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

Update in clinical science: Autoimmune hepatitis

Autoimmune hepatitis (AIH) is an enigmatic, relatively rare disease with a variable spectrum of presentation whose pathogenesis, diagnosis and management remain a major challenge. We have performed a review of recent developments in basic science, epidemiology, clinical science, therapeutics, and regulatory science, evaluating the challenges associated with the application of translational research and clinical trial design to a condition that is a chameleon in nature, where outcomes range from relatively benign disease through cirrhosis and acute liver failure. This review is focused on developments from 2020 onwards so we can present a forward-looking view on the challenges and remaining questions that must be addressed to improve patient care and outcomes in AIH. We also outline areas of debate and offer insights into these areas.

Post-COVID-19 Pandemic Sequelae in Liver Diseases

During the coronavirus disease 2019 (COVID-19) pandemic, several studies highlighted a worse prognosis for patients with alterations in liver function tests, especially those with pre-existing liver diseases. However, further studies are needed to define the long-term impact of the COVID-19 pandemic on liver diseases. Long COVID-19 encompasses a wide range of signs and symptoms, including exacerbations of pre-existing chronic conditions or new onset conditions developed after the COVID-19 acute phase. Therefore, the long-term effects of COVID-19 extensively include hepatic manifestations. The co-expression of angiotensin-converting receptor 2 (ACE2) and transmembrane serine protease 2 (TMPRSS2) has been demonstrated also in enterocytes, cholangiocytes, and hepatocytes. Studies on the post-COVID-19 sequelae have shown the presence of steatosis and necroinflammation in the liver, concomitantly with an alteration of inflammation, cytolysis and cholestasis indices. Some studies also demonstrated an increased risk for hepatobiliary pathologies, including secondary biliary cholangitis and worsening of the severity of metabolic-associated fatty liver disease (MASLD). Based on these premises, this review aims to provide an overview of the pathophysiological mechanisms contributing to COVID-19-related liver and hepatobiliary damage; explore its implications for liver inflammation and fibrosis, with a particular focus on MASLD and metabolic dysfunction-associated steatohepatitis (MASH); and analyze the short- and long-term COVID-19 sequelae. A literature search was conducted using the PubMed database for relevant studies published in English.

Post COVID Condition and Long-Term COVID-19 Impact on Hepatic Decompensation and Survival in Cirrhosis: A Propensity Matched Observational Study

Aims

Patients with cirrhosis are susceptible to decompensation events, including ascites, variceal bleeding (VB), hepatic encephalopathy, or death after COVID-19 infection. Patients may experience post-COVID condition (PCC) with multisystem involvement that persists for at least 2 months.

Methods

Hospitalized patients with cirrhosis and COVID-19 between January 2021 and January 2023 were assessed for decompensation events and mortality and compared to a propensity-matched cohort of cirrhosis and non-COVID-19 sepsis. Both groups were followed for outcomes over 1 year.

Results

Of 252 patients with Cirrhosis+ COVID-19 (73% men, aged 48.9 ± 13.7 years, 31%-diabetes, 44%-hypertension, 35%-alcohol-associated, 34.5%-metabolic dysfunction-associated steatotic liver disease; MASLD), 72 (28.6%) died in hospital and 180 (71.4%) recovered, similar to Cirrhosis+ non-COVID-sepsis (58/214, 27.1%). Finally,60 (33.3%) met criteria for PCC, 19 (10.5%) had no post COVID-19 sequelae and 101 (56.1%) patients died (N = 45) or were lost to follow up (N = 56). Late Mortality was higher in Cirrhosis+ COVID-19 than non-COVID-sepsis (56.1% vs. 35.3%, p = 0.026). Patients with PCC were aged 47.6 years, 63.3%-men, Charlson Comorbidity Index > 4 (51.7%), 45%-diabetes, 56.7%-hypertension, with 33.3%, 23.3%, and 43.3% in Child-Turcotte-Pugh class A, B and C, respectively. PCC symptoms included persistent dyspnea (34, 43%), cognitive impairment (20, 25.3%), and anxiety (47, 59.4%). On multivariable analysis, predictors of the development of PCC were baseline MELDNa (HR 1.12, 95% CI: 1.05-1.17, p < 0.001) and age (HR 0.9, 95% CI: 0.91-0.99, p = 0.012). Predictors of mortality following COVID-19 recovery were MELDNa (HR 1.03, 95% CI: 1.01-1.05, p = 0.008), age (HR 1.2, 95% CI: 1.1-1.5, p = 0.002) and hypertension (HR 1.63, 95% CI: 1.07-2.49, p = 0.025).

