Chitotriosidase Activity in Lung Injury Associated with Coronavirus Disease 2019 (COVID-19)

Abstract

RATIONALE: Chitotriosidase (CHIT1) is an enzyme secreted by activated macrophages. The role of CHIT1 in the pathogenesis of some pulmonary diseases such as pulmonary fibrosis, bronchial asthma, chronic obstructive pulmonary disease, pulmonary infections and pulmonary sarcoidosis was reported. The potential role of CHIT1 in Coronavirus disease 2019 (COVID-19) remains unclear. The present study aimed to determine if serum CHIT1 activity is elevated in a group of COVID-19 patients. METHODS: The single-center case-control study included 40 patients hospitalized for COVID-19 associated pneumonia confirmed by high-resolution CT and 40 non-COVID-19 patients with no signs of lung damage as a control group. We compared the serum CHIT1 activity levels between the two groups. Nonparametric Mann-Whitney U test and Spearman's ρ were used for statistical processing. RESULTS: The groups were comparable in age, sex and body mass index. The median of lung involvement percentage was 36.50% (15.0-48.0%). The median of serum CHIT1 activity level in COVID-19 patients was 42.50 U/ml (27.25-70.00) that is significantly higher than 30.00 U/ml (15.50-45.00) in the control group (U=543, p=0.013). There was no correlation between CHIT1 activity and the percentage of lung tissue damage. A moderate negative correlation between serum CHIT1 activity and the duration of illness was found (ρ=-0.502, p=0.001). CONCLUSIONS: Present study did not confirm the interrelation between the activity of CHIT1 and the severity of lung damage. Still, due to CHIT1 taking part in cytokine release syndrome, it could be an early marker of macrophage activation in COVID-19.