Impact of COVID-19 on the liver and on the care of patients with chronic liver disease, hepatobiliary cancer, and liver transplantation: An updated EASL position paper

Immunogenicity of COVID-19 vaccines in patients with cirrhosis: A meta-analysis

The immunogenicity of COVID-19 vaccines in patients with liver cirrhosis remains largely unknown. The purpose of this meta-analysis was to investigate the immunogenicity of COVID-19 vaccines in patients with cirrhosis and compare the humoral and cellular immune responses following complete COVID-19 vaccination between cirrhosis patients and healthy controls. A systematic literature search was conducted in PubMed, EMBASE, and Web of Science from 1 January 2020 to 22 August 2023. Sixteen studies with 2127 cirrhosis patients were included. The pooled seroconversion rate in patients with cirrhosis following complete COVID-19 vaccination was 92.4% (95% CI, 86.2%-96%, I2 = 90%) with significant between-study heterogeneity. Moreover, COVID-19 vaccination elicited a higher humoral immune response in patients of compensated cirrhosis as compared with decompensated cirrhosis (RR = 1.069, 95% CI, 1.011-1.131, I2 = 17%, p = .019). Additionally, 10 studies were included for comparison analysis of seroconversion rate between cirrhosis patients and healthy controls. The results showed that the seroconversion rate in patients with cirrhosis was slightly lower compared with healthy controls (RR = 0.972, 95% CI, 0.955-0.989, I2 = 66%, p = .001). Meanwhile, the pooled RR of cellular immune response rate for cirrhosis patients vs. healthy controls was 0.678 (95% CI, 0.563-0.817, I2 = 0, p < .0001). Our meta-analysis demonstrated that COVID-19 vaccination elicited diminished humoral and cellular immune responses in patients of cirrhosis. Patients with cirrhosis particularly decompensated cirrhosis who have completed full-doses of COVID-19 vaccination should receive continuous attention and preemptive measures.

Impact of COVID-19 on liver transplant recipients: A nationwide cohort study evaluating hospitalization, transplant rejection, and inpatient mortality

BACKGROUND

The coronavirus disease 2019 (COVID-19) pandemic has posed a major public health concern worldwide. Patients with comorbid conditions are at risk of adverse outcomes following COVID-19. Solid organ transplant recipients with concurrent immunosuppression and comorbidities are more susceptible to a severe COVID-19 infection. It could lead to higher rates of inpatient complications and mortality in this patient population. However, studies on COVID-19 outcomes in liver transplant (LT) recipients have yielded inconsistent findings.

AIM

To evaluate the impact of the COVID-19 pandemic on hospital-related outcomes among LT recipients in the United States.

METHODS

We conducted a retrospective cohort study using the 2019-2020 National Inpatient Sample database. Patients with primary LT hospitalizations and a secondary COVID-19 diagnosis were identified using the International Classification of Diseases, Tenth Revision coding system. The primary outcomes included trends in LT hospitalizations before and during the COVID-19 pandemic. Secondary outcomes included comparative trends in inpatient mortality and transplant rejection in LT recipients.

RESULTS

A total of 15720 hospitalized LT recipients were included. Approximately 0.8% of patients had a secondary diagnosis of COVID-19 infection. In both cohorts, the median admission age was 57 years. The linear trends for LT hospitalizations did not differ significantly before and during the pandemic (P = 0.84). The frequency of in-hospital mortality for LT recipients increased from 1.7% to 4.4% between January 2019 and December 2020. Compared to the pre-pandemic period, a higher association was noted between LT recipients and in-hospital mortality during the pandemic, with an odds ratio (OR) of 1.69 [95% confidence interval (CI): 1.55-1.84), P < 0.001]. The frequency of transplant rejections among hospitalized LT recipients increased from 0.2% to 3.6% between January 2019 and December 2020. LT hospitalizations during the COVID-19 pandemic had a higher association with transplant rejection than before the pandemic [OR: 1.53 (95%CI: 1.26-1.85), P < 0.001].

CONCLUSION

The hospitalization rates for LT recipients were comparable before and during the pandemic. Inpatient mortality and transplant rejection rates for hospitalized LT recipients were increased during the COVID-19 pandemic.

COVID-19 vaccine-induced liver injury

PURPOSE OF REVIEW

The rapid rollout and uptake of novel coronavirus disease 2019 (COVID-19) vaccines has been accompanied by a small yet noticeable accumulation of reports of liver injury occurring after vaccination. This review describes the present evidence surrounding COVID-19 vaccine-induced liver injury (VILI).

RECENT FINDINGS

Liver injury occurring after the COVID-19 vaccine often presents clinically similar to autoimmune hepatitis, with positive autoantibodies and a portal and lobular inflammatory infiltrate and varying degrees of necrosis on biopsy. The overwhelming majority of patients recover, often spontaneously or with a limited course of immunosuppression. The overall incidence of this phenomenon appears to be exceedingly low.

SUMMARY

Providers should remain vigilant for ongoing reports of VILI after COVID-19 and yet feel reassured by the low incidence and high likelihood of recovery. Ongoing genetic and histological study, as well as longer-term follow-up of presently identified cases, will shed further light on the clinical entity of VILI.

NAFLD and NASH are obesity-independent risk factors in COVID-19: Matched real-world results from the large PINC AI™ Healthcare Database

BACKGROUND & AIMS

Non-alcoholic fatty liver disease (NAFLD) and non-alcoholic steatohepatitis (NASH) are potential risk factors for severe pneumonia and other infections. Available data on the role of NAFLD/NASH in worsening outcomes for COVID-19 are controversial and might be confounded by comorbidities.

METHODS

We used the PINC AI™ Healthcare Data Special Release (PHD-SR) to identify patients with COVID-19 (ICD-10) at approximately 900 hospitals in the United States. We performed exact matching (age, gender, and ethnicity) for patients with or without NAFLD/NASH, adjusting for demographics (admission type, region) and comorbidities (e.g., obesity, diabetes) through inverse probability of treatment weighting and then analysed hospitalisation-related outcomes.

RESULTS

Among 513 623 patients with SARS-CoV-2 (COVID-19), we identified 14 667 with NAFLD/NASH who could be matched to 14 667 controls. Mean age was 57.6 (±14.9) years, 50.8% were females and 43.7% were non-Hispanic whites. After matching, baseline characteristics (e.g., age, ethnicity, and gender) and comorbidities (e.g., hypertension, obesity, diabetes, and cardiovascular disease) were well balanced (standard difference (SD) <.10), except for cirrhosis and malignancies. Patients with COVID-19 and NAFLD/NASH had higher FIB-4 scores, a significantly longer hospital length of stay (LOS) and intensive care LOS than controls (9.4 vs. 8.3 days, and 10.4 vs. 9.3, respectively), even after adjusting for cirrhosis and malignancies. Patients with COVID-19 and NAFLD/NASH also had significantly higher risk of needing invasive mandatory ventilation (IMV) (odds ratio 1.0727; 95% CI 1.0095-1.1400). Other outcomes were similar in both groups.

