The Global Impact of COVID-19 on Solid Organ Transplantation: Two Years Into a Pandemic

Worldwide organization and structures for kidney transplantation services

BACKGROUND

Kidney transplantation (KT) is the preferred modality of kidney replacement therapy with better patient outcomes and quality of life compared with dialytic therapies. This study aims to evaluate the epidemiology, accessibility and availability of KT services in countries and regions around the world.

METHODS

This study relied on data from an international survey of relevant stakeholders (clinicians, policymakers and patient advocates) from countries affiliated with the International Society of Nephrology that was conducted from July to September 2022. Survey questions related to the availability, access, donor type and cost of KT.

RESULTS

In total, 167 countries responded to the survey. KT services were available in 70% of all countries, including 86% of high-income countries, but only 21% of low-income countries. In 80% of countries, access to KT was greater in adults than in children. The median global prevalence of KT was 279.0 [interquartile range (IQR) 58.0-492.0] per million people (pmp) and the median global incidence was 12.2 (IQR 3.0-27.8) pmp. Pre-emptive KT remained exclusive to high- and upper-middle-income countries, and living donor KT was the only available modality for KT in low-income countries. The median cost of the first year of KT was $26 903 USD and varied 1000-fold between the most and least expensive countries.

CONCLUSION

The availability, access and affordability of KT services, especially in low-income countries, remain limited. There is an exigent need to identify strategies to ensure equitable access to KT services for people with kidney failure worldwide, especially in the low-income countries.

Attenuation of Torque teno viral load over time in kidney transplantation recipients treated with calcineurin inhibitors is mitigated after conversion to belatacept

Torque Teno Virus (TTV) is a non-pathogenic anellovirus, highly prevalent in healthy populations. Variations in its viral load have been associated with states of diminished immunity, as occurs after organ transplantation. It is hypothesized that TTV-load might be used as a diagnostic tool to guide prescription and dosing of immunosuppressive drugs. Not much is known about the effects of combined immunosuppressive drugs on TTV replication in renal transplantation. Belatacept was introduced to counter side-effects of calcineurin inhibitors (CNI). It was never widely adopted, mainly because its association with increased risk of rejection. To investigate the differential effects of a regimen based on calcineurin inhibitors versus belatacept on TTV-loads, we measured TTV-levels in 105 patients from two randomized controlled trials in kidney transplant recipients (KTRs). We observed that time after transplantation was inversely related to TTV-levels of patients that remained on a CNI-containing regime, whereas this decline over time was diminished after conversion to belatacept. In addition, a correlation with tacrolimus-trough levels and age were found. Our study is the first report on the impact of conversion from CNI to belatacept on TTV-levels in KTR. In conclusion, the time-related decline in TTV-levels is mitigated after conversion from CNI to belatacept.

Excess mortality in COVID-19-affected solid organ transplant recipients across the pandemic

The excess mortality of coronavirus disease 2019 (COVID-19) solid organ transplant recipients (SOTRs) throughout the pandemic remains unclear. This prospective cohort study based on the Japanese nationwide registry included 1632 SOTRs diagnosed with COVID-19 between February 1, 2020, and July 31, 2022, categorized based on dominant phases of variants of concern (VOCs): Waves 1 to 3 (Beta), 4 (Alpha), 5 (Delta), 6 (Omicron BA.1/BA.2), and 7 (Omicron BA.5). Excess mortality of COVID-19-affected SOTRs was analyzed by calculating standardized mortality ratios (SMRs). Overall, 1632 COVID-19-confirmed SOTRs included 1170 kidney, 408 liver, 25 lung, 20 heart, 1 small intestine, and 8 multiorgan recipients. Although disease severity and all-cause mortality decreased as VOCs transitioned, SMRs of SOTRs were consistently higher than those of the general population throughout the pandemic, showing a U-shaped gap that peaked toward the Omicron BA.5 phase; SMR (95% CI): 6.2 (3.1-12.5), 4.0 (1.5-10.6), 3.0 (1.3-6.7), 8.8 (5.3-14.5), and 21.9 (5.5-87.6) for Waves 1 to 3 (Beta), Wave 4 (Alpha), Wave 5 (Delta), Wave 6 (Omicron BA.1/2), and Wave 7 (Omicron BA.5), respectively. In conclusion, COVID-19 SOTRs had greater SMRs than the general population across the pandemic. Vaccine boosters, immunosuppression optimization, and other protective measures, particularly for older SOTRs, are paramount.

Chronological and Geographical Variations in the Incidence and Acceptance of COVID-19-Positive Donors and Outcomes Among Abdominal Transplant Patients

INTRODUCTION

Given the importance of understanding COVID-19-positive donor incidence and acceptance, we characterize chronological and geographic variations in COVID-19 incidence relative to COVID-19-positive donor acceptance.

METHODS

Data on deceased donors and recipients of liver and kidney transplants were obtained from the UNOS database between 2020 and 2023. Hierarchical cluster analysis was used to assess trends in COVID-19-positive donor incidence. Posttransplant graft and patient survival were assessed using Kaplan-Meier curves.

RESULTS

From among 38 429 deceased donors, 1517 were COVID-19 positive. Fewer kidneys (72.4% vs. 76.5%, p < 0.001) and livers (56.4% vs. 62.0%, p < 0.001) were used from COVID-19-positive donors versus COVID-19-negative donors. Areas characterized by steadily increased COVID-19 donor incidence exhibit the highest transplantation acceptance rates (92.33%), followed by intermediate (84.62%) and rapidly increased (80.00%) COVID-19 incidence areas (p = 0.016). Posttransplant graft and patient survival was comparable among recipients, irrespective of donor COVID-19 status.

CONCLUSIONS

Regions experiencing heightened rates of COVID-19-positive donors are associated with decreased acceptance of liver and kidney transplantation. Similar graft and patient survival is noted among recipients, irrespective of donor COVID-19 status. These findings emphasize the need for adaptive practices and unified medical consensus in navigating a dynamic pandemic.

International Travel for Organ Transplantation: A Survey of Professional Experiences and Attitudes Toward Data Collection and Reporting

Background

Lack of data regarding international travel for organ transplantation (ITOT) hampers efforts to evaluate, understand, and respond to trends in ITOT activities, such as those suggestive of organ trafficking or "transplant tourism." This study aimed to assess transplant professionals' experience of ITOT and their attitudes toward reporting ITOT data to a global registry.

Methods

An international cross-sectional anonymous survey of transplant professionals was conducted online (from October to December 2022). The English language questionnaire assessed professional experiences in providing care to individuals who had traveled to or from a country for living donation or transplantation, and attitudes toward reporting of ITOT data. Data were analyzed with descriptive statistics.

Results

Two hundred thirty-nine individuals from 68 countries completed the entire questionnaire, of whom 79% had provided care for ≥1 patient who had traveled internationally for donation or transplantation. Of these, 60.8% of individuals (n = 115) had cared for ≥1 person who engaged in ITOT between 2019 and 2022, with the most recent case experiences involving 89 countries and 157 unique routes of international travel. Predominant concerns regarding reporting of ITOT data to a global registry related to prevention of harm and protection of patient privacy; most (52.7%; n = 126) respondents expressed a preference for anonymous reporting of ITOT data.

Conclusions

ITOT is a global phenomenon and transplant professionals' experience with ITOT cases is more common than anticipated. Systems for the collection of ITOT activity data should be carefully designed to address potential ethical concerns of transplant professionals which may influence reporting practices.

