Successful management of life-threatening post-COVID-19 cryptosporidiosis in a renal transplant patient: a case report.

Worldwide, Cryptosporidium spp. is a common parasite that affects domestic and wild animals, including humans, and causes diarrhea in both immunocompetent and immunocompromised hosts. The fecal-oral pathway accounts for the majority of its transfer. Although C. parvum and C. hominis are the most common zoonotic species in humans, other zoonotic species can also infect immunocompetent and immunocompromised people. Patients undergoing renal transplants are more likely to contract cryptosporidiosis, which can cause severe and potentially fatal diarrhea. A 41-year-old male patient who presented to the emergency department complained of a sudden onset, severe and continuous fatigue, and a feverish sensation of two-day duration. Two days prior to the current admission, the patient started to complain of weakness affecting his whole body, as well as a fever of 39°C and continuous yellowish diarrhea occurring 4-5 times daily without blood. Stool analysis revealed a cryptosporidium infection. The patient underwent surgery for kidney transplantation. The donated kidney was the left one from his brother and was attached to the patient´s right groin. As illustrated by our example, cryptosporidiosis should be considered a significant cause of acute, persistent, watery diarrhea in immunocompromised kidney transplant recipients. Patients undergoing renal transplants should be instructed to wash their hands frequently, stay away from young animals, sick people, and swimming pools in order to lower their risk of infection.

Projecting the future: modelling Australian dialysis prevalence 2021-30.

Objectives To project the prevalence of people receiving dialysis in Australia for 2021-30 to inform service planning and health policy. Methods Estimates were based on data from 2011 to 2020 from the Australia & New Zealand Dialysis & Transplant (ANZDATA) Registry and the Australian Bureau of Statistics. We projected dialysis and functioning kidney transplant recipient populations for the years 2021-30. Discrete-time, non-homogenous Markov models were built on probabilities for transition between three mutually exclusive states (Dialysis, Functioning Transplant, Death), for five age groups. Two scenarios were employed - stable transplant rate vs a continued increase - to assess the impact of these scenarios on the projected prevalences. Results Models projected a 22.5-30.4% growth in the dialysis population from 14 554 in 2020 to 17 829 ('transplant growth') - 18 973 ('transplant stable') by 2030. An additional 4983-6484 kidney transplant recipients were also projected by 2030. Dialysis incidence per population increased and dialysis prevalence growth exceeded population ageing in 40-59 and 60-69 year age groups. The greatest dialysis prevalence growth was seen among those aged ≥70 years. Conclusion Modelling of the future prevalence of dialysis use highlights the increasing demand on services expected overall and especially by people aged ≥70 years. Appropriate funding and healthcare planning must meet this demand.

Gastrointestinal manifestations of long-term effects after COVID-19 infection in patients with dialysis or kidney transplantation: An observational cohort study.

BACKGROUND: Prolonged symptoms after corona virus disease 2019 (Long-COVID) in dialysis-dependent patients and kidney transplant (KT) recipients are important as a possible risk factor for organ dysfunctions, especially gastrointestinal (GI) problems, during immunosuppressive therapy. AIM: To identify the characteristics of GI manifestations of Long-COVID in patients with dialysis-dependent or KT status. METHODS: This observational, prospective study included patients with COVID-19 infection, confirmed by reverse transcription polymerase chain reaction, with the onset of symptoms between 1 January 2022 and 31 July 2022 which was explored at 3 mo after the onset, either through the out-patient follow-up or by telephone interviews. RESULTS: The 645 eligible participants consisted of 588 cases with hemodialysis (HD), 38 patients with peritoneal dialysis (PD), and 19 KT recipients who were hospitalized with COVID-19 infection during the observation. Of these, 577 (89.5%) cases agreed to the interviews, while 64 (10.9%) patients with HD and 4 (10.5%) cases of PD were excluded. The mean age was 52 ± 11 years with 52% women. The median dialysis duration was 7 ± 3 and 5 ± 1 years for HD and PD groups, respectively, and the median time post-transplantation was 6 ± 2 years. Long-COVID was identified in 293/524 (56%) and 21/34 (62%) in HD and PD, respectively, and 7/19 (37%) KT recipients. Fatigue was the most prevalent (96%) of the non-GI tract symptoms, whereas anorexia (90.9%), loss of taste (64.4%), and abdominal pain (62.5%) were the first three common GI manifestations of Long-COVID. Notably, there were 6 cases of mesenteric panniculitis from 19 patients with GI symptoms in the KT group. CONCLUSION: Different from patients with non-chronic kidney disease, there was a high prevalence of GI manifestations of Long-COVID in dialysis-dependent patients and KT recipients. An appropriate long-term follow-up in these vulnerable populations after COVID-19 infection is possibly necessary.