CONCLUSIONS

In this large real-world cohort of patients hospitalised for COVID-19 in the United States, NAFLD/NASH were obesity-independent risk factors for complicated disease courses.

COVID-19, Possible Hepatic Pathways and Alcohol Abuse-What Do We Know up to 2023?

The pandemic period due to coronavirus disease 2019 (COVID-19) revolutionized all possible areas of global health. Significant consequences were also related to diverse extrapulmonary manifestations of this pathology. The liver was found to be a relatively common organ, beyond the respiratory tract, affected by severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2). Multiple studies revealed the essential role of chronic liver disease (CLD) in the general outcome of coronavirus infection. Present concerns in this field are related to the direct hepatic consequences caused by COVID-19 and pre-existing liver disorders as risk factors for the severe course of the infection. Which mechanism has a key role in this phenomenon-previously existing hepatic disorder or acute liver failure due to SARS-CoV-2-is still not fully clarified. Alcoholic liver disease (ALD) constitutes another not fully elucidated context of coronavirus infection. Should the toxic effects of ethanol or already developed liver cirrhosis and its consequences be perceived as a causative or triggering factor of hepatic impairment in COVID-19 patients? In the face of these discrepancies, we decided to summarize the role of the liver in the whole picture of coronavirus infection, paying special attention to ALD and focusing on the pathological pathways related to COVID-19, ethanol toxicity and liver cirrhosis.

Immunogenicity and risk factors for poor humoral immune response to SARS-CoV-2 vaccine in patients with autoimmune hepatitis: a systematic review and meta-analysis

BACKGROUND

Research on the immunogenicity of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccine in patients with autoimmune hepatitis (AIH) has produced varied results, and the determinants of the immunological response remain largely elusive.

METHODS

A comprehensive search of three primary databases (PubMed, Embase, and Web of Science) yielded pertinent studies on the topic. The data extraction was a collaborative effort among three independent researchers, who subsequently reconvened to validate the key data that were collated. The primary outcomes were the magnitudes of humoral and cellular immune responses to the vaccines. The secondary outcomes were related to factors affecting the humoral immune response post-vaccination.

RESULT

Our systematic review incorporated eight studies, and the meta-analysis involved three. The average antibody response rates after one, two, and three doses of the SARS-CoV-2 vaccine were 86%, 82%, and 91%, respectively. Unexpectedly, the antibody concentrations of seropositive patients were markedly lower than those of their healthy counterparts. The cellular immune response rates after two and three vaccine doses were 74% and 56%, respectively. Treatment with mycophenolate mofetil and corticosteroids was associated with a notable decrease in seropositivity [pooled odds ratio (95% confidence interval): 2.62 (2.12-3.25) and 2.4 (1.51-3.82), respectively]. In contrast, azathioprine had no discernable impact on the humoral response.

CONCLUSION

In patients with AIH, the immune response to COVID-19 vaccination is attenuated. Specific immunosuppressive agents, such as steroids and MMF, have been found to reduce antibody responses. Recognizing these determinants is foundational to formulating individualized vaccination strategies for patients with AIH. Further research with an emphasis on post-vaccination cellular immunity will be essential to refine the vaccination approaches for this demographic.

Hepatitis B reactivation: A possible cause of coronavirus disease 2019 vaccine induced hepatitis

BACKGROUND AND AIMS

Coronavirus disease 2019 (COVID-19) vaccines were rapidly implemented globally and vaccine-associated immune-related hepatitis was recently reported. We aim to investigate its impact in regions endemic of chronic hepatitis B (CHB).

METHODS

We retrospectively collected patients who developed hepatitis within 90 days after COVID-19 vaccination in Taiwan. The mechanisms of hepatitis included vaccine induced liver injury (VILI) and immune-related hepatitis, which are direct liver injuries defined as aspartate or alanine aminotransferase (AST or ALT) increased ≥ 5-fold upper limit of normal (ULN) and/or AST or ALT ≥ 3-fold of ULN with concurrent total bilirubin ≥ 2-fold of ULN. Indirect liver injury due to HBV reactivation was defined as HBsAg reverse seroconversion or significant rise in HBV DNA level. The demographics, clinical data, and course of hepatitis were compared statistically.

RESULTS

Twenty-five patients were included with a median age of 54. The culprit vaccines were ChAdOx1 nCoV-19 (n = 9), mRNA-1273 (n = 12), and BNT162b2 (n = 4). The characteristics of hepatitis were comparable regardless of vaccine subtypes. The median onset of hepatitis was 25 days post vaccination, with a peak of 10-fold ALT-increase. The etiologies included HBV reactivation (n = 10), VILI (n = 10), and immune-related hepatitis (n = 5). HBV reactivation accounts for 90% of vaccine-induced hepatitis in patients of CHB (n = 10), and two patients died. Patients with initial AST levels >500 U/L increased 27-fold risks of liver injury greater than moderate severity compared with those without.

CONCLUSION

COVID-19 vaccine induced hepatitis is a clinical significant complication, and HBV reactivation may account for a possible mechanism.

Liver biopsy for assessment of suspected drug-induced liver injury in metabolic dysfunction-associated steatohepatitis clinical trials: Expert consensus from the Liver Forum

BACKGROUND

Causality assessment of suspected drug-induced liver injury (DILI) during metabolic dysfunction-associated steatohepatitis (MASH) clinical trials can be challenging, and liver biopsies are not routinely performed as part of this evaluation. While the field is moving away from liver biopsy as a diagnostic and prognostic tool, information not identified by non-invasive testing may be provided on histology.

AIM

To address the appropriate utilisation of liver biopsy as part of DILI causality assessment in this setting.

METHODS

From 2020 to 2022, the Liver Forum convened a series of webinars on issues pertaining to liver biopsy during MASH trials. The Histology Working Group was formed to generate a series of consensus documents addressing these challenges. This manuscript focuses on liver biopsy as part of DILI causality assessment.

RESULTS

Expert opinion, guidance and recommendations on the role of liver biopsy as part of causality assessment of suspected DILI occurring during clinical trials for a drug(s) being developed for MASH are provided. Lessons learned from prior MASH programs are reviewed and gaps identified.