Clinical characteristics and outcomes of hospitalized kidney transplant recipients with COVID-19 infection in China during the Omicron wave: a single-center cohort study

BACKGROUND: Following the short-term outbreak of coronavirus disease 2019 (COVID-19) in December 2022 in China, clinical data on kidney transplant recipients (KTRs) with COVID-19 are lacking. METHODS: We conducted a single-center retrospective study to describe the clinical features, complications, and mortality rates of hospitalized KTRs infected with COVID-19 between Dec. 16, 2022 and Jan. 31, 2023. The patients were followed up until Mar. 31, 2023. RESULTS: A total of 324 KTRs with COVID-19 were included. The median age was 49 years. The median time between the onset of symptoms and admission was 13 d. Molnupiravir, azvudine, and nirmatrelvir/ritonavir were administered to 67 (20.7%), 11 (3.4%), and 148 (45.7%) patients, respectively. Twenty-nine (9.0%) patients were treated with more than one antiviral agent. Forty-eight (14.8%) patients were treated with tocilizumab and 53 (16.4%) patients received baricitinib therapy. The acute kidney injury (AKI) occurred in 81 (25.0%) patients and 39 (12.0%) patients were admitted to intensive care units. Fungal infections were observed in 55 (17.0%) patients. Fifty (15.4%) patients lost their graft. The 28-d mortality rate of patients was 9.0% and 42 (13.0%) patients died by the end of follow-up. Multivariate Cox regression analysis identified that cerebrovascular disease, AKI incidence, interleukin (IL)‍-6 level of >6.8 pg/mL, daily dose of corticosteroids of >50 mg, and fungal infection were all associated with an increased risk of death for hospitalized patients. CONCLUSIONS: Our findings demonstrate that hospitalized KTRs with COVID-19 are at high risk of mortality. The administration of immunomodulators or the late application of antiviral drugs does not improve patient survival, while higher doses of corticosteroids may increase the death risk.

Alternative Therapies in Transplantology as a Promising Perspective in Medicine

Despite continuous and rapid progress in the transplantation of cells, tissues, and organs, many patients die before receiving them. This is because of an insufficient number of donors, which leads to a significant disproportion between the need for donors and their availability. This review aims to present the possibilities offered by alternative therapies. We use the term "functional transplantology" to describe such alternative methods of transplantation that could help change the current state of transplantation medicine. Its purpose is not to replace a defective or removed organ with another but to replace its functions using complementary biological, mechanical, or biomechanical structures or devices. Implementation of many innovative solutions shown in the work for clinical applications is already a fact. In the case of others, it should be considered a future vision. We hope that the role of a defective or damaged tissue or a group of tissues will be taken over by different structures that are functionally complementary with the organ being substituted. Undoubtedly, developing the described methods based on functional transplantology will change the face of transplantation medicine. Thus, we show current trends and new directions of thinking and actions in transplantation medicine that combine technology and transplantology. The review considers the latest technologies, including 3D bioprinting, nanotechnology, cell encapsulation, and organoids. We discuss not only the advantages of new approaches but also the limitations and challenges that must be overcome to achieve significant progress in transplantation. That is the only option to provide a safe and efficient way of improving the quality of life of many patients.

Clinical Outcomes of Solid Organ Transplant Recipients Hospitalized with COVID-19: A Propensity Score-Matched Cohort Study

BACKGROUND

Solid-organ transplant recipients (SOTRs) receiving immunosuppressive therapy are expected to have worse clinical outcomes from coronavirus disease 2019 (COVID-19). However, published studies have shown mixed results, depending on adjustment for important confounders such as age, variants, and vaccination status.

MATERIALS AND METHODS

We retrospectively collected the data on 7,327 patients hospitalized with COVID-19 from two tertiary hospitals with government-designated COVID-19 regional centers. We compared clinical outcomes between SOTRs and non-SOTRs by a propensity score-matched analysis (1:2) based on age, gender, and the date of COVID-19 diagnosis. We also performed a multivariate logistic regression analysis to adjust other important confounders such as vaccination status and the Charlson comorbidity index.

RESULTS

After matching, SOTRs (n=83) had a significantly higher risk of high-flow nasal cannula use, mechanical ventilation, acute kidney injury, and a composite of COVID-19 severity outcomes than non-SOTRs (n=160) (all P <0.05). The National Early Warning Score was significantly higher in SOTRs than in non-SOTRs from day 1 to 7 of hospitalization (P for interaction=0.008 by generalized estimating equation). In multivariate logistic regression analysis, SOTRs (odds ratio [OR], 2.14; 95% confidence interval [CI], 1.12-4.11) and male gender (OR, 2.62; 95% CI, 1.26-5.45) were associated with worse outcomes, and receiving two to three doses of COVID-19 vaccine (OR, 0.43; 95% CI, 0.24-0.79) was associated with better outcomes.

CONCLUSION

Hospitalized SOTRs with COVID-19 had a worse prognosis than non-SOTRs. COVID-19 vaccination should be implemented appropriately to prevent severe COVID-19 progression in this population.

Sequelae of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) Infection among Kidney Transplant Recipients: A Large Single-Center Experience

Background

Kidney transplant recipients (KTRs) are a vulnerable immunocompromised population at risk of severe COVID-19 disease and mortality after SARS-CoV-2 infection. We sought to characterize the post-infection sequelae in KTRs at our center.

Methods

We studied all adult KTRs (with a functioning allograft) who had their first episode of SARS-CoV-2 infection between 04/2020 and 04/2022. Outcomes of interest included risk factors for hospitalization, all-cause mortality, COVID-19-related mortality, and allograft failure.

Results

Of 979 KTRs with SARS-CoV-2 infection, 381 (39%) were hospitalized. In the multivariate analysis, risk factors for hospitalization included advanced age/year (HR: 1.03, 95% CI: 1.02-1.04), male sex (HR: 1.29, 95% CI: 1.04-1.60), non-white race (HR: 1.48, 95% CI: 1.17-1.88), and diabetes as a cause of ESKD (HR: 1.77, 95% CI: 1.41-2.21). SARS-CoV-2 Vaccination was associated with decreased risk of hospitalization (HR: 0.73, 95% CI: 0.59-0.90), all-cause mortality (HR: 0.52, 95% CI: 0.37-0.74), and COVID-19-related mortality (HR: 0.47, 95% CI: 0.31-0.71) in the univariate and multivariate analyses. Risk factors for both all-cause and COVID-19-related mortality in the multivariate analyses included advanced age, hospitalization, and respiratory symptoms for hospital admission. Furthermore, additional risk factors for all-cause mortality in the multivariate analysis included being a non-white recipient and diabetes as a cause of ESKD, with being a recipient of a living donor as protective.

Conclusions

Hospitalization due to COVID-19-associated symptoms is associated with increased mortality. Vaccination is a protective factor against hospitalization and mortality.

A prospective observational cohort study of covid-19 epidemiology and vaccine seroconversion in South Western Sydney, Australia, during the 2021-2022 pandemic period

BACKGROUND

It is known that COVID-19 disproportionally adversely affects the immunocompromised, including kidney transplant recipients (KTR), as compared to the general population. Risk factors for adverse outcomes and vaccine seroconversion patterns are not fully understood. Australia was uniquely positioned to reduce initial case numbers during the 2021-2022 pandemic period due to its relative isolation and several significant public health interventions. South-Western Sydney Local Heath District was one of the predominant regions affected.

METHODS

A single centre, prospective cohort study of prevalent renal transplant recipients was conducted between 25th July 2021 and 1st May 2022. Baseline characteristics, COVID-19 vaccination status, COVID-19 diagnosis and outcomes were determined from the electronic medical record, Australian vaccination register and Australian and New Zealand Dialysis and Transplant Registry. Assessment of vaccine-induced seroconversion was assessed with ELISA in a subpopulation. Analysis was performed using SPSS v.28.

RESULTS

We identified 444 prevalent transplant recipients (60% male, 50% diabetic, median age 58 years (Interquartile range (IQR)21.0) and eGFR 56 ml/min/1.73m2 (IQR 21.9). COVID-19 was identified in 32% (n = 142) of patients, of which 38% (n = 54) required hospitalisation and 7% (n = 10) died. At least one COVID-19 vaccination was received by 95% (n = 423) with 17 (4%) patients remaining unvaccinated throughout the study period. Seroconversion after 2 and 3 doses of vaccine was 22% and 48% respectively. Increased COVID-19 related deaths were associated with older age (aOR 1.1, 95% CI 1.004-1.192, p = 0.040), smoking exposure (aOR 8.2, 05% CI 1.020-65.649, p = 0.048) and respiratory disease (aOR 14.2, 95%CI:1.825-110.930, p = 0.011) on multi-variable regression analysis. Receipt of three doses of vaccination was protective against acquiring COVID-19 (aOR 0.48, 95% CI 0.287-0.796, p = 0.005) and death (aOR 0.6, 95% CI: 0.007-0.523, p = 0.011), but not against hospitalisation (p = 0.32). Seroconversion was protective for acquiring COVID-19 on multi-variable regression independent of vaccination dose (aOR 0.1, 95%CI: 0.0025-0.523, p = 0.011).

