The use of quantitative pupillometry in brain death determination: preliminary findings

PURPOSE

Quantitative pupillometry (QP) has been increasingly applied in neurocritical care as an easy-to-use and reliable technique for evaluating the pupillary light reflex (PLR). Here, we report our preliminary findings on using QP for clinical brain death (BD) determination.

MATERIALS

This retrospective study included 17 patients ≥ 18 years (mean age, 57.3 years; standard deviation, 15.8 years) with confirmed BD, as defined by German Guidelines for the determination of BD. The PLR was tested using the NPi®-200 Pupillometer (Neuroptics, Laguna Hill, USA), a handheld infrared device automatically tracking and analyzing pupil dynamics over 3 s. In addition, pupil diameter and neurological pupil index (NPi) were also evaluated.

RESULTS

Intracerebral bleeding, subarachnoid hemorrhage, and hypoxic encephalopathy were the most prevalent causes of BD. In all patients, the NPi was 0 for both eyes, indicating the cessation of mid-brain function. The mean diameter was 4.9 mm (± 1.3) for the right pupil and 5.2 mm (±1.2) for the left pupil.

CONCLUSIONS

QP is a valuable tool for the BD certification process to assess the loss of PLR due to the cessation of brain stem function. Furthermore, implementing QP before the withdrawal of life-sustaining therapy in brain-injured patients may reduce the rate of missed organ donation opportunities. Further studies are warranted to substantiate the feasibility and potential of this technique in treating patients and identify suitable candidates for this technique during the BD certification process.

Cellular and molecular mechanisms of cell damage and cell death in ischemia-reperfusion injury in organ transplantation

Ischemia-reperfusion injury (IRI) is a critical pathological condition in which cell death plays a major contributory role, and negatively impacts post-transplant outcomes. At the cellular level, hypoxia due to ischemia disturbs cellular metabolism and decreases cellular bioenergetics through dysfunction of mitochondrial electron transport chain, causing a switch from cellular respiration to anaerobic metabolism, and subsequent cascades of events that lead to increased intracellular concentrations of Na+, H+ and Ca2+ and consequently cellular edema. Restoration of blood supply after ischemia provides oxygen to the ischemic tissue in excess of its requirement, resulting in over-production of reactive oxygen species (ROS), which overwhelms the cells' antioxidant defence system, and thereby causing oxidative damage in addition to activating pro-inflammatory pathways to cause cell death. Moderate ischemia and reperfusion may result in cell dysfunction, which may not lead to cell death due to activation of recovery systems to control ROS production and to ensure cell survival. However, prolonged and severe ischemia and reperfusion induce cell death by apoptosis, mitoptosis, necrosis, necroptosis, autophagy, mitophagy, mitochondrial permeability transition (MPT)-driven necrosis, ferroptosis, pyroptosis, cuproptosis and parthanoptosis. This review discusses cellular and molecular mechanisms of these various forms of cell death in the context of organ transplantation, and their inhibition, which holds clinical promise in the quest to prevent IRI and improve allograft quality and function for a long-term success of organ transplantation.

AXL inhibition suppresses early allograft monocyte-to-macrophage differentiation and prolongs allograft survival

Innate immune cells are important in the initiation and potentiation of alloimmunity in transplantation. Immediately upon organ anastomosis and reperfusion, recipient monocytes enter the graft from circulation and differentiate to inflammatory macrophages to promote allograft inflammation. However, factors that drive their differentiation to inflammatory macrophages are not understood. Here, we show that the receptor tyrosine kinase AXL was a key driver of early intragraft differentiation of recipient infiltrating monocytes to inflammatory macrophages in the presence of allogeneic stimulation and cell-to-cell contact. In this context, the differentiated inflammatory macrophages were capable of efficient alloantigen presentation and allostimulation of T cells of the indirect pathway. Consequently, early and transient AXL inhibition with the pharmacological inhibitor bemcentinib resulted in a profound reduction of initial allograft inflammation and a significant prolongation of allograft survival in a murine heart transplant model. Our results support further investigation of AXL inhibition as part of an induction regimen for transplantation.

Prevention of Cytomegalovirus Infection in Solid Organ Transplant Recipients: Guidelines by the Korean Society of Infectious Diseases and the Korean Society for Transplantation

Cytomegalovirus (CMV) is the most important opportunistic viral pathogen in solid organ transplant (SOT) recipients. The Korean guideline for the prevention of CMV infection in SOT recipients was developed jointly by the Korean Society for Infectious Diseases and the Korean Society of Transplantation. CMV serostatus of both donors and recipients should be screened before transplantation to best assess the risk of CMV infection after SOT. Seronegative recipients receiving organs from seropositive donors face the highest risk, followed by seropositive recipients. Either antiviral prophylaxis or preemptive therapy can be used to prevent CMV infection. While both strategies have been demonstrated to prevent CMV infection post-transplant, each has its own advantages and disadvantages. CMV serostatus, transplant organ, other risk factors, and practical issues should be considered for the selection of preventive measures. There is no universal viral load threshold to guide treatment in preemptive therapy. Each institution should define and validate its own threshold. Valganciclovir is the favored agent for both prophylaxis and preemptive therapy. The evaluation of CMV-specific cell-mediated immunity and the monitoring of viral load kinetics are gaining interest, but there was insufficient evidence to issue recommendations. Specific considerations on pediatric transplant recipients are included.

Emergency department evaluation of transplanted children with COVID-19

BACKGROUND

Children usually have an asymptomatic or mild course of SARS-CoV-2 infection, studies in immunocompromised patients have shown a different evolution. The aim of this study was to describe the clinical, laboratory, and radiologic manifestations of pediatric solid organ transplant (SOT) and hematopoietic stem cell transplant (HSCT) patients testing positive for SARS-CoV-2.

METHODS

A multicenter retrospective, observational descriptive study was conducted in 3 tertiary hospitals in Madrid (Spain) between March 2020 and December 2022. Consecutive patients aged 0-18 attending the corresponding pediatric emergency departments with a positive result in the real-time polymerase chain reaction test or antigenic test to detect SARS-CoV-2 in the nasopharyngeal sample were included.

RESULTS

A total of 31 children were included in the study. Sixteen (51.6%) were patients with HSCT and 15 (48.3) were patients with SOT. The median time from transplantation to COVID-19 was 1.2 years (IQR:0.5-5.1). The SOT cohort included liver (n = 4, 12.9%), kidney (n = 4, 12.9%), heart (n = 3, 9.7%), multivisceral (n = 3, 9.7%), and lung (n = 1, 3.2%). Of the 31 patients, only one was asymptomatic. The most common symptom on presentation was fever (76.7%). Abnormalities were seen on chest X-ray in 8 (66.6%) of the 12 patients. There was no significant difference in clinical manifestations, lymphopenia and radiological findings regardless of the type of transplantation or immunosuppression status. Thirteen patients (41.9%) were hospitalized. There were no patient deaths.

CONCLUSIONS

In our study, we found that the clinical course and outcome of SOT and HSCT pediatric patients with COVID-19 were generally favorable.

A humanized IL-2 mutein expands Tregs and prolongs transplant survival in preclinical models

Long-term organ transplant survival remains suboptimal, and life-long immunosuppression predisposes transplant recipients to an increased risk of infection, malignancy, and kidney toxicity. Promoting the regulatory arm of the immune system by expanding Tregs may allow immunosuppression minimization and improve long-term graft outcomes. While low-dose IL-2 treatment can expand Tregs, it has a short half-life and off-target expansion of NK and effector T cells, limiting its clinical applicability. Here, we designed a humanized mutein IL-2 with high Treg selectivity and a prolonged half-life due to the fusion of an Fc domain, which we termed mIL-2. We showed selective and sustainable Treg expansion by mIL-2 in 2 murine models of skin transplantation. This expansion led to donor-specific tolerance through robust increases in polyclonal and antigen-specific Tregs, along with enhanced Treg-suppressive function. We also showed that Treg expansion by mIL-2 could overcome the failure of calcineurin inhibitors or costimulation blockade to prolong the survival of major-mismatched skin grafts. Validating its translational potential, mIL-2 induced a selective and sustainable in vivo Treg expansion in cynomolgus monkeys and showed selectivity for human Tregs in vitro and in a humanized mouse model. This work demonstrated that mIL-2 can enhance immune regulation and promote long-term allograft survival, potentially minimizing immunosuppression.

