COVID-19 in liver transplant recipients: incidence, hospitalization and outcome in an Italian prospective double-centre study

The Impact and Evolution of COVID-19 on Liver Transplant Recipients Throughout the Pandemic "Waves" in a Single Center

Liver transplant recipients (LTRs) have been considered a population group that is vulnerable to COVID-19 as they are chronically immunosuppressed patients with frequent comorbidities. This study describes the course of the SARS-CoV-2 disease from February 2020 to December 2023 along seven pandemic "waves". We carried out an observational study on 307 COVID-19 cases in a cohort of LTRs with the aim of evaluating the changes in the disease characteristics over time and determining the risk factors for severe COVID-19. An older age and serum creatinine level ≥ 2 mg/dL were found to be risk factors for hospital admission and respiratory failure. The use of calcineurin inhibitors was a protective factor for death, hospitalization, and respiratory failure from COVID-19. One hundred percent of patients who died (N = 12) were on mycophenolate mofetil, which was a determinant for respiratory failure. Azathioprine was associated with admission to the intensive care unit (ICU) and with invasive mechanical ventilation (IMV). Vaccination was a protective factor for hospitalization, respiratory failure, and mortality. The severe COVID-19 rate was higher during the first five waves, with a peak of 57.14%, and the highest mortality rate (21.43%) occurred in the fourth wave. The IMV and ICU admission rates did not show significant differences across the periods studied.

Drug-induced liver injury during the era of COVID-19 polypharmacy: a statement of account, lessons learned, and a proposed approach

The coronavirus disease 2019 (COVID-19) causes a systemic illness that can result in various manifestations. In addition to severe acute respiratory syndrome, patients often exhibit complications unrelated to the respiratory system. Potential liver damage can occur in 14.8 to 53.0% of the affected patients. Liver impairment in COVID-19 can also occur because of the use of polypharmacy during disease management. It is essential to be aware of drug-induced liver injury (DILI) in patients diagnosed with COVID-19, especially when considering the off-label usage of medications in both preventative and therapeutic regimens used on a wide scale. This review aims to give pertinent information regarding drugs utilized thus far in COVID-19 patients and their potential toxicity to the liver. We also present a suggested management approach to DILI in COVID-19 patients and lessons learned from the pharmacological management of this pandemic.

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.

Epidemiology and Management of Infections in Liver Transplant Recipients

Background: Improvements in liver transplant (LT) outcomes are attributed to advances in surgical techniques, use of potent immunosuppressants, and rigorous pre-LT testing. Despite these improvements, post-LT infections remain the most common complication in this population. Bacteria constitute the most common infectious agents, while fungal and viral infections are also frequently encountered. Multi-drug-resistant bacterial infections develop because of polymicrobial overuse and prolonged hospital stays. Immediate post-LT infections are commonly caused by viruses. Conclusions: Appropriate vaccination, screening of both donor and recipients before LT and antiviral prophylaxis in high-risk individuals are recommended. Antimicrobial drug resistance is common in high-risk LT and associated with poor outcomes; epidemiology and management of these cases is discussed. Additionally, we also discuss the effect of coronavirus disease 2019 (COVID-19) infection and monkeypox in the LT population.

Clinical characteristics and outcomes of liver transplant recipients infected by Omicron during the opening up of the dynamic zero-coronavirus disease policy in China: A prospective, observational study

