Outcomes following SARS-CoV-2 infection in individuals with and without solid organ transplantation-A Danish nationwide cohort study

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

SARS-CoV-2 vaccine-elicited immune responses in solid organ transplant recipients

Solid organ transplant recipients (SOTRs) are considered a high-risk group for coronavirus disease 2019 (COVID-19). The adaptive immune responses generated by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccination include humoral and cellular immune responses. Most studies on the SARS-CoV-2 vaccine have focused primarily on humoral immunity, but cellular immunity is vital for effectively controlling progression to severe COVID-19. In SOTRs, the vaccine-induced adaptive immune response is significantly attenuated compared to the response in healthy individuals. Nevertheless, vaccinated SOTRs exhibit a reduced rate and severity of SARS-CoV-2 infection. This review aims to provide a concise overview of the current understanding of SARS-CoV-2 vaccine-induced immune responses in SOTRs.

Delphi Panel Consensus Statement Generation: COVID-19 Vaccination Recommendations for Immunocompromised Populations in the European Union

INTRODUCTION

The coronavirus disease 2019 (COVID-19) pandemic has caused unprecedented pressure on healthcare systems globally. The lack of quality guidelines on the management of COVID-19 in rheumatologic disease, renal disease, hematological malignancy, and solid organ transplant recipients has resulted in a wide variation in clinical practice.

METHODS

Using a Delphi process, a panel of 16 key opinion leaders developed clinical practice statements regarding vaccine recommendations in areas where standards are absent or limited. Agreement among practicing physicians with consensus statements was also assessed via an online physician survey. The strength of the consensus was determined by the following rating system: a strong rating was defined as all four key opinion leaders (KOLs) rating the statement ≥ 8, a moderate rating was defined as three out of four KOLs rating the statement ≥ 8, and no consensus was defined as less than three out of four KOLs provided a rating of ≤ 8. Specialists voted on agreement with each consensus statement for their disease area using the same ten-point scoring system.

RESULTS

Key opinion leaders in rheumatology, nephrology, and hematology achieved consensuses for all nine statements pertaining to the primary and booster series with transplant physicians reaching consensus on eight of nine statements. Experts agreed that COVID-19 vaccines are safe, effective, and well tolerated by patients with rheumatological conditions, renal disease, hematologic malignancy, and recipients of solid organ transplants. The Delphi process yielded strong to moderate suggestions for the use of COVID-19 messenger ribonucleic acid (mRNA) vaccines and the necessity of the COVID-19 booster for the immunocompromised population. The expert panel had mixed feelings concerning the measurement of antibody titers, higher-dose mRNA vaccines, and the development of disease-specific COVID-19 guidance.

CONCLUSIONS

These results confirmed the necessity of COVID-19 vaccines and boosters in immunocompromised patients with rheumatologic disease, renal disease, hematological malignancy, and solid organ transplant recipients. Statements where consensus was not achieved were due to absent or limited evidence.

The burden of COVID-19 mortality among solid organ transplant recipients in the United States

Solid organ transplant recipients (SOTRs) have a heightened risk of adverse coronavirus disease 2019 (COVID-19) outcomes because of immunosuppression and medical comorbidity. We quantified the burden of COVID-19 mortality in United States (US) SOTRs. A sample of deaths documented in the US solid organ transplant registry from June 2020 through December 2022 was linked to the National Death Index to identify COVID-19 deaths and weighted to represent all SOTR deaths during the study period. Among 505 757 SOTRs, 57 575 deaths occurred, and based on the linkage, 12 396 (21.5%) were due to COVID-19. COVID-19 mortality was higher in males (mortality rate ratio [MRR]: 1.13), SOTRs aged 65 years and older (MRR: 1.50 in ages 65-74 vs ages 55-64 years), and non-Hispanic Black and Hispanic SOTRs (MRRs: 1.55 and 1.79 vs non-Hispanic White SOTRs). Kidney and lung recipients had the highest COVID-19 mortality, followed by heart, and then liver recipients. COVID-19 mortality also varied over time and across US states. Overall, SOTRs had a 7-fold increased risk of COVID-19 death compared to the US general population. SOTRs comprised 0.13% of the US population but accounted for 1.46% of all US COVID-19 deaths. SOTRs experience greatly elevated COVID-19 mortality. Clinicians should continue to prioritize COVID-19 prevention and treatment in this high-risk population.

