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.