Gender disparities in kidney replacement therapies and transplantation in Colombia

BACKGROUND

In chronic kidney disease (CKD), there are historical inequities in multiple stages of the pathway for organ transplantation. Women have been recognized as disadvantaged within this process even after several efforts. Therefore, we aimed to analyze the prevalence and incidence of CKD by gender and their access to Kidney replacement therapy (KRT) in Colombia.

METHODS

A cross-sectional study based on secondary analysis of national information on CKD, hypertension, diabetes, waiting list, deceased, and living donor transplantation between 2015 and 2020.

RESULTS

In Colombia, 4.934.914 patients were diagnosed with hypertension, diabetes, or CKD. 60,64% were female, with a mean age of 63.84 years (SD 14,36). Crude incidence for hypertension (10.85 vs. 7.21 /1000 inhabitants), diabetes mellitus (3.77 vs. 2.98 /1000 inhabitants), and CKD (4 vs. 2 /1000 inhabitants) was higher for females. Crude incidence for KRT was 86.45 cases /100.0000 inhabitants. In 2020, 2978 patients were on the waiting list, 44% female. There were 251 deaths on the waiting list, 38% female. This year, 517 kidney transplants were performed, and only 40% were female.

CONCLUSION

In Colombia, there are proportionally more females with CKD and precursor comorbidities. Nevertheless, there are fewer females on the waiting list and transplanted annually.

Eosinophils restrain humoral alloimmunity after lung transplantation

While the function of many leukocytes in transplant biology has been well defined, the role of eosinophils is controversial and remains poorly explored. Conflicting data exist regarding eosinophils' role in alloimmunity. Due to their prevalence in the lung, and their defined role in other pulmonary pathologies such as asthma, we set out to explore the role of eosinophils in the long-term maintenance of the lung allograft. We noted that depletion of eosinophils results in the generation of donor-specific antibodies. Eosinophil depletion increased memory B cell, plasma cell, and antibody-secreting cell differentiation and resulted in de novo generation of follicular germinal centers. Germinal center formation depended on the expansion of CD4+Foxp3-Bcl6+CXCR5+PD-1+ T follicular helper (Tfh) cells, which increase in number after eosinophil depletion. Mechanistically, we demonstrate that eosinophils prevent Tfh cell generation by acting as the dominant source of IFN-γ in an established lung allograft, thus facilitating Th1 rather than Tfh polarization of naive CD4+ T cells. Our data thus describe what we believe is a unique and previously unknown role for eosinophils in maintaining allograft tolerance and suggest that indiscriminate administration of eosinophil-lytic corticosteroids for treatment of acute cellular rejection may inadvertently promote humoral alloimmunity.

Organ procurement in forensic deaths: A retrospective analysis of the Italian context with a focus on the Puglia Region virtuous experience

Organ transplantation is one the most important contributions of modern medicine to society since it provides a unique therapy for terminal organ failure. However, the development of this therapeutic approach is hindered by the limited organ supply. In Italy, organ procurement requires a multidisciplinary medical-surgical approach in which legal medical doctors (LMDs) are generally tasked with ascertaining the reality of death. Sometimes, a medico-legal report is required when the deceased's family deny their consent to the organs and tissues removal from a potential deceased donor. LMDs can also be appointed by law to carry out post-mortem examinations of potential deceased donors. In these cases, the public prosecutors' interest in preserving the corpse integrity for forensic purposes seems to conflict with the ethical-humanitarian interest in promoting, at most, the opportunity to donate; however, a LMD can act as a mediator and allow both goals. This paper aims to illustrate the Apulia Region experience in reconciling the justice interests with those of a culture promoting deceased organ and tissue donation. It has been pursued by analyzing the virtuous regional organ procurement trend in forensic deaths before and after a crucial 2015 initiative, comparing the results with the national ones, and contextualizing them in the relevant literature to show systemic strengths and weaknesses and inform future Italian policy development.

Associations between the stanford integrated psychosocial assessment for transplant and one-year lung transplant medical and psychosocial outcomes

The Stanford Integrated Psychosocial Assessment for Transplant (SIPAT) is a standardized measure of the psychosocial risk profile of solid organ transplant candidates. While studies have found associations between this measure and transplant outcomes, to date this has not been examined in lung transplant recipients. We examined relations between pre-transplant SIPAT scores and 1-year lung transplant medical and psychosocial outcomes in a sample of 45 lung transplant recipients. The SIPAT was significantly associated with 6-minute walk test (χ2(1) = 6.47, p = .010), number of readmissions (χ2(1) = 6.47, p = .011), and mental health services utilization (χ2(1) = 18.15, p < .001). It was not a significantly associated with the presence of organ rejection or mortality (ps > 0.10). Results suggest that the SIPAT can help identify patients who are at an elevated risk for transplant complications and thus would benefit from services to mitigate risk factors and improve outcomes.

p40 homodimers bridge ischemic tissue inflammation and heterologous alloimmunity in mice via IL-15 transpresentation

Virus-induced memory T cells often express functional cross-reactivity, or heterologous immunity, to other viruses and to allogeneic MHC molecules that is an important component of pathogenic responses to allogeneic transplants. During immune responses, antigen-reactive naive and central memory T cells proliferate in secondary lymphoid organs to achieve sufficient cell numbers to effectively respond, whereas effector memory T cell proliferation occurs directly within the peripheral inflammatory microenvironment. Mechanisms driving heterologous memory T cell proliferation and effector function expression within peripheral tissues remain poorly understood. Here, we dissected proliferation of heterologous donor-reactive memory CD8+ T cells and their effector functions following infiltration into heart allografts with low or high intensities of ischemic inflammation. Proliferation within both ischemic conditions required p40 homodimer-induced IL-15 transpresentation by graft DCs, but expression of effector functions mediating acute allograft injury occurred only in high-ischemic allografts. Transcriptional responses of heterologous donor-reactive memory CD8+ T cells were distinct from donor antigen-primed memory CD8+ T cells during early activation in allografts and at graft rejection. Overall, the results provide insights into mechanisms driving heterologous effector memory CD8+ T cell proliferation and the separation between proliferation and effector function that is dependent on the intensity of inflammation within the tissue microenvironment.

B cells mediate lung ischemia/reperfusion injury by recruiting classical monocytes via synergistic B cell receptor/TLR4 signaling

Ischemia/reperfusion injury-mediated (IRI-mediated) primary graft dysfunction (PGD) adversely affects both short- and long-term outcomes after lung transplantation, a procedure that remains the only treatment option for patients suffering from end-stage respiratory failure. While B cells are known to regulate adaptive immune responses, their role in lung IRI is not well understood. Here, we demonstrated by intravital imaging that B cells are rapidly recruited to injured lungs, where they extravasate into the parenchyma. Using hilar clamping and transplant models, we observed that lung-infiltrating B cells produce the monocyte chemokine CCL7 in a TLR4-TRIF-dependent fashion, a critical step contributing to classical monocyte (CM) recruitment and subsequent neutrophil extravasation, resulting in worse lung function. We found that synergistic BCR-TLR4 activation on B cells is required for the recruitment of CMs to the injured lung. Finally, we corroborated our findings in reperfused human lungs, in which we observed a correlation between B cell infiltration and CM recruitment after transplantation. This study describes a role for B cells as critical orchestrators of lung IRI. As B cells can be depleted with currently available agents, our study provides a rationale for clinical trials investigating B cell-targeting therapies.

CD3 downregulation identifies high-avidity, multipotent SARS-CoV-2 vaccine- and recall antigen-specific Th cells with distinct metabolism

Functional avidity is supposed to critically shape the quality of immune responses, thereby influencing host protection against infectious agents including SARS-CoV-2. Here we show that after human SARS-CoV-2 vaccination, a large portion of high-avidity spike-specific CD4+ T cells lost CD3 expression after in vitro activation. The CD3- subset was enriched for cytokine-positive cells, including elevated per-cell expression levels, and showed increased polyfunctionality. Assessment of key metabolic pathways by flow cytometry revealed that superior functionality was accompanied by a shift toward fatty acid synthesis at the expense of their oxidation, whereas glucose transport and glycolysis were similarly regulated in SARS-CoV-2-specific CD3- and CD3+ subsets. As opposed to their CD3+ counterparts, frequencies of vaccine-specific CD3- T cells positively correlated with both the size of the naive CD4+ T cell pool and vaccine-specific IgG levels. Moreover, their frequencies negatively correlated with advancing age and were impaired in patients under immunosuppressive therapy. Typical recall antigen-reactive T cells showed a comparable segregation into functionally and metabolically distinct CD3+ and CD3- subsets but were quantitatively maintained upon aging, likely due to earlier recruitment in life. In summary, our data identify CD3- T helper cells as correlates of high-quality immune responses that are impaired in at-risk populations.