CONCLUSIONS

COVID-19 was associated with a high mortality rate. Older age, respiratory disease and prior smoking exposure may be risk factors for increased mortality. Vaccination of 3 doses is protective against acquiring COVID-19 and death, however not hospitalisation. Antibody response is protective for acquiring COVID-19, however seroconversion rates are low.

Post-COVID-19 pandemic organ donation activities in Germany: a multicenter retrospective analysis

Introduction

The COVID-19 pandemic had a negative impact on the number of solid organ transplantations. After a global decline of 16% in 2020, their numbers subsequently returned to pre-pandemic levels. In contrast, numbers in Germany remained almost constant in 2020 and 2021 but fell by 6.9% in 2022. The reasons for this divergent development are unknown.

Methods

The number of deceased with a severe brain damage, potential and utilized donors after braindeath and the intensive care unit treatment capacity were retrospectively compared for the years 2022 and 2021 at five university hospitals in North Rhine-Westphalia, Germany. Reasons for a donation not utilized were reviewed. To enable a comparison of the results with the whole of Germany and the pre-pandemic period, numbers of potential and utilized donors were extracted from official organ donation activity reports of all harvesting hospitals in Germany for the years 2019-2022.

Results

The numbers of deceased with a severe brain damage (-10%), potential (-9%), and utilized donors after braindeath (-44%), and intensive care unit treatment capacities (-7.2%) were significantly lower in 2022 than 2021. A COVID-19 infection was a rarer (-79%), but donor instability (+44%) a more frequent reason against donation in 2022, whereas preserved brain stem reflexes remained the most frequent reason in both years (54%). Overall numbers of potential and utilized donations in Germany were lower in 2022 than in the pre-pandemic period, but this was mainly due to lower numbers in hospitals of lower care. The number of potential donors in all university hospitals were higher in 2022 but utilized donations still lower than in 2019.

Conclusion

The decrease in potential and utilized donations was a result of reduced intensive care unit treatment capacities and a lower conversion rate at the five university hospitals. A COVID-19 infection did not play a role in 2022. These results indicate that ICU treatment capacities must be restored to increase donations. The lower number of potential donors and the even lower conversion rate in 2022 throughout Germany show that restructuring the organ procurement process in Germany needs to be discussed to increase the number of donations.

COVID-19 Outcomes and Vaccinations in Swedish Solid Organ Transplant Recipients 2020-2021: A Nationwide Multi-Register Comparative Cohort Study

Increased COVID-19-related morbidity and mortality have been reported in solid organ transplant recipients (SOTRs). Most studies are underpowered for rigorous matching. We report infections, hospitalization, ICU care, mortality from COVID-19, and pertinent vaccination data in Swedish SOTRs 2020-2021. We conducted a nationwide cohort study, encompassing all Swedish residents. SOTRs were identified with ICD-10 codes and immunosuppressant prescriptions. Comparison cohorts were weighted based on a propensity score built from potential confounders (age, sex, comorbidities, socioeconomic factors, and geography), which achieved a good balance between SOTRs and non-SOTR groups. We included 10,372,033 individuals, including 9073 SOTRs. Of the SARS-CoV-2 infected, 47.3% of SOTRs and 19% of weighted comparator individuals were hospitalized. ICU care was given to 8% of infected SOTRs and 2% of weighted comparators. The case fatality rate was 7.7% in SOTRs, 6.2% in the weighted comparison cohort, and 1.3% in the unweighted comparison cohort. SOTRs had an increased risk of contracting COVID-19 (HR = 1.15 p < 0.001), being hospitalized (HR = 2.89 p < 0.001), receiving ICU care (HR = 4.59 p < 0.001), and dying (HR = 1.42 p < 0.001). SOTRs had much higher morbidity and mortality than the general population during 2020-2021. Also compared with weighted comparators, SOTRs had an increased risk of contracting COVID-19, being hospitalized, receiving ICU care, and dying. In Sweden, SOTRs were vaccinated earlier than weighted comparators. Lung transplant recipients had the worst outcomes. Excess mortality among SOTRs was concentrated in the second half of 2021.

Characteristics of COVID-19 Disease in Renal Transplant Recipients

Background and Objectives: Kidney transplant recipients are at risk of developing more severe forms of COVID-19 infection. The aim of this study was to compare the clinical course of COVID-19 infection among kidney transplant patients and a control group. Materials and Methods: We examined 150 patients hospitalized with COVID-19 infection. Patients were divided into study (kidney transplant recipients, n = 53) and control (without a history of kidney transplantation, n = 97) groups. Demographics, clinical characteristics, treatment data, and clinical outcomes were assessed. Results: The median patient age was 56.0 (46.0-64.0) years, and seventy-seven patients (51.3%) were men. The median Charlson comorbidity index was higher in the study group (3.0 vs. 2.0, p < 0.001). There was a higher incidence of hypoxemia in the control group upon arrival (52.6% vs. 22.6%, p = 0.001) and a higher NEWS index median (2.0 vs. 1.0 points, p = 0.009) and incidence of pneumonia during hospitalization (88.7% vs. 73.6%, p = 0.023). In the study group, there were more cases of mild (26.4% vs. 11.3%, p = 0.023) and critically severe forms of COVID-19 infection (26.4% vs. 3.1%, p < 0.001), kidney failure was more prevalent (34.0% vs. 1.0%, p < 0.001), and a greater number of patients were transferred to the intensive care unit (22.6% vs. 3.1%, p < 0.001) and died (18.9% vs. 1.0%, p < 0.001). Multivariable analysis revealed that treatment in the intensive care unit correlated with a higher mortality rate than transplantation itself (HR = 20.71, 95% CI 2.01-213.33, p = 0.011). Conclusions: The course of the COVID-19 disease in kidney transplant recipients is heterogeneous and can be more severe than in the general population. Even though patients may be hospitalized with fewer symptoms, complications and death are more likely to occur.

Immediate Impact of the COVID-19 Pandemic on Heart and Kidney Transplantation and the Recovery Trends in 30 Developed and Less-Developed Countries

BACKGROUND The COVID-19 pandemic had multifaceted and disproportionate impacts on various countries. We investigated the decline of heart and kidney transplantation in 2020 and recovery trends in 2020, 2021, and 2022 in 30 developed and developing countries, considering COVID-19 incidence and mortality and pandemic-time economic variables. MATERIAL AND METHODS Data were obtained from reliable open databases. Nations were grouped by hierarchical cluster analysis into high-gross domestic product (GDP), mid-GDP, and low-GDP countries. Expected transplant numbers for 2020 to 2021 were estimated by the artificial neural network method using data from 2015 to 2019. Effect size and its inference were determined through the Hodges-Lemann estimate and Wilcoxon signed-rank test, respectively. The possible disproportionate effect was estimated by the Jonckheere-Tersptra test. Associations between transplantation and economic variables, COVID-19 caseload, and mortality were examined using Kendall rank correlation analysis. RESULTS All nations experienced a decline in 2020 and some real recovery in 2020 to 2022. For high-GDP countries, decline was insignificant and recovery was marginal; for mid-GDP countries, decline was significant for heart and deceased kidneys and recovery was modest; for low-GDP countries, decline was significant for heart, live kidneys, and deceased kidneys and recovery was marginal. The low-GDP countries were disproportionally negatively impacted, although the associations between the impact and economic variables, COVID-19 incidence, and COVID-19 mortality were statistically insignificant. CONCLUSIONS More inclusive studies of socioeconomic and cultural factors that affected the impact of the COVID-19 pandemic in different countries can be useful for better preparedness and reducing disruption in healthcare in future global pandemics.

COVID-19 and Access to Kidney Transplantation for Older Candidates in the United States: A National Registry Study

Rationale & Objective

Coronavirus disease (COVID)-19 has likely impacted accessibility to transplantation services among older adults (age ≥65 years). We quantified the impact of COVID-19 on kidney transplantation access for older kidney-only candidates registered on the United States (US) kidney waitlist.

Study Design

Retrospective analysis of registry data.

Setting & Participants

57,222 older adults who were part of or added to the US kidney waitlist between January 1, 2016 and February 28, 2022, identified using the Scientific Registry of Transplant Recipients (SRTR).