Tocilizumab for treatment of chronic active antibody-mediated rejection in kidney transplant recipients.

BACKGROUND: The optimal treatment for chronic active antibody-mediated rejection (ca-AMR) remains unclear. Tocilizumab (TCZ), a monoclonal antibody against IL-6, has been proposed as a therapeutic option. We reported our experience treating ca-AMR with TCZ either as the first line option or as a rescue therapy. METHODS: We studied 11 adult kidney transplant recipients with biopsy-proven ca-AMR and preserved kidney function (eGFR 57 ± 18) who were treated with TCZ (8 mg/kg IV monthly). All biopsies were prompted by abnormal surveillance biomarker testing with DSA and/or dd-cfDNA. Clinical monitoring included dd-cfDNA and DSA testing every 3 months during the treatment with TCZ. RESULTS: In this cohort, ca-AMR was diagnosed at a median of 90 months (range 14-224) post-transplant, and 4 of 11 patients had DSA negative ca-AMR. Patients received a minimum of 3 months of TCZ, with 6 patients receiving at least 12 months of TCZ. Dd-cfDNA was elevated in all patients, with a median 2.24% at the start of TCZ treatment. After 6 months of TCZ treatment, 8/11 patients had dd- cfDNA <1%, and 3/11 had values <0.5%. Among those who completed at least 12 months of TCZ, dd-cfDNA decreased by 29% at 6 months (p = .05) and 47% by 12 months (p = .04). DSA also stabilized and, by 12 months, was reduced by 29% (p = .047). Graft function remained stable with no graft loss during treatment. There was a nonsignificant trend towards proteinuria reduction. During the course of treatment with tocilizumab, two patients experienced moderate to severe infections. CONCLUSIONS: In our early short-term experience, TCZ appears to reduce graft injury as measured by dd-cfDNA and modulate the immune response as evident by a modest reduction in immunodominant DSA MFI. Allograft function and proteinuria also stabilized.

Early recurrence of focal segmental glomerulosclerosis in a kidney transplant recipient with APOL1 one risk variant.

Apolipoprotein 1 (APOL1) risk variants (G1 and G2) are associated with focal segmental glomerulosclerosis (FSGS) in patients of African ancestry. The prevalence of APOL1 two risk variants is lower in Hispanics and very rare in European and Asian populations. APOL1 two risk variants in donor kidneys is associated with recipient kidney graft loss, however the effect of recipient risk variant in the kidney transplant outcome is unclear. Here, we present a late adolescent male with FSGS and end stage renal disease with one APOL1 risk variant (G2) who had immediate recurrence of FSGS in the post-KT period. There was an excellent response to few sessions of plasmapheresis and Rituximab with no further recurrence of FSGS in the 1 year follow-up period. It needs to be seen whether the recipient APOL1 single risk variant causes increased susceptibility to kidney graft loss on a long run via recurrent or de novo pathologies.

Optimizing COVID-19 Vaccination Strategy in Pediatric Kidney Transplant Recipients: Humoral and Cellular Response to SARS-CoV-2 mRNA Vaccination.

In this retrospective cohort study, we analyze the early humoral and cellular response in 64 adolescents KTx recipients, after two or three doses of mRNA vaccine BNT162b2 against different variants of COVID-19. After 2 doses, 77.8% % of children with no history of infection had a positive humoral response with a median anti-S IgG level of 1107 (IQR, 593-2,658) BAU/mL. All the patients with a history of infection responded with a higher median IgG level (3,265 (IQR, 1,492-8,178) BAU/mL). In non-responders after 2 doses, 75% responded after a third dose with a median Ab titer at 355 (IQR, 140-3,865 BAU/mL). Neutralizing activity was significantly lower against the delta and the omicron variants compared to the wild-type strain and did not improve after a 3rd dose, while infection did provide higher levels of neutralizations against the variants. T cell specific response correlated with humoral response and no patient displayed a cellular response without a humoral response. Adolescent KTx recipients exhibit a high seroconversion rate after only two doses. A third injection, induces a response in the majority of the non-responders patients but did not counterbalance the strong decrease in neutralizing antibody activities against variants highlighting the need for boosters with specific vaccines.

Beyond donation to organ utilization in the USA.

