Association of Low Molecular Weight Plasma Aminothiols with the Severity of Coronavirus Disease 2019

Abstract

Objective. Aminothiols (glutathione (GSH), cysteinylglycine (CG)) may play an important role in the pathogenesis of coronavirus disease 2019 (COVID-19), but the possible association of these indicators with the severity of COVID-19 has not yet been investigated. Methods. The total content ( $t$ ) and reduced forms ( $r$ ) of aminothiols were determined in patients with COVID-19 ( $n=59$ ) on admission. Lung injury was characterized by computed tomography (CT) findings in accordance with the CT0-4 classification. Results. Low tGSH level was associated with the risk of severe COVID-19 ( $\text{tGSH}\le 1.5\mu \text{M}$ , mild vs. moderate/severe: $\text{risk}\text{ratio}\left(\text{RR}\right)=3.09$ , $p=0.007$ ) and degree of lung damage ( $\text{tGSH}\le 1.8\mu \text{M}$ , $\text{CT}<2$ vs. $\text{CT}\ge 2$ : $\text{RR}=2.14$ , $p=0.0094$ ). The rGSH level showed a negative association with D-dimer levels ( $\rho =-0.599$ , $p=0.014$ ). Low rCG level was also associated with the risk of lung damage ( $\text{rCG}\le 1.3\mu \text{M}$ , $\text{CT}<2$ vs. $\text{CT}\ge 2$ : $\text{RR}=2.28$ , $p=0.001$ ). Levels of rCG ( $\rho =-0.339$ , $p=0.012$ ) and especially tCG ( $\rho =-0.551$ , $p=0.004$ ) were negatively associated with platelet count. In addition, a significant relationship was found between the advanced oxidation protein product level and tGSH in patients with moderate or severe but not in patients with mild COVID-19. Conclusion. Thus, tGSH and rCG can be seen as potential markers for the risk of severe COVID-19. GSH appears to be an important factor to oxidative damage prevention as infection progresses. This suggests the potential clinical efficacy of correcting glutathione metabolism as an adjunct therapy for COVID-19.