Genomic and transcriptomic analysis of cutaneous squamous cell carcinoma arising in immunocompetent and immunosuppressed patients

BACKGROUND

Cutaneous squamous cell carcinoma (cSCC) is the most common skin malignancy arising in immunocompromised patients such as solid organ transplant recipients. In addition to an abundance in number, the morbidity and mortality of these tumors in this patient population exceeds that of immune competent individuals. Here, we used whole exome and bulk RNA sequencing to analyze mutation profiles between tumors arising in immunocompetent and immunosuppressed patients.

METHODS

DNA and RNA extracted from twenty formalin-fixed, paraffin embedded tumors and adjacent skin was sequenced. Bioinformatic analysis revealed tumor mutational burden, mutational signatures, microsatellite instability, and aberrant signaling pathways.

RESULTS

Similar median tumor mutational burden was found in both the tumors from the immunocompetent and the immunosuppressed cohorts. Mutation signature analysis revealed UVR signatures and evidence of azathioprine exposure. 50% of tumors from the immunosuppressed patients have mutations consistent with microsatellite instability, yet mismatch repair protein expression was preserved in the samples analyzed. Additionally, frequently mutated genes in this cohort belong to the extracellular matrix receptor interaction and calcium signaling pathways, suggesting these may be targets for future treatments of this disease.

CONCLUSIONS

This study utilizes whole exome and bulk RNA sequencing to identify difference between cSCC arising in immunosuppressed and immunocompetent patients using the patient's photo exposed, but histologically normal appearing skin as the "germline" comparison. We demonstrate an enrichment in microsatellite instability in the tumors from immunosuppressed patients and differences in oxidative phosphorylation and epithelial-mesenchymal transition which may be targets for therapeutic intervention based on identification of mutations.

Risk of herpes simplex virus infection in solid organ transplant recipients: A population-based cross-sectional study

BACKGROUND

Herpes simplex virus (HSV) is an opportunistic infection antigen in solid organ transplant (SOT) recipients. However, this phenomenon has received limited attention from epidemiologists. Our study aims to determine the HSV infection risk in SOT recipients.

METHODS

This was a nationwide population-based cross-sectional study based on the National Health Insurance Research Database from 2002 to 2015. We used propensity score matching to avoid selection bias and analyzed the association between HSV infection and SOT recipients with multiple logistic regression analysis.

RESULTS

At a 3-year follow-up, SOT recipients had a higher risk of developing HSV, with an adjusted odds ratio (aOR) of 3.28 (95% confidence interval (CI), 2.51-4.29). Moreover, at 6-month, 1-year, and 2-year follow-ups, SOT recipients also had an increased risk of HSV than general patients with aORs of 3.85 (95% CI, 2.29-6.49), 4.27 (95% CI, 2.86-6.36), and 3.73 (95% CI, 2.74-5.08), respectively. In the subgroup analysis, lung transplant recipients (aOR = 8.01; 95% CI, 2.39-26.88) exhibited a significantly higher chance of HSV among SOT recipients, followed by kidney transplant recipients (aOR = 3.33; 95% CI, 2.11-5.25) and liver transplant recipients (aOR = 3.15; 95% CI, 2.28-4.34).

CONCLUSION

HSV can develop at any time after organ transplantation. SOT recipients had a higher risk of HSV infection than the general population at 6 months, 1 year, 2 years, and 3 years after transplantation, with the highest chance at 1 year after. In addition, the patients who underwent lung transplantion were at higher risk for HSV infection than liver or kidney transplant recipients.

Incidence and Features of Lymphoid Proliferation and Lymphomas after Solid Organ or Hematopoietic Stem Cell Transplantation in a National Database Cohort

PURPOSE

Post-transplantation lymphoproliferative disorders (PTLDs) after hematopoietic stem transplantation (HCT) or solid organ transplantation (SOT) result in poorer outcomes, including death. There are limited large cohort data on the incidence and natural course of PTLD in Asians.

MATERIALS AND METHODS

We investigated PTLD using Korean national health insurance claims data of 47,518 patients who underwent HCT or SOT in 2008-2020. Patient demographics, time and type of PTLD diagnosis, type of PTLD treatment, and death data were collected. We used Fine and Gray subdistribution hazard models to calculate the cumulative incidence and risk factors for PTLD.

RESULTS

During median follow-up of 5.32 years, PTLD occurred in 294 of 36,945 SOT patients (0.79%) and 235 of 10,573 HCT patients (2.22%). Cumulative incidence of PTLD were 0.49% at 1 year, 1.02% at 5 years, and 1.50% at 10 years post-transplantation. Age < 20 years (subdistribution hazard ratio [SHR] of 1.67 in age 10-19, SHR 1.51 in age 0-9), HCT (SHR 3.02), heart transplantation (SHR 2.27), and liver transplantation (SHR 1.47) were significant risk factors for PTLD. The presence of PTLD was associated with an increased risk of death (hazard ratio of 2.84). Overall, 5-year survival of PTLD patients was 68.9% (95% confidence interval, 64.9 to 73.2).

CONCLUSION

We observed a steady increase in PTLD over 10 years after HCT or SOT in this large cohort study. Pediatric age group, HCT, liver transplantation, and heart transplantation were suggested to be risk factors for PTLD, and PTLD was associated with a higher risk of death.

Sotrovimab in solid organ transplant recipients with COVID-19: a systematic review and meta-analysis

Background

Despite widespread implementation of vaccination against coronavirus disease 2019 (COVID-19), solid organ transplant recipients (SOTRs) can remain particularly vulnerable to this disease. The present study was conducted to investigate the efficacy and safety of sotrovimab in the treatment of SOTRs with COVID-19.

Methods

A search was performed of PubMed, Cochrane Library, Web of Science, medRxiv, and Google Scholar to gather relevant evidence through July 25, 2023. The quality of the included studies was assessed using the risk of bias tool. Comprehensive Meta-Analysis software (ver. 3.0, Biostat) was employed for data analysis.

Results

Ten studies, involving a total of 1,569 patients, were included. The meta-analysis revealed significant differences between the patients administered sotrovimab and those treated with the standard of care. These differences were observed in mortality rate (odds ratio [OR], 0.15; 95% confidence interval [CI], 0.03-0.67), hospitalization rate (OR, 0.35; 95% CI, 0.21-0.57), intensive care unit (ICU) admission rate (OR, 0.16; 95% CI, 0.04-0.62), the need for supplemental oxygen therapy (OR, 0.22; 95% CI, 0.09-0.51), and the need for mechanical ventilation (OR, 0.09; 95% CI, 0.01-0.70). However, no significant difference was observed between sotrovimab and other treatments regarding the rates of hospitalization or ICU admission (P>0.05). Regarding safety, sotrovimab was associated with a lower rate of adverse events compared to the absence of sotrovimab (OR, 0.15; 95% CI, 0.02-0.86).

Conclusions

These results suggest that sotrovimab may improve efficacy outcomes among SOTRs with COVID-19. Nevertheless, additional high-quality trials are necessary to confirm these findings.

Unveiling transplantation research productivity of United States: A bibliometric analysis

BACKGROUND

The United States has witnessed significant advancements in the field of organ transplantation over the course of the last five decades, as demonstrated by a notable increase in the quantity of academic research. The presence of a highly dynamic research environment necessitates continuous evaluations to maintain the integrity and progress of the field.

AIM

To evaluate the total output and thematic emphasis of transplant research conducted in the United States.

METHODS

On January 10, 2023, we conducted a bibliometric search of United States research output in transplantation journals from the Web of Science database's Science Citation Index Expanded. We excluded editorials, meeting abstracts, and other non-article types. We analyzed annual trends, authors, institutions, articles, keywords, and countries collaborating with the United States, using VOSviewer 1.6.18 to create figures and tables.

RESULTS

The United States published 25956 papers (3078 reviews and 22878 articles) representing 37.7% of the world's scientific output. Canada emerged as the top collaborator with the United States, co-authoring 1263 articles. Leading institutions in United States transplantation research were the University of Pittsburgh (1749 articles), Mayo Clinic (1605 articles), Harvard Medical School (1549 articles), and Johns Hopkins University (1280 articles). The top three keywords with over 2000 occurrences were "recipients," "survival," and "outcomes," indicating a focus on graft and recipient outcome markers by United States researchers.

