Prevalence of liver injury in patients with coronavirus disease 2019 (COVID-19) : a systematic review and meta-analysis

Background and study aims : The coronavirus disease 2019 (COVID-19) represents a public health emergency of international concern, causing thousands of deaths worldwide. We performed a systematic review with meta-analysis in order to investigate the prevalence of COVID-19-induced liver injury. Patients and methods : We searched MEDLINE, Scopus, Web of Science and the Cochrane Library, for studies reporting laboratory data about COVID-19 patients, with last update on 25th March 2020. The primary outcome was the pooled prevalence of COVID-19-induced liver damage, mainly represented by increase in serum transaminases and bilirubin. The secondary outcome was the description of abnormalities in serum albumin and prothrombin time (PT). We focused on laboratory data only on hospital admission, and adopted random-effects model for meta-analysis. Results : Eleven studies were eligible for meta-analysis. Out of 793 included patients, the pooled prevalence of COVID-19-related liver damage was 22.17% (95% CI 17.64 to 27.07), mostly indicated by hypertransaminasemia. Serum bilirubin was increased in 5.53% (95% CI 3.60 to 7.85) of cases. Abnormal serum albumin was observed in 78.92% (95% CI 39.82 to 99.56), and increased PT value in 19.98% (95% CI 2.49 to 78.23), but these results derived from significantly heterogeneous studies. Conclusions : COVID-19-induced liver injury must not be ignored, as it is observed in one fifth of infected patients. Prospective studies evaluating liver function during the course of COVID-19 are needed to provide a complete overview of hepatic involvement during this viral infection.