Exposures

Four COVID-19 waves and one nonwave period based on the national incidence of COVID-19 in the US (initial: March 15-May 30, 2020; winter 2020-2021: December 1, 2020-January 31, 2021; delta: August 1, 2021-September 30, 2021; omicron: December 1, 2021-February 28, 2022; nonwave: inter-wave periods).

Outcomes

Waitlist registrations, deceased-donor kidney transplants, living-donor kidney transplants, waitlist mortality, and waitlist removals due to deteriorating condition (hereafter referred to as removals).

Analytical Approach

Poisson regression for the adjusted incidence rate ratio (aIRR) of each outcome during the COVID-19 waves and the nonwave period relative to reference (January 1, 2016-December 31, 2019), adjusted for seasonality and secular trends.

Results

Waitlist registrations initially declined and increased henceforth. Deceased-donor kidney transplants and living-donor kidney transplants remained below-expected levels during all waves. Waitlist mortality peaked during the winter 2020-2021 wave (aIRR: 1.701.982.30) and has declined since; mortality rates were 139%, 107%, and 251% above expected for Black candidates, men, and candidates aged ≥75 years, respectively, during the winter 2020-2021 wave. Removals increased from 22% below expected levels (initial wave) to 26% above expected levels (omicron wave); removals were nonsignificantly higher than expected during the omicron wave for older Black and Hispanic candidates.

Limitations

The findings are not generalizable to those listed at earlier ages with prolonged waitlist times. Additionally, using national COVID-19 incidence does not consider local policy and health care variations. Lastly, aIRRs must be interpreted cautiously due to smaller daily event counts.

Conclusions

COVID-19 was associated with fewer transplants and increased mortality and removals in older kidney transplant candidates. Transplant providers should consider this impact and implement policies and practices to ensure the continuity of care.

Plain-Language Summary

The proportion of older adults on the kidney transplant waitlist is increasing, but the impact of COVID-19 on this population is not well characterized. In this study, we looked at incident waitlist registrations, deceased- and living-donor kidney transplants, and waitlist mortality and removals due to deteriorating condition over 4 waves of COVID-19. We found that transplantation services did not fully recover to prepandemic levels as of March 2022. Notably, racial/ethnic minorities and older men experienced lower rates of kidney transplants and higher rates of waitlist mortality, respectively, relative to White candidates and older women. Identifying vulnerable subpopulations affected by COVID-19 and its long-term impact is crucial for creating strategies to ensure the continuity of care in this population during public health emergencies.

Effectiveness of a Fourth COVID-19 mRNA Vaccine Dose Against the Omicron Variant in Solid Organ Transplant Recipients

BACKGROUND

The effectiveness of booster doses of COVID-19 vaccines in solid organ transplant recipients is unclear. We conducted a population-based matched cohort study using linked administrative healthcare databases from Ontario, Canada to estimate the marginal vaccine effectiveness of a fourth versus third dose of the BNT162b2 and mRNA-1273 vaccines against clinically important outcomes (ie, hospitalization or death) and infection during the era of the Omicron variant.

METHODS

We matched 3120 solid organ transplant recipients with a third COVID-19 vaccine dose (reference) to 3120 recipients with a fourth dose. Recipients were matched on the third dose date (±7 d). We used a multivariable Cox proportional hazards model to estimate the marginal vaccine effectiveness with outcomes occurring between December 21, 2021 and April 30, 2022.

RESULTS

The cumulative incidence of COVID-19-related hospitalization or death was 2.8% (95% confidence interval [CI], 2.0-3.7) in the third dose group compared with 1.1% (95% CI, 0.59-1.8) in the fourth dose group after 84 d of follow-up (P < 0.001). The adjusted marginal vaccine effectiveness was 70% (95% CI, 47-83) against clinically important outcomes and 39% (95% CI, 21-52) against SARS-CoV-2 infection.

CONCLUSIONS

Compared with a third dose, a fourth dose of the COVID-19 vaccine was associated with improved protection against hospitalization, death, and SARS-CoV-2 infection during the Omicron era. Results highlight the importance of a booster COVID-19 vaccine dose in solid organ transplant recipients.

Impact of Capacity Building in the Organ Donation Activity During an International Society of Nephrology The Transplantation Society Sister Transplant Center (ISN-TTS STC) Partnership

This article explores the impact of a partnership program involving the International Society of Nephrology-The Transplantation Society, the Southern Philippines Medical Center, and the University of Barcelona. The program included capacity building and partnership with the Donation and Transplant Institute, leading to the creation of 5 Intermediate Transplant Procurement Management courses for Southern Philippines Medical Center's healthcare professionals. The study analyzed organ donation activity and training records from 2016 to 2022, dividing the periods pre- and postSister Transplant Center partnership, and further subdividing to assess the impact of the COVID-19 pandemic. Results showed an increase of 474.39% in donor referrals by 2019, which then dropped significantly during the COVID-19 pandemic. In 2022, a reimplementation of training opportunities led to a 657% increase in referrals. Capacity building through education, training, and partnerships has a direct and positive impact on organ donation activity, even in the face of challenging circumstances like a global pandemic.

Clinical experience in the treatment of COVID-19 with monoclonal antibodies in solid organ transplant recipients

Solid organ transplant (SOT) recipients are at high risk for complications from coronavirus disease 2019 (COVID-19). SOT recipients mount lower immunological responses to vaccines than general population and are at high risk for breakthrough COVID-19 infections. Passive immunotherapy in the form of anti-Spike monoclonal antibodies (MoAbs) may be an alternative for the prophylaxis and treatment of COVID-19 in these patients. SARS-CoV-2 has evolved by accumulating resistance mutations that have escaped the neutralizing action of most MoAbs. However, MoAbs directed at more conserved epitopes and that maintain effector functions could maintain efficacy in the treatment of these patients. According to published data, SOT recipients with low anti-spike antibody responses to vaccination could benefit from the use of MoAbs in pre-exposure prophylaxis, in the treatment of COVID-19 mild to moderate and severe COVID-19 with less than 15 days of symptom duration and low oxygen requirements. Combination therapy could be more effective than monotherapy for the treatment of mild-to-moderate SARS-CoV-2 infection.

Critical care and pandemic preparedness and response

Critical care was established partially in response to a polio epidemic in the 1950s. In the intervening 70 yr, several epidemics and pandemics have placed critical care and allied services under extreme pressure. Pandemics cause wholesale changes to accepted standards of practice, require reallocation and retargeting of resources and goals of care. In addition to clinical acumen, mounting an effective critical care response to a pandemic requires local, national, and international coordination in a diverse array of fields from research collaboration and governance to organisation of critical care networks and applied biomedical ethics in the eventuality of triage situations. This review provides an introduction to an array of topics that pertain to different states of pandemic acuity: interpandemic preparedness, alert, surge activity, recovery and relapse through the literature and experience of recent pandemics including COVID-19, H1N1, Ebola, and SARS.

Worldwide and Country-Specific Impact of the COVID-19 Pandemic on Heart Transplantation Volumes: A Longitudinal Analysis of 2020 and 2021

COVID-19 pandemic hampered operational efficiency of heart transplant (HT) programs worldwide. Little is known about the global and country-specific changes in HT volumes during the pandemic years 2020-2021. We aimed to describe the global and country-level impact of the COVID-19 pandemic on HT volumes in 2020-2021. This is a cross-sectional study of the Global Observatory on Donation and Transplantation, including the years 2019-2021. Among 60 countries that reported HT data in the years 2019-2020, we analyzed 52 countries with ≥1 transplant during each year. Overall, the number of HTs decreased during 2020 by 9.3% (1.82 to 1.65 PMP). While 75% (n = 39/52) of countries experienced a decrease in HT volumes in 2020, volumes were maintained/increased in the remaining countries. Countries with maintained HT volumes had a higher organ donation rate in 2020 compared to those with decreased volumes (P = 0.03), the only significant predictor of change in HT volumes (P = 0.005). In 2021, a 6.6% recovery from the previous year's drop in global HT rate was noticed, reaching 1.76 HT PMP. Only 1 in 5 countries with reduced volumes in 2020 recovered their baseline volumes in 2021. Only 30.8% of countries with maintained volumes in 2020 had continued growth in HT volumes in 2021. The latter group encompassed the United States of America, the Netherlands, Poland, and Portugal. Further work should define underlying causes of this heterogeneity in HT volume during the pandemic. Identifying policies and practices that helped certain countries mitigate the effect of the pandemic on HT activities may help other countries during similar health crises in the future.