CONCLUSION

Our findings demonstrate the United States leadership in organ transplantation research, contributing significantly to the global scientific output in this field. However, opportunities exist for fostering expansive partnerships, particularly with developing countries. This study provides valuable insights into the transplantation research landscape in the United States, emphasizing the importance of ongoing evaluations to maintain and propel advancements in this critical medical discipline. The results may facilitate future collaborations, knowledge exchange, and the pursuit of innovative solutions in the realm of organ transplantation.

Application potential of senolytics in clinical treatment

Of the factors studied in individual ageing, the accumulation of senescent cells has been considered as an essential cause of organ degeneration to eventually initiate age-related diseases. Cellular senescence is attributed to the accumulation of damage for an inducement in the activation of cell cycle inhibitory pathways, resulting the cell permanently withdraw from the cell proliferation cycle. Further, senescent cells will activate the inflammatory factor secretion pathway to promote the development of various age-related diseases. Senolytics, a small molecule compound, can delay disease development and extend mammalian lifespan. The evidence from multiple trials shows that the targeted killing of senescent cells has a significant clinical application for the treatment of age-related diseases. In addition, senolytics are also significant for the development of ageing research in solid organ transplantation, which can fully develop the potential of elderly organs and reduce the age gap between demand and supply. We conclude that the main characteristics of cellular senescence, the anti-ageing drug senolytics in the treatment of chronic diseases and organ transplantation, and the latest clinical progress of related researches in order to provide a theoretical basis for the prevention and treatment of ageing and related diseases.

Cryptosporidium sp. infection in solid organ transplant recipients: A systematic review and meta-analysis

(1) Background: Organ transplant recipients (OTRs) are vulnerable groups at risk of parasitic infections. This systematic review and meta-analysis aimed to evaluate the overall prevalence of Cryptosporidium sp. in OTRs and shed light on this potentially serious complication of organ transplantation. (2) Methods: We systematically searched studies on Cryptosporidium sp. infections in OTRs in four databases (Academia, PubMed, Scopus, and Science Direct). Random effects models were used to calculate pooled prevalence estimates with 95% confidence intervals (CIs). Sub-group and meta-regression analyses were conducted. A quality assessment of the included studies was also performed. (3) Results: Among 876 articles retrieved, 21 were included, accounting for 2,642 OTRs. Twenty studies were cross-sectional in design, of which seven reported data on a comparison group, and one was a retrospective cohort. The pooled prevalence of Cryptosporidium sp. in OTRs was 15% (95% CI: 7.4-24.6). Subgroup analysis revealed that the prevalence of Cryptosporidium sp. infection was higher in adults, symptomatics and developing countries and in studies using only non-molecular methods. However, substantial heterogeneity was reported. Low to moderate heterogeneity was observed in subgroups reporting lower prevalence Cryptosporidium sp. including children (5.8; 95% CI: 2.8-9.6), studies conducted in developed countries (5.8; 95% CI: 3.0-9.4) and studies using both molecular and non-molecular diagnostics (11.4; 95% CI: 6.4-17.4). The majority of the listed research reported low-medium quality scores. (4) Conclusion: Cryptosporidium sp. infection is a significant complication in OTRs with underreported prevalence. Preventive strategies to reduce the burden should include Cryptosporidium sp. routine screening for OTRs, particularly post-transplantation in patients with diarrhea. Additional well-designed research studies are required to determine the extent of the Cryptosporidium sp. burden in OTRs.

Donation After Cardiac Death: Origins, Current State, and New Directions

Donation after cardiac death (DCD) is a growing source of organs for transplantation. DCD can be challenging to understand due to variations in practice. DCD also holds great potential for ethical compromise making it uncomfortable for many practitioners. This article traces the origin of DCD from the beginnings of organ transplant and lays out the general pattern of the process before touching on advances to this rapidly changing field.

The Relationship Between Spiritual Well-Being and Post-Traumatic Growth in Turkish Patients Undergoing Solid Organ Transplantation

This study was conducted to determine the relationship between spiritual well-being and post-traumatic growth in solid organ transplant patients. This cross-sectional study was conducted with 366 patients who presented to the organ transplantation polyclinic of a university hospital between September 2021 and February 2022 in Turkey. The mean Post-Traumatic Growth Inventory and Spiritual Well-Being Scale scores of solid organ transplant patients were 81.33 ± 20.28 and 37.18 ± 8.69, respectively. There was a significant positive correlation between post-traumatic growth and spiritual well-being. According to linear regression analysis, spiritual well-being, gender, marital status, transplanted organ, donor type, and previous mental disorders were statistically significant predictive factors that affected post-traumatic growth. Spiritual well-being was an important variable that affected post-traumatic growth in solid organ transplant patients. Therefore, healthcare providers can provide individualized psychosocial-spiritual care and counseling services that increase post-traumatic growth in patients after organ transplantation.

Antimicrobial Stewardship in Immunocompromised Patients: Current State and Future Opportunities

Immunocompromised (IC) patients are high risk for complications due to a high rate of antibiotic exposure. Antimicrobial stewardship interventions targeted to IC patients can be challenging due to limited data in this population and a high risk of severe infection-related outcomes. Here, the authors review immunocompromised antimicrobial stewardship barriers, metrics, and opportunities for antimicrobial use and testing optimization. Last, the authors highlight future steps in the field.

Nontuberculous Mycobacterial Pulmonary Disease in the Immunocompromised Host

The immunocompromised host is at an increased risk for pulmonary and extrapulmonary NTM infections. Where data are available in these specific populations, increased mortality is observed with NTM disease. Prior to starting therapy for NTM disease, providers should ensure diagnostic criteria are met as treatment is long and often associated with significant side effects and toxicities. Treatment should involve 2 to 4 agents and be guided by cultures and antimicrobial susceptibilities. Drug interactions are important to consider, especially in those with HIV or transplant recipients. Whenever possible, immunosuppression should be reduced or changed.

[Diagnosis of brain death in Germany-Implementation of the guidelines of the German Medical Association]

BACKGROUND

The 4th update of the guidelines of the German Medical Association on the diagnosis of irreversible loss of brain function (brain death, BD) has introduced important new regulations regarding the required qualification of the examiners, approved procedures for ancillary testing, and a clarification regarding the sequencing of diagnostic steps.

OBJECTIVE

Investigation of the implementation and practical effects on the diagnosis of brain death.

METHOD

Descriptive evaluation of the routine documentation of the German Organ Procurement Organization, comparing the periods July 2011-June 2015 (3rd update) and July 2015-June 2019 (4th update).

RESULTS

Patient numbers decreased from 6100 to 5403. The largest decrease affected hospitals without neurosurgery. Children were not affected. With the 4th update, clinical diagnostics were increasingly performed during on-call hours by external neurologists. Of the patients 83.8% now received ancillary tests compared to 80.1% previously. Computed tomography angiography (CTA), first introduced in the 4th update, was applied in 23.2% and established complete loss of cerebral circulation in 89.4%. The time between first documentation of the clinical signs of BD and certification of BD increased from 7.0 ± 12.7 h to 8.2 ± 14.2 h. The diagnosis was slightly less frequent with 95.3% compared to 96.6%.

CONCLUSION

The updated standards were implemented in accordance with the guidelines. The demand for external consulting neurologists and neurosurgeons as well as the time required for BD assessment have increased. Negative effects on pediatric BD diagnostics were not apparent. CTA is widely and successfully used in adults as a new ancillary diagnostic procedure.

Temsirolimus is a promising immunomodulatory agent for enhanced transplantation outcomes

BACKGROUND

Identifying effective immunosuppressive strategies is critical for addressing immunological rejection following organ transplantation. This study explores the potential immunosuppressive effects and mechanisms of temsirolimus, a rapamycin derivative, in organ transplantation.

METHODS

A mouse cardiac allograft model was established using a cervical cannula technique with BALB/c donors and C57BL/6 recipients. Mice were administered temsirolimus intragastrically and graft survival was evaluated. Histological staining was used to assess pathological changes. The BrdU assay was used to measure splenic T cell proliferation. Flow cytometry was used to quantify regulatory T cells (Tregs), CD4+ T cells, and CD8+ T cells. ELISA and qPCR assays were used to determine Foxp3, IL-4, IFN-γ, and TGF-β expression.

RESULTS

Temsirolimus displayed potent immunosuppressive effects at 20 mg/kg/day, significantly inhibiting T cell proliferation (84.6%, P < 0.0001) and prolonging graft survival (median 49 days vs. 8.5 days in controls, P < 0.0001). However, median survival decreased to 34.5 days upon withdrawal. Temsirolimus also reduced splenic CD4+ and CD8+ T cells (2.85% and 2.92%, P < 0.001) and antibody levels (IgM, IgG1, IgG2) by 11.85-29.09% (P < 0.0001) and increased Tregs, Foxp3, IL-4 (P < 0.01), and TGF-β (P < 0.05), while decreasing IFN-γ (P < 0.001).