CONCLUSIONS

Although there are no pathognomonic features, histologic evaluation of suspected DILI during MASH clinical trials may alter patient management, define the pattern and severity of injury, detect findings that favour a diagnosis of DILI versus MASH progression, identify prognostic features, characterise the clinicopathological phenotype of DILI, and/or define lesions that influence decisions about trial discontinuation and further development of the drug.

Immune responses and clinical outcomes after COVID-19 vaccination in patients with liver disease and liver transplant recipients

BACKGROUND & AIMS

Comparative assessments of immunogenicity following different COVID-19 vaccines in patients with distinct liver diseases are lacking. SARS-CoV-2-specific T-cell and antibody responses were evaluated longitudinally after one to three vaccine doses, with long-term follow-up for COVID-19-related clinical outcomes.

METHODS

A total of 849 participants (355 with cirrhosis, 74 with autoimmune hepatitis [AIH], 36 with vascular liver disease [VLD], 257 liver transplant recipients [LTRs] and 127 healthy controls [HCs]) were recruited from four countries. Standardised immune assays were performed pre and post three vaccine doses (V1-3).

RESULTS

In the total cohort, there were incremental increases in antibody titres after each vaccine dose (p <0.0001). Factors associated with reduced antibody responses were age and LT, whereas heterologous vaccination, prior COVID-19 and mRNA platforms were associated with greater responses. Although antibody titres decreased between post-V2 and pre-V3 (p = 0.012), patients with AIH, VLD, and cirrhosis had equivalent antibody responses to HCs post-V3. LTRs had lower and more heterogenous antibody titres than other groups, including post-V3 where 9% had no detectable antibodies; this was heavily influenced by intensity of immunosuppression. Vaccination increased T-cell IFNγ responses in all groups except LTRs. Patients with liver disease had lower functional antibody responses against nine Omicron subvariants and reduced T-cell responses to Omicron BA.1-specific peptides compared to wild-type. 122 cases of breakthrough COVID-19 were reported of which 5/122 (4%) were severe. Of the severe cases, 4/5 (80%) occurred in LTRs and 2/5 (40%) had no serological response post-V2.

CONCLUSION

After three COVID-19 vaccines, patients with liver disease generally develop robust antibody and T-cell responses to vaccination and have mild COVID-19. However, LTRs have sustained no/low antibody titres and appear most vulnerable to severe disease.

IMPACT AND IMPLICATIONS

Standardised assessments of the immune response to different COVID-19 vaccines in patients with liver disease are lacking. We performed antibody and T-cell assays at multiple timepoints following up to three vaccine doses in a large cohort of patients with a range of liver conditions. Overall, the three most widely available vaccine platforms were immunogenic and appeared to protect against severe breakthrough COVID-19. This will provide reassurance to patients with chronic liver disease who were deemed at high risk of severe COVID-19 during the pre-vaccination era, however, liver transplant recipients had the lowest antibody titres and remained vulnerable to severe breakthrough infection. We also characterise the immune response to multiple SARS-CoV-2 variants and describe the interaction between disease type, severity, and vaccine platform. These insights may prove useful in the event of future viral infections which also require rapid vaccine development and delivery to patients with liver disease.

Serological response and breakthrough infection after COVID-19 vaccination in patients with cirrhosis and post-liver transplant

BACKGROUND

Vaccine hesitancy and lack of access remain major issues in disseminating COVID-19 vaccination to liver patients globally. Factors predicting poor response to vaccination and risk of breakthrough infection are important data to target booster vaccine programs. The primary aim of the current study was to measure humoral responses to 2 doses of COVID-19 vaccine. Secondary aims included the determination of factors predicting breakthrough infection.

METHODS

COVID-19 vaccination and Biomarkers in cirrhosis And post-Liver Transplantation is a prospective, multicenter, observational case-control study. Participants were recruited at 4-10 weeks following first and second vaccine doses in cirrhosis [n = 325; 94% messenger RNA (mRNA) and 6% viral vaccine], autoimmune liver disease (AILD) (n = 120; 77% mRNA and 23% viral vaccine), post-liver transplant (LT) (n = 146; 96% mRNA and 3% viral vaccine), and healthy controls (n = 51; 72% mRNA, 24% viral and 4% heterologous combination). Serological end points were measured, and data regarding breakthrough SARS-CoV-2 infection were collected.

RESULTS

After adjusting by age, sex, and time of sample collection, anti-Spike IgG levels were the lowest in post-LT patients compared to cirrhosis (p < 0.0001), AILD (p < 0.0001), and control (p = 0.002). Factors predicting reduced responses included older age, Child-Turcotte-Pugh B/C, and elevated IL-6 in cirrhosis; non-mRNA vaccine in AILD; and coronary artery disease, use of mycophenolate and dysregulated B-call activating factor, and lymphotoxin-α levels in LT. Incident infection occurred in 6.6%, 10.6%, 7.4%, and 15.6% of cirrhosis, AILD, post-LT, and control, respectively. The only independent factor predicting infection in cirrhosis was low albumin level.

CONCLUSIONS

LT patients present the lowest response to the SARS-CoV-2 vaccine. In cirrhosis, the reduced response is associated with older age, stage of liver disease and systemic inflammation, and breakthrough infection with low albumin level.

SARS-CoV-2 and the liver: clinical and immunological features in chronic liver disease

SARS-CoV-2 infection may affect the liver in healthy individuals but also influences the course of COVID-19 in patients with chronic liver disease (CLD). As described in healthy individuals, a strong SARS-CoV-2-specific adaptive immune response is important for the outcome of COVID-19, however, knowledge on the adaptive immune response in CLD is limited.Here, we review the clinical and immunological features of SARS-CoV-2 infection in individuals with CLD. Acute liver injury occurs in many cases of SARS-CoV-2 infection and may be induced by multiple factors, such as cytokines, direct viral infection or toxic effects of COVID-19 drugs. In individuals with CLD, SARS-CoV-2 infection may have a more severe course and promote decompensation and particularly in patients with cirrhosis. Compared with healthy individuals, the SARS-CoV-2-specific adaptive immune responses is impaired in patients with CLD after both, natural infection and vaccination but improves at least partially after booster vaccination.Following SARS-CoV-2 vaccination, rare cases of acute vaccine-induced liver injury and the development of autoimmune-like hepatitis have been reported. However, the concomitant elevation of liver enzymes is reversible under steroid treatment.