PURPOSE OF REVIEW: The deceased donor organ pool has broadened beyond young, otherwise healthy head trauma victims. But an abundance of donated organs only benefits patients if they are accepted, expeditiously transported and actually transplanted. This review focuses on postdonation challenges and opportunities to increase the number of transplants through improved organ utilization. RECENT FINDINGS: We build upon recently proposed changes in terminology for measuring organ utilization. Among organs recovered for transplant, the nonuse rate (NUR REC ) has risen above 25% for kidneys and pancreata. Among donors, the nonuse rate (NUR DON ) has risen to 40% for livers and exceeds 70% for thoracic organs. Programme-level variation in offer acceptance rates vastly exceeds variation in the traditional, 1-year survival benchmark. Key opportunities to boost utilization include donation after circulatory death and hepatitis C virus (HCV)+ organs; acute kidney injury and suboptimal biopsy kidneys; older and steatotic livers. SUMMARY: Underutilization of less-than-ideal, yet transplant-worthy organs remains an obstacle to maximizing the impact of the U.S. transplant system. The increased risk of inferior posttransplant outcomes must always be weighed against the risks of remaining on the waitlist. Advanced perfusion technologies; tuning allocation systems for placement efficiency; and data-driven clinical decision support have the potential to increase utilization of medically complex organs.

Efficacy and safety of a fourth dose of the COVID-19 vaccine in kidney transplant recipients: A systematic review and meta-analysis.

BACKGROUND: Kidney transplant recipients (KTRs) who become infected with SARS-CoV-2 are at greater risk of serious illness and death than the general population. To date, the efficacy and safety of the fourth dose of the COVID-19 vaccine in KTRs have not been systematically discussed. METHODS: This systematic review and meta-analysis included articles from PubMed, Embase, the Cochrane Library, Web of Science, China National Knowledge Infrastructure, and Wanfang Med Online published before May 15, 2022. Studies evaluating the efficacy and safety of a fourth dose of the COVID-19 vaccine in kidney transplant recipients were selected. RESULTS: Nine studies were included in the meta-analysis, with a total of 727 KTRs. The overall pooled seropositivity rate after the fourth COVID-19 vaccine was 60% (95% CI, 49%-71%, I2 = 87.83%, p > 0.01). The pooled proportion of KTRs seronegative after the third dose that transitioned to seropositivity after the fourth dose was 30% (95% CI, 15%-48%, I2 = 94.98%, p < 0.01). CONCLUSIONS: The fourth dose of the COVID-19 vaccine was well tolerated in KTRs with no serious adverse effects. Some KTRs showed a reduced response even after receiving the fourth vaccine dose. Overall, the fourth vaccine dose effectively improved seropositivity in KTRs, as recommended by the World Health Organization for the general population.

Development and validation of multivariable prediction models of serological response to SARS-CoV-2 vaccination in kidney transplant recipients.

Repeated vaccination against SARS-CoV-2 increases serological response in kidney transplant recipients (KTR) with high interindividual variability. No decision support tool exists to predict SARS-CoV-2 vaccination response to third or fourth vaccination in KTR. We developed, internally and externally validated five different multivariable prediction models of serological response after the third and fourth vaccine dose against SARS-CoV-2 in previously seronegative, COVID-19-naïve KTR. Using 20 candidate predictor variables, we applied statistical and machine learning approaches including logistic regression (LR), least absolute shrinkage and selection operator (LASSO)-regularized LR, random forest, and gradient boosted regression trees. For development and internal validation, data from 590 vaccinations were used. External validation was performed in four independent, international validation cohorts comprising 191, 184, 254, and 323 vaccinations, respectively. LASSO-regularized LR performed on the whole development dataset yielded a 20- and 10-variable model, respectively. External validation showed AUC-ROC of 0.840, 0.741, 0.816, and 0.783 for the sparser 10-variable model, yielding an overall performance 0.812. A 10-variable LASSO-regularized LR model predicts vaccination response in KTR with good overall accuracy. Implemented as an online tool, it can guide decisions whether to modulate immunosuppressive therapy before additional active vaccination, or to perform passive immunization to improve protection against COVID-19 in previously seronegative, COVID-19-naïve KTR.

Blood unconjugated bilirubin and tacrolimus are negative predictors of specific cellular immunity in kidney transplant recipients after SAR-CoV-2 inactivated vaccination.

The immunogenicity of SARS-CoV-2 vaccines is poor in kidney transplant recipients (KTRs). The factors related to poor immunogenicity to vaccination in KTRs are not well defined. Here, observational study demonstrated no severe adverse effects were observed in KTRs and healthy participants (HPs) after first or second dose of SARS-CoV-2 inactivated vaccine. Different from HPs with excellent immunity against SARS-CoV-2, IgG antibodies against S1 subunit of spike protein, receptor-binding domain, and nucleocapsid protein were not effectively induced in a majority of KTRs after the second dose of inactivated vaccine. Specific T cell immunity response was detectable in 40% KTRs after the second dose of inactivated vaccine. KTRs who developed specific T cell immunity were more likely to be female, and have lower levels of total bilirubin, unconjugated bilirubin, and blood tacrolimus concentrations. Multivariate logistic regression analysis found that blood unconjugated bilirubin and tacrolimus concentration were significantly negatively associated with SARS-CoV-2 specific T cell immunity response in KTRs. Altogether, these data suggest compared to humoral immunity, SARS-CoV-2 specific T cell immunity response are more likely to be induced in KTRs after administration of inactivated vaccine. Reduction of unconjugated bilirubin and tacrolimus concentration might benefit specific cellular immunity response in KTRs following vaccination.

