Impact of COVID-19 pandemic on liver, liver diseases, and liver transplantation programs in intensive care units

Table 1 Reported definitions for liver injury in coronavirus disease 2019

Term	Definition(s)
Liver disorder	Serum ALT or AST > 2 × ULN, TB > 2 × ULN, ALP ≥ 2 ULN[75]
Liver injury or acute liver injury	ALT and/or AST above 3 × ULN, ALP, GGT, and/or TB above 2 × ULN[9,34]
	ALT and/or AST ≥ 2 × ULN, with TB ≥ 2 × ULN and/or INR ≥ 1.7[70]
	ALT levels above 3 × the ULN[28]
Mild liver injury	ALT above the ULN and below 2 × the ULN[25]
Moderate liver injury	ALT between 2-5 × the ULN[25]
Severe liver injury	ALT above 5 × the ULN[25]
	Any elevation of enzymes above 3 × the ULN and bilirubin above 2 × the ULN[5]
Liver test abnormalities	Elevation of the following serum liver enzymes: ALT > 40 U/L, AST > 40 U/L, GGT > 49 U/L, ALP > 135 U/L, and TB > 17.1 μmol/L[34]
De novo LFTs abnormality	The occurrence of abnormal LFTs in patients with normal LFTs at admission[27]
LFTs elevation	Increase in serum liver enzyme levels above the ULN[27,28]
Mild LFTs elevations	Elevation 1-2 times above the ULN[25,34]
Hepatocellular or hepatocyte type	The pattern of abnormal LFTs with predominantly elevated ALT and AST[27]
	Patients with raised ALT and/or AST more than 3 × the ULN[34]
	AST/ALT activity is higher than the ALP/GGT activity, with liver enzyme activities calculated by multiples of their ULN[34]
Cholestatic or cholangiocyte type	Pattern of abnormal LFTs with predominantly elevated ALP and GGT[27]
	Patients with raised ALP or GGT 2 × the ULN[34]
	ALP/GGT activity was higher than the AST/ALT activity, with the liver enzyme activities calculated by multiples of their ULN[34]
Mixed type	Mixed pattern when the extents of AST/ALT and ALP/GGT are similar[27]
	A combination of both ALT/AST elevated more than 3 × the ULN and ALP/GGT twice the ULN[34]
Drug-induced liver injury	Any elevation in liver enzymes or TB after the initiation of the drug in the absence of identified common causes of liver disease[5]

ALT: Alanine aminotransferase; ALP: Alkaline phosphatase; AST: Aspartate aminotransferase; GGT: Gamma-glutamyl transpeptidase; INR: International normalized ratio; LFTs: Liver function tests; TB: Total bilirubin; ULN: Upper limit of normal.