We analyzed the characteristics, risk factors, outcomes, and post-coronavirus disease 2019 (COVID-19) symptoms in liver transplant recipients in China's late 2022 COVID-19 wave. Recipients with COVID-19 were enrolled from December 1, 2022, to January 31, 2023, and followed up until May 31, 2023. Baseline and characteristic data were collected. A total of 930 recipients were included, with a vaccination rate (non-mRNA) of 40.0%. Among 726 (78.1%) recipients with COVID-19, 641 (88.3%) patients were treated at home, 81 (11.2%) patients required hospitalization in general wards, 4 (0.6%) patients required intensive care, and 1 (0.1%) patient died because of COVID-19. Severe acute respiratory syndrome coronavirus 2 infection was related to close contact with confirmed cases (P < .001) and the condition of end-stage kidney disease (P < .046). Older age, male sex, less vaccination, and hypertension were independent risk factors for hospitalization. Fatigue (36.9%) was the most common symptom post-COVID-19, followed by memory loss (35.7%) and sleep disturbance (23.9%). Two doses of vaccines had a protective effect against these post-COVID-19 symptoms (P < .05). During this Omicron outbreak, liver transplant recipients were susceptible to COVID-19, with frequent hospitalization but low mortality. Two doses of non-mRNA COVID-19 vaccines could protect against liver transplant recipient hospitalization and post-COVID-19 symptoms.

Impact of COVID-19 vaccination on liver transplant recipients. Experience in a reference center in Mexico

BACKGROUND AND AIMS

COVID-19 vaccination has proved to be effective to prevent symptomatic infection and severe disease even in immunocompromised patients including liver transplant patients. We aim to assess the impact of COVID-19 vaccination on the mortality and development of severe and critical disease in our center.

METHODS

A retrospective cohort study of LT patients in a reference center between March 2020 and February 2022. Demographic data, cirrhosis etiology, time on liver transplantation, immunosuppressive therapies, and vaccination status were recorded at the time of diagnosis. Primary outcome was death due to COVID-19, and secondary outcomes included the development of severe COVID-19 and intensive care unit (ICU) requirement.

RESULTS

153 of 324 LT recipients developed COVID-19, in whom the main causes of cirrhosis were HCV infection and metabolic-associated fatty liver disease. The vaccines used were BNT162b2 (48.6%), ChAdOx1 nCoV-19 (21.6%), mRNA-1273 vaccine (1.4%), Sputnik V (14.9%), Ad5-nCoV-S (4.1%) and CoronaVac (9.5%). Case fatality and ICU requirement risk were similar among vaccinated and unvaccinated LT patients (adjusted relative case fatality for vaccinated versus unvaccinated of 0.68, 95% CI 0.14-3.24, p = 0.62; adjusted relative risk [aRR] for ICU requirement of 0.45, 95% CI 0.11-1.88, p = 0.27). Nonetheless, vaccination was associated with a lower risk of severe disease (aRR for severe disease of 0.32, 95% CI 0.14-0.71, p = 0.005).

CONCLUSIONS

Vaccination reduces the risk of severe COVID-19 in LT patients, regardless of the scheme used. Vaccination should be encouraged for all.

COVID-19-associated liver injury: Adding fuel to the flame

COVID-19 is mainly characterized by respiratory disorders and progresses to multiple organ involvement in severe cases. With expansion of COVID-19 and SARS-CoV-2 research, correlative liver injury has been revealed. It is speculated that COVID-19 patients exhibited abnormal liver function, as previously observed in the SARS and MERS pandemics. Furthermore, patients with underlying diseases such as chronic liver disease are more susceptible to SARS-CoV-2 and indicate a poor prognosis accompanied by respiratory symptoms, systemic inflammation, or metabolic diseases. Therefore, COVID-19 has the potential to impair liver function, while individuals with preexisting liver disease suffer from much worse infected conditions. COVID-19 related liver injury may be owing to direct cytopathic effect, immune dysfunction, gut-liver axis interaction, and inappropriate medication use. However, discussions on these issues are infancy. Expanding research have revealed that angiotensin converting enzyme 2 (ACE2) expression mediated the combination of virus and target cells, iron metabolism participated in the virus life cycle and the fate of target cells, and amino acid metabolism regulated immune response in the host cells, which are all closely related to liver health. Further exploration holds great significance in elucidating the pathogenesis, facilitating drug development, and advancing clinical treatment of COVID-19-related liver injury. This article provides a review of the clinical and laboratory hepatic characteristics in COVID-19 patients, describes the etiology and impact of liver injury, and discusses potential pathophysiological mechanisms.

