance in children.