Confounding and Negative Control Methods in Observational Study of SARS-CoV-2 Vaccine Effectiveness: A Nationwide, Population-Based Danish Health Registry Study

Background

Observational studies of SARS-CoV-2 vaccine effectiveness are prone to confounding, which can be illustrated using negative control methods.

Methods

Nationwide population-based cohort study including two cohorts of Danish residents 60-90 years of age matched 1:1 on age and sex: A vaccinated and a non-vaccinated cohort, including 61052 SARS-CoV-2 vaccinated individuals between 1 March and 1 July 2021 and 61052 individuals not vaccinated preceding 1 July 2021. From these two cohorts, we constructed negative control cohorts of individuals diagnosed with SARS-CoV-2 infection or acute myocardial infarction, stroke, cancer, low energy fracture, or head-trauma. Outcomes were SARS-CoV-2 infection, negative control outcomes (eg, mammography, prostate biopsy, operation for cataract, malignant melanoma, examination of eye and ear), and death. We used Cox regression to calculate adjusted incidence and mortality rate ratios (aIRR and aMRR).

Results

Risks of SARS-CoV2 infection and all negative control outcomes were elevated in the vaccinated population, ranging from an aIRR of 1.15 (95% CI: 1.09-1.21) for eye examinations to 3.05 (95% CI: 2.24-4.14) for malignant melanoma. Conversely, the risk of death in the SARS-CoV-2 infected cohort and in all negative control cohorts was lower in vaccinated individuals, ranging from an aMRR of 0.23 (95% CI: 0.19-0.26) after SARS-CoV-2 infection to 0.50 (95% CI: 0.37-0.67) after stroke.

Conclusion

Our findings indicate that observational studies of SARS-CoV-2 vaccine effectiveness may be subject to substantial confounding. Therefore, randomized trials are essential to establish vaccine efficacy after the emergence of new SARS-CoV-2 variants and the rollout of multiple booster vaccines.

Longitudinal outcomes of COVID-19 in solid organ transplant recipients from 2020 to 2023

Data regarding coronavirus disease 2019 (COVID-19) outcomes in solid organ transplant recipients (SOTr) across severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) waves, including the impact of different measures, are lacking. This cohort study, conducted from March 2020 to May 2023 in Toronto, Canada, aimed to analyze COVID-19 outcomes in 1975 SOTr across various SARS-CoV-2 waves and assess the impact of preventive and treatment measures. The primary outcome was severe COVID-19, defined as requiring supplemental oxygen, with secondary outcomes including hospitalization, length of stay, intensive care unit (ICU) admission, and 30-day and 1-year all-cause mortality. SARS-CoV-2 waves were categorized as Wildtype/Alpha/Delta (318 cases, 16.1%), Omicron BA.1 (268, 26.2%), Omicron BA.2 (268, 13.6%), Omicron BA.5 (561, 28.4%), Omicron BQ.1.1 (188, 9.5%), and Omicron XBB.1.5 (123, 6.2%). Severe COVID-19 rate was highest during the Wildtype/Alpha/Delta wave (44.6%), and lower in Omicron waves (5.7%-16.1%). Lung transplantation was associated with severe COVID-19 (OR: 4.62, 95% CI: 2.71-7.89), along with rituximab treatment (OR: 4.24, 95% CI: 1.04-17.3), long-term corticosteroid use (OR: 3.11, 95% CI: 1.46-6.62), older age (OR: 1.51, 95% CI: 1.30-1.76), chronic lung disease (OR: 2.11, 95% CI: 1.36-3.30), chronic kidney disease (OR: 2.18, 95% CI: 1.17-4.07), and diabetes (OR: 1.97, 95% CI: 1.37-2.83). Early treatment and ≥3 vaccine doses were associated with reduced severity (OR: 0.29, 95% CI: 0.19-0.46, and 0.35, 95% CI: 0.21-0.60, respectively). Tixagevimab/cilgavimab and bivalent boosters did not show a significant impact. The study concludes that COVID-19 severity decreased across different variants in SOTr. Lung transplantation was associated with worse outcomes and may benefit more from preventive and early therapeutic interventions.