Evolution of humoral immune response to SARS-CoV-2 mRNA vaccine in liver transplant recipients - a longitudinal study

BACKGROUND AND AIM

Liver transplant recipients show suboptimal vaccine-elicited immune responses to severe acute respiratory coronavirus 2 (SARS-CoV-2) vaccination. This study aimed to assess real-world data on SARS-CoV-2 antibodies after the second and third SARS-CoV-2 vaccination in liver transplant recipients in Switzerland.

METHODS

We enrolled liver transplant recipients who attended regular follow-up visits between 01/07/2021 and 30/04/2022 at the outpatient clinic of the Department of Visceral Surgery and Medicine at Bern University Hospital, Switzerland. Following the Swiss Federal Office of Public Health recommendations, we measured SARS-CoV-2 anti-spike IgG antibodies in 117 liver transplant recipients ≥4 weeks after the second SARS-CoV-2 mRNA vaccination from 07/2021-04/2022. In case of antibody levels of <100 AU/ml, patients received a third vaccination and antibodies were re-measured. Patients with antibody levels of >100 AU/ml were defined as "responders", those with 12-100 AU/ml as "partial responders" and those with <12 AU/ml as "non-responders".

RESULTS

After two vaccinations, 36/117 (31%) were responders, 42/117 (36%) were partial responders and 39/117 (33%) were non-responders. The humoral immune response improved significantly after the third vaccination, resulting in 31/55 (56%) responders among the previous partial or non-responders. A total of 26 patients developed COVID-19, of whom two had a moderate or severe course (both non-responders after three doses).

DISCUSSION

One third of liver transplant recipients showed an optimal response following two vaccinations; a third dose achieved a complete antibody response in more than half of partial and non-responders. We observed only one severe course of COVID-19 and no deaths from COVID-19 in the vaccinated liver transplant recipients.

COVID-19 and Liver Disease: An Evolving Landscape

The COVID-19 pandemic has resulted in significant worldwide morbidity and mortality. In this review, we examine the intricate relationships between COVID-19 and liver diseases. While respiratory manifestations of COVID-19 are well known, its impact and consequences in patients with liver diseases remain an area of ongoing investigation. COVID-19 can induce liver injury through various mechanisms and is associated with higher mortality in individuals with preexisting chronic liver disease. Mortality increases with the severity of chronic liver disease and the level of care required. The outcomes in patients with autoimmune hepatitis remain unclear, whereas liver transplant recipients are more likely to experience symptomatic COVID-19 but have comparable outcomes to the general population. Despite suboptimal immunological response, COVID-19 vaccinations are safe and effective in liver disease, although cases of autoimmune hepatitis-like syndrome have been reported. In conclusion, COVID-19 has significant implications in liver diseases; early recognition and treatments are important for improving patient outcomes.

Effect of COVID-19 Pandemic on Patients Who Have Undergone Liver Transplantation: Retrospective Cohort Study

BACKGROUND

In liver transplant (LT) recipients, immunosuppressive therapy may potentially increase the risk of severe COVID-19 and may increase the mortality in patients. However, studies have shown conflicting results, with various studies reporting poor outcomes while the others show no difference between the LT recipients and healthy population. The aim of this study is to determine the impact of the COVID-19 pandemic on survival of LT recipients.

METHODS

This is a retrospective cohort study analyzing the data from 387 LT recipients diagnosed with COVID-19. LT recipients were divided into two groups: survival (n = 359) and non-survival (n = 28) groups. A logistic regression model was used to determine the independent risk factors for mortality. Machine learning models were used to analyze the contribution of independent variables to the mortality in LT recipients.