Conclusion

COVID-19 is associated with long-term mortality in cirrhosis even after recovery from respiratory infection. Long COVID is seen in a third of COVID-19 survivors in patients with cirrhosis.

SARS-CoV-2 Infection and Liver Transplant: How Are We Now?

BACKGROUND

The Omicron variant of SARS-CoV-2 emerged as a new variant of concern, characterized by high transmissibility and lower severity compared with previous variants, and became the majority variant in the sixth wave in Spain. This study aims to assess the impact of SARS-CoV-2 infection on liver transplant recipients (LTRs) during 2023 in the population of Cantabria.

METHODS

The study included 295 LTRs undergoing follow-up at the Liver Transplant Unit of the Marqués de Valdecilla University Hospital. Data on patient characteristics, comorbidities, and vaccination schedules were collected. Humoral response to mRNA vaccines was evaluated using IgG antibodies against the S protein and an adequate response was defined as antibody titers of >260 BAU/mL 1 month after the third vaccine dose.

RESULTS

In Cantabria, 0.75% of the general population and 7.10% of LTRs were infected with SARS-CoV-2. Most LTRs were men with comorbidities, mainly cardiovascular disease and hypertension. Of the LTRs, 95.2% were fully vaccinated and received 3 doses of the Moderna mRNA vaccine, and all had an adequate response after 4 to 5 doses. Most infections in LTRs were asymptomatic or mild, with lower hospitalization rates. No LTRs required intensive care admission or died owing to SARS-CoV-2 infection.

CONCLUSIONS

LTRs are targets for SARS-CoV-2 vaccination. The Omicron variant has shown greater transmissibility but causes milder disease in vaccinated LTRs. All vaccinated LTRs showed an adequate response after 4 to 5 doses. Therefore, vaccination protects against severe disease and mortality in LTRs, and booster vaccinations with variant-adapted vaccines are recommended.

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.

Immune Response to SARS-CoV-2 XBB.1.5 and JN.1 Variants Following XBB.1.5 Booster Vaccination in Liver Transplant Recipients

BACKGROUND/OBJECTIVES

The efficacy of monovalent BNT162b2 Omicron XBB.1.5 booster vaccination in liver transplant recipients (LTRs) has yet to be described, particularly regarding the immune response to emerging variants like JN.1.

METHODS

This study evaluated humoral and cellular immune responses in 34 liver transplant recipients (LTRs) with varying SARS-CoV-2 immune histories before and after receiving a BNT162b2 Omicron XBB.1.5 booster vaccination. The assessment involved variant-specific serology, pseudovirus neutralization tests, and Interferon-γ release assays.

RESULTS

Participants had a median of four prior vaccinations, with 91.2% having a history of infection. Post-vaccination, significant increases in both Wuhan anti-S and Omicron-specific IgG antibodies and improved neutralization of B.1, XBB.1.5, and JN.1 pseudovirus particles were observed. Also, T-cell responses significantly increased post-vaccination. However, 17.6% of LTRs had no neutralizing antibodies against XBB.1.5 and JN.1, while 100% of healthy controls did. Shortly after vaccination, 18% of patients developed mild COVID-19. These LTRs had particularly low immune responses at baseline.

CONCLUSIONS

The monovalent XBB.1.5 booster improved overall SARS-CoV-2-specific immunity. However, some LTRs still showed low or undetectable immune responses, indicating that ongoing monitoring and further booster doses are necessary in this high-risk group.

The immune response in chronic HBV infection

Hepatitis B virus (HBV) is an ancient virus that has evolved unique strategies to persist as a chronic infection in humans. Here, I summarize the innate and adaptive features of the HBV-host interaction, and I discuss how different profiles of antiviral immunity cannot be predicted only on the basis of virological and clinical parameters.

Impact of SARS-CoV-2 vaccination in patients with vascular liver diseases: Observations from a VALDIG multicenter study

Background & Aims

Patients with vascular liver diseases (VLD) are at higher risk of both severe courses of COVID-19 disease and thromboembolic events. The impact of SARS-CoV-2 vaccination in patients with VLD has not been described and represents the aim of our study.

Methods

International, multicenter, prospective observational study in patients with VLD analyzing the incidence of COVID-19 infection after vaccination, severity of side effects, occurrence of thromboembolic events and hepatic decompensation. In a subgroup of patients, the humoral and cellular responses to vaccination were also analyzed.

