Pooled analysis of 9 studies each showed significantly higher levels of ALT and AST in COVID - 19 patients with severe illness compared to patients without severe illness : mean differences ( 95 % CIs ) of 9 . 15 U / L ( 1 . 47 , 16 . 82 ; p = 0 . 02 ) and 12 . 60 U / L ( 8 . 43 , 16 . 77