CONCLUSIONS

Temsirolimus exhibited potent immunosuppressive effects, emerging as a strong candidate to mitigate organ transplant rejection.

Primary plasmablastic lymphoma of the gastrointestinal tract: A series of 13 HIV-negative cases and a review of literature

CONTEXT

Primary gastrointestinal plasmablastic lymphoma (GI-PBL) is a rare variant of diffuse B-cell lymphoma with an aggressive clinical course. PBL was initially reported among HIV-positive patients; however, subsequent studies have shown that it also occurs among HIV-negative patients. Its clinical characteristics remain poorly understood. This study aims to retrospectively analyze the clinicopathological findings of primary GI-PBLs in HIV-negative patients.

DESIGN

Primary HIV-negative GI-PBL cases from 2008 to 2022 were reviewed. Clinicopathologic features and outcomes were analyzed.

RESULTS

The cohort of 13 patients had a male-to-female ratio of 9:1 (3 patients' genders not available), with an average age of 61 (range, 30-92) years. The most involved location was the colon (n = 7 [53.8 %]), followed by the small bowel (n = 3 [23.1 %]), stomach (n = 2 [15.4 %]), rectum (n = 1 [7.7 %]), and anus (n = 1 [7.7 %]). Most patients (n = 10 [77 %]) showed isolated GI tract involvement. Eight patients had chronic inflammatory and/or immunocompromised status, including 4 with inflammatory bowel disease (all of whom underwent treatment), 3 with post-organ transplant status, and 1 with irritable bowel syndrome. All cases exhibited cytokeratin-/CD20-/PAX-5-/CD138+ and/or MUM1+ immunophenotype. Based on available data, 8 of 11 (72.7 %) patients had Epstein-Barr virus reactivation. Among 11 patients with follow-up data, the mean follow-up duration was 13.5 (range, 3-40) months; at the end of follow-up, 45.5 % of patients (5 of 11 patients) showed complete remission after chemotherapy.

CONCLUSION

Primary HIV-negative GI-PBL occurs predominantly in the colon of relatively elderly males with immunosuppression. Its clinical course can be heterogenous, presenting a comorbidity with inflammatory bowel disease or post-organ transplantation status.

Comparison of in-gel and in-solution proteolysis in the proteome profiling of organ perfusion solutions

PURPOSE

The organ perfusion solution (perfusate), collected at clinically and temporally significant stages of the organ preservation and transplantation process, provides a valuable insight into the biological status of an organ over time and prior to reperfusion (transplantation) in the recipient. The objective of this study was to assess two bottom-up proteomics workflows for the extraction of tryptic peptides from the perfusate.

EXPERIMENTAL DESIGN

Two different kinds of perfusate samples from kidney and liver trials were profiled using liquid chromatography-mass spectrometry (LC-MS/MS). The preparation of clean peptide mixtures for downstream analysis was performed considering different aspects of sample preparation; protein estimation, enrichment, in-gel and urea-based in-solution digestion.

RESULTS

In-solution digestion of perfusate allowed identification of the highest number of peptides and proteins with greater sequence coverage and higher confidence data in kidney and liver perfusate. Key pathways identified by gene ontology analysis included complement, coagulation and antioxidant pathways, and a number of biomarkers previously linked to ischemia-reperfusion injury were also observed in perfusate.

CONCLUSIONS

This study showed that in-solution digestion is a more efficient method for LC-MS/MS analysis of kidney and liver organ perfusion solutions. This method is also quicker and easier than in-gel digestion, allowing for greater sample throughput, with fewer opportunities for experimental error or peptide loss.

Virus-specific TRM cells of both donor and recipient origin reside in human kidney transplants

Tissue-resident lymphocytes (TRLs) are critical for local protection against viral pathogens in peripheral tissue. However, it is unclear if TRLs perform a similar role in transplanted organs under chronic immunosuppressed conditions. In this study, we aimed to characterize the TRL compartment in human kidney transplant nephrectomies and examine its potential role in antiviral immunity. The TRL compartment of kidney transplants contained diverse innate, innate-like, and adaptive TRL populations expressing the canonical residency markers CD69, CD103, and CD49a. Chimerism of donor and recipient cells was present in 43% of kidney transplants and occurred in all TRL subpopulations. Paired single-cell transcriptome and T cell receptor (TCR) sequencing showed that donor and recipient tissue-resident memory T (TRM) cells exhibit striking similarities in their transcriptomic profiles and share numerous TCR clonotypes predicted to target viral pathogens. Virus dextramer staining further confirmed that CD8 TRM cells of both donor and recipient origin express TCRs with specificities against common viruses, including CMV, EBV, BK polyomavirus, and influenza A. Overall, the study results demonstrate that a diverse population of TRLs resides in kidney transplants and offer compelling evidence that TRM cells of both donor and recipient origin reside within this TRL population and may contribute to local protection against viral pathogens.

"This family and the Games are my world": Conceptualizing the British and European Transplant Games as therapeutic landscapes

The first Transplant Games took place in 1978 in Portsmouth, England. Since then, numerous Olympic-style sporting 'Games' have been established, each aiming to increase public awareness of organ donation, demonstrate the benefits of transplantation, and encourage patient fitness. Despite this, there is limited research exploring the psycho-social and health impacts of the Games. Drawing on qualitative research conducted at the 2022 British Transplant Games and the 2022 European Transplant and Dialysis Games, this paper explores the Games through a therapeutic landscapes framework, a concept that examines the ways in which environments contribute to health and wellbeing. Building upon work that acknowledges the relational and contingent nature of health-in-place, I argue that the Games are a therapeutic landscape of social relations for transplant recipients in three ways: providing a landscape of belonging, a landscape of hope, and a landscape of motivation. Through this therapeutic landscapes perspective, the Transplant Games are presented as a peer-to-peer clinic - a care space where individuals are more actively involved in their health on a reciprocal level than in the traditional hospital clinic. In turn, this paper emphasises the crucial role of affective peer support in producing health-promoting environments. This research seeks to make a practical contribution to the wider transplant community by promoting the Games as an environment which may positively contribute to both physical and mental wellbeing.

Mapping trust relationships in organ donation and transplantation: a conceptual model

The organ donation and transplantation (ODT) system heavily relies on the willingness of individuals to donate their organs. While it is widely believed that public trust plays a crucial role in shaping donation rates, the empirical support for this assumption remains limited. In order to bridge this knowledge gap, this article takes a foundational approach by elucidating the concept of trust within the context of ODT. By examining the stakeholders involved, identifying influential factors, and mapping the intricate trust relationships among trustors, trustees, and objects of trust, we aim to provide a comprehensive understanding of trust dynamics in ODT. We employ maps and graphs to illustrate the functioning of these trust relationships, enabling a visual representation of the complex interactions within the ODT system. Through this conceptual groundwork, we pave the way for future empirical research to investigate the link between trust and organ donation rates, informed by a clarified understanding of trust in ODT. This study can also provide valuable insights to inform interventions and policies aimed at enhancing organ donation rates.

Multiscale genetic architecture of donor-recipient differences reveals intronic LIMS1 mismatches associated with kidney transplant survival

Donor-recipient (D-R) mismatches outside of human leukocyte antigens (HLAs) contribute to kidney allograft loss, but the mechanisms remain unclear, specifically for intronic mismatches. We quantified non-HLA mismatches at variant-, gene-, and genome-wide scales from single nucleotide polymorphism (SNP) data of D-Rs from 2 well-phenotyped transplant cohorts: Genomics of Chronic Allograft Rejection (GoCAR; n = 385) and Clinical Trials in Organ Transplantation-01/17 (CTOT-01/17; n = 146). Unbiased gene-level screening in GoCAR uncovered the LIMS1 locus as the top-ranked gene where D-R mismatches associated with death-censored graft loss (DCGL). A previously unreported, intronic, LIMS1 haplotype of 30 SNPs independently associated with DCGL in both cohorts. Haplotype mismatches showed a dosage effect, and minor-allele introduction to major-allele-carrying recipients showed greater hazard of DCGL. The LIMS1 haplotype and the previously reported LIMS1 SNP rs893403 are expression quantitative trait loci (eQTL) in immune cells for GCC2 (not LIMS1), which encodes a protein involved in mannose-6-phosphase receptor (M6PR) recycling. Peripheral blood and T cell transcriptome analyses associated the GCC2 gene and LIMS1 SNPs with the TGF-β1/SMAD pathway, suggesting a regulatory effect. In vitro GCC2 modulation impacted M6PR-dependent regulation of active TGF-β1 and downstream signaling in T cells. Together, our data link LIMS1 locus D-R mismatches to DCGL via GCC2 eQTLs that modulate TGF-β1-dependent effects on T cells.