Comparison of Short-Term Outcomes in Kidney Transplant Recipients from SARS-CoV-2-Infected versus Noninfected Deceased Donors

BACKGROUND

Acceptable post-transplant outcomes were reported in kidney transplant recipients from donors with coronavirus disease 2019 (COVID-19); however, there are no comparative studies with well-matched controls.

METHODS

This multicenter, prospective observational study, which included three transplant centers in the United States, enrolled 61 kidney recipients from severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-infected deceased donors. Using optimal matching methods, we matched every recipient to three comparators receiving kidneys from SARS-CoV-2-negative deceased donors with otherwise highly similar characteristics in the same transplant centers to compare 6-month eGFR.

RESULTS

Among recipients of SARS-CoV-2-infected donor kidneys, one recipient died with a functional graft within 6 months. Mean 6-month eGFR was not significantly different between SARS-CoV-2-infected and noninfected donor groups (55±21 and 57±25 ml/min per 1.73 m 2 , respectively; P = 0.61). Six-month eGFR in recipients from SARS-CoV-2-infected donors who died of reasons other than COVID-19 was not significantly different from those from SARS-CoV-2-negative donors (58±22 and 56±25 ml/min per 1.73 m 2 , respectively; P = 0.51). However, recipients from donors who died of COVID-19 had significantly lower 6-month eGFR than those from SARS-CoV-2-negative donors (46±17 and 58±27 ml/min per 1.73 m 2 , respectively; P = 0.03). No donor-to-recipient SARS-CoV-2 transmission was observed.

CONCLUSIONS

Six-month eGFR was not significantly different between recipients of kidneys from SARS-CoV-2-infected and noninfected donors. However, those receiving kidneys from donors who died of COVID-19 had significantly lower 6-month eGFR. Donor-to-recipient SARS-CoV-2 transmission was not observed.

Excess Mortality in Kidney and Kidney-Pancreas Transplant Recipients in the COVID-19 Pandemic in Portugal-A Cohort Study

The COVID-19 pandemic increased morbidity and mortality worldwide, particularly in the Kidney and Kidney-Pancreas Transplant Recipient (KTR/KPTR) population. Aiming at assessing the absolute and relative excess mortality (EM) in a Portuguese KTR/KPTR cohort, we conducted a retrospective observational study of two KTR/KPTRs cohorts: cohort 1 (P1; n = 2,179) between September/2012 and March/2020; cohort 2 (P2; n = 2067) between March/2020, and August/2022. A correlation between relative and absolute EM and age, sex, time from transplantation and cause of death was explored. A total of 145 and 84 deaths by all causes were observed in P1 and P2, respectively. The absolute EM in P2 versus P1 was 19.2 deaths (observed/expected mortality ratio 1.30, p = 0.006), and the relative EM was 1.47/1,000 person-months (95% CI 1.11-1.93, p = 0.006). Compared to the same period in the general population, the standardized mortality rate by age in P2 was 3.86 (95% CI 2.40-5.31), with a peak at 9.00 (95% CI 4.84-13.16) in P2C. The higher EM identified in this population was associated, mainly, with COVID-19 infection, with much higher values during the second seasonal COVID-19 peak when compared to the general population, despite generalized vaccination. These highlight the need for further preventive measures and improved therapies in these patients.

COVID-19 Outcomes in Kidney Transplant Recipients in a German Transplant Center

Kidney transplant recipients (KTRs) show higher morbidity and mortality from COVID-19 than the general population and have an impaired response to vaccination. We analyzed COVID-19 incidence and clinical outcomes in a single-center cohort of approximately 2500 KTRs. Between 1 February 2020 and 1 July 2022, 578 KTRs were infected with SARS-CoV-2, with 25 (4%) recurrent infections. In total, 208 KTRs (36%) were hospitalized, and 39 (7%) died. Among vaccinated patients, infection with the Omicron variant had a mortality of 2%. Unvaccinated patients infected with the Omicron variant showed mortality (9% vs. 11%) and morbidity (hospitalization 52% vs. 54%, ICU admission 12% vs. 18%) comparable to the pre-Omicron era. Multivariable analysis revealed that being unvaccinated (OR = 2.15, 95% CI [1.38, 3.35]), infection in the pre-Omicron era (OR = 3.06, 95% CI [1.92, 4.87]), and higher patient age (OR = 1.04, 95% CI [1.03, 1.06]) are independent risk factors for COVID-19 hospitalization, whereas a steroid-free immunosuppressive regimen was found to reduce the risk of COVID-19 hospitalization (OR = 0.51, 95% CI [0.33, 0.79]). This suggests that both virological changes in the Omicron variant and vaccination reduce the risk for morbidity and mortality from COVID-19 in KTRs. Our data extend the knowledge from the general population to KTRs and provide important insights into outcomes during the Omicron era.

Update of the recommendations on the management of the SARS-CoV-2 coronavirus pandemic (COVID-19) in kidney transplant patients

SARS-CoV-2 infection (COVID-19) has had a significant impact on transplant activity in our country. Mortality and the risk of complications associated with COVID-19 in kidney transplant recipients (KT) were expected to be higher due to their immunosuppressed condition and the frequent associated comorbidities. Since the beginning of the pandemic in March 2020 we have rapidly improved our knowledge about the epidemiology, clinical features and management of COVID-19 post-transplant, resulting in a better prognosis for our patients. KT units have been able to adapt their programs to this new reality, normalizing both donation and transplantation activity in our country. This manuscript presents a proposal to update the general recommendations for the prevention and treatment of infection in this highly vulnerable population such as KT.

Quantification and persistence of COVID-19 virus in recently deceased individuals before and after embalming

The COVID-19 pandemic severely affected the medical education worldwide. The infection risk for medical students and healthcare personnel who work with COVID-19 positive cadavers or tissues remains unclear. Moreover, COVID-19 positive cadavers have been rejected by medical schools, adversely impacting the continuum of medical education. Herein, the viral genome abundance in tissues from four COVID-19 positive donors before and after embalming were compared. Tissue samples were collected from the lungs, liver, spleen, and brain both pre- and postembalming. The possible presence of infectious COVID-19 was determined by inoculating human tissue homogenates onto a monolayer of human A549-hACE2 cells and observing for cytopathic effects up to 72 h postinoculation. A real- time quantitative reverse transcription polymerase chain reaction was performed to quantify COVID-19 present in culture supernatants. Fully intact viral genome sequence was possible to obtain in samples with higher levels of virus, even several days postmortem. The embalming procedure described above substantially reduces the abundance of viable COVID-19 genomes in all tissues, sometimes even to undetectable levels. However, in some cases, COVID-19 RNA can still be detected, and a cytopathic effect can be seen both pre- and postembalmed tissues. This study suggests that embalmed COVID-19 positive cadavers might be used safely with appropriate precautions followed in gross anatomy laboratories and in clinical and scientific research. Deep lung tissue is the best specimen to test for the virus. If the tests on the lung tissues are negative, there is a very low likelihood that other tissues will show positive results.

Reduction in the risk of progression of solid organ transplant recipients infected by SARS-CoV-2 treated with monoclonal antibodies

Recipients of solid organ transplants (SOT) are at higher risk of infection by SARS-CoV-2 virus especially due to chronic immunosuppression therapy and frequent multiple comorbid conditions. COVID-19 is a potentially life-threatening disease in SOT recipients, with an increased likelihood of progressing to severe disease, with the need of hospitalization, admission to the intensive care unit (ICU) and mechanical ventilatory support. This article presents an updated review of different aspects related to the outcome of COVID-19 in SOT recipients. In nvaccinated SOT recipients, COVID-19 is associated with a high mortality rate, in-patient care and ICU admission, and impaired graft function or rejection in severe disease. In vaccinated SOT recipients even after full vaccination, there is a reduction of the risk of mortality, but the course of COVID-19 may continue to be severe, influenced by the time from transplant, the net state of immunosuppression and having suffered graft rejection or dysfunction. SOT recipients develop lower immunity from mRNA vaccines with suboptimal response. Treatment with mAbs provides favorable outcomes in non-hospitalized SOT recipients at high risk for severe disease, with lower rates of hospitalization, emergency department visits, ICU care, progression to severe disease, and death. However, broad vaccination and therapeutic options are required, particularly in light of the tendency of the SARS-CoV-2 virus to adapt and evade both natural and vaccine-induced immunity.