RESULTS

The COVID-19-related mortality rate in LT recipients was 7.2%. Multivariate analysis showed that everolimus use (p = 0.012; OR = 6.2), need for intubation (p = 0.001; OR = 38.4) and discontinuation of immunosuppressive therapy (p = 0.047; OR = 7.3) were independent risk factors for mortality. Furthermore, COVID-19 vaccination reduced the risk of mortality by 100 fold and was the single independent factor determining the survival of the LT recipients.

CONCLUSION

The effect of COVID-19 infection on LT recipients is slightly different from the effect of the disease on the general population. The COVID-19-related mortality is lower than the general population and vaccination for COVID-19 significantly reduces the risk of mortality.

The Italian data on SARS-CoV-2 infection in transplanted patients support an organ specific immune response in liver recipients

Introduction

The study of immune response to SARSCoV-2 infection in different solid organ transplant settings represents an opportunity for clarifying the interplay between SARS-CoV-2 and the immune system. In our nationwide registry study from Italy, we specifically evaluated, during the first wave pandemic, i.e., in non-vaccinated patients, COVID-19 prevalence of infection, mortality, and lethality in liver transplant recipients (LTRs), using non-liver solid transplant recipients (NL-SOTRs) and the Italian general population (GP) as comparators.

Methods

Case collection started from February 21 to June 22, 2020, using the data from the National Institute of Health and National Transplant Center, whereas the data analysis was performed on September 30, 2020.To compare the sex- and age-adjusted distribution of infection, mortality, and lethality in LTRs, NL-SOTRs, and Italian GP we applied an indirect standardization method to determine the standardized rate.

Results

Among the 43,983 Italian SOTRs with a functioning graft, LTRs accounted for 14,168 patients, of whom 89 were SARS-CoV-2 infected. In the 29,815 NL-SOTRs, 361 cases of SARS-CoV-2 infection were observed. The geographical distribution of the disease was highly variable across the different Italian regions. The standardized rate of infection, mortality, and lethality rates in LTRs resulted lower compared to NL-SOTRs [1.02 (95%CI 0.81-1.23) vs. 2.01 (95%CI 1.8-2.2); 1.0 (95%CI 0.5-1.5) vs. 4.5 (95%CI 3.6-5.3); 1.6 (95%CI 0.7-2.4) vs. 2.8 (95%CI 2.2-3.3), respectively] and comparable to the Italian GP.

Discussion

According to the most recent studies on SOTRs and SARS-CoV-2 infection, our data strongly suggest that, in contrast to what was observed in NL-SOTRs receiving a similar immunosuppressive therapy, LTRs have the same risk of SARS-CoV-2 infection, mortality, and lethality observed in the general population. These results suggest an immune response to SARS-CoV-2 infection in LTRS that is different from NL-SOTRs, probably related to the ability of the grafted liver to induce immunotolerance.

Effect of COVID-19 Pandemic on Patients Who Have Undergone Liver Transplantation Because of Hepatocellular Carcinoma

BACKGROUND AND AIM

Many clinical studies have shown that the COVID-19 case fatality rate is higher in older patients, those with comorbidities, those with immunosuppressive conditions, and those who stay in the intensive care unit. This study aims to evaluate the clinical outcomes of 66 liver transplant (LT) patients with primary liver cancer who were exposed to COVID-19 infection.

METHODS

Demographic and clinical data of 66 patients with primary liver cancer (hepatocellular carcinoma = 64, hepatoblastoma = 1, cholangiocarcinoma = 1) who underwent LT in our institute and were exposed to COVID-19 infection between March 2020 and November 2021 were analyzed in this cross-sectional study. The following data of the patients were recorded: age, sex, body mass index (kg/m2), blood group, underlying primary liver disease, smoking, tumor characteristics, post-transplant immunosuppressive agents, COVID-19 symptoms, hospitalization, intensive care unit stay, intubation, and other clinical features.