Deficient Immune Response following SARS-CoV-2 Vaccination in Patients with Hepatobiliary Carcinoma: A Forgotten, Vulnerable Group of Patients

Introduction

Data on immune response rates following vaccination for severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) in patients with hepatobiliary carcinoma (HBC) are rare. However, impaired immunogenicity must be expected due to the combination of chronic liver diseases (CLDs) with malignancy and anticancer treatment.

Methods

In this prospective, longitudinal study, 101 patients were included, of whom 59 were patients with HBC under anticancer treatment. A cohort of patients with a past medical history of gastrointestinal cancer, of whom 28.6% had HBC without detectable active tumor disease having been off therapy for at least 12 months, served as control. Levels of SARS-CoV-2 anti-spike IgG, surrogate neutralization antibodies (sNABs), and cellular immune responses were compared. In uni- and multivariable subgroup analyses, risk factors for impaired immunogenicity were regarded. Data on rates and clinical courses of SARS-CoV-2 infections were documented.

Results

In patients with HBC under active treatment, levels of SARS-CoV-2 anti-spike IgG were significantly lower (2.55 log10 BAU/mL; 95% CI: 2.33-2.76; p < 0.01) than in patients in follow-up care (3.02 log10 BAU/mL; 95% CI: 2.80-3.25) 4 weeks after two vaccinations. Antibody levels decreased over time, and differences between the groups diminished. However, titers of SARS-CoV-2 sNAB were for a longer time significantly lower in patients with HBC under treatment (64.19%; 95% CI: 55.90-72.48; p < 0.01) than in patients in follow-up care (84.13%; 95% CI: 76.95-91.31). Underlying CLD and/or liver cirrhosis Child-Pugh A or B (less than 8 points) did not seem to further impair immunogenicity. Conversely, chemotherapy and additional immunosuppression were found to significantly reduce antibody levels. After a third booster vaccination for SARS-CoV-2, levels of total and neutralization antibodies were equalized between the groups. Moreover, cellular response rates were balanced. Clinically, infection rates with SARS-CoV-2 were low, and no severe courses were observed.

Conclusion

Patients with active HBC showed significantly impaired immune response rates to basic vaccinations for SARS-CoV-2, especially under chemotherapy, independent of underlying cirrhotic or non-cirrhotic CLD. Although booster vaccinations balanced differences, waning immunity was observed over time and should be monitored for further recommendations. Our data help clinicians decide on individual additional booster vaccinations and/or passive immunization or antiviral treatment in patients with HBC getting infected with SARS-CoV-2.

Impact and management of COVID-19 in liver transplant candidates and recipients

The COVID-19 outbreak has had severe consequences for global public health, medical communities, and the socioeconomic status of a considerable number of countries. The emergence of COVID-19 has also significantly impacted the world of liver transplantation (LT). Studies from transplantation centers around the world have shown that LTs during the COVID-19 pandemic have been restricted because of the high risk of serious COVID-19 infection in this population. According to the Centers for Disease Control and Prevention, patients with liver disease are considered at higher risk for severe COVID-19 infection. In March 2020, the American Association for the Study of Liver Diseases recommended that LT should be limited to emergency cases. The COVID-19 treatment guidelines published by the National Institutes of Health are being constantly updated according to new epidemiology trends and treatment regimens. Immunocompromised patients have a higher risk of developing severe disease or death from COVID-19 compared with the general population. In this review, we summarize the available evidence regarding treatment guidelines and considerations for the evaluation and management of LT candidates and recipients in the era of COVID-19. In addition, we present data regarding COVID-19 among LT patients in our local transplantation center.

Excess Deaths of Gastrointestinal, Liver, and Pancreatic Diseases During the COVID-19 Pandemic in the United States

Objectives: To evaluate excess deaths of gastrointestinal, liver, and pancreatic diseases in the United States during the COVID-19 pandemic. Methods: We retrieved weekly death counts from National Vital Statistics System and fitted them with a quasi-Poisson regression model. Cause-specific excess deaths were calculated by the difference between observed and expected deaths with adjustment for temporal trend and seasonality. Demographic disparities and temporal-spatial patterns were evaluated for different diseases. Results: From March 2020 to September 2022, the increased mortality (measured by excess risks) for Clostridium difficile colitis, gastrointestinal hemorrhage, and acute pancreatitis were 35.9%; 24.8%; and 20.6% higher than the expected. For alcoholic liver disease, fibrosis/cirrhosis, and hepatic failure, the excess risks were 1.4-2.8 times higher among younger inhabitants than older inhabitants. The excess deaths of selected diseases were persistently observed across multiple epidemic waves with fluctuating trends for gastrointestinal hemorrhage and fibrosis/cirrhosis and an increasing trend for C. difficile colitis. Conclusion: The persistently observed excess deaths of digestive diseases highlights the importance for healthcare authorities to develop sustainable strategies in response to the long-term circulating of SARS-CoV-2 in the community.

Fib-4 score is able to predict intra-hospital mortality in 4 different SARS-COV2 waves

Increased values of the FIB-4 index appear to be associated with poor clinical outcomes in COVID-19 patients. This study aimed to develop and validate predictive mortality models, using data upon admission of hospitalized patients in four COVID-19 waves between March 2020 and January 2022. A single-center cohort study was performed on consecutive adult patients with Covid-19 admitted at the Fondazione Policlinico Gemelli IRCCS (Rome, Italy). Artificial intelligence and big data processing were used to retrieve data. Patients and clinical characteristics of patients with available FIB-4 data derived from the Gemelli Generator Real World Data (G2 RWD) were used to develop predictive mortality models during the four waves of the COVID-19 pandemic. A logistic regression model was applied to the training and test set (75%:25%). The model's performance was assessed by receiver operating characteristic (ROC) curves. A total of 4936 patients were included. Hypertension (38.4%), cancer (12.15%) and diabetes (16.3%) were the most common comorbidities. 23.9% of patients were admitted to ICU, and 12.6% had mechanical ventilation. During the study period, 762 patients (15.4%) died. We developed a multivariable logistic regression model on patient data from all waves, which showed that the FIB-4 score > 2.53 was associated with increased mortality risk (OR = 4.53, 95% CI 2.83-7.25; p ≤ 0.001). These data may be useful in the risk stratification at the admission of hospitalized patients with COVID-19.

COVID-19 in patients with liver disease and liver transplant: clinical implications, prevention, and management

The coronavirus disease 2019 (COVID-19) pandemic has had enormous implications for the care of patients with chronic liver disease (CLD), cirrhosis, and liver transplant (LT). Clinical outcomes of COVID-19 vary in patients with CLD and cirrhosis compared to healthy controls, and in patients with LT compared to patients without LT. Several special considerations apply to the approach to vaccination and treatment in patients with CLD and LT. The practice of liver transplantation has also been heavily impacted by the pandemic, including persistent reductions in living donor LT and increases in LT for an indication of alcohol-related liver disease. Recent medical society guidelines strive to standardize severe acute respiratory syndrome coronavirus 2 testing in donors and recipients and the approach to transplantation after recovered from COVID-19 infection, but certain controversies remain.