Anti-SARS-CoV-2 IgG antibody titer after BNT162b2 mRNA COVID-19 vaccination in Japanese patients who underwent renal replacement therapy, hemodialysis, peritoneal dialysis, and kidney transplantation

BACKGROUND

Coronavirus disease (COVID-19) vaccination is recommended for patients undergoing renal replacement therapy (RRT), including hemodialysis (HD), peritoneal dialysis (PD), and kidney transplantation (KT). However, the difference in the immune response between RRT patients and healthy individuals after mRNA vaccines remains uncertain.

METHODS

This retrospective observational study evaluated the anti-severe-acute-respiratory-syndrome-coronavirus-2 (anti-SARS-CoV-2) IgG antibody acquisition, titers and their changes, normal response rate (reaching titers of healthy individuals), factors associated with a normal response, and effectiveness of booster vaccination in Japanese RRT patients.

RESULTS

Most HD and PD patients acquired anti-SARS-CoV-2 IgG antibodies after the second vaccination; however, their antibody titers and normal response rates (62-75%) were low compared with those of healthy subjects. Approximately 62% of KT recipients acquired antibodies, but the normal response rate was low (23%). Anti-SARS-CoV-2 IgG antibody waning occurred in the control, HD, and PD groups, while negative or very low titers remained in KT recipients. Third booster vaccination was effective in most HD and PD patients. However, the effect was mild in KT recipients - only 58% reached a normal response level. Multivariate logistic regression analyses demonstrated that younger age, higher serum albumin level, and RRT other than KT were significantly associated with a normal response after the second vaccination.

CONCLUSIONS

RRT patients, particularly KT recipients, exhibited poor vaccine responses. Booster vaccination would be beneficial for HD and PD patients; however, its effect in KT recipients was mild. Further COVID-19 vaccinations using the latest vaccine or alternative procedures should be considered in RRT patients.

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.

Early Outcomes of Adult Heart Transplantation From COVID-19 Infected Donors

BACKGROUND

There is a paucity of data on heart transplantation (HT) using COVID-19 donors.

OBJECTIVES

This study investigated COVID-19 donor use, donor and recipient characteristics, and early post-HT outcomes.

METHODS

Between May 2020 and June 2022, study investigators identified 27,862 donors in the United Network for Organ Sharing, with 60,699 COVID-19 nucleic acid amplification testing (NAT) performed before procurement and with available organ disposition. Donors were considered "COVID-19 donors" if they were NAT positive at any time during terminal hospitalization. These donors were subclassified as "active COVID-19" (aCOV) donors if they were NAT positive within 2 days of organ procurement, or "recently resolved COVID-19" (rrCOV) donors if they were NAT positive initially but became NAT negative before procurement. Donors with NAT-positive status >2 days before procurement were considered aCOV unless there was evidence of a subsequent NAT-negative result ≥48 hours after the last NAT-positive result. HT outcomes were compared.

RESULTS

During the study period, 1,445 "COVID-19 donors" (COVID-19 NAT positive) were identified; 1,017 of these were aCOV, and 428 were rrCOV. Overall, 309 HTs used COVID-19 donors, and 239 adult HTs from COVID-19 donors (150 aCOV, 89 rrCOV) met study criteria. Compared with non-COV, COVID-19 donors used for adult HT were younger and mostly male (∼80%). Compared with HTs from non-COV donors, recipients of HTs from aCOV donors had increased mortality at 6 months (Cox HR: 1.74; 95% CI: 1.02-2.96; P = 0.043) and 1 year (Cox HR: 1.98; 95% CI: 1.22-3.22; P = 0.006). Recipients of HTs from rrCOV and non-COV donors had similar 6-month and 1-year mortality. Results were similar in propensity-matched cohorts.

CONCLUSIONS

In this early analysis, although HTs from aCOV donors had increased mortality at 6 months and 1 year, HTs from rrCOV donors had survival similar to that seen in recipients of HTs from non-COV donors. Continued evaluation and a more nuanced approach to this donor pool are needed.

Beyond donation to organ utilization in the UK

PURPOSE OF REVIEW

Optimizing deceased donor organ utilization is gaining recognition as a topical and important issue, both in the United Kingdom (UK) and globally. This review discusses pertinent issues in the field of organ utilization, with specific reference to UK data and recent developments within the UK.

RECENT FINDINGS

A multifaceted approach is likely required in order to improve organ utilization. Having a solid evidence-base upon which transplant clinicians and patients on national waiting lists can base decisions regarding organ utilization is imperative in order to bridge gaps in knowledge regarding the optimal use of each donated organ. A better understanding of the risks and benefits of the uses of higher risk organs, along with innovations such as novel machine perfusion technologies, can help clinician decision-making and may ultimately reduce the unnecessary discard of precious deceased donor organs.

SUMMARY

The issues facing the UK with regards to organ utilization are likely to be similar to those in many other developed countries. Discussions around these issues within organ donation and transplantation communities may help facilitate shared learning, lead to improvements in the usage of scarce deceased donor organs, and enable better outcomes for patients waiting for transplants.

Humoral vaccine response and breakthrough infections in kidney transplant recipients during the COVID-19 pandemic: a nationwide cohort study

Background

Kidney transplant recipients (KTRs) experienced reduced SARS-CoV-2 vaccine response and were at increased risk of severe COVID-19. It is unknown if level of vaccine induced anti-receptor binding domain IgG (anti-RBD IgG) correlates with protection from and survival following COVID-19. We aimed to evaluate the effect of vaccine response on risk of breakthrough infections (BTI) and COVID-19 death in KTRs.

Methods

We performed a nationwide study, examining the competing risk of SARS-CoV-2 infection, COVID-19 related/unrelated death, and vaccine efficacy as assessed by level of anti-RBD IgG response 4-10 weeks after each vaccination. The study included all KTR in Norway alive and with a functioning graft on February 20th, 2020, and events after November 11th, 2022 were right-censored. A pre-pandemic reference-cohort from January 1st 2019 to January 1st 2020 was included to evaluate excess mortality. The study was conducted at Oslo University Hospital, Rikshospitalet, Norway.

Findings

The study included 3607 KTRs (59 [48-70] years) with a functioning graft at February 20th, 2020, who received (median [IQR]) 4 [3-4] vaccines (range 2-6, 99% mRNA). Anti-RBD IgG was measured in 12 701 serum samples provided by 3213 KTRs. Vaccine response was assessed 41 [31-57] days after vaccination. A total of 1090 KTRs were infected with SARS-CoV-2, 1005 (92%) were BTI, and vaccine response did not protect against BTI. The hazard ratio for COVID-19 related death 40 days post-infection was 1.71 (95% CI: 1.14, 2.56) comparing vaccine response levels (≥5 vs. ≥5000 BAU/mL). No excess non-COVID-19 mortality was registered in KTRs surviving SARS-CoV-2 infection compared to a 2019 pre-pandemic reference.

Interpretation

Our findings suggested that SARS-CoV-2 mRNA vaccine response did not predict protection against infection, but prevention of fatal disease progression in KTRs and greater vaccine response further reduced the risk of COVID-19 death. No excess non-COVID-19 mortality was seen during the pandemic.

Funding

CEPI and internal funds.