RESULTS

There were 55 (83.3%) male and 11 (16.7%) female patients, with a median age of 58 years. Sixty-four patients were exposed to COVID-19 only once, whereas the remaining 2 patients were exposed 2 and 4 times, respectively. After exposure to COVID-19, it was determined that 37 patients used antiviral drugs, 25 were hospitalized, 9 were followed in the intensive care unit, and 3 were intubated. One intubated patient was under hospital follow-up because of biliary complications before exposure to COVID-19, and this patient died from sepsis.

CONCLUSION

The low mortality rate of LT patients with primary liver cancer exposed to COVID-19 infection can be attributed to background immunosuppression that prevents cytokine storm. However, it is appropriate to support this study with multicenter studies to make strong comments on this issue.

COVID-19 and liver injury: Pathophysiology, risk factors, outcome and management in special populations

The coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus-2 is an ongoing health concern. In addition to affecting the respiratory system, COVID-19 can potentially damage other systems in the body, leading to extra-pulmonary manifestations. Hepatic manifestations are among the common consequences of COVID-19. Although the precise mechanism of liver injury is still questionable, several mechanisms have been hypothesized, including direct viral effect, cytokine storm, hypoxic-ischemic injury, hypoxia-reperfusion injury, ferroptosis, and hepatotoxic medications. Risk factors of COVID-19-induced liver injury include severe COVID-19 infection, male gender, advanced age, obesity, and underlying diseases. The presentations of liver involvement comprise abnormalities in liver enzymes and radiologic findings, which can be utilized to predict the prognosis. Increased gamma-glutamyltransferase, aspartate aminotransferase, and alanine aminotransferase levels with hypoalbuminemia can indicate severe liver injury and anticipate the need for intensive care units’ hospitalization. In imaging, a lower liver-to-spleen ratio and liver computed tomography attenuation may indicate a more severe illness. Furthermore, chronic liver disease patients are at a higher risk for severe disease and death from COVID-19. Nonalcoholic fatty liver disease had the highest risk of advanced COVID-19 disease and death, followed by metabolic-associated fatty liver disease and cirrhosis. In addition to COVID-19-induced liver injury, the pandemic has also altered the epidemiology and pattern of some hepatic diseases, such as alcoholic liver disease and hepatitis B. Therefore, it warrants special vigilance and awareness by healthcare professionals to screen and treat COVID-19-associated liver injury accordingly.

Orthotopic Liver Transplantation of a SARS-CoV-2 Negative Recipient from a Positive Donor: The Border between Uncertainty and Necessity in a Pandemic Era- Case Report and Overview of the Literature

(1) Introduction: Liver transplantation represents the gold-standard therapy in eligible patients with acute liver failure or end-stage liver disease. The COVID-19 pandemic dramatically affected the transplantation landscape by reducing patients' addressability to specialized healthcare facilities. Since evidence-based acceptance guidelines for non-lung solid organ transplantation from SARS-CoV-2 positive donors are lacking, and the risk of bloodstream-related transmission of the disease is debatable, liver transplantation from SARS-CoV-2 positive donors could be lifesaving, even if long-term interactions are unpredictable. The aim of this case report is to highlight the relevance of performing liver transplantation from SARS-CoV-2 positive donors to negative recipients by emphasizing the perioperative care and short-term outcome. (2) Case presentation: A 20-year-old female patient underwent orthotropic liver transplantation for Child-Pugh C liver cirrhosis secondary to overlap syndrome, from a SARS-CoV-2 positive brain death donor. The patient was not infected nor vaccinated against SARS-CoV-2, and the titer of neutralizing antibodies against the spike protein was negative. The liver transplantation was performed with no significant complications. As immunosuppression therapy, the patient received 20 mg basiliximab (Novartis Farmacéutica S.A., Barcelona, Spain) and 500 mg methylprednisolone (Pfizer Manufacturing Belgium N.V, Puurs, Belgium) intraoperatively. Considering the risk of non-aerogene-related SARS-CoV-2 reactivation syndrome, the patient received remdesivir 200 mg (Gilead Sciences Ireland UC, Carrigtohill County Cork, Ireland) in the neo-hepatic stage, which was continued with 100 mg/day for 5 days. The postoperative immunosuppression therapy consisted of tacrolimus (Astellas Ireland Co., Ltd., Killorglin, County Kerry, Ireland) and mycophenolate mofetil (Roche România S.R.L, Bucharest, Romania) according to the local protocol. Despite the persistent negative PCR results for SARS-CoV-2 in the upper airway tract, the blood titer of neutralizing antibodies turned out positive on postoperative day 7. The patient had a favorable outcome, and she was discharged from the ICU facility seven days later. (3) Conclusions: We illustrated a case of liver transplantation of a SARS-CoV-2 negative recipient, whose donor was SARS-CoV-2 positive, performed in a tertiary, university-affiliated national center of liver surgery, with a good outcome, in order to raise the medical community awareness on the acceptance limits in the case of COVID-19 incompatibility for non-lung solid organs transplantation procedures.

