Analysis of Chitinase-3-Like Protein 1, IL-1-Alpha, and IL-6 as Novel Inflammatory Biomarkers for COVID-19

The aim of our study was to investigate the potential role of IL-1-alpha, IL-6, and chitinase 3-like protein-1 (CHI3L1) as potential biomarkers for COVID-19. Sixty adult SARS Cov-2 PCR-positive patients (22 mild, 25 moderate, and 13 severe) and 50 healthy controls were included in this study. The serum levels of CHI3L1, IL-1-alpha, and IL-6 for all study participants were measured by protein-specific ELISAs. Mean serum CHI3L1 levels in patients with severe disease (7,185.5 ± 1,109.4) were significantly higher than in the moderate (3,977.4 ± 1,260.3), mild (1,379.5 ± 598.8), and control (329.5 ± 128.4) groups (P = 0.001). There was no difference in IL-1-alpha levels between the patient and control groups (P = 0.083). IL-6 levels differed significantly, being lowest in the control group (35.9 ± 13.7), 89.1 ± 23.4 in the mild group, 156.2 ± 29.6 in the moderate group, and the highest in the severe group (214.9 ± 28.1) (P = 0.001). A strong significant correlation was found between disease severity and serum IL-6 and CHI3L1 values (r = 0.894 and r = 0.905, respectively, and P < 0.001 for both). Serum CHI3L1 and IL-6 levels exhibited a linear correlation with the clinical course of COVID-19 infection. These results indicate that inhibitors of IL-6 and/or CHI3L1 may provide useful treatments for COVID-19.