Th1-dominant cytokine responses in kidney patients after COVID-19 vaccination are associated with poor humoral responses

Cytokines are regulators of the immune response against severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2). However, the contribution of cytokine-secreting CD4⁺ and CD8⁺ memory T cells to the SARS-CoV-2-specific humoral immune response in immunocompromised kidney patients is unknown. Here, we profiled 12 cytokines after stimulation of whole blood obtained 28 days post second 100 μg mRNA-1273 vaccination with peptides covering the SARS-CoV-2 spike (S)-protein from patients with chronic kidney disease (CKD) stage 4/5, on dialysis, kidney transplant recipients (KTR), and healthy controls. Unsupervised hierarchical clustering analysis revealed two distinct vaccine-induced cytokine profiles. The first profile was characterized by high levels of T-helper (Th)₁ (IL-2, TNF-α, and IFN-γ) and Th₂ (IL-4, IL-5, IL-13) cytokines, and low levels of Th₁₇ (IL-17A, IL-22) and Th₉ (IL-9) cytokines. This cluster was dominated by patients with CKD, on dialysis, and healthy controls. In contrast, the second cytokine profile contained predominantly KTRs producing mainly Th₁ cytokines upon re-stimulation, with lower levels or absence of Th₂, Th₁₇, and Th₉ cytokines. Multivariate analyses indicated that a balanced memory T cell response with the production of Th₁ and Th₂ cytokines was associated with high levels of S1-specific binding and neutralizing antibodies mainly at 6 months after second vaccination. In conclusion, seroconversion is associated with the balanced production of cytokines by memory T cells. This emphasizes the importance of measuring multiple T cell cytokines to understand their influence on seroconversion and potentially gain more information about the protection induced by vaccine-induced memory T cells.

Current Status of Genetically Engineered Pig to Monkey Kidney Xenotransplantation in Korea

BACKGROUND

In South Korea, pig-to-nonhuman primate trials of solid organs have only been performed recently, and the results are not sufficiently satisfactory to initiate clinical trials. Since November 2011, we have performed 30 kidney pig-to-nonhuman primate xenotransplantations at Konkuk University Hospital.

METHODS

Donor αGal-knockout-based transgenic pigs were obtained from 3 institutes. The knock-in genes were CD39, CD46, CD55, CD73, and thrombomodulin, and 2-4 transgenic modifications with GTKO were done. The recipient animal was the cynomolgus monkey. We used the immunosuppressants anti-CD154, rituximab, anti-thymocyte globulin, tacrolimus, mycophenolate mofetil, and steroids.

RESULTS

The mean survival duration of the recipients was 39 days. Except for a few cases for which survival durations were <2 days because of technical failure, 24 grafts survived for >7 days, with an average survival duration of 50 days. Long-term survival was observed 115 days after the removal of the contralateral kidney, which is currently the longest-recorded graft survival in Korea. We confirmed functioning grafts for the surviving transplanted kidneys after the second-look operation, and no signs of hyperacute rejection were observed.

CONCLUSIONS

Although our survival results are relatively poor, they are the best-recorded results in South Korea, and the ongoing results are improving. With the support of government funds and the volunteering activities of clinical experts, we aim to further improve our experiments and contribute to the commencement of clinical trials of kidney xenotransplantation in Korea.

SARS-CoV-2 vaccine antibody response and breakthrough infections in transplant recipients

Rates and modulators of SARS-CoV-2 vaccine nonresponse and breakthrough infections remain unclear in serially vaccinated transplant recipients. In a prospective, mono-centric, observational study, 1878 adult solid organ and hematopoietic cell transplant recipients, with prior SARS-CoV-2 vaccination, were included between March 2021 and February 2022. SARS-CoV-2 anti-spike IgG antibodies were measured at inclusion and details on SARS-CoV-2 vaccine doses and infection were collected. No life-threatening adverse events were reported after a total of 4039 vaccine doses. In transplant recipients without prior SARS-CoV-2 infection (n = 1636), antibody response rates ranged widely, from 47% in lung transplant to 90% in liver transplant and 91% in hematopoietic cell transplant recipients after third vaccine dose. Antibody positivity rate and levels increased after each vaccine dose in all types of transplant recipients. In multivariable analysis, older age, chronic kidney disease and daily dose of mycophenolate and corticosteroids were negatively associated with antibody response rate. Overall rate of breakthrough infections was 25.2% and mainly (90.2%) occurred after third and fourth vaccine dose. Lung transplant recipients had the highest rates of severe breakthrough infection (10.5%) and death (2.5%). In multivariable analysis, older age, daily dose of mycophenolate and corticosteroids were associated with severe breakthrough infection. Transplant recipients with infection before first vaccine dose (n = 160) had higher antibody response rates and levels after each vaccine dose, and a significantly lower overall rate of breakthrough infections compared to those without prior infection. Antibody response after SARS-CoV-2 vaccination and rate of severe breakthrough infections vary largely between different transplant types and are modulated by specific risk factors. The observed heterogeneity supports a tailored approach against COVID-19 in transplant recipients.

Impact of COVID-19 on abdominal organ transplantation: A bibliometric analysis

BACKGROUND

Abdominal solid organ transplant (SOT) programs have been hit hard by the COVID-19 pandemic, which was officially declared as such on March 11, 2020. Over two years, the tightening and softening of limitations in response to the "waves" of infection and COVID-19 fluctuations have provided distinct issues for waitlisted patients, transplant recipients, and transplant organizations.

METHOD

We searched Scopus using the terms "transplant" and "transplantation," and organ-related phrases like "intestin*," "liver," "kidney," "hepatic," "renal," and "pancrea*," as well as COVID-19 terms such as "COVID-19," "coronavirus," and "SARS-CoV-2." We included articles, reviews, conference papers, letters, notes, editorials, brief surveys, book chapters, and errata and studied nations, institutions, authors, journals, keywords, and articles. VOSviewer 1.6.18 and Excel were used to create tables and figures.

RESULTS

We included 1,251 of 1,256 studies. Among them, 289 (23.1%), 489 (39.1%), and 473 (37.8%) papers were published in 2020, 2021, and 2022, with mean (SD) citations of 30.3 (53.3), 14.3 (26.8), and 4.79 (6.38), respectively. Compared to other abdominal organs, the field of kidney transplants had the highest number of articles describing the impact of COVID-19. The United States contributed the most articles, and the American Journal of Transplantation published the most articles.

CONCLUSION

To our knowledge, this is the first bibliometric investigation of the impact of COVID-19 on SOT. This report provides an overview of the research conducted on SOT and COVID-19. There is potential for this bibliometric analysis to serve as a beneficial and practical resource for ongoing and future research.

Vaccine Effectiveness Against the SARS-CoV-2 B.1.1.529 Omicron Variant in Solid Organ and Islet Transplant Recipients in England: A National Retrospective Cohort Study

BACKGROUND

The effectiveness of vaccines against the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) B.1.1.529 Omicron variant in immunosuppressed solid organ and islet transplant (SOT) recipients is unclear.

METHODS

National registries in England were linked to identify SARS-CoV-2 positive tests, noninjury hospitalization within 14 d, and deaths within 28 d between December 7, 2020, and March 31, 2022 in adult SOT recipients. Incidence rate ratios (IRRs) for infection, and hospitalization or death, were adjusted for recipient demographics and calendar month for the Omicron-dominant period (December 20, 2021, to March 31, 2022). Mortality risk following SARS-CoV-2 infection was adjusted for recipient demographics and dominant variant using a Cox proportional-hazards model for the entire time period.

RESULTS

During the Omicron-dominant period, infection IRRs (95% confidence intervals) were higher in those receiving 2, 3, and 4 vaccine doses than in unvaccinated patients (1.25 [1.08-1.45], 1.46 [1.28-1.67], and 1.79 [1.54-2.06], respectively). However, hospitalization or death IRRs during this period were lower in those receiving 3 or 4 vaccine doses than in unvaccinated patients (0.62 [0.45-0.86] and 0.39 [0.26-0.58], respectively). Risk-adjusted analyses for deaths after SARS-CoV-2 infection between December 7, 2020, and March 31, 2022, found hazard ratios (95% confidence intervals) of 0.67 (0.46-0.98), 0.46 (0.30-0.69), and 0.18 (0.09-0.35) for those with 2, 3, and 4 vaccine doses, respectively, when compared with the unvaccinated group.

CONCLUSIONS

In immunosuppressed SOT recipients, vaccination is associated with incremental, dose-dependent protection against hospitalization or death after SARS-CoV-2 infection, including against the Omicron variant.