Impact of COVID-19 in individuals with and without pre-existent digestive disorders with a particular focus on elderly patients

Coronavirus disease 2019 (COVID-19) has several extrapulmonary symptoms. Gastrointestinal (GI) symptoms are among the most frequent clinical manifestations of COVID-19, with severe consequences reported in elderly patients. Furthermore, the impact of COVID-19 on patients with pre-existing digestive diseases still needs to be fully elucidated, particularly in the older population. This review aimed to investigate the impact of COVID-19 on the GI tract, liver, and pancreas in individuals with and without previous digestive diseases, with a particular focus on the elderly, highlighting the distinctive characteristics observed in this population. Finally, the effectiveness and adverse events of the anti-COVID-19 vaccination in patients with digestive disorders and the peculiarities found in the elderly are discussed.

Liver Transplantation 2023: Status Report, Current and Future Challenges

Liver transplantation offers live-saving therapy for patients with complications of cirrhosis and stage T2 hepatocellular carcinoma. The demand for organs far outstrips the supply, and innovations aimed at increasing the number of usable deceased donors as well as alternative donor sources are a major focus. The etiologies of cirrhosis are shifting over time, with more need for transplantation among patients with alcohol-associated liver disease and nonalcoholic/metabolic fatty liver disease and less for viral hepatitis, although hepatitis B remains an important indication for transplant in countries with high endemicity. The rise in transplantation for alcohol-associated liver disease and nonalcoholic/metabolic fatty liver disease has brought attention to how patients are selected for transplantation and the strategies needed to prevent recurrent disease. In this review, we present a status report on the most pressing topics in liver transplantation and future challenges.

Comprehensive DNA methylation profiling of COVID-19 and hepatocellular carcinoma to identify common pathogenesis and potential therapeutic targets

BACKGROUND & AIMS

The effects of SARS-CoV-2 infection can be more complex and severe in patients with hepatocellular carcinoma (HCC) as compared to other cancers. This is due to several factors, including pre-existing conditions such as viral hepatitis and cirrhosis, which are commonly associated with HCC.

METHODS

We conducted an analysis of epigenomics in SARS-CoV-2 infection and HCC patients, and identified common pathogenic mechanisms using weighted gene co-expression network analysis (WGCNA) and other analyses. Hub genes were identified and analyzed using LASSO regression. Additionally, drug candidates and their binding modes to key macromolecular targets of COVID-19 were identified using molecular docking.

RESULTS

The epigenomic analysis of the relationship between SARS-CoV-2 infection and HCC patients revealed that the co-pathogenesis was closely linked to immune response, particularly T cell differentiation, regulation of T cell activation and monocyte differentiation. Further analysis indicated that CD4⁺ T cells and monocytes play essential roles in the immunoreaction triggered by both conditions. The expression levels of hub genes MYLK2, FAM83D, STC2, CCDC112, EPHX4 and MMP1 were strongly correlated with SARS-CoV-2 infection and the prognosis of HCC patients. In our study, mefloquine and thioridazine were identified as potential therapeutic agents for COVID-19 in combined with HCC.

CONCLUSIONS

In this research, we conducted an epigenomics analysis to identify common pathogenetic processes between SARS-CoV-2 infection and HCC patients, providing new insights into the pathogenesis and treatment of HCC patients infected with SARS-CoV-2.

COVID-19 and severity of liver diseases: Possible crosstalk and clinical implications

COVID-19-infected individuals and those who recovered from the infection have been demonstrated to have elevated liver enzymes or abnormal liver biochemistries, particularly with preexisting liver diseases, liver metabolic disorders, viral hepatitis, and other hepatic comorbidities. However, possible crosstalk and intricate interplay between COVID-19 and liver disease severity are still elusive, and the available data are murky and confined. Similarly, the syndemic of other blood-borne infectious diseases, chemical-induced liver injuries, and chronic hepatic diseases continued to take lives while showing signs of worsening due to the COVID-19 crisis. Moreover, the pandemic is not over yet and is transitioning to becoming an epidemic in recent years; hence, monitoring liver function tests (LFTs) and assessing hepatic consequences of COVID-19 in patients with or without liver illnesses would be of paramount interest. This pragmatic review explores the correlations between COVID-19 and liver disease severity based on abnormal liver biochemistries and other possible mechanisms in individuals of all ages from the emergence of the COVID-19 pandemic to the post-pandemic period. The review also alludes to clinical perspectives of such interactions to curb overlapping hepatic diseases in people who recovered from the infection or living with long COVID-19.

Unraveling the Molecular and Cellular Pathogenesis of COVID-19-Associated Liver Injury

The coronavirus disease 2019 (COVID-19) pandemic, caused by severe acute respiratory syndrome coronavirus (SARS-CoV-2) continues to cause substantial morbidity and mortality. Most infections are mild; however, some patients experience severe and potentially fatal systemic inflammation, tissue damage, cytokine storm, and acute respiratory distress syndrome. Patients with chronic liver disease have been frequently affected, experiencing high morbidity and mortality. In addition, elevated liver enzymes may be a risk factor for disease progression, even in the absence of underlying liver disease. While the respiratory tract is a primary target of SARS-CoV-2, it has become evident that COVID-19 is a multisystemic infectious disease. The hepatobiliary system might be influenced during COVID-19 infection, ranging from a mild elevation of aminotransferases to the development of autoimmune hepatitis and secondary sclerosing cholangitis. Furthermore, the virus can promote existing chronic liver diseases to liver failure and activate the autoimmune liver disease. Whether the direct cytopathic effects of the virus, host reaction, hypoxia, drugs, vaccination, or all these risk factors cause liver injury has not been clarified to a large extent in COVID-19. This review article discussed the molecular and cellular mechanisms involved in the pathogenesis of SARS-CoV-2 virus-associated liver injury and highlighted the emerging role of liver sinusoidal epithelial cells (LSECs) in virus-related liver damage.

