key: cord-283120-hyzk59qv
authors: Sharma, Ashish; Jaiswal, Pragya; Kerakhan, Yasameen; Saravanan, Lakshmi; Murtaza, Zeba; Zergham, Azka; Honganur, Nagaraj-Sanchitha; Akbar, Aelia; Deol, Aran; Francis, Benedict; Patel, Shakumar; Mehta, Deep; Jaiswal, Richa; Singh, Jagmeet; Patel, Urvish; Malik, Preeti
title: Liver disease and outcomes among COVID-19 hospitalized patients- a systematic review and meta-analysis
date: 2020-10-16
journal: Ann Hepatol
DOI: 10.1016/j.aohep.2020.10.001
sha: 
doc_id: 283120
cord_uid: hyzk59qv

INTRODUCTION AND OBJECTIVES: The coronavirus disease 2019 (COVID-19) pandemic has been a challenge globally. In severe acute respiratory syndrome (SARS) epidemic 60% of patients had hepatic injury, due to phylogenetic similarities of the viruses it is assumed that COVID-19 is associated with acute liver injury. In this meta-analysis, we aim to study the occurrence and association of liver injury, comorbid liver disease and elevated liver enzymes in COVID-19 confirmed hospitalizations with outcomes. MATERIALS AND METHODS: Data from observational studies describing comorbid chronic liver disease, acute liver injury, elevated aspartate aminotransferase (AST), alanine aminotransferase (ALT) levels and outcomes of COVID-19 hospitalized patients from December 1, 2019, to June 30, 2020 was extracted following PRISMA guidelines. Adverse outcomes were defined as admission to intensive care unit (ICU), oxygen saturation <90%, invasive mechanical ventilation (IMV), severe disease and in-hospital mortality. Odds ratio (OR) and 95% confidence interval (95%CI) were obtained. RESULTS: 24 studies with 12882 confirmed COVID-19 patients were included. Overall prevalence of CM-CLD was 2.6%, COVID-19-ALI was 26.5%, elevated AST was 41.1% and elevated ALT was 29.1%. CM-CLD had no significant association with poor outcomes (pooledOR:0.96;95%CI:0.71–1.29; p = 0.78). COVID-19-ALI (1.68;1.04–2.70; p = 0.03), elevated AST (2.98;2.35–3.77; p < 0.00001) and elevated ALT (1.85;1.49–2.29; p < 0.00001) were significantly associated with higher odds of poor outcomes. CONCLUSION: Our meta-analysis suggests that acute liver injury and elevated liver enzymes were significantly associated with COVID-19 severity. Future studies should evaluate changing levels of biomarkers amongst liver disease patients to predict poor outcomes of COVID-19 and causes of liver injury during COVID-19 infection.

The WHO declared coronavirus disease 2019 (COVID-19) as a global pandemic on March 11, 2020 (1) .

With approximately 5 million cases and over 160,220 deaths, the USA remains the worst affected country as of August 8, 2020 (2) . Following this, India (4.3M), Brazil (4.1M), and Russia (1M), are among the other countries that are greatly affected. Total cases worldwide are around 27 million, and thus it remains an emergency of international concern (3).

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV2) mainly affects the respiratory system but as we are gaining more insight about this novel disease, many published studies have also provided evidence of its organotropism and multisystem organ inflammation nature (4, 5) . Multiple studies have observed association of elevated liver enzymes in patients with COVID-19 infection assuming that it can cause liver damage either via direct hepatotoxic injury with viral infection, or drug toxicity, or immune mediated response. In the past, it has been reported that 60% of patients developed liver damage due to the SARS epidemic (6) . Since SARS-CoV-2 belongs to the same coronavirus family, we assume it may cause liver injury. The biliary epithelium has expression of angiotensinconverting enzyme (ACE-2) receptor, which is also the binding site of SARS-CoV-2 (7) . The ACE2 receptor expression in hepatocytes has been shown to be upregulated in animals' models of liver injury but hepatocytes have lower expression in humans (8, 9) . (10) . Hence, we aim to systematically study the occurrence of liver injury, comorbid liver disease and elevated liver enzymes in COVID-19 confirmed hospitalizations and also identify their association with outcomes.