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.

COVID-19 Reinfection Has Better Outcomes Than the First Infection in Solid Organ Transplant Recipients

BACKGROUND

Solid organ transplant recipients face an increased risk of severe coronavirus disease 2019 (COVID-19) and are vulnerable to repeat severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections. In nonimmunocompromised individuals, SARS-CoV-2 reinfections are milder likely because of cross-protective immunity. We sought to determine whether SARS-CoV-2 reinfection exhibits milder manifestations than primary infection in transplant recipients.

METHODS

Using a large, prospective cohort of adult transplant patients with COVID-19, we identified patients with SARS-CoV-2 reinfections. We performed a 1:1 nearest neighbor propensity score matching to control potential confounders, including the COVID-19 variant. We compared outcomes including oxygen requirement, hospitalization, and intensive care unit admission within 30 d after diagnosis between patients with reinfection and those with the first episode of COVID-19.

RESULTS

Between 2020 and 2023, 103 reinfections were identified in a cohort of 1869 transplant recipients infected with SARS-CoV-2 (incidence of 2.7% per year). These included 50 kidney (48.5%), 27 lung (26.2%), 7 heart (6.8%), 6 liver (5.8%), and 13 multiorgan (12.6%) transplants. The median age was 54.5 y (interquartile range [IQR], 40.5-65.5) and the median time from transplant to first infection was 6.6 y (IQR, 2.8-11.2). The time between the primary COVID-19 and reinfection was 326 d (IQR, 226-434). Three doses or more of SARS-CoV-2 vaccine are received by 87.4% of patients. After propensity score matching, reinfections were associated with significantly lower hospitalization (5.8% versus 19.4%; risk ratio, 0.3; 95% CI, 0.12-0.71) and oxygen requirement (3.9% versus 13.6%; risk ratio, 0.29; 95% CI, 0.10-0.84). In a within-patient analysis only in the reinfection group, the second infection was milder than the first (3.9% required oxygen versus 19.4%, P  < 0.0001), and severe first COVID-19 was the only predictor of severe reinfection.

CONCLUSIONS

Transplant recipients with COVID-19 reinfection present better outcomes than those with the first infection, providing clinical evidence for the development of cross-protective immunity.

Clinical characteristics and prognosis of SARS-CoV-2 infection in lung transplant recipients

Objective

This study aimed to investigate the clinical manifestations and prognosis of lung transplant (LTx) recipients infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) during the coronavirus disease (COVID-19) pandemic.

Methods

The research participants were LTx recipients who underwent surgery and were regularly followed up at our center. From 1 December 2022 to 28 February 2023, during the COVID-19 pandemic in China, research participants were interviewed either online or in person. SARS-CoV-2 nucleic acid or self-tested antigens were detected according to accessibility. Diagnosis and treatment were performed according to the Diagnosis and Treatment Plan for COVID-19 (10th edition) issued by the National Health Commission of the People's Republic of China. Hospitalized patients underwent chest imaging examinations, routine blood tests, biomarkers for infection and inflammation, and biochemical tests, all of which were taken and recorded. Data were analyzed to describe the features of COVID-19 in LTx recipients.

Results

In total, 52 patients were enrolled in this study, comprising 48 men and 4 women, with a mean age of 51.71 ± 11.67 years. By 1 December 2022, the mean survival period was 33.87 ± 25.97 months, of which 84.61% of the patients (44/52) had a survival period longer than 12 months. The SARS-CoV-2 infection rate in these LTx recipients was 82.69% (43/52), with 3.85% (2/52) of the infected recipients being asymptomatic, 50.00% (26/52) of the infected recipients experiencing mild COVID-19, 11.54% (6/52) having moderate COVID-19, and 17.31% (9/52) having severe or critical COVID-19. The mortality rate among severe and critical patients was 66.67% (6/9).