Diagnosis, treatment protocols, and outcomes of liver transplant recipients infected with COVID-19

Several cases of fatal pneumonia during November 2019 were linked initially to severe acute respiratory syndrome coronavirus 2, which the World Health Organization later designated as coronavirus disease 2019 (COVID-19). The World Health Organization declared COVID-19 as a pandemic on March 11, 2020. In the general population, COVID-19 severity can range from asymptomatic/mild symptoms to seriously ill. Its mortality rate could be as high as 49%. The Centers for Disease Control and Prevention have acknowledged that people with specific underlying medical conditions, among those who need immunosuppression after solid organ transplantation (SOT), are at an increased risk of developing severe illness from COVID-19. Liver transplantation is the second most prevalent SOT globally. Due to their immunosuppressed state, liver transplant (LT) recipients are more susceptible to serious infections. Therefore, comorbidities and prolonged immunosuppression among SOT recipients enhance the likelihood of severe COVID-19. It is crucial to comprehend the clinical picture, immunosuppressive management, prognosis, and prophylaxis of COVID-19 infection because it may pose a danger to transplant recipients. This review described the clinical and laboratory findings of COVID-19 in LT recipients and the risk factors for severe disease in this population group. In the following sections, we discussed current COVID-19 therapy choices, reviewed standard practice in modifying immunosuppressant regimens, and outlined the safety and efficacy of currently licensed drugs for inpatient and outpatient management. Additionally, we explored the clinical outcomes of COVID-19 in LT recipients and mentioned the efficacy and safety of vaccination use.

Safety and Immunogenicity of Anti-SARS-CoV-2 Booster Dose in Patients with Chronic Liver Disease

The low response to vaccines is a well-known problem in cirrhosis. We evaluated the safety and immunogenicity of booster doses in patients with chronic liver disease (CLD), comparing the humoral response in cirrhotic vs. non-cirrhotic patients, and the impact of different factors on immune response. From September 2021 to April 2022, outpatients with CLD who completed the primary vaccination course and the booster dose against SARS-CoV-2 were enrolled. Blood samples were collected after second and third doses for detecting anti-spike protein IgG. We enrolled 340 patients; among them, 91 subjects were cirrhotic. After primary vaccination course, 60 (17.6%) patients did not develop a positive antibody titer, without significant differences between cirrhotic and non-cirrhotic patients (p = 0.076); most of them (88.3%) developed it after booster dose. At multivariable analysis, factors associated with higher humoral response after booster dose were only porto-sinusoidal vascular disorder (p = 0.007) as an etiology of CLD and the use of the mRNA-1273 vaccine (p = 0.001). In conclusion, in patients with CLD, a booster dose against SARS-CoV-2 induces an excellent immunogenicity and leads to an adequate antibody response. Cirrhosis is not associated with a worse humoral response, compared to patients with non-cirrhotic CLD.

