Commentary

COVID-19 and liver disease: Answering the key questions

Publish date: September 3, 2021

Do immunosuppressed patients face unique risks from infection?

Data from a limited case series, patient registries, and multicenter international studies have indicated that the clinical outcome of SARS-CoV-2 infection in adults with autoimmune hepatitis (AIH) was comparable to that noted in nonimmunosuppressed persons. However, it has also been suggested that a more complicated relationship exists between this virus and autoimmunity because immunosuppression may actually protect against the inappropriate immune response, or cytokine storm, engendered during severe SARS-CoV-2 infection.

The complexity of this relationship is further illustrated by a report from Bril and colleagues that described a case of AIH that developed after a patient had received a COVID-19 vaccine. The authors were careful to state that a causal relationship between receipt of the vaccine and the onset of AIH cannot be proven.

What’s the impact on liver transplant recipients?

Findings are limited regarding clinical outcomes and disease severity of SARS-CoV-2 infection in liver transplant recipients, but initial reports raised concern for high rates of adverse outcomes.^16-25

Tien and colleagues reported an increased risk for COVID-related death among liver transplant recipients. Separate international multicenter studies published in 2020 and 2021 found that liver transplant patients with COVID-19 had a significantly higher risk for hospitalization but no higher risk for mortality, thrombosis, or ICU requirement, compared with patients with COVID-19 who had not undergone liver transplantation. Increased age and the presence of comorbidities were determinants of the severity of SARS-CoV-2 infection and of mortality among liver transplant recipients.

Clearly, more data are needed to address the influence of liver transplantation in patients with COVID-19; however, some risk/protective factors have been cited. For example, Belli and colleagues reported that the use of tacrolimus was associated with a better outcome. Conversely, baseline immunosuppression containing mycophenolate mofetil was an independent predictor of severe COVID-19 in liver transplant recipients.

Do COVID-19 vaccines work differently in patients with liver disease?

Unfortunately, we haven’t been able to address many of our patients’ questions related to vaccine efficacy, safety, and durability. Data are limited because immunocompromised patients were excluded from the phase 3 trials of the COVID-19 vaccines.

We also need greater clarity on the robustness of the response to these vaccines in liver transplant recipients. Rabinowich and colleagues evaluated humoral antibody responses after vaccination with the mRNA-based vaccine BNT162b2 (BioNTech/Pfizer) and confirmed lower immunogenicity in liver transplant recipients. Antibodies were detectable in only 48% of patients, compared with 100% of healthy controls; in addition, antibody titers were significantly lower. Unfortunately, there are no data on the correlation of protection from SARS-CoV-2 with antibody titers.

Additional data will be required to assess vaccine effectiveness in protecting against severe COVID-19 as well as to determine the magnitude of humoral vaccine responses in recipients treated with high-dose steroids and mycophenolate mofetil. In addition, we eagerly await studies that determine whether booster doses are required.

What’s the bottom line?

In the face of the COVID-19 pandemic, our understanding of the impact on our patients remains a work in progress.

As we await more clarity, there are a few practical points of clinical relevance we take away from the literature, the recently released joint Statement on COVID-19 Vaccination in Solid Organ Transplant Recipients, and the American Association for the Study of Liver Diseases (AASLD) consensus statement. These suggest clinicians take the following steps:

When assessing patients with SARS-CoV-2 infection and elevated AST and ALT levels, the first objective is to rule out etiologies unrelated to COVID-19, specifically other viruses and drug-induced injury, as well as nonhepatic causes (e.g., myositis, cardiac injury, ischemia).
Reduction in immunosuppression in SARS-CoV-2–infected patients with AIH should be considered carefully and generally undertaken only in those with severe illness.
Pretransplant SARS-CoV-2 vaccination is recommended for all liver transplant candidates and liver transplant recipients as well as their household members and caregivers, to reduce exposure for these patients, along with continued adherence to protective measures (masking and social distancing).
Continuation of a stable posttransplant immunosuppression regimen at the time of vaccination is recommended to avoid the risk for organ rejection until more comprehensive data are available.

For updated responses to the evolving guidelines, visit the AASLD’s resource center.

William F. Balistreri, MD, is the Dorothy M.M. Kersten Professor of Pediatrics; director emeritus, pediatric liver care center; medical director emeritus, liver transplantation; and professor, University of Cincinnati College of Medicine, department of pediatrics, Cincinnati Children’s Hospital Medical Center. He has served as director of the division of gastroenterology, hepatology and nutrition at Cincinnati Children’s for 25 years and frequently covers gastroenterology, liver, and nutrition-related topics for this news organization. Dr Balistreri is currently editor-in-chief of the Journal of Pediatrics, having previously served as editor-in-chief of several journals and textbooks. He also became the first pediatrician to act as president of the American Association for the Study of Liver Diseases. He has disclosed no relevant financial relationships.