Conclusion

LTx recipients in this cohort exhibited a notable susceptibility to SARS-CoV-2, with 82.69% of individuals diagnosed with COVID-19. Moreover, the mortality rate among critically ill patients was high.

SARS-CoV-2 Variants Omicron BA.4/5 and XBB.1.5 Significantly Escape T Cell Recognition in Solid-organ Transplant Recipients Vaccinated Against the Ancestral Strain

BACKGROUND

Immune-suppressed solid-organ transplant recipients (SOTRs) display impaired humoral responses to COVID-19 vaccination, but T cell responses are incompletely understood. SARS-CoV-2 variants Omicron BA.4/5 (BA.4/5) and XBB.1.5 escape neutralization by antibodies induced by vaccination or infection with earlier strains, but T cell recognition of these lineages in SOTRs is unclear.

METHODS

We characterized Spike-specific T cell responses to ancestral SARS-CoV-2 and BA.4/5 peptides in 42 kidney, liver, and lung transplant recipients throughout a 3- or 4-dose ancestral Spike mRNA vaccination schedule. As the XBB.1.5 variant emerged during the study, we tested vaccine-induced T cell responses in 10 additional participants using recombinant XBB.1.5 Spike protein. Using an optimized activation-induced marker assay, we quantified circulating Spike-specific CD4 + and CD8 +  T cells based on antigen-stimulated expression of CD134, CD69, CD25, CD137, and/or CD107a.

RESULTS

Vaccination strongly induced SARS-CoV-2-specific T cells, including BA.4/5- and XBB.1.5-reactive T cells, which remained detectable over time and further increased following a fourth dose. However, responses to BA.4/5 (1.34- to 1.67-fold lower) XBB.1.5 (2.0- to 18-fold lower) were significantly reduced in magnitude compared with ancestral strain responses. CD4 + responses correlated with anti-receptor-binding domain antibodies and predicted subsequent antibody responses in seronegative individuals. Lung transplant recipients receiving prednisone and older adults displayed weaker responses.

CONCLUSIONS

Ancestral strain vaccination stimulates BA.4/5 and XBB.1.5-cross-reactive T cells in SOTRs, but at lower magnitudes. Antigen-specific T cells can predict future antibody responses. Our data support monitoring both humoral and cellular immunity in SOTRs to track COVID-19 vaccine immunogenicity against emerging variants.

Current Trends and Future Directions of Malignancy After kidney Transplantation: A 1970-2022 Bibliometric Analysis

BACKGROUND Malignancy after kidney transplantation (MKT) remains a leading cause of death in transplant recipients and over the past few decades there have been many reports on this topic. However, the task of extracting crucial information from intricate events poses a significant challenge in guiding clinical work. Hence, bibliometrics was employed to summarize and predict the future in this study. MATERIAL AND METHODS Reviews and articles on MKT were extracted from the Web of Science Core Collection (WoSCC) and were analyzed by the software VOSviewer, CiteSpace, Scimago Graphica, and R package Bibliometrix for bibliometric analysis. RESULTS The analysis considered 5700 publications from 28 647 authors and 4924 institutions across 100 countries, spanning the years 1970-2022. Reference co-citation analysis showed that "renal cell carcinoma", "skin cancer", "post-transplant lymphoproliferative disorder" and "COVID-19 vaccine" were research hotspots. Keywords that co-occurred early were "immunosuppressant", "cancer", "Epstein-Barr virus", "squamous cell carcinoma", and "infection", etc., while "impact","risk factor", "outcomes", "mortality", "management" frequently co-occurred later. From 2020 to 2022, newly emerging keywords such as "SARS-CoV-2" and "COVID-19", together with citation bursts for "immune checkpoint inhibitors" and "ipilimumab," were observed. CONCLUSIONS The focus of MKT-related studies has evolved from exploring the spectrum, risk factors, and outcomes of MKT, to examining the pathogenesis, individualized screening, prevention, and treatment, including appropriate use of immune checkpoint inhibitors. Reports of renal transplant recipients infected with SARS-CoV-2 or COVID-19 have also gained attention since 2019. These suggest that individualized management remains a frontier for research and a future direction in MKT topics.