Boosting compromised SARS-CoV-2-specific immunity with mRNA vaccination in liver transplant recipients

BACKGROUND & AIMS

Liver transplant recipients (LTRs) demonstrate a reduced response to COVID-19 mRNA vaccination; however, a detailed understanding of the interplay between humoral and cellular immunity, especially after a third (and fourth) vaccine dose, is lacking.

METHODS

We longitudinally compared the humoral, as well as CD4+ and CD8+ T-cell, responses between LTRs (n = 24) and healthy controls (n = 19) after three (LTRs: n = 9 to 16; healthy controls: n = 9 to 14 per experiment) to four (LTRs: n = 4; healthy controls: n = 4) vaccine doses, including in-depth phenotypical and functional characterization.

RESULTS

Compared to healthy controls, development of high antibody titers required a third vaccine dose in most LTRs, while spike-specific CD8+ T cells with robust recall capacity plateaued after the second vaccine dose, albeit with a reduced frequency and epitope repertoire compared to healthy controls. This overall attenuated vaccine response was linked to a reduced frequency of spike-reactive follicular T helper cells in LTRs.

CONCLUSION

Three doses of a COVID-19 mRNA vaccine induce an overall robust humoral and cellular memory response in most LTRs. Decisions regarding additional booster doses may thus be based on individual vaccine responses as well as evolution of novel variants of concern.

IMPACT AND IMPLICATIONS

Due to immunosuppressive medication, liver transplant recipients (LTR) display reduced antibody titers upon COVID-19 mRNA vaccination, but the impact on long-term immune memory is not clear. Herein, we demonstrate that after three vaccine doses, the majority of LTRs not only exhibit substantial antibody titers, but also a robust memory T-cell response. Additional booster vaccine doses may be of special benefit for a small subset of LTRs with inferior vaccine response and may provide superior protection against evolving novel viral variants. These findings will help physicians to guide LTRs regarding the benefit of booster vaccinations.

COVID-19 in liver transplant patients: Impact and considerations

The coronavirus disease 2019 pandemic has significantly impacted liver tran splantation worldwide, leading to major effects on the transplant process, including the pretransplant, perioperative, and post-transplant periods. It is believed that patients with chronic liver disease, especially those with cirrhosis, have a higher risk of complications from coronavirus disease 2019 infection compared to the general population. However, evaluation of coronavirus disease 2019 effects on liver transplant patients has not uniformly demonstrated worse outcomes. Nonetheless, the pandemic created significant challenges and restrictions on transplant policies and organ allocation.

Liver transplantation amidst the COVID-19 era: Our center’s experience

Coronavirus disease 2019 significantly impacted the liver transplant process worldwide. Consequently, it brought significant challenges and limitations to transplant policies and organ allocation forcing liver transplant centers to adjust their protocols to ensure maximum benefit and avoid harm to their patients. Our center, like many others, was obliged to adapt to the challenges. This paper provided an overview of the effects of coronavirus disease 2019 on liver transplantations and detailed our center’s experience and efforts during this unprecedented pandemic to serve as a guide for future public health crises.

Pathogenetic Mechanisms of Liver-Associated Injuries, Management, and Current Challenges in COVID-19 Patients

The global outbreak of COVID-19 possesses serious challenges and adverse impacts for patients with progression of chronic liver disease and has become a major threat to public health. COVID-19 patients have a high risk of lung injury and multiorgan dysfunction that remains a major challenge to hepatology. COVID-19 patients and those with liver injury exhibit clinical manifestations, including elevation in ALT, AST, GGT, bilirubin, TNF-α, and IL-6 and reduction in the levels of CD4 and CD8. Liver injury in COVID-19 patients is induced through multiple factors, including a direct attack of SARS-CoV-2 on liver hepatocytes, hypoxia reperfusion dysfunction, cytokine release syndrome, drug-induced hepatotoxicity caused by lopinavir and ritonavir, immune-mediated inflammation, renin-angiotensin system, and coagulopathy. Cellular and molecular mechanisms underlying liver dysfunction are not fully understood in severe COVID-19 attacks. High mortality and the development of chronic liver diseases such as cirrhosis, alcoholic liver disease, autoimmune hepatitis, nonalcoholic fatty liver disease, and hepatocellular carcinoma are also associated with patients with liver damage. COVID-19 patients with preexisting or developing liver disease should be managed. They often need hospitalization and medication, especially in conjunction with liver transplants. In the present review, we highlight the attack of SARS-CoV-2 on liver hepatocytes by exploring the cellular and molecular events underlying the pathophysiological mechanisms in COVID-19 patients with liver injury. We also discuss the development of chronic liver diseases during the progression of SARS-CoV-2 replication. Lastly, we explore management principles in COVID-19 patients with liver injury and liver transplantation.