Results

A total of 898 patients from 14 European centers - part of the VALDIG network - were included, 872 (97.1%) patients received two vaccine doses (fully vaccinated), and 674 (75.1%) three doses. Of the total cohort, 151/898 had a COVID-19 infection prior to vaccination, of whom 9/151 (5.9%) were re-infected. Of the 747/898 patients who were not previously infected, 11.2% (84/747) were diagnosed with a COVID-19 infection during the study period. Two infected patients required intensive care unit admission and infection was fatal in two fully vaccinated patients. Adverse effects were reported in around 40% of patients, with local side effects being the most frequent. During the study period, 31 (3.5%) patients had thromboembolic events and 21 (2.3%) hepatic decompensations. No cases of vaccine-induced thrombocytopenia were reported. Vaccine immunogenicity was assessed in 36 patients; seroconversion reached 100% and IFNy T-cell responses significantly increased post two mRNA-1273 vaccine doses.

Conclusion

Patients with VLD seem to have a preserved immune response to SARS-CoV-2 vaccination, which appears to be safe and effective in preventing severe COVID-19 infection. Our study cannot definitively establish a direct link between vaccination and thrombotic events, though the contribution of vaccination as a cofactor in VLD remains to be elucidated.

Impact and implications

Patients with vascular liver disease (VLD) are at increased risk of both SARS-CoV-2 infection and severe COVID-19 disease. The potential risks associated with vaccination against this infection need thorough investigation. Our research enhances the understanding of the effects of COVID-19 vaccination in patients with VLD, highlighting its good tolerability. Moreover, patients with VLD appear to have a preserved immune response to SARS-CoV-2 vaccination, providing protection against severe COVID-19 infection. Our study cannot definitively establish a direct link between vaccination and thrombotic events, and no cases of vaccine-induced thrombocytopenia were reported.

Safety and Efficacy of SARS-CoV-2 Vaccines in Patients With Chronic Liver Diseases: A Systematic Review and Meta-Analysis

Objectives

This review aimed to assess the safety and efficacy of SARS-CoV-2 vaccines in patients with chronic liver disease (CLD).

Methods

Cochrane Central Register of Controlled Trials, PubMed, Embase, and Web of Science were searched from 2020 to 2024. Data was extracted following Preferred Reporting Items for Systematic Review and Meta-Analyses guidelines. The random-effects model (when I2 ≥ 50%) or fixed effect model (I2 < 50%) was used.

Results

29 studies were included in this review. Compared to healthy controls (HCs), patients with CLD had a higher incidence of mild adverse events (RR = 1.60, p < 0.001), while the incidence of severe adverse events was similar (RR = 1.08, p = 0.92). Seropositivity rates of three antibodies in patients were lower than in HCs [neutralizing antibody (RR = 0.86, p = 0.002), anti-spike antibody (RR = 0.97, p = 0.06) and anti-receptor binding domain antibody (RR = 0.95, p = 0.04)]. Compared to unvaccinated patients, vaccinated patients had lower rates of SARS-CoV-2 infection, hospitalization and death (p ≤ 0.05).

Conclusion

SARS-CoV-2 vaccines showed good safety and efficacy in CLD patients, but antibody response appeared to be decreased. Therefore, SARS-CoV-2 vaccines and booster doses should be given priority in this vulnerable population.

Liver transplantation for cirrhosis and its complications

OBJECTIVES

To review the current indications for liver transplantation (LT) in cirrhosis, including evolving criteria for hepatocellular carcinoma (HCC) and other malignancies, how donor organ allocation is established, and to address challenges of long-term complications post-transplantation.

METHODS

A comprehensive review of the literature was conducted to evaluate advancements in LT indications, pretransplant evaluation protocols, organ allocation strategies, and management approaches for long-term post-transplant complications.

RESULTS

Liver transplantation remains the definitive treatment for cirrhosis and offers substantial survival benefits for patients with early-stage HCC. Recent advancements have expanded eligibility criteria to include patients with multiple comorbidities, advanced-stage HCC, and select malignancies, provided they meet specific selection criteria. The increasing demand for donor organs has driven innovations in donor pool expansion, which presents new challenges in recipient management, including the need for tailored pretransplant workups and strategies to mitigate long-term complications.

CONCLUSION

The field of liver transplantation continues to evolve, with broader indications and innovative approaches to donor pool expansion. These advancements necessitate careful patient selection, rigorous pretransplant evaluation, and effective long-term management strategies to optimize outcomes for transplant recipients.