Miracles of science: Birth after uterus transplantation

AIM

The concept of regaining childbearing ability via uterus transplantation (UTx) motivates many infertile women to pursue giving birth to their own children. This article provides insight into maternal and neonatal outcomes of the procedure globally and facilitates quality of care in related medical fields.

METHODS

The authors searched ISI Web of Science, MEDLINE, non-PubMed-indexed journals, and common search engines to identify peer-review publications and unpublished sources in scientific reference databases.

RESULTS

The feasibility of the procedure has been proven with 46 healthy children in 88 procedures so far. Success relies upon dedicated teamwork involving transplantation surgery, obstetrics and reproductive medicine, neonatology, pediatrics, psychology, and bioethics. However, challenges exist owing to donor, recipient, and fetus. Fetal growth in genetically foreign uterine allograft with altered feto-maternal interface and vascular anatomy, immunosuppressive exposure, lack of graft innervation leading to "unable-to-feel" uterine contractions and conception via assisted reproductive technology create notable risks during pregnancy. Significant portion of women are complicated by at least one or more obstetric problems. Preeclampsia, gestational hypertension and diabetes mellitus, elevated kidney indices, and preterm delivery are common complications.

CONCLUSIONS

UTx has short- and long-term satisfying outcome. Advancements in the post-transplant management would undoubtedly lead this experimental procedure into mainstream clinical practice in the near future. However, both women and children of UTx need special consideration due to prematurity-related neonatal problems and the long-term effects of transplant pregnancy. Notable health risks for the recipient and fetus should be discussed with potential candidates for UTx.

COVID-19 Hospitalization in Solid Organ Transplant Recipients on Immunosuppressive Therapy

Importance

Solid organ transplant recipients are at high risk of severe infection with SARS-CoV-2 compared with the general population. However, factors associated with COVID-19-related severity in this population are still insufficiently explored in the literature.

Objective

To examine which health conditions and immunosuppressive drugs for preventing graft rejection are associated with the risk of COVID-19-related hospitalization in solid organ transplant recipients.

Design, Setting, and Participants

Using the French National Health Data System, this cohort study assessed patients of any age who received transplants between their date of birth and entry into the cohort on February 15, 2020. The cohort was followed up between February 15, 2020, and July 31, 2022.

Exposures

Immunosuppressive drugs, including steroids, and health conditions (age, sex, and comorbidities).

Main Outcomes and Measures

The main outcome was hospitalization for COVID-19, defined by main diagnostic International Statistical Classification of Diseases and Related Health Problems, Tenth Revision (ICD-10) codes. Factors associated with the outcome were identified with a nonconditional logistic regression. Confounding by indication was controlled using a multivariable model with adjustment for individual confounders. Each transplanted organ was examined separately.

Results

Overall, 60 456 participants (median [IQR] age, 59 [47-67] years; 63.7% male) were included in the study, of whom 41 463 (68.6%) had kidney transplants, 14 464 (23.9%) had liver transplants, 5327 (8.8%) had heart transplants, and 2823 (4.6%) had lung transplants. Among them, 12.7% of kidney transplant recipients, 6.4% of liver transplant recipients, 12.9% of heart transplant recipients, and 18.0% of lung transplant recipients were hospitalized for COVID-19. In kidney transplant recipients, steroids (adjusted odds ratio [AOR], 1.60; 95% CI, 1.49-1.73) and mycophenolic acid (AOR, 1.37; 95% CI, 1.25-1.51) were associated with a high risk of hospitalization. In liver transplant recipients, tacrolimus (AOR, 0.77; 95% CI, 0.61-0.98) was associated with a decreased risk, and steroids (AOR, 1.60; 95% CI, 1.38-1.86) and mycophenolic acid (AOR, 1.61; 95% CI, 1.37-1.90) were associated with an increased risk of hospitalizations. In heart transplant recipients, cyclosporine (AOR, 0.67; 95% CI, 0.47-0.94) was associated with a decreased risk, and steroids (AOR, 1.42; 95% CI, 1.11-1.82), mycophenolic acid (AOR, 1.29; 95% CI, 1.02-1.64), sirolimus (AOR, 2.71; 95% CI, 1.20-6.09), and everolimus (AOR, 1.24; 95% CI, 1.01-1.51) were associated with an increased risk of hospitalization. Only steroids (AOR, 1.72; 95% CI, 1.19-2.48) were associated with a high risk of COVID-19 hospitalization in lung transplant recipients.

