Plasma S-Adenosylmethionine Is Associated with Lung Injury in COVID-19.

OBJECTIVE: S-Adenosylmethionine (SAM) and S-adenosylhomocysteine (SAH) are indicators of global transmethylation and may play an important role as markers of severity of COVID-19. METHODS: The levels of plasma SAM and SAH were determined in patients admitted with COVID-19 (n = 56, mean age = 61). Lung injury was identified by computed tomography (CT) in accordance with the CT0-4 classification. RESULTS: SAM was found to be a potential marker of lung damage risk in COVID-19 patients (SAM > 80 nM; CT3,4 vs. CT 0-2: relative ratio (RR) was 3.0; p = 0.0029). SAM/SAH > 6.0 was also found to be a marker of lung injury (CT2-4 vs. CT0,1: RR = 3.47, p = 0.0004). There was a negative association between SAM and glutathione level (ρ = -0.343, p = 0.011). Interleukin-6 (IL-6) levels were associated with SAM (ρ = 0.44, p = 0.01) and SAH (ρ = 0.534, p = 0.001) levels. CONCLUSIONS: A high SAM level and high methylation index are associated with the risk of lung injury in patients with COVID-19. The association of SAM with IL-6 and glutathione indicates an important role of transmethylation in the development of cytokine imbalance and oxidative stress in patients with COVID-19.

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