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.