Conclusions and Relevance

This study suggests that mycophenolic acid, sirolimus, and steroids are associated with an increased risk of COVID-19-related hospitalization in solid organ transplant recipients. These results should be considered by clinicians treating transplant recipients and may help inform epidemic-related decisions for this population in the future.

Outcomes following SARS-CoV-2 infection in individuals with and without inflammatory rheumatic diseases: a Danish nationwide cohort study

OBJECTIVE

In a setting with an extensive SARS-CoV-2 test strategy and availability of effective vaccines, we aimed to investigate if patients with inflammatory rheumatic diseases (IRD) face greater risk of contracting SARS-CoV-2 and have a worse prognosis of increased risk of hospitalisation, assisted ventilation and death compared with the general population.

METHODS

This was a nationwide, population-based register study that compared outcomes of SARS-CoV-2 infection in Danish patients with IRD (n=66 840) with matched population controls (n=668 400). The study period was from March 2020 to January 2023. Cox regression analyses were used to calculate incidence rate ratios (IRRs) for SARS-CoV-2-related outcomes.

RESULTS

We observed a difference in time to first and second positive SARS-CoV-2 test in patients with IRD compared with the general population (IRR 1.06, 95% CI 1.05 to 1.07) and (IRR 1.21, 95% CI 1.15 to 1.27). The risks of hospital contact with COVID-19 and severe COVID-19 were increased in patients with IRD compared with population controls (IRR 2.11, 95% CI 1.99 to 2.23) and (IRR 2.18, 95% CI 1.94 to 2.45). The risks of assisted ventilation (IRR 2.33, 95% CI 1.89 to 2.87) and COVID-19 leading to death were increased (IRR 1.98, 95% CI 1.69 to 2.33). Patients with IRD had more comorbidities compared with the general population. A third SARS-CoV-2 vaccination was associated with a reduced need for hospitalisation with COVID-19 and reduced the risk of death.

CONCLUSION

Patients with IRD have a risk of SARS-CoV-2, which nearly corresponds to the general population but had a substantial increased risk of hospitalisation with COVID-19, severe COVID-19, requiring assisted ventilation and COVID-19 leading to death, especially in patients with comorbidities.

Pre-Operative SARS-CoV-2 Testing in Asymptomatic Heart Transplantation Recipients

INTRODUCTION

From the start of the coronavirus disease 2019 (COVID-19) pandemic, international guidelines have recommended pre-operative screening for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) before heart transplantation (HTx). Due to the changing prevalence of COVID-19, the chances of false positive results have increased. Because of increased immunity in the population and evolution of SARS-CoV-2 to current Omicron variants, associated mortality and morbidity have decreased. We set out to investigate the yield and side effects of SARS-CoV-2 screening in our center.

METHODS

We performed a retrospective cohort study in the University Medical Center Utrecht. The study period was from March 2019 to January 2023. All data from patients who underwent HTx were collected, including all pre-operative and post-operative SARS-CoV-2 tests. Furthermore, all clinical SARS-CoV-2 tests for the indication of potential HTx were screened.