Recommendations for SARS-CoV-2 testing and organ procurement from deceased donors in the Republic of Korea

We present a summary of the evidence on testing for severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) and organ procurement from deceased donors and provide recommendations based on current clinical data and the guidelines from major transplant organizations. Because of the limited historical experience with coronavirus disease 2019 (COVID-19), certain recommendations in this document are based on theoretical rationales rather than clinical data. The recommendations in this manuscript may be subject to revision as subsequent clinical studies provide definitive evidence regarding COVID-19 in organ procurement.

Impact of tacrolimus intra-patient variability in adverse outcomes after organ transplantation

Tacrolimus (Tac) is currently the most common calcineurin-inhibitor employed in solid organ transplantation. High intra-patient variability (IPV) of Tac (Tac IPV) has been associated with an increased risk of immune-mediated rejection and poor outcomes after kidney transplantation. Few data are available concerning the impact of high Tac IPV in non-kidney transplants. However, even in kidney transplantation, there is still a controversy whether high Tac IPV is indeed detrimental in respect to graft and/or patient survival. This may be due to different methods employed to evaluate IPV and distinct time frames adopted to assess graft and patient survival in those reports published up to now in the literature. Little is also known about the influence of high Tac IPV in the development of other untoward adverse events, update of the current knowledge regarding the impact of Tac IPV in different outcomes following kidney, liver, heart, lung, and pancreas tran splantation to better evaluate its use in clinical practice.

Long-term immunosuppressive treatment is not associated with worse outcome in patients hospitalized in the intensive care unit for septic shock: the PACIFIC study

BACKGROUND

Except in a few retrospective studies mainly including patients under chemotherapy, information regarding the impact of immunosuppressive therapy on the prognosis of patients admitted to the intensive care unit (ICU) for septic shock is scarce. Accordingly, the PACIFIC study aimed to asses if immunosuppressive therapy is associated with an increased mortality in patients admitted to the ICU for septic shock.

METHODS

This was a retrospective epidemiological multicentre study. Eight high enroller centres in septic shock randomised controlled trials (RCTs) participated in the study. Patients in the "exposed" group were selected from the screen failure logs of seven recent RCTs and excluded because of immunosuppressive treatment. The "non-exposed" patients were those included in the placebo arm of the same RCTs. A multivariate logistic regression model was used to estimate the risk of death.

RESULTS

Among the 433 patients enrolled, 103 were included in the "exposed" group and 330 in the "non-exposed" group. Reason for immunosuppressive therapy included organ transplantation (n = 45 [44%]) or systemic disease (n = 58 [56%]). ICU mortality rate was 24% in the "exposed" group and 25% in the "non-exposed" group (p = 0.9). Neither in univariate nor in multivariate analysis immunosuppressive therapy was associated with a higher ICU mortality (OR: 0.95; [95% CI 0.56-1.58]: p =  0.86 and 1.13 [95% CI 0.61-2.05]: p =  0.69, respectively) or 3-month mortality (OR: 1.13; [95% CI 0.69-1.82]: p =  0.62 and OR: 1.36 [95% CI 0.78-2.37]: p =  0.28, respectively).

CONCLUSIONS

In this study, long-term immunosuppressive therapy excluding chemotherapy was not associated with significantly higher or lower ICU and 3-month mortality in patients admitted to the ICU for septic shock.

Outcomes of COVID-19 in immunocompromised patients: a single center experience

Malignancy, bone marrow and organ transplantation are associated with deficient and defective immune systems. Immunocompromised patients are at risk for severe and chronic complication of COVID-19 infection. However, the pathogenesis, diagnosis and management of this comorbidity remain to be elucidated. The purpose of the present study was to describe key aspects of COVID-19 infection in immunocompromised patients. In this retrospective, cross-sectional study, lab findings and outcomes of 418 COVID-19 patients with secondary immunodeficiency disorders admitted to Taleghani Hospital in Tehran, from March 2020 to September 2022 were investigated. Of the 418 immunocompromised patients with COVID-19, 236 (56.5%) ‌ were male and the median age of all studied patients was 56.6 ± 16.4 with range of 14 to 92 years. Totally, 198 (47.4%) of the patients died during hospitalization. Remdesivir was used for treatment of all patients. Mortality rate among patients admitted to ICU ward (86.8%) was significantly higher than non ICU admission (p < 0.001). The death rate in patients with CKD was substantially higher than other underlying disease (p < 0.001). In terms of laboratory finding, there was a significant relationship between ICU admission and worse outcome with WBC count (HR = 1.94, 95% CI = 1. 46-2.59, p < 0.001), PMN count (HR = 1.93, 95% CI = 1.452.56, p < 0.001), Hb (HR = 1.49, 95% CI = 1.042.13, p = 0.028), AST (HR = 2.55, 95% CI = 1.913.41, p < 0.001), BUN (HR = 2.56, 95% CI = 2.063.69, p < 0.001), Cr (HR = 2.63, 95% CI = 1.89-3.64, p < 0.001), Comorbidities index (HR = 1.71, 95% CI = 1.29-2.27, p < 0.001) and aging (HR = 1.91, 95% CI = 1.4-2.54, p < 0.001). Immunocompromised status increased the risk of mortality or worse outcome in patients diagnosed with COVID-19. Our finding showed outcome predicting markers in whom the waned immune system encounter new emerging disease and improved our understanding of COVID-19 virus behavior in immunocompromised individuals.

Value of blood lipid in predicting graft dysfunction after organ and tissue transplantation: A study of Mendelian randomization

Background

While immunosuppressive regimens have improved outcomes in solid organ transplantation, non-immune factors have also been identified as contributors to graft prognosis. Age, gender, hormones, heredity, and other diseases have been recognized to affect organ transplantation. However, the causal relationship between blood lipids and graft dysfunction remains unverified in human clinical investigations. In this study, we employed two-sample Mendelian randomization (MR) to examine the causality between different types of blood lipids and graft dysfunction following organ and tissue transplantation.

Methods

We conducted a two-sample MR study using available genome-wide association summary data from the online database MRBASE (http://app.mrbase.org/), which encompasses over 11 billion associations between genetic factors and health-related outcomes, enabling researchers to explore various potential determinants of poor health. The exposure factors included four types of blood lipids: high-density lipoprotein, low-density lipoprotein, cholesterol, and triglycerides. For each exposure factor, three databases were selected for analysis. The outcome factor was the failure and rejection of transplanted organs and tissues. All databases consisted of European population samples, without specific subgroups. The related studies were conducted between 2016 and 2022, and the "TwoSampleMR" R package was employed for variant selection.

Results

A total of 13 sample groups were collected and analyzed. The results revealed a causal association between blood lipids and graft dysfunction following organ and tissue transplantation. Specifically, the two-sample MR analysis confirmed that low-density lipoprotein and cholesterol levels were significant risk factors for increased graft dysfunction risk after transplantation. Moreover, high-density lipoprotein potentially reduced the risk of allograft dysfunction, while triglycerides possibly elevated the risk.

Conclusions

Our recent study provides the initial confirmation that blood lipids may initiate causal pathological processes leading to graft dysfunction after organ and tissue transplantation.

Safely navigating kidney transplantation during the COVID-19 pandemic: the Singapore General Hospital's experience

Background

The coronavirus disease 2019 (COVID-19) pandemic curtailed transplant activities worldwide, driven by concerns about increased COVID-19-related mortality among kidney transplant recipients (KTRs), infections originating from donors, and decreased availability of surgical and intensive care resources as healthcare resources are reallocated for pandemic response. We examined the outcomes of KTRs at our center before and during the COVID-19 pandemic.

Methods

We conducted a retrospective single-center cohort study examining the characteristics and outcomes of patients undergoing kidney transplantation during two periods January 1, 2017 to December 31, 2019 (pre-COVID-19 era) and January 1, 2020 to June 30, 2022 (COVID-19 era). We reviewed perioperative and COVID-19 infection-related outcomes in both groups.

Results

A total of 114 transplants were performed during the pre-COVID-19 era, while 74 transplants were conducted during the COVID-19 era. No differences in baseline demographics were observed. Additionally, there were no significant differences in perioperative outcomes, except for a longer cold ischemia time during the COVID-19 era. However, this did not result in an increased incidence of delayed graft function. Among the KTRs infected with COVID-19 during the pandemic era, no severe complications such as pneumonia, acute kidney injury, or death were reported.

