Liver-spleen axis dysfunction in COVID-19

Table 1 Main studies reporting liver involvement in patients without pre-existing liver disease

Ref.	Country	Patients	Liver involvement criteria	Patients with liver involvement, n (%)	Main findings
Fan et al[33]	China	148	ALT > 40 U/L or AST > 35 U/L	55 (37.2)	Abnormal liver function is common in COVID-19 inpatients, leading to a longer hospital stay
Goyal et al[17]	United States	375	ALT > 40 U/L	120 (32)	Mechanically ventilated patients more likely to have liver involvement.
Lenti et al[29]	Italy	100	ALT or GGT > 50 U/L	58/93 (62.4)	Liver involvement correlate to higher mortality and ICU need in those who develop ARDS
Medetalibeyoglu et al[32]	Turkey	554	ALT or AST > 40 U/L	153 (27.6)	Higher rate of moderate-to-severe pneumonia and ICU admission need in patients with liver involvement
Phipps et al[31]	United States	2273	ALT > 50 U/L	537 (24)	Severe liver involvement was rare (6.4%) and led to worse outcomes (ICU admission, higher mortality)
Ponziani et al[30]	Italy	515	AST > 45 U/I orALT > 45 U/I orGGT > 61	161 (31.3)	No cases of severe liver injury in this cohort. Liver involvement was generally mild and, although correlated to a higher need of ICU care, not associated to higher mortality
Richardson et al[7]	United States	5700	ALT > 60	2176 (39)	Acute liver injury occurred in 1% of the included patients and was associated with higher mortality
Schattenberg et al[28]	Germany	44	ALT >50 U/L	6/38 (15.8)	Severe liver involvement was rare (9%), with AST more commonly deranged than ALT

ALT: Alanine aminotransferase; ARDS: Acute severe respiratory distress syndrome; AST: Aspartate aminotransferase; COVID-19: Coronavirus disease 2019; GGT; Gamma-glutamyl transpeptidase; ICU: Intensive care unit.