RESULTS

In the period under study, 51 patients underwent HTx. None of the recipients reported any symptoms of a viral infection. Fifty HTx recipients were screened for SARS-CoV-2. Forty-nine out of fifty patients tested negative. One patient had a false positive result, potentially delaying the HTx procedure. There were no cancelled HTx procedures due to a true positive SARS-CoV-2 test result.

CONCLUSION

Pre-operative SARS-CoV-2 screening in asymptomatic HTx recipients did not lead to any true positive cases. In 2% of the cases, screening resulted in a false positive test result. With the current Omicron variants, in combination with a low-prevalence situation, we propose to abandon pre-operative SARS-CoV-2 screening and initiate a symptom-driven approach for the general viral testing of patients who are called in for a potential HTx.

Patterns of testing in the extensive Danish national SARS-CoV-2 test set-up

BACKGROUND

The Danish national SARS-CoV-2 mass test system was among the most ambitious worldwide. We describe its set-up and analyse differences in patterns of testing per demography and time period in relation to the three waves of SARS-CoV-2 transmission in Denmark.

METHODS

We included all reported PCR- and rapid antigen-tests performed between 27 February 2020 and 10 March 2022 among all residents aged 2 years or above. Descriptive statistics and Poisson regression models were used to analyse characteristics of individuals tested for SARS-CoV-2 using a national cohort study design.

RESULTS

A total of 63.7 million PCR-tests and 60.0 million rapid antigen-tests were performed in the study period, testing 90.9% and 78.8% of the Danish population at least once by PCR or antigen, respectively. Female sex, younger age, Danish heritage and living in the capital area were all factors positively associated with the frequency of PCR-testing. The association between COVID-19 vaccination and PCR-testing changed from negative to positive over time.

CONCLUSION

We provide details of the widely available, free-of-charge, national SARS-CoV-2 test system, which served to identify infected individuals, assist isolation of infectious individuals and contact tracing, and thereby mitigating the spread of SARS-CoV-2 in the Danish population. The test system was utilized by nearly the entire population at least once, and widely accepted across different demographic groups. However, demographic differences in the test uptake did exist and should be considered in order not to cause biases in studies related to SARS-CoV-2, e.g., studies of transmission and vaccine effectiveness.

Protective Effect of Vaccine Doses and Antibody Titers Against SARS-CoV-2 Infection in Kidney Transplant Recipients

Patients undergoing kidney transplantation have a poor response to vaccination and a higher risk of disease progression of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The effectiveness of vaccine doses and antibody titer tests against the mutant variant in these patients remains unclear. We retrospectively analyzed the risk of SARS-CoV-2 infection in a single medical center according to vaccine doses and immune responses before the outbreak. Among 622 kidney transplant patients, there were 77 patients without vaccination, 26 with one dose, 74 with two doses, 357 with three, and 88 with four doses. The vaccination status and infection rate proportion were similar to the general population. Patients undergoing more than three vaccinations had a lower risk of infection (odds ratio = 0.6527, 95% CI = 0.4324-0.9937) and hospitalization (odds ratio = 0.3161, 95% CI = 0.1311-0.7464). Antibody and cellular responses were measured in 181 patients after vaccination. Anti-spike protein antibody titer of more than 1,689.3 BAU/mL is protective against SARS-CoV-2 infection (odds ratio = 0.4136, 95% CI = 0.1800-0.9043). A cellular response by interferon-γ release assay was not correlated with the disease (odds ratio = 1.001, 95% CI = 0.9995-1.002). In conclusion, despite mutant strain, more than three doses of the first-generation vaccine and high antibody titers provided better protection against the omicron variant for a kidney transplant recipient.