Hypocalcemia on Admission Is a Predictor of Disease Progression in COVID-19 Patients with Cirrhosis: A Multicenter Study in Hungary

Hypocalcemia is a common condition in liver cirrhosis and is associated with the severity of SARS-CoV-2 infection. However, there is a lack of data demonstrating the prognostic value of hypocalcemia in COVID-19 patients with cirrhosis. This study aimed to evaluate the prognostic value of hypocalcemia for COVID-19 severity, mortality and its associations with abnormal liver function parameters. We selected 451 COVID-19 patients in this retrospective study and compared the laboratory findings of 52 COVID-19 patients with cirrhosis to those of 399 COVID-19 patients without cirrhosis. Laboratory tests measuring albumin-corrected total serum calcium were performed on admission, and the levels were monitored during hospitalization. The total serum calcium levels were significantly lower in cirrhosis cases (2.16 mmol/L) compared to those without cirrhosis (2.32 mmol/L). Multivariate analysis showed that hypocalcemia in COVID-19 patients with cirrhosis was a significant predictor of in-hospital mortality, with an OR of 4.871 (p < 0.05; 95% CI 1.566-15.146). ROC analysis showed the AUC value of total serum calcium was 0.818 (95% CI 0.683-0.953, p < 0.05), with a sensitivity of 88.3% and a specificity of 75%. The total serum calcium levels showed a significant negative correlation with the Child-Turcette-Pugh score (r = -0.400, p < 0.05). Hypocalcemia on admission was a significant prognostic factor of disease progression in COVID-19 patients with cirrhosis.

Gastrointestinal disorders in post-COVID syndrome. Clinical guidelines

Summary Post- COVID syndrome refers to the long-term consequences of a new coronavirus infection COVID-19, which includes a set of symptoms that develop or persist after COVID-19. Symptoms of gastrointestinal disorders in post- COVID syndrome, due to chronic infl ammation, the consequences of organ damage, prolonged hospitalization, social isolation, and other causes, can be persistent and require a multidisciplinary approach. The presented clinical practice guidelines consider the main preventive and therapeutic and diagnostic approaches to the management of patients with gastroenterological manifestations of postCOVID syndrome. The Guidelines were approved by the 17th National Congress of Internal Medicine and the 25th Congress of Gastroenterological Scientifi c Society of Russia.

The Intersection of COVID-19 and Metabolic-Associated Fatty Liver Disease: An Overview of the Current Evidence

The global population is currently experiencing the impact of the SARS-CoV-2 coronavirus, which has caused the Coronavirus Disease 2019 (COVID-19) pandemic. With our profound comprehension of COVID-19, encompassing the involvement sequence of the respiratory tract, gastrointestinal system, and cardiovascular apparatus, the multiorgan symptoms of this infectious disease have been discerned. Metabolic-associated fatty liver disease (MAFLD), formerly known as non-alcoholic fatty liver disease (NAFLD), is a pervasive public health concern intricately linked with metabolic dysregulation and estimated to afflict one-fourth of the global adult population. The burgeoning focus on the association between COVID-19 and MAFLD is justified by the potential role of the latter as a risk factor for both SARS-CoV-2 infection and the subsequent emergence of severe COVID-19 symptoms. Investigations have suggested that changes in both innate and adaptive immune responses among MAFLD patients may play a role in determining the severity of COVID-19. The remarkable similarities observed in the cytokine pathways implicated in both diseases imply the existence of shared mechanisms governing the chronic inflammatory responses characterizing these conditions. The effect of MAFLD on the severity of COVID-19 illness remains uncertain, as indicated by conflicting results in cohort investigations.

Liver and Biliary Tract Disease in Patients with Coronavirus disease-2019 Infection

Coronavirus disease-2019 (COVID-19) had become a global pandemic since March 2020. Although, the most common presentation is of pulmonary involvement, hepatic abnormalities can be encountered in up to 50% of infected individuals, which may be associated with disease severity, and the mechanism of liver injury is thought to be multifactorial. Guidelines for management in patients with chronic liver disease during COVID-19 era are being regularly updated. Patients with chronic liver disease and cirrhosis, including liver transplant candidates and liver transplant recipients are strongly recommended to receive SARS-CoV-2 vaccination because it can reduce rate of COVID-19 infection, COVID-19-related hospitalization, and mortality.

Global treatment rate and barriers to direct-acting antiviral therapy: A systematic review and meta-analysis of 146 studies and 1 760 352 hepatitis C virus patients

BACKGROUND

Global data on the treatment rate with direct-acting antivirals (DAAs) for chronic hepatitis C (CHC) are sparse. We aimed to evaluate the CHC treatment rate and barriers to treatment in the DAA era.

METHODS

We searched PubMed, EMBASE and Cochrane from inception to 5 August 2021, for relevant articles. Patients treated with DAAs without interferon (IFN) therapy were categorized as IFN-free DAAs. Patients receiving DAA with IFN or unclear IFN status were categorized as DAA/IFN.

RESULTS

We identified and analysed data from 146 studies (1 760 352 CHC patients). DAA/IFN treatment rate was 16.0% (95% CI: 9.9-23.3, 49 studies, 886 535 patients). IFN-free DAA treatment rate was 52.3% (95% CI: 46.2-58.4, 123 studies, 1 276 754 patients): 45.4% in North America, 64.2% in South America (1 study), 90.4% in Africa (most data from Egypt), 54.4% in Europe, 60.7% in Australia and 60.5% in Asia, (p < .0001); 49% with hepatitis B co-infection and 32.3% with hepatocellular carcinoma (HCC). Treatment was not a priority in 22.8% of patients in Europe and 16.7% in Australia, compared to only 4.8% in North America and 2.1% in Asia (p < .0001). Poor adherence to clinical follow-up was the cause of no treatment in 74.7% of patients in Australia, 37.0% in North America, 7.9% in Europe and 14.3% in Asia (p < .0001).

CONCLUSION

Though a marked improvement from IFN/DAA, the treatment rate with IFN-free DAA remains suboptimal (52.3% overall, 32.3% in HCC patients). Non-adherence to clinical follow-up and lack of disease awareness were treatment barriers.

Liver injury in COVID-19 patients with non-alcoholic fatty liver disease: an update

The coronavirus disease 2019 (COVID-19) pandemic has revolutionized the priorities of the medical society worldwide. Although most patients infected with SARS-CoV-2 exhibit respiratory symptoms, other organs may also be involved, including the liver, often resulting in liver injury. Non-alcoholic fatty liver disease (NAFLD) is the most common chronic liver disease in the world, and its prevalence is expected to increase together with the epidemics of type 2 diabetes and obesity. Data about liver injury during COVID-19 are numerous, while overviews of this infection in patients with NAFLD, both in terms of respiratory and liver, are emerging. In this review, we summarise the current research focusing on COVID-19 in NAFLD patients and discuss the association between liver injury in COVID-19 subjects and non-alcoholic fatty liver disease.