Immune Response to Third and Fourth COVID-19 Vaccination in Hemodialysis Patients and Kidney Transplant Recipients

Severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2) is a serious hazard for hemodialysis (HD) patients and kidney transplant (KTX) recipients as they suffer from an impaired immune response to SARS-CoV-2 vaccination. In addition, a definition of SARS-CoV-2 IgG titer that indicates a sufficient immune response, especially against new omicron variants, is urgently needed. In the present study, the immune response to either a third or a fourth dose of a mRNA vaccine was investigated in 309 dialysis and 36 KTX patients. SARS-CoV-2 IgG titer thresholds indicating neutralizing activity against wild type (WT) and the omicron variant BA.1 were quantified. After four vaccine doses, a high-neutralizing activity against WT was evidenced in HD patients, whereas the neutralizing rate against BA.1 was significant lower. Concerning KTX recipients, humoral and cellular immune responses after a third vaccination were still highly impaired. This calls for modified omicron-targeting vaccines.

COVID-19-associated liver injury, role of drug therapy and management: a review

The ongoing COVID-19 pandemic is known to affect several body organs, including the liver. This results from several factors such as direct effect of SARS-CoV-2 on the liver, side effects of drug therapy and pre-existing liver diseases. Drug-induced liver injury can result from a range of drugs used in the treatment of COVID-19 such as antiviral drugs, anti-inflammatory drugs, antibiotics, herbal medications and vaccines. Metabolism of most drugs occurs in the liver, and this leaves the liver at risk of medication-induced liver damage. Being among pathologies from the disease, COVID-19 liver injury presents with abnormally high liver-related enzymes, such as aspartate aminotransferase, alanine aminotransferase, alkaline phosphate (ALP), and gamma-glutamyl transferase. It is reversible, generally not severe and occurs more mildly in children. However, COVID-19-associated liver injury is worsened by chronic liver diseases and vice versa. There is a high risk of abnormal ALT and AST, in-hospital liver injury and prolonged SARS-CoV-2 shedding in COVID-19 patients with previously existing metabolic-associated fatty liver disease. COVID-19-associated liver injury also appears to be severe and significantly associated with life-threatening COVID-19 and mortality in persons with a history of liver transplant. Where necessary, only supportive management is usually indicated. This paper evaluates the aetiology, clinical and laboratory features, occurrence and management of COVID-19-associated liver injury. It also elaborated on the role of drug therapy in the development of COVID-19 liver injury.

Successful liver transplantation in patients with active SARS-CoV-2 infection

The Coronavirus Disease 2019 (COVID-19) pandemic has substantially impacted solid organ transplantation, including temporary inactivation of waitlist candidates with COVID-19 infection. We report two cases of liver transplantation (LT) in individuals with asymptomatic COVID-19 infection. The first patient is a 68-year-old female with decompensated cirrhosis complicated by worsening frailty and sarcopenia. The second patient is a 22-year-old female with acute liver failure likely secondary to drug/toxin exposure. Both patients were treated with COVID-19-directed therapies and neither patient developed symptomatic disease. These cases demonstrate that LT can be safely performed in select patients with asymptomatic COVID-19 infection at the time of transplant.