Conclusions

With the global transition to an endemic phase of COVID-19, it is imperative to revitalize organ transplant activities. Effective containment workflow, good vaccination uptake, and prompt COVID-19 treatment are essential to ensure that transplants can proceed safely.

Reply to reaction on 'Organ donation after euthanasia starting at home in a patient with multiple system atrophy - case report'

We would like to respond to the comment we received from our colleagues on our case report about organ donation after euthanasia starting at home. We reply to their statements on medical and legal aspects, and provide more information on our view of informed consent.

Single cell transcriptomic analysis of renal allograft rejection reveals insights into intragraft TCR clonality

Bulk analysis of renal allograft biopsies (rBx) identified RNA transcripts associated with acute cellular rejection (ACR); however, these lacked cellular context critical to mechanistic understanding of how rejection occurs despite immunosuppression (IS). We performed combined single cell RNA transcriptomic and TCRα/β sequencing on rBx from patients with ACR under differing IS: tacrolimus, iscalimab, and belatacept. We found distinct CD8+ T cell phenotypes (e.g., effector, memory, exhausted) depending upon IS type, particularly within clonally expanded cells (CD8EXP). Gene expression of CD8EXP identified therapeutic targets that were influenced by IS type. TCR analysis revealed a highly restricted number of CD8EXP, independent of HLA mismatch or IS type. Subcloning of TCRα/β cDNAs from CD8EXP into Jurkat76 cells (TCR-/-) conferred alloreactivity by mixed lymphocyte reaction. Analysis of sequential rBx samples revealed persistence of CD8EXP that decreased, but were not eliminated, after successful anti-rejection therapy. In contrast, CD8EXP were maintained in treatment-refractory rejection. Finally, most rBx-derived CD8EXP were also observed in matching urine samples, providing precedent for using urine-derived CD8EXP as a surrogate for those found in the rejecting allograft. Overall, our data define the clonal CD8+ T cell response to ACR, paving the next steps to improve detection, assessment, and treatment of rejection.

A nanotherapeutic strategy that engages cytotoxic and immunosuppressive activities for the treatment of cancer recurrence following organ transplantation

BACKGROUND

Long-term treatment with immunosuppressants is necessary to attenuate allograft rejection following organ transplantation (OT). Consequently, the overall survival of OT recipients with malignancies has been substantially compromised by tumour recurrence. Rapamycin (RAPA) is a clinically approved immunosuppressive agent with antitumour activity that is considered beneficial in preventing posttransplant tumour recurrence. However, the clinical outcome of RAPA is impeded by acquired drug resistance and its poor oral bioavailability.

METHODS

A nanotherapeutic strategy was developed by supramolecular assembly of RAPA into a polymer cytotoxic 7-ethyl-10-hydroxycamptothecin (SN38) prodrug nanoparticle (termed SRNP) for simultaneous codelivery of cytotoxic/immunosuppressive agents. Cell-based experiments were used to evaluate the cytotoxicity of SRNPs against hepatocellular carcinoma (HCC). The therapeutic efficacy of SRNPs was evaluated in multiple preclinical models including an orthotopic HCC mouse model, an orthotopic liver transplantation (OLT) rat model and a clinically relevant cancer-transplant model to examine its antitumour and immunosuppressive activity.

FINDINGS

The combination of SN38 with RAPA resulted in synergetic effects against HCC cells and alleviated RAPA resistance by abrogating Akt/mTOR signalling activation. SRNPs exhibited potent antitumour efficiency in the orthotopic HCC model while substantially prolonging the survival of allografts in the OLT model. In the cancer-transplant model that simultaneously bears tumour xenografts and skin allografts, SRNPs not only effectively inhibited tumour growth but also attenuated allograft damage.

INTERPRETATION

The nanotherapy presented here had enhanced efficacy against tumours and maintained satisfactory immunosuppressive activity and thus has great potential to improve the survival outcomes of patients with a high risk of tumour recurrence following OT.

FUNDING

This work was supported by the National Natural Science Foundation of China (32171368 and 31671019), the Zhejiang Provincial Natural Science Foundation of China (LZ21H180001), the Zhejiang Province Preeminence Youth Fund (LR19H160002), and the Jinan Provincial Laboratory Research Project of Microecological Biomedicine (JNL-2022039c).

Double-Effect Donation or Bodily Respect? A "Third Way" Response to Camosy and Vukov

Is it possible to donate unpaired vital organs, foreseeing but not intending one's own death? We argue that this is indeed psychologically possible, and thus far agree with Charles Camosy and Joseph Vukov in their recent paper on "double effect donation." Where we disagree with these authors is that we see double-effect donation not as a morally praiseworthy act akin to martyrdom but as a morally impermissible act that necessarily disrespects human bodily integrity. Respect for bodily integrity goes beyond avoiding the aim to kill: not all side effects of deliberate bodily interventions can be outweighed by intended benefits for another even if the subject fully consents. It is not any necessary intention to kill or harm another or oneself that makes lethal donation/harvesting illicit but the more immediate intention to accept or perform surgery on an (innocent) person combined with the foresight of lethal harm and no health-related good for him or her. Double-effect donation falls foul of the first condition of double-effect reasoning in that the immediate act is wrong in itself. We argue further that the wider effects of such donation would be socially disastrous and corrupting of the medical profession: doctors should retain a sense of nonnegotiable respect for bodily integrity even when they intervene on willing subjects for the benefit of others. Summary: Lethal organ donation (for example, donating one's heart) is not a praiseworthy but a morally impermissible act. This is not because such donation necessarily involves any aim to kill oneself (if one is the donor) or to kill the donor (if one is the surgeon). Respect for bodily integrity goes beyond avoiding any hypothetical aim to kill or harm oneself or another innocent person. 'Double effect donation' of unpaired vital organs, defended by Camosy and Vukov, is in our view a form of lethal bodily abuse and would also harm the transplant team, the medical profession and society at large.

Heterologous versus homologous boosting regimens elicit qualitatively distinct, BA.5-cross reactive T cells in transplant recipients

BACKGROUND

The Omicron BA.5 subvariant of SARS-CoV-2 markedly escapes neutralizing antibodies induced by vaccination due to mutations in the Spike (S) protein. Solid organ transplant recipients (SOTRs) suffer high COVID-19 morbidity and demonstrate poor Omicron strain recognition after COVID-19 vaccination. T cell responses may provide a crucial second line of defense. Therefore, it is critical to understand which vaccine regimens induce robust, conserved T cell responses.

METHODS

We evaluated anti-S IgG titers, subvariant pseudo-neutralization, and S-specific CD4+ and CD8+ T cell responses from SOTRs in a national, prospective observational trial (n=75). Participants were selected if they received 3 doses of mRNA (homologous boosting) or two doses of mRNA followed by Ad26.COV2.S (heterologous boosting).

RESULTS

Homologous boosting with three mRNA doses induced the highest anti-S IgG titers. However, antibodies induced by both vaccine regimens demonstrated significantly lower pseudo-neutralization against BA.5 compared to the ancestral strain. In contrast, vaccine-induced S-specific T cells maintained cross-reactivity against BA.5 compared to ancestral recognition. Homologous boosting induced higher frequencies of activated polyfunctional CD4+ T cell responses, with polyfunctional IL-21+ peripheral T follicular helper cells increased in mRNA-1273 compared to BNT¬¬162b2. IL-21+ cells robustly correlated with antibody titers. Heterologous boosting with Ad26.COV2.S did not increase CD8+ responses compared to homologous boosting.

CONCLUSIONS

These data demonstrate that boosting with the ancestral strain can induce cross-reactive T cell responses against emerging variants of concern in SOTRs, but alterative vaccine strategies are required to induce robust CD8+ T cell responses.

TRIAL REGISTRATION

IRB00248540FUNDING. U01AI138897, U54CA260492, Emory COVID-19 research repository.

Granzyme B-responsive fluorescent probe for non-invasive early diagnosis of transplant rejection

Allograft rejection has always been a major obstacle in organ transplantation. The current clinical diagnostic gold standard for allograft rejection is an invasive biopsy. However, biopsy has some limitations, such as sampling errors, risk of serious complications, and high cost. In this study, we have rationally developed an activatable fluorescent probe CYGB for imaging of granzyme B, which is a biomarker released by CD8⁺T cells attacking the graft. Moreover, the ability of CYGB to detect rejection early in mouse heart and skin transplantation models was evaluated. The probe CYGB consists of a caged hemicyanine-based fluorophore and a GzmB-specifically cleaved peptide substrate linked via a self-immolating spacer, p-aminobenzyl alcohol. Endogenous GzmB in CD8⁺ T cells specifically activated the near-infrared fluorescence (NIRF) signal of CYGB. In vivo imaging in mice skin and heart graft models, showed that CYGB preferentially accumulates in grafts, enabling early diagnosis of rejection. Moreover, CYGB enables non-invasive assessment of the level of immunosuppression in allogeneic mice treated with FK506. This study provides an alternative method for monitoring the status of allografts without biopsy.