Cirrhosis is associated with lower serological responses to COVID-19 vaccines in patients with chronic liver disease

Background & Aims

The response of patients with chronic liver disease (CLD) to COVID-19 vaccines remains unclear. Our aim was to assess the humoral immune response and efficacy of two-dose COVID-19 vaccines among CLD patients of different etiologies and disease stages.

Methods

357 patients were recruited in clinical centers from 6 European countries. 132 healthy volunteers served as controls. Serum IgG, IgM (nM) and neutralizing antibodies (NAb; %) against the Wuhan-Hu-1, B.1.617 and B.1.1.529 SARS-CoV-2 spike proteins were determined prior to vaccination (T0), 14 days (T2) and 6 months (T3) after second dose vaccination. Patients fulfilling inclusion criteria at T2 (n=212) were stratified into "low" or "high" responders according to IgG levels. Infection rates and severity were collected throughout the study.

Results

Wuhan-Hu-1 IgG, IgM and neutralization levels significantly increased from T0 to T2 in patients vaccinated with either BNT162b2 (70.3%), mRNA-1273 (18.9%) or ChAdOx1 (10.8%). In multivariate analysis, age, cirrhosis and type of vaccine (ChAdOx1 > BNT162b2 > mRNA-1273) predicted "low" humoral response, while viral hepatitis and antiviral therapy predicted "high" humoral response. Comparing with Wuhan-Hu-1, B.1.617 and, further, B.1.1.529 IgG levels were significantly lower at both T2 and T3. Compared with healthy individuals, CLD patients presented with lower B.1.1.529 IgGs at T2 with no additional key differences. No major clinical or immune IgG parameters associated with SARS-COV-2 infection rates or vaccine efficacy.

Conclusions

Patients with CLD and cirrhosis exhibit lower immune responses to COVID-19 vaccination, irrespective of disease etiology. The type of vaccine leads to different antibody responses, that appear not to associate with distinct efficacy, although this needs validation in larger cohorts with a more balanced representation of all vaccines.

Lay summary

In patients with CLD vaccinated with two-dose vaccines, age, cirrhosis and type of vaccine (Vaxzevria > Pfizer BioNTech > Moderna) predict a "lower" humoral response, while viral hepatitis etiology and prior antiviral therapy predict a "higher" humoral response. This differential response appears not to associate with SARS-COV-2 infection incidence or vaccine efficacy. Still, compared with Wuhan-Hu-1, humoral immunity was lower for the Delta and Omicron variants, and all decreased after 6 months. As such, patients with CLD, particularly those older and with cirrhosis, should be prioritized for receiving booster doses and/or recently approved adapted vaccines.

Liver involvement in patients with COVID-19 infection: A comprehensive overview of diagnostic imaging features

During the first wave of the pandemic, coronavirus disease 2019 (COVID-19) infection has been considered mainly as a pulmonary infection. However, different clinical and radiological manifestations were observed over time, including involvement of abdominal organs. Nowadays, the liver is considered one of the main affected abdominal organs. Hepatic involvement may be caused by either a direct damage by the virus or an indirect damage related to COVID-19 induced thrombosis or to the use of different drugs. After clinical assessment, radiology plays a key role in the evaluation of liver involvement. Ultrasonography (US), computed tomography (CT) and magnetic resonance imaging (MRI) may be used to evaluate liver involvement. US is widely available and it is considered the first-line technique to assess liver involvement in COVID-19 infection, in particular liver steatosis and portal-vein thrombosis. CT and MRI are used as second- and third-line techniques, respectively, considering their higher sensitivity and specificity compared to US for assessment of both parenchyma and vascularization. This review aims to the spectrum of COVID-19 liver involvement and the most common imaging features of COVID-19 liver damage.

Impact of chronic liver disease on SARS-CoV-2 infection outcomes: Roles of stage, etiology and vaccination

Since the first identification in December of 2019 and the fast spread of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, it has represented a dramatic global public health concern. Though affecting mainly the respiratory system, SARS-CoV-2 disease, defined as coronavirus disease 2019 (COVID-19), may have a systemic involvement leading to multiple organ dysfunction. Experimental evidence about the SARS-CoV-2 tropism for the liver and the increasing of hepatic cytolysis enzymes during infection support the presence of a pathophysiological relationship between liver and SARS-CoV-2. On the other side, patients with chronic liver disease have been demonstrated to have a poor prognosis with COVID-19. In particular, patients with liver cirrhosis appear extremely vulnerable to infection. Moreover, the etiology of liver disease and the vaccination status could affect the COVID-19 outcomes. This review analyzes the impact of the disease stage and the related causes on morbidity and mortality, clinical outcomes during SARS-CoV-2 infection, as well as the efficacy of vaccination in patients with chronic liver disease.

COVID-19 and hepatic injury: cellular and molecular mechanisms in diverse liver cells

The coronavirus disease 2019 (COVID-19) represents a global health and economic challenge. Hepatic injuries have been approved to be associated with severe acute respiratory syndrome coronavirus (SARS-CoV-2) infection. The viral tropism pattern of SARS-CoV-2 can induce hepatic injuries either by itself or by worsening the conditions of patients with hepatic diseases. Besides, other factors have been reported to play a crucial role in the pathological forms of hepatic injuries induced by SARS-CoV-2, including cytokine storm, hypoxia, endothelial cells, and even some treatments for COVID-19. On the other hand, several groups of people could be at risk of hepatic COVID-19 complications, such as pregnant women and neonates. The present review outlines and discusses the interplay between SARS-CoV-2 infection and hepatic injury, hepatic illness comorbidity, and risk factors. Besides, it is focused on the vaccination process and the role of developed vaccines in preventing hepatic injuries due to SARS-CoV-2 infection.

Non-alcoholic fatty liver disease and COVID-19: Harmless companions or disease intensifier?

The pandemics of coronavirus disease 2019 (COVID-19) and non-alcoholic fatty liver disease (NAFLD) coexist. Elevated liver function tests are frequent in COVID-19 and may influence liver damage in NAFLD, while preexisting liver damage from NAFLD may influence the course of COVID-19. However, the prognostic relevance of this interaction, though, is unclear. Obesity is a risk factor for the presence of NAFLD as well as a severe course of COVID-19. Cohort studies reveal conflicting results regarding the influence of NAFLD presence on COVID-19 illness severity. Striking molecular similarities of cytokine pathways in both diseases, including postacute sequelae of COVID-19, suggest common pathways for chronic low-activity inflammation. This review will summarize existing data regarding the interaction of both diseases and discuss possible mechanisms of the influence of one disease on the other.