J o u r n a l P r e -p r o o f

The aim of the study is to evaluate the role of the comorbid chronic liver disease (CM-CLD), elevated liver enzymes and COVID-19 associated acute liver injury (COVID-19 ALI) in predicting the outcomes in confirmed COVID-19 hospitalized patients. COVID-19 confirmation was evaluated by combined findings of RT-PCR, serology, symptoms, and MRI chest in majority of those studies. Poor outcomes were defined by intensive care unit (ICU) admission, oxygen saturation<90%, invasive mechanical ventilation (IMV) utilization, severe disease, and in-hospital mortality. Study-specific poor outcomes and definitions of CM-CLD, COVID-19 ALI and cut-off levels of liver enzymes in each individual study are mentioned in Table 1 .

A systematic search was conducted on published studies using PRISMA guidelines (11) Abstracts were reviewed, and articles were retrieved and reviewed for availability of data on comorbid liver disease, elevated liver enzymes, acute liver injury and outcomes of COVID-19 patients. Studies which gave details on outcomes were selected for quantitative analysis. PM and DM independently screened all identified studies and assessed full-texts to decide eligibility. Any disagreement was resolved through discussion with another reviewer UP.

From the included studies, we extracted the following variables including comorbid liver disease, elevated AST and ALT levels, acute liver injury and outcomes. Details on binary outcomes like ICU vs.

non-ICU admission, severe vs non-severe disease, IMV vs no-IMV use, oxygen saturation <90% vs >90%, in-hospital mortality vs discharged alive and survivors were collected using prespecified data collection forms by two authors (PM and DM) with a common consensus of author (UP) upon disagreement. We have presented the study characteristics like the first author's last name, publication month and year, country of origin, sample size, mean or median age, males, outcomes and definitions of comorbid liver disease and acute liver injury and cut offs for elevated AST and ALT levels assessed in that individual study in Table 1 (References for the studies are in Supplemental file 1.1).

Data analysis was performed using Review Manager version 5.3 (The Nordic Cochrane Centre, The Cochrane Collaboration, Copenhagen, Denmark). If the study has more than one outcome comparison J o u r n a l P r e -p r o o f then we have used data from the most severe outcome in the analysis to minimize the overall selection bias of our study.

The Maentel-Haenszel formula was used to calculate dichotomous variables to obtain odds ratios (ORs) along with its 95% confidence intervals to describe the association of comorbid liver disease, elevated liver enzymes, acute liver injury and outcomes of COVID-19 patients in each study. Random-effect models were used regardless of heterogeneity to estimate the combined effect and its precision, to give a more conservative estimate of the ORs and 95%CI. The I² statistic was used to assess statistical heterogeneity and I² >50% was considered significant heterogeneity. The p<0.05 was considered significant. Publication bias was assessed visually using funnel plots and the Newcastle-Ottawa Scale (NOS). Newcastle Ottawa Scale (NOS) (13) was used to assess the quality and bias in the included studies, which rates selection, comparability and outcome (Supplemental file1.2) . All studies were assessed to be of high quality.

The pooled OR and 95% CI are represented in the form of forest plots. Each square on the chart area represents individual study and the area of each square is equivalent to the weight of the study, which is the inverse of the study variance. The diamond represents the pooled OR and the width corresponds to the 95% CI. J o u r n a l P r e -p r o o f DISCUSSION In our meta-analysis, we found that acute liver injury and elevated ALT and AST levels were associated with poor outcomes. However, our study could not provide significant evidence of the effect of preexisting chronic liver disease on COVID-19 patient outcomes. In support of our findings, a recent metaanalysis found that the frequency of underlying chronic liver disease was not statistically different between severe and non-severe diseases (14) . However, another study by Singh et al. reported that patients with preexisting liver disease, particularly cirrhosis, are at higher risk for hospitalizations and mortality (15) . Few studies have reported that the frequency of patients with liver injury was higher in severe cases compared to mild cases, consistent with our findings of liver injury associated with poor outcomes (16) (17) (18) . There are several theories proposed for liver damage in COVID-19 such as direct effect of the virus on hepatocytes or biliary epithelium via Angiotensin-converting enzyme 2 (ACE 2) receptors expression, liver injury related to increased immune response (cytokine storm) and immune mediated damage, drug toxicity (because of drugs like acetaminophen, antivirals and hydroxychloroquine), and liver failure occurring in patients having multiorgan dysfunction (19) (20) (21) .