Outcome of Transplant Recipients Infected with Omicron BA.1 and BA.2: A Single-Center Retrospective Study in Saudi Arabia

The outcome of transplant recipients is variable depending on the study population, vaccination status and COVID-19 variants. Our aim was to study the impact of Omicron subvariants on the mortality of transplant recipients. We reviewed the results of SARS-CoV-2 whole genome sequence of random isolates collected from 29 December 2021 until 17 May 2022 in King Faisal Specialist Hospital and Research center, Jeddah (KFSHRC-J), Saudi Arabia performed as hospital genomic surveillance program for COVID-19 variants. We included 25 transplant patients infected with confirmed Omicron variants.17 (68%) and 8 (32%) patients had Omicron BA.1 and BA.2, respectively. 12 (68%) patients had renal transplants. Only 36% of patients received three doses of COVID-19 vaccines. 23 (92%) patients required hospitalization. 20 (80%) patients survived and 6 (25%) required intensive care unit (ICU) admission. Among ICU patients, 66.7% were more than 50 years, 50% had two to three comorbidities and 5 out of 6 (83%) died. The mortality of transplant patients infected with Omicron variants in our cohort was higher than other centers as a limited number of patients received booster vaccines. Optimizing booster vaccination is the most efficient method to improve the mortality of COVID-19 in transplant recipients recognizing the inefficacy of monoclonal antibodies in the presence of SARS-CoV-2 emerging variants. We did not show a difference in mortality in transplant patients infected with Omicron BA.1 and BA.2 knowing the limitation of our sample size.

Clinical Outcomes of SARS-CoV-2 Breakthrough Infections in Liver Transplant Recipients during the Omicron Wave

At the start of the pandemic, liver transplant recipients (LTR) were at high risk of developing severe COVID-19. Here, the outcomes of breakthrough infections in fully vaccinated LTR (n = 98) during the Omicron wave were assessed. In most patients, a mild disease course was observed, but 11 LTR (11.2%) required hospitalization for COVID-19-related complications. All patients survived. The LTR requiring hospitalization were older (67 years vs. 54 years; p < 0.001), had a higher Charlson comorbidity index (9 vs. 5; p < 0.001), and a lower anti-S RBD titer (Roche Elecsys) prior to infection (508.3 AU/mL vs. 2044 AU/mL; p = 0.03). Long-lasting symptoms for ≥4 weeks were reported by 37.5% of LTR (30/80). Risk factors in LTR included female sex (p = 0.01; Odds Ratio (OR) = 4.92 (95% confidence interval (CI) (1.5-16.5)) and dyspnea (p = 0.009; OR = 7.2 (95% CI (1.6-31.6)) during infection. Post-infection high anti-S RBD antibody levels were observed in LTR, and healthy controls (HC), while the cellular immune response, assessed by interferon-gamma release assay (EUROIMMUN), was significantly lower in LTR compared with HC (p < 0.001). In summary, in fully vaccinated LTR, SARS-CoV-2 breakthrough infections during the Omicron wave led to mild disease courses in the majority of patients and further boosted the humoral and cellular hybrid anti-SARS-CoV-2-directed immune response. While all patients survived, older and multimorbid LTR with low baseline antibody titers after vaccination still had a substantial risk for a disease course requiring hospitalization due to COVID-19-related complications.

Outcome of SARS-CoV-2 infection among patients with common variable immunodeficiency and a matched control group: A Danish nationwide cohort study

The risk of severe adult respiratory coronavirus-2 (SARS-CoV-2) infection and the course of the infection among individuals with common variable immunodeficiency (CVID) relative to the general population have been a matter of debate. We conducted a Danish nationwide study comparing the timing of SARS-CoV-2 vaccination, the risk of first confirmed SARS-CoV-2 infection, re-infection, and the outcome of infection among individuals with CVID relative to an age- and gender matched control group. Cox regression was used to calculate incidence rate ratios. The CVID patients received SARS-CoV-2 vaccinations earlier than those included in the population control group. Even so, the risks of both first infection and re-infection were increased among the individuals with CVID. The CVID group also had increased risk for hospital contacts due to SARS-CoV-2 infection relative to the general population. However, reassuringly, the risk of mechanical ventilation and death did not differ between the groups, but the numbers were low in both groups, making the estimates uncertain. Though this is the largest study to investigate the risk of SARS-CoV-2 infections and outcomes hereof among individuals with CVID relative to the general population, we cannot rule out minor differences in severity, which might only be detectable with an even larger sample size.

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.