Effectiveness of COVID-19 Vaccination with mRNA Vaccines for Patients with Cirrhosis in Hungary: Multicentre Matched Cohort Study

Patients with cirrhosis are vulnerable to hepatic decompensation events and death following COVID-19 infection. Therefore, primary vaccination with COVID-19 vaccines is fundamental to reducing the risk of COVID-19 related deaths in patients with cirrhosis. However, limited data are available about the effectiveness of mRNA vaccines compared to other vaccines. The aim of our study was to investigate the efficacy of mRNA vaccines versus other vaccines in cirrhosis. In this retrospective study, we compared clinical characteristics and vaccine effectiveness of 399 COVID-19 patients without cirrhosis (GROUP A) to 52 COVID-19 patients with cirrhosis (GROUP B). 54 hospitalised cirrhosis controls without COVID-19 (GROUP C) were randomly sampled 1:1 and matched by gender and age. Of the cirrhosis cases, we found no difference (p = 0.76) in mortality rates in controls without COVID-19 (11.8%) compared to those with COVID-19 (9.6%). However, COVID-19 patients with cirrhosis were associated with higher rates of worsening hepatic encephalopathy, ascites and esophageal varices. Patients with cirrhosis receiving mRNA vaccines had significantly better survival rates compared to viral vector or inactivated vaccines. Primary vaccination with the BNT162b2 vaccine was the most effective in preventing acute hepatic decompensating events, COVID-19 infection requiring hospital admission and in-hospital mortality.

COVID-19 Alcoholic Cirrhosis and Non-Alcoholic Steatohepatitis Cirrhosis Outcomes among Hospitalized Patients in the United States: Insight from National Inpatient Sample Database

Patients with co-morbidities like cirrhosis are at risk of worse outcome from COVID-19 infection. Given limited prior studies, we evaluated outcomes associated with COVID-19 infection in alcoholic and non-alcoholic steatohepatitis cirrhotic (CC+) versus cirrhotic without COVID-19 (CC−). We performed retrospective analysis of 822,604 patients including 28,610 COVID-19 patients from the National Inpatient Sample database with alcoholic and NASH cirrhosis enrolled between 1 January 2020 to 31 December 2020, with univariate and multivariate regression analyses. Primary outcome was mortality and secondary outcomes was mechanical ventilation, vasopressor use, length of stay, hospitalization expense and predictors of mortality. In-hospital mortality was three time higher in the CC+ group compared to those in the CC− group(18.6% vs. 5.96%, p < 0.001, adjusted odds ratio (OR)3.39 (95% 3.08−3.74 CI). Hospitalization was more likely for underrepresented racial and ethnic groups with COVID-19 and cirrhosis. CC+ group had over twice the rates of mechanical ventilation (19.92% vs. 9.07%, adjusted OR 2.71 2.71 (95% 2.51−2.93 CI)),1.7 times likelihood of receiving vasopressors (4.12% vs. 2.45%, p < 0.001, adjusted OR 1.71 (95% CI 1.46−2.01). COVID-19 is associated with increased mortality in patients with alcoholic and NASH cirrhosis, and patients with alcoholic cirrhosis and COVID-19 have a slightly higher mortality compared to NASH cirrhosis.

Hepatic manifestations of coronavirus disease 2019 infection: Clinical and laboratory perspective

The novel coronavirus disease 2019 (COVID-19) pandemic, caused by severe acute respiratory syndrome coronavirus 2, has become a global challenge of unprecedented nature since December 2019. Although most patients with COVID-19 exhibit mild clinical manifestations and upper respiratory tract involvement, in approximately 5%-10% of patients, the disease is severe and involves multiple organs, leading to multi-organ dysfunction and failure. The liver and gastrointestinal tract are also frequently involved in COVID-19. In the context of liver involvement in patients with COVID-19, many key aspects need to be addressed in both native and transplanted organs. This review focuses on the clinical presentations and laboratory abnormalities of liver function tests in patients with COVID-19 with no prior liver disease, patients with pre-existing liver diseases and liver transplant recipients. A brief overview of the history of COVID-19 and etiopathogenesis of the liver injury will also be described as a prelude to better understanding the above aspects.

Challenges in liver transplantation in the context of a major pandemic

Coronavirus disease-2019 (COVID-19) has led to a temporary suspension of liver transplant activity across the world and the remodeling of care for patients on the waiting list and transplant recipients with the increasing use of remote consultations. Emerging evidence shows that patients with more advanced liver disease are at increased risk of severe COVID-19 and death, whereas transplant recipients have similar risk with the general population which is mainly driven by age and metabolic comorbidities. Tacrolimus immunosuppression might have a protective role in the post-transplant population. Vaccines that have become rapidly available seem to be safe in liver patients, but the antibody response in transplant patients is likely suboptimal. Most transplant centers were gradually able to resume activity soon after the onset of the pandemic and after modifying their pathways to optimize safety for patients and workforce. Preliminary evidence regarding utilizing grafts from positive donors and/or transplanting recently recovered or infected recipients under certain circumstances is encouraging and may allow offering life-saving transplant to patients at the greatest need. This review summarizes the currently available data on liver transplantation in the context of a major pandemic and discusses areas of uncertainty and future challenges. Lessons learnt from the COVID-19 pandemic might provide invaluable guidance for future pandemics.

COVID-19-associated liver injury: Clinical characteristics, pathophysiological mechanisms and treatment management

Coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), has become a global epidemic and poses a major threat to public health. In addition to COVID-19 manifesting as a respiratory disease, patients with severe disease also have complications in extrapulmonary organs, including liver damage. Abnormal liver function is relatively common in COVID-19 patients; its clinical manifestations can range from an asymptomatic elevation of liver enzymes to decompensated hepatic function, and liver injury is more prevalent in severe and critical patients. Liver injury in COVID-19 patients is a comprehensive effect mediated by multiple factors, including liver damage directly caused by SARS-CoV-2, drug-induced liver damage, hypoxia reperfusion dysfunction, immune stress and inflammatory factor storms. Patients with chronic liver disease (especially alcohol-related liver disease, nonalcoholic fatty liver disease, cirrhosis and hepatocellular carcinoma) are at increased risk of severe disease and death after infection with SARS-CoV-2, and COVID-19 aggravates liver damage in patients with chronic liver disease. This article reviews the latest SARS-CoV-2 reports, focusing on the liver damage caused by COVID-19 and the underlying mechanism, and expounds on the risk, treatment and vaccine safety of SARS-CoV-2 in patients with chronic liver disease and liver transplantation.