One of the most critical health issues in the world is the COVID-19 pandemic from the Coronaviridae family. There is a lack of knowledge regarding the disease, and liver involvement is controversial. Objectives: We aimed to analyze the laboratory investigations of COVID-19 patients focusing on liver enzymes and association with outcomes. Methods: We enrolled 93 patients with COVID-19 referring to the Mazandaran University of Medical Sciences' hospitals and 186 people from the normal population

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... f Tabari Cohort. The laboratory tests included CBC, Aspartate Aminotransferase (AST), Alanine Aminotransferase (ALT), Alkaline Phosphatase (ALP), direct bilirubin, and total bilirubin. The lengths of hospital stay, critical care transfers, and deaths were the outcome measures investigated with lab results. Results: The counts of lymphocytes (833.3 ± 564.4 vs. 2465.1 ± 796.6 per mm 3 , P < 0.001) and platelets (209.4 ± 62.7 vs. 255.2 ± 63.8 per mm 3 , P < 0.001) were significantly lower in patients than in controls. Also, AST (39.5 ± 34.9 vs. 19.9 ± 7.5 U/L, P < 0.001), ALT (40.4 ± 46.5 vs. 21.6 ± 12.7 U/L, P < 0.001), and ALP (192.6 ± 91.2 vs. 222.2 ± 70.6 U/L, P = 0.004) were higher in patients than in controls. The most common hepatic impairment events were increased direct bilirubin (45.8%), ALT (30.3%), AST (29.2%), ALP (17%), and total bilirubin (10.2%), in sequence. The risk of transfer to intensive and critical care units was strongly associated with elevated levels of AST and direct bilirubin, and AST = 30.5 (U/L) had a sensitivity of 71.4% and specificity of 68.5% for critical and intensive care transfer. The mortality rate significantly increased with increased AST levels (P = 0.023). Conclusions: Abnormal liver enzymes are frequent in COVID-19 patients. As AST is not specific for liver damage, the systemic inflammation induced by the virus might be responsible for these findings.