GPT and COVID-19: We found a significant association of COVID-19 severity with increased levels of ALT [SMD: 1.40 U/L; 95% CI (0.93, 1.88); P < 0.05, I2 = 96.5%, PHeterogenity = 0.000 ], AST [SMD: 2.11 U/L; 95% CI (1.40, 2.83); P < 0.05, I2 = 97.9%, PHeterogenity = 0.000], LDH [SMD: 3.88 U/L; 95% CI (2.70, 5); P < 0.05, I2 = 98.7%, PHeterogenity = 0.000] and TBil [SMD: 1.08 mol/L; 95% CI (0.44, 1.72); P = 0.001, I2 = 97.7, PHeterogenity = 0.000], whereas, ALP values [SMD: 0.31; 95% CI (-1.57, 2.20); P = 0.74] was not significant between severe and non-severe COVID-19 patients.