Decreased Long-Term Severe Acute Respiratory Syndrome Coronavirus 2-Specific Humoral Immunity in Liver Transplantation Recipients 12 Months After Coronavirus Disease 2019

Clinical application of COVID-19 vaccine in liver transplant recipients

BACKGROUND

Solid organ transplant (SOT) activities, such as liver transplant, have been greatly influenced by the pandemic of coronavirus disease 2019 (COVID-19), a disease caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Immunosuppressed individuals of liver transplant recipients (LTRs) tend to have a high risk of COVID-19 infection and related complications. Therefore, COVID-19 vaccination has been recommended to be administered as early as possible in LTRs.

DATA SOURCES

The keywords "liver transplant", "SARS-CoV-2", and "vaccine" were used to retrieve articles published in PubMed.

RESULTS

The antibody response following the 1st and 2nd doses of vaccination was disappointingly low, and the immune responses among LTRs remarkably improved after the 3rd or 4th dose of vaccination. Although the 3rd or 4th dose of COVID-19 vaccine increased the antibody titer, a proportion of patients remained unresponsive. Furthermore, recent studies showed that SARS-CoV-2 vaccine could trigger adverse events in LTRs, including allograft rejection and liver injury.

CONCLUSIONS

This review provides the recently reported data on the antibody response of LTRs following various doses of vaccine, risk factors for poor serological response and adverse events after vaccination.

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.

Microbiome and intestinal pathophysiology in post-acute sequelae of COVID-19

Long COVID, also known for post-acute sequelae of COVID-19, describes the people who have the signs and symptoms that continue or develop after the acute COVID-19 phase. Long COVID patients suffer from an inflammation or host responses towards the virus approximately 4 weeks after initial infection with the SARS CoV-2 virus and continue for an uncharacterized duration. Anyone infected with COVID-19 before could experience long-COVID conditions, including the patients who were infected with SARS CoV-2 virus confirmed by tests and those who never knew they had an infection early. People with long COVID may experience health problems from different types and combinations of symptoms over time, such as fatigue, dyspnea, cognitive impairments, and gastrointestinal (GI) symptoms (e.g., nausea, vomiting, diarrhea, decreased or loss of appetite, abdominal pain, and dysgeusia). The critical role of the microbiome in these GI symptoms and long COVID were reported in clinical patients and experimental models. Here, we provide an overall view of the critical role of the GI tract and microbiome in the development of long COVID, including the clinical GI symptoms in patients, dysbiosis, viral-microbiome interactions, barrier function, and inflammatory bowel disease patients with long COVID. We highlight the potential mechanisms and possible treatment based on GI health and microbiome. Finally, we discuss challenges and future direction in the long COVID clinic and research.

SARS-CoV-2-Specific T Cell Responses in Immunocompromised Individuals with Cancer, HIV or Solid Organ Transplants

Adaptive immune responses play an important role in the clinical course of SARS-CoV-2 infection. While evaluations of the virus-specific defense often focus on the humoral response, cellular immunity is crucial for the successful control of infection, with the early development of cytotoxic T cells being linked to efficient viral clearance. Vaccination against SARS-CoV-2 induces both CD4+ and CD8+ T cell responses and permits protection from severe COVID-19, including infection with the currently circulating variants of concern. Nevertheless, in immunocompromised individuals, first data imply significantly impaired SARS-CoV-2-specific immune responses after both natural infection and vaccination. Hence, these high-risk groups require particular consideration, not only in routine clinical practice, but also in the development of future vaccination strategies. In order to assist physicians in the guidance of immunocompromised patients, concerning the management of infection or the benefit of (booster) vaccinations, this review aims to provide a concise overview of the current knowledge about SARS-CoV-2-specific cellular immune responses in the vulnerable cohorts of cancer patients, people living with HIV (PLWH), and solid organ transplant recipients (SOT). Recent findings regarding the virus-specific cellular immunity in these differently immunocompromised populations might influence clinical decision-making in the future.

Major Update 2: Antibody Response and Risk for Reinfection After SARS-CoV-2 Infection-Final Update of a Living, Rapid Review

BACKGROUND

The durability of the antibody response after SARS-CoV-2 infection and the role of antibodies in protection against reinfection are unclear.

PURPOSE

To synthesize evidence on the SARS-CoV-2 antibody response and reinfection risk with a focus on gaps identified in our prior reports.

DATA SOURCES

MEDLINE (Ovid), EMBASE, CINAHL, World Health Organization Research Database, and reference lists from 16 December 2021 through 8 July 2022, with surveillance through 22 August 2022.

STUDY SELECTION

English-language, cohort studies evaluating IgG antibody duration at least 12 months after SARS-CoV-2 infection, the antibody response among immunocompromised adults, predictors of nonseroconversion, and reinfection risk.

DATA EXTRACTION

Two investigators sequentially extracted study data and rated quality.

DATA SYNTHESIS

Most adults had IgG antibodies after SARS-CoV-2 infection at time points greater than 12 months (low strength of evidence [SoE]). Although most immunocompromised adults develop antibodies, the overall proportion with antibodies is lower compared with immunocompetent adults (moderate SoE for organ transplant patients and low SoE for patients with cancer or HIV). Prior infection provided substantial, sustained protection against symptomatic reinfection with the Delta variant (high SoE) and reduced the risk for severe disease due to Omicron variants (moderate SoE). Prior infection was less protective against reinfection with Omicron overall (moderate SoE), but protection from earlier variants waned rapidly (low SoE).

LIMITATION

Single review for abstract screening and sequential review for study selection, data abstraction, and quality assessment.

CONCLUSION

Evidence for a sustained antibody response to SARS-CoV-2 infection is considerable for both Delta and Omicron variants. Prior infection protected against reinfection with both variants, but, for Omicron, protection was weaker and waned rapidly. This information may have limited clinical applicability as new variants emerge.

PRIMARY FUNDING SOURCE

Agency for Healthcare Research and Quality. (PROSPERO: CRD42020207098).

COVID-19 and liver disease

Knowledge on SARS-CoV-2 infection and its resultant COVID-19 in liver diseases has rapidly increased during the pandemic. Hereby, we review COVID-19 liver manifestations and pathophysiological aspects related to SARS-CoV-2 infection in patients without liver disease as well as the impact of COVID-19 in patients with chronic liver disease (CLD), particularly cirrhosis and liver transplantation (LT). SARS-CoV-2 infection has been associated with overt proinflammatory cytokine profile, which probably contributes substantially to the observed early and late liver abnormalities. CLD, particularly decompensated cirrhosis, should be regarded as a risk factor for severe COVID-19 and death. LT was impacted during the pandemic, mainly due to concerns regarding donation and infection in recipients. However, LT did not represent a risk factor per se of worse outcome. Even though scarce, data regarding COVID-19 specific therapy in special populations such as LT recipients seem promising. COVID-19 vaccine-induced immunity seems impaired in CLD and LT recipients, advocating for a revised schedule of vaccine administration in this population.