A study by Chai et al., has reported that expression of ACE 2 receptors was 57.9 % in bile duct cells (Cholangiocytes) and 2.6% in hepatocytes (7). Cholangiocytes play a vital role in liver regeneration and immune response (22) . Hence one possible theory for liver injury in COVID-19 patients is destruction of Cholangiocytes by SARS-CoV-2 virus via ACE 2 receptors. Additionally, it was also observed that expression of ACE 2 in hepatocytes increases in cases of liver injury (9) . Recently, post mortem liver biopsies of COVID-19 patients have shown moderate microvesicular steatosis and mild lobular and portal activity, indicating the injury could have been caused by either SARS-CoV-2 infection or druginduced liver injury (23) . Whether this liver injury is caused by the virus itself or is due to a severe J o u r n a l P r e -p r o o f inflammatory response with liver damage or sepsis or multisystem organ failure or drug toxicity is not well understood (24) . Therefore, temporal relationship of COVID-19 induced liver damage cannot be established.

Furthermore, increased liver enzymes (AST and ALT) occur in the setting of hepatocyte damage (abnormal liver function). According to initial studies, more than a third of patients had elevated AST and ALT (Transaminitis) which was associated with longer hospital stay(17, 25, 26) . In a study done by Cai et al., 76 .3% of COVID-19 patients had abnormal liver tests while 21.5% developed liver injury during hospitalization, which was defined by ALT, AST, total bilirubin and gamma-glutamyl transferase levels elevated to more than 3x the upper limit of normal (27). The study also found that patients with abnormal liver tests had significantly higher odds of developing severe pneumonia (27). These findings are also consistent with our study that shows a significant elevation in AST and ALT among COVID-19 patients may be helpful in predicting poor outcomes among these patients.

SARS-CoV-2 is phylogenetically similar to SARS-CoV and MERS and, studies have given evidence of association of SARS-CoV and MERS with liver injury. and elevated transaminases associated with severe disease (20, (28) (29) (30) (31) (32) .Additionally, autopsies of SARS patients found not only virus particles in the hepatocytes and hepatic vascular endothelial cells but also significant increase in mitotic cells, with eosinophilic bodies and ballooning hepatocytes, suggesting that SARS-CoV may induce liver cells apoptosis and thus cause liver injury (33, 34) . Hence, liver injury due to SARS-CoV, MERS and SARS- 

The data used in this study is deidentified and collected from the studies published online thus informed consent or IRB approval was not needed for this study.

The data is collected from the studies published online, publicly available, and specific details related to data and/or analysis will be made available upon request. J o u r n a l P r e -p r o o f 

WHO Director-General's opening remarks at the media briefing on COVID-19 -11

COVID-19 CORONAVIRUS PANDEMIC. Worldometer

Multiorgan and Renal Tropism of SARS-CoV-2

Age-Adjusted Risk Factors Associated with Mortality and Mechanical Ventilation Utilization Amongst

Systematic Review and Meta-Analysis. SN Comprehensive Clinical Medicine

COVID-19 and Liver

Specific ACE2 Expression in Cholangiocytes May Cause Liver Damage After 2019-nCoV Infection. bioRxiv

Chronic liver injury in rats and humans upregulates the novel enzyme angiotensin converting enzyme 2

Upregulation of hepatic angiotensin-converting enzyme 2 (ACE2) and angiotensin-(1-7) levels in experimental biliary fibrosis

Comorbidity and its impact on 1590 patients with COVID-19 in China: a nationwide analysis

Preferred reporting items for systematic reviews and meta-analyses: the PRISMA statement