Lack of seroresponse to SARS-CoV-2 booster vaccines given early post-transplant in patients primed pre-transplantation

SARS-CoV-2 vaccines are recommended pre-transplantation, however, waning immunity and evolving variants mandate booster doses. Currently there no data to inform the optimal timing of booster doses post-transplant, in patients primed pre-transplant. We investigated serial serological samples in 204 transplant recipients who received 2 or 3 SARS-CoV-2 vaccines pre-transplant. Spike protein antibody concentrations, [anti-S], were measured on the day of transplantation and following booster doses post-transplant. In infection-naïve patients, post-booster [anti-S] did not change when V3 (1^st booster) was given at 116(78-150) days post-transplant, falling from 122(32-574) to 111(34-682) BAU/ml, p=0.78. Similarly, in infection-experienced patients, [anti-S] on Day-0 and post-V3 were 1090(133-3667) and 2207(650-5618) BAU/ml respectively, p=0.26. In patients remaining infection-naïve, [anti-S] increased post-V4 (as 2^nd booster) when given at 226(208-295) days post-transplant, rising from 97(34-1074) to 5134(229-5680) BAU/ml, p=0.0016. Whilst in patients who had 3 vaccines pre-transplant, who received V4 (as 1^st booster) at 82(49-101) days post-transplant, [anti-S] did not change, falling from 981(396-2666) to 871(242-2092) BAU/ml, p=0.62. Overall, infection pre-transplant and [anti-S] at the time of transplantation predicted post-transplant infection risk. As [Anti-S] fail to respond to SARS-CoV-2 booster vaccines given early post-transplant, passive immunity may be beneficial to protect patients during this period.

Transplantation Amid a Pandemic: The Fall and Rise of Kidney Transplantation in the United States

Following the outbreak of coronavirus disease 2019 (COVID-19) in the United States, the number of kidney waitlist additions and living-donor and deceased-donor kidney transplants (LDKT/DDKT) decreased substantially but began recovering within a few months. Since then, there have been several additional waves of infection, most notably, the Delta and Omicron surges beginning in August and December 2021, respectively.

Methods

Using SRTR data, we compared observed waitlist registrations, waitlist mortality, waitlist removal due to deteriorating condition, LDKT, and DDKT over 5 distinct pandemic periods to expected events based on calculations from preepidemic data while accounting for seasonality and secular trends.

Results

Although the number of daily waitlist additions has been increasing since May 2020, the size of the active waitlist has consistently declined, reaching a minimum of 52 556 on February 27, 2022. The recent Omicron surge knocked LDKT from 25% below baseline (incidence rate ratio [IRR] = 0.690.750.81) during the Delta wave to 38% below baseline (IRR = 0.580.620.67). DDKT, however, was less affected by the Omicron wave (IRR = 0.850.890.93 and 0.880.920.96 during the Delta and Omicron waves, respectively). Waitlist death decreased from 56% above baseline (IRR = 1.431.561.70) during Delta to 41% above baseline during Omicron, whereas waitlist removal due to deteriorating condition remained at baseline/expected levels during the Delta wave (IRR = 0.931.021.12) and the Omicron wave (IRR = 0.991.071.16).

Conclusions

Despite exceptionally high COVID-19 incidence during the Omicron wave, the transplant system responded similarly to prior waves that imposed a lesser disease burden, demonstrating the transplant system's growing adaptations and resilience to this now endemic disease.

Best practices during COVID-19 pandemic in solid organ transplant programs in Spain

Clinical management of transplant patients abruptly changed during the first months of COVID-19 pandemic (March to May 2020). The new situation led to very significant challenges, such as new forms of relationship between healthcare providers and patients and other professionals, design of protocols to prevent disease transmission and treatment of infected patients, management of waiting lists and of transplant programs during state/city lockdown, relevant reduction of medical training and educational activities, halt or delays of ongoing research, etc. The two main objectives of the current report are: 1) to promote a project of best practices in transplantation taking advantage of the knowledge and experience acquired by professionals during the evolving situation of the COVID-19 pandemic, both in performing their usual care activity, as well as in the adjustments taken to adapt to the clinical context, and 2) to create a document that collects these best practices, thus allowing the creation of a useful compendium for the exchange of knowledge between different Transplant Units. The scientific committee and expert panel finally standardized 30 best practices, including for the pretransplant period (n = 9), peritransplant period (n = 7), postransplant period (n = 8) and training and communication (n = 6). Many aspects of hospitals and units networking, telematic approaches, patient care, value-based medicine, hospitalization, and outpatient visit strategies, training for novelties and communication skills were covered. Massive vaccination has greatly improved the outcomes of the pandemic, with a decrease in severe cases requiring intensive care and a reduction in mortality. However, suboptimal responses to vaccines have been observed in transplant recipients, and health care strategic plans are necessary in these vulnerable populations. The best practices contained in this expert panel report may aid to their broader implementation.

[Update of the recommendations on the management of the SARS-CoV-2 coronavirus pandemic (COVID-19) in kidney transplant patients.]

SARS-CoV-2 infection (COVID-19) has had a significant impact on transplant activity in our country. Mortality and the risk of complications associated with COVID-19 in kidney transplant recipients (KT) were expected to be higher due to their immunosuppressed condition and the frequent associated comorbidities. Since the beginning of the pandemic in March 2020 we have rapidly improved our knowledge about the epidemiology, clinical features and management of COVID-19 post-transplant, resulting in a better prognosis for our patients. KT units have been able to adapt their programs to this new reality, normalizing both donation and transplantation activity in our country.This manuscript presents a proposal to update the general recommendations for the prevention and treatment of infection in this highly vulnerable population such as KT.

Impact of the COVID-19 Pandemic on Solid Organ Transplant and Rejection Episodes in Brazil's Unified Healthcare System

BACKGROUND

Brazil has the world's largest public organ transplant program, which was severely affected by the COVID-19 pandemic. The primary aim of the study was to evaluate differences in solid organ transplants and rejection episodes during the COVID-19 pandemic compared to the five years before the pandemic in the country.

METHODS

A seven-year database was built by downloading data from the DATASUS server. The pandemic period was defined as March 2020 to December 2021. The pre-pandemic period was from January 2015 to March 2020.

RESULTS

During the pandemic, the number of solid organ transplants decreased by 19.3% in 2020 and 22.6% in 2021 compared to 2019. We found a decrease for each evaluated organ, which was more pronounced for lung, pancreas, and kidney transplants. The seasonal plot of rejection data indicated a high rejection rate between 2018 and 2021. There was also an 18% (IRR 1.18 (95% CI 1.01 to 1.37), p = 0.04) increase in the rejection rate during the COVID-19 pandemic.

CONCLUSIONS

The total number of organ transplants performed in 2021 represents a setback of six years. Transplant procedures were concentrated in the Southeast region of the country, and a higher proportion of rejections occurred during the pandemic. Together, these findings could have an impact on transplant procedures and outcomes in Brazil.

SARS-CoV-2 Vaccination in Solid-Organ Transplant Recipients

The coronavirus disease 2019 (COVID-19) pandemic has posed significant global challenges for solid organ transplant (SOT) recipients. Mortality rates of COVID-19 in this patient population remain high, despite new available therapeutic options and Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) vaccination. Priority access to SARS-CoV-2 vaccination for waitlisted candidates and for SOT patients and their family members is recommended since the advantage from vaccination reduces the risk of COVID-19-related complications. However, immunogenicity and efficacy of COVID-19 vaccines are lower in waitlisted candidates and SOT recipients than in the general population. Routine systematic assessment of humoral and cellular immune responses after SARS-CoV-2 vaccination is controversial, although highly recommended for investigation and improvement of knowledge. SOT recipients should continue to adhere to preventive protective measures despite vaccination and may undergo passive antibody prophylaxis. This article seeks to provide an update on SARS-CoV-2 vaccination and preventive measures in SOT recipients based on existing literature and international guidelines.

Ethical Issues in Kidney Transplant and Donation During COVID-19 Pandemic

The coronavirus disease-19 pandemic caused by the severe acute respiratory syndrome coronavirus has faced the transplant community with unprecedented clinical challenges in a highly vulnerable patient category. These were associated with many uncertainties for patients and health care professionals and prompted many ethical debates regarding the safe delivery of kidney transplantation. In this article, we highlight some of the most important ethical questions that were raised during the pandemic and attempt to analyze ethical arguments in light of core principles of medical ethics to either suspend or continue kidney transplantation, and to mandate vaccination in transplant patients, transplant candidates, and, finally, health care providers. We have come up with frameworks to deal responsibly with these ethical challenges, and formulated recommendations to cope with the issues imposed on patients and transplant professionals.