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

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 () and reduced forms () of aminothiols were determined in patients with COVID-19 ( = 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 (tGSH ≤ 1.5 M, mild vs. moderate/severe: risk ratio (RR) = 3.09, = 0.007) and degree of lung damage (tGSH ≤ 1.8 M, CT < 2 vs. CT ≥ 2: RR = 2.14, = 0.0094). The rGSH level showed a negative association with D-dimer levels ( = -0.599, = 0.014). Low rCG level was also associated with the risk of lung damage (rCG ≤ 1.3 M, CT < 2 vs. CT ≥ 2: RR = 2.28, = 0.001). Levels of rCG ( = -0.339, = 0.012) and especially tCG ( = -0.551, = 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.