Increased clonal hematopoiesis involving DNA damage response genes in patients undergoing lung transplantation

BACKGROUNDCellular stressors influence the development of clonal hematopoiesis (CH). We hypothesized that environmental, inflammatory, and genotoxic stresses drive the emergence of CH in lung transplant recipients. METHODSWe performed a cross-sectional cohort study of 85 lung transplant recipients to characterize CH prevalence. We evaluated somatic variants using duplex error-corrected sequencing and germline variants using whole exome sequencing. We evaluated CH frequency and burden using χ2 and Poisson regression, and we evaluated associations with clinical and demographic variables and clinical outcomes using χ2, logistic regression, and Cox regression. RESULTSCH in DNA damage response (DDR) genes TP53, PPM1D, and ATM was increased in transplant recipients compared with a control group of older adults (28% versus 0%, adjusted OR [aOR], 12.9 [1.7-100.3], P = 0.0002). Age (OR, 1.13 [1.03-1.25], P = 0.014) and smoking history (OR 4.25 [1.02-17.82], P = 0.048) were associated with DDR CH. Germline variants predisposing to idiopathic pulmonary fibrosis were identified but not associated with CH. DDR CH was associated with increased cytomegalovirus viremia versus patients with no (OR, 7.23 [1.95-26.8], P = 0.018) or non-DDR CH (OR, 7.64 [1.77-32.89], P = 0.024) and mycophenolate discontinuation (aOR, 3.8 [1.3-12.9], P = 0.031). CONCLUSIONCH in DDR genes is prevalent in lung transplant recipients and is associated with posttransplant outcomes including cytomegalovirus activation and mycophenolate intolerance. FUNDINGNIH/NHLBI K01HL155231 (LKT), R25HL105400 (LKT), Foundation for Barnes-Jewish Hospital (LKT), Evans MDS Center at Washington University (KAO, MJW), ASH Scholar Award (KAO), NIH K12CA167540 (KAO), NIH P01AI116501 (AEG, DK), NIH R01HL094601 (AEG), and NIH P01CA101937 (DCL).

Long-term durability of sustained virologic response for hepatitis C virus infection in solid organ transplant recipients receiving direct-acting antivirals

Data are limited regarding the long-term durability of sustained virologic response (SVR) in solid organ transplant recipients who achieve SVR₁₂ with direct-acting antivirals (DAAs) for hepatitis C virus (HCV). We reported the virologic outcomes in 42 recipients who received DAAs for acute or chronic HCV infection after heart, liver, and kidney transplantation. After achieving SVR₁₂, all recipients received HCV RNA surveys at SVR₂₄, and biannually until the last visit. If HCV viremia was detected during the follow-up period, direct sequencing and phylogenetic analysis were performed to confirm late relapse or reinfection. Sixteen (38.1%), 11 (26.2%), and 15 (35.7%) patients underwent heart, liver and, kidney transplantation. Thirty-eight (90.5%) received sofosbuvir (SOF)-based DAAs. No recipients had late relapse or reinfection after a median (range) of post-SVR₁₂ follow-up 4.0 (1.0-6.0) years. We demonstrate that the durability of SVR in solid organ transplant recipients is excellent once SVR₁₂ is achieved with DAAs.

Intervention programme to improve knowledge, attitudes, and behaviour of nursing students towards organ donation and transplantation: A randomised controlled trial

AIM

To develop and evaluate an educational programme aimed at undergraduate training to increase and improve knowledge, attitudes and behaviour towards the organ and tissue donation and transplants (OTDT).

BACKGROUND

The request for OTDT falls on the health personnel and the reduction of family refusals depends on their attitude and competence, which is vital to increase OTDT. The evidence highlights the efficacy of starting training at early stages and the implementation of educational programmes in universities is recommended to reduce family refusals.

DESIGN

A randomised controlled trial.

METHODS

A randomised controlled trial with an experimental group (EG) -theory class and round table- and a control group (CG) -theory class- that transitions to a delayed experimental group. A sample of 73 students was distributed in parallel randomised groups.

RESULTS

The groups increased their knowledge and improved their attitude, significantly changing their behaviour in the follow-up. These changes in the experimental groups were more significant than in CG in perceived quality of information (z = -4.948; p = <0.001), level of knowledge (EG1 and CG z = -2.245; p = 0.025) (EG2 and CG z = -2.215; p = 0.027), attitude (EG1 and CG z = -2.687; p = 0.007) (EG2 and CG z = -2.198; p = 0.028) and behaviour (EG1 and CG t = 2.054; p = 0.044) (EG2 and CG z = -2.797; p = 0.005).

CONCLUSIONS

The education programme has proven effective, promoting knowledge, change and entrenchment of attitudes, facilitating conversations with families, enabling willingness to donate and increasing potential donors.

HLA expression as a risk factor for metastases of cutaneous squamous-cell carcinoma in organ- transplant recipients

BACKGROUND

Solid organ-transplant recipients (SOTR) have an increased risk of cutaneous squamous-cell carcinoma (cSCC), metastasis and death from cSCC. In immunocompetent patients with mucosal SCC, downregulation of HLA class I is associated with poor prognosis. Since the degree of HLA expression on tumor cells could play a role in immunogenicity and pathophysiology of cSCC metastasis, we hypothesized that decreased HLA expression is associated with an increased risk of metastasis.

METHODS

We compared HLA expression between primary metastasized cSCCs, their metastases, and non-metastasized cSCCs from the same patients. Samples were stained for HLA-A, HLA-B/-C and quantified by calculating the difference in immunoreactivity score (IRS) of the primary cSCC compared with all non-metastasized cSCCs.

RESULTS

The mean IRS score for HLA-B/C expression was 2.07 point higher in metastasized compared to non-metastasized cSCCs (p = 0.065, 95 % CI -0.18-4.32). 83.3 % of the primary metastasized cSCCs had an IRS score of 4 or higher, compared to 42.9 % in non-metastasized cSCCs. Moderately to poorly differentiated cSCCs had more HLA class I expression compared to well-differentiated cSCCs.

CONCLUSION

Contrary to immunocompetent patients, HLA-B/C expression tends to be upregulated in metastasized cSCC compared to non-metastasized cSCC in SOTR, suggesting that different tumor escape mechanisms play a role in SOTR compared to immunocompetent patients.

ClinCirc identifies alterations of the circadian peripheral oscillator in critical care patients

BackgroundAssessing circadian rhythmicity from infrequently sampled data is challenging; however, these types of data are often encountered when measuring circadian transcripts in hospitalized patients.MethodsWe present ClinCirc. This method combines 2 existing mathematical methods (Lomb-Scargle periodogram and cosinor) sequentially and is designed to measure circadian oscillations from infrequently sampled clinical data. The accuracy of this method was compared against 9 other methods using simulated and frequently sampled biological data. ClinCirc was then evaluated in 13 intensive care unit (ICU) patients as well as in a separate cohort of 29 kidney-transplant recipients. Finally, the consequences of circadian alterations were investigated in a retrospective cohort of 726 kidney-transplant recipients.ResultsClinCirc had comparable performance to existing methods for analyzing simulated data or clock transcript expression of healthy volunteers. It had improved accuracy compared with the cosinor method in evaluating circadian parameters in PER2:luc cell lines. In ICU patients, it was the only method investigated to suggest that loss of circadian oscillations in the peripheral oscillator was associated with inflammation, a feature widely reported in animal models. Additionally, ClinCirc was able to detect other circadian alterations, including a phase shift following kidney transplantation that was associated with the administration of glucocorticoids. This phase shift could explain why a significant complication of kidney transplantation (delayed graft dysfunction) oscillates according to the time of day kidney transplantation is performed.ConclusionClinCirc analysis of the peripheral oscillator reveals important clinical associations in hospitalized patients.FundingUK Research and Innovation (UKRI), National Institute of Health Research (NIHR), Engineering and Physical Sciences Research Council (EPSRC), National Institute on Academic Anaesthesia (NIAA), Asthma+Lung UK, Kidneys for Life.