Meta-analysis of observational studies in epidemiology: a proposal for reporting. Meta-analysis Of Observational Studies in Epidemiology (MOOSE) group

Scale (NOS) for assessing the quality of nonrandomised studies in meta-analyses

Coronavirus disease (COVID-19) and the liver: a comprehensive systematic review and meta-analysis

Clinical Characteristics and Outcomes of Coronavirus Disease 2019 Among Patients With Preexisting Liver Disease in the United States: A Multicenter Research Network Study

Clinical features of patients infected with 2019 novel coronavirus in Wuhan

Epidemiological and clinical characteristics of 99 cases of 2019 novel coronavirus pneumonia in Wuhan, China: a descriptive study. The Lancet

COVID-19 in a designated infectious diseases hospital outside Hubei Province

Tissue distribution of ACE2 protein, the functional receptor for SARS coronavirus. A first step in understanding SARS pathogenesis

Clinical characteristics and mechanism of liver injury in patients with severe acute respiratory syndrome

Risk factors related to hepatic injury in patients with corona virus disease 2019. medRxiv

Cholangiocyte pathobiology

associated with acute respiratory distress syndrome. The Lancet Respiratory Medicine

COVID-19 and Liver Dysfunction: Current Insights and Emergent Therapeutic Strategies

Clinical Features of COVID-19-Related Liver Functional Abnormality

Clinical features of patients infected with 2019 novel coronavirus in Wuhan

COVID-19: Abnormal liver function tests

Organ distribution of severe acute respiratory syndrome (SARS) associated coronavirus (SARS-CoV) in SARS patients: implications for pathogenesis and virus transmission pathways

Clinical significance of hepatic derangement in severe acute respiratory syndrome

Clinical characteristics and mechanism of liver damage in patients with severe acute respiratory syndrome

Clinical aspects and outcomes of 70 patients with Middle East respiratory syndrome coronavirus infection: a single-center experience in Saudi Arabia

Critically Ill Patients With the Middle East Respiratory Syndrome: A Multicenter Retrospective Cohort Study

Angiotensin-converting enzyme 2 is a functional receptor for the SARS coronavirus

SARS-associated viral hepatitis caused by a novel coronavirus: report of three cases

, and pneumonia can be seen in imaging. Severe cases: Meeting any of the followingrespiratory distress, respiratory rate ≥ 30 breaths/min; SpO2 ≤ 93% at rest; and PaO2/FIO2 ≤ 300. Patients with >50% lesion progression within 24 to 48 hours. Critical/extremely severe cases: if they have one of the following: respiratory failure requiring mechanical ventilation, shock, and other organ failure requiring ICU treatment. ***Patients were included in the mild disease group if they did not need high-flow oxygen support and in the severe disease group if they were provided with high-flow oxygen support. #Not mentioned; ##General COVID-19 included following criteria:(i) obvious alleviation of respiratory symptoms (e.g. cough, chest distress and breath shortness) after treatment; (ii) maintenance of normal body temperature for ≥3 days without the use of corticosteroid or antipyretics; (iii) improvement in radiological abnormalities on chest CT or X-ray after treatment; (iv) a hospital stays of ≤10 days.Otherwise, it was classified as refractory COVID-19; $ All the studies mentioned chronic liver disease as a comorbidity. ^Liver enzyme abnormalities, ^^acute liver injury defined as an increase in alanine aminotransferase (ALT) over two times the upper limit of the normal range (ULN) or an increase in conjugated bilirubin or a combined increase in aspartate aminotransferase (AST), alkaline phosphatase and total bilirubin provided that one of them was above two times ULN. ^^^ Acute liver injury was defined as Jaundice with a total bilirubin level of 3mg/dl or higher and an acute increase in ALT of at least 5 times the upper limit of the normal range and/or an increase alkaline phosphatase of at least twice the upper limit of the normal range. ^*Liver injury was judged ALT and AST levels @ Studies considered AST (aspartate aminotransferase) and ALT (alanine aminotransferase) levels >40IU/L as elevated levels.References of the included studies in meta-analysis is in eSupplemental file 1