Immunogenicity and safety of two-dose SARS-CoV-2 vaccination via different platforms in kidney transplantation recipients.

After kidney transplantation, patients exhibit a poor response to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccination. However, the efficacy and adverse effects of vaccines based on different platforms in these patients remain unclear. We prospectively analyzed both anti-spike protein antibody and cellular responses 1 month after the first and second doses of SARS-CoV-2 vaccines in 171 kidney transplant patients. Four vaccines, including one viral vector (ChAdOx1 nCov-19, n = 30), two mRNA (mRNA1273, n = 81 and BNT162b2, n = 38), and one protein subunit (MVC-COV1901, n = 22) vaccines were administered. Among the four vaccines, mRNA1273 elicited the strongest humoral response and induced the highest interferon-γ levels in patients with a positive cellular response against the spike protein. Antiproliferative agents were negatively associated with both the antibody and cellular responses. A transient elevation in creatinine levels was noted in approximately half of the patients after the first dose of mRNA1273 or ChadOx1, and only one of them presented with borderline cellular rejection without definite causality to vaccination. In conclusion, mRNA1273 had better immunogenicity than the other vaccines. Further, renal function needs to be carefully monitored after vaccination, and vaccination strategies should be tailored according to the transplant status and vaccine characteristics.

Knowing When to Ignore the Numbers: Single-Center Experience Transplanting Deceased Donor Kidneys with Poor Perfusion Parameters.

BACKGROUND: Hypothermic machine perfusion is frequently used in evaluating marginal kidneys with poor perfusion parameters (PPP) contributing to delays in kidney placement or discard. We examined outcomes in deceased donor kidney transplants with PPP compared with those with optimal perfusion parameters (OPP). STUDY DESIGN: We conducted a retrospective single-center cohort study from 2001 to 2021 comparing PPP (n = 91) with OPP (n = 598) deceased donor kidney transplants. PPP was defined as terminal flow ≤80 mL/min and terminal resistance ≥0.40 mmHg/mL/min. OPP was defined as terminal flow ≥120 mL/min and terminal resistance ≤0.20 mmHg/mL/min. RESULTS: Mean terminal flow was PPP 66 ± 16 vs OPP 149 ± 21 mL/min and resistance was PPP 0.47 ± 0.10 vs OPP 0.15 ± 0.04 mmHg/mL/min (both p < 0.001). Donor age, donation after cardiac death, and terminal serum creatinine levels were similar between groups. Mean Kidney Donor Profile Index was higher among PPP donors (PPP 65 ± 23% vs OPP 52 ± 27%, p < 0.001). The PPP transplant group had more females and lower weight and BMI. Delayed graft function was comparable (PPP 32% vs OPP 27%, p = 0.33) even though cold ischemia times trended toward longer in PPP kidneys (PPP 28 ± 10 vs OPP 26 ± 9 hours, p = 0.09). One-year patient survival (PPP 98% vs OPP 97%, p = 0.84) and graft survival (PPP 91% vs OPP 92%, p = 0.23) were equivalent. PPP did predict inferior overall and death-censored graft survival long-term (overall hazard ratio 1.63, 95% CI 1.19 to 2.23 and death-censored hazard ratio 1.77, 95% CI 1.15 to 2.74). At 1 year, the estimated glomerular filtration rate was higher with OPP kidneys (PPP 40 ± 17 vs OPP 52 ± 19 mL/min/1.73 m 2 , p < 0.001). CONCLUSIONS: Short-term outcomes in PPP kidneys were comparable to OPP kidneys despite higher Kidney Donor Profile Index and longer cold ischemia times, suggesting a role for increased utilization of these organs with careful recipient selection.

COVID-19 and Kidney Disease: Progress in Health Inequity From Low-Income Settings.

The acute coronavirus disease-2019 (COVID-19) pandemic has had a significant impact on the incidence and prevalence of acute kidney injury and chronic kidney disease globally and in low-income settings. Chronic kidney disease increases the risk of developing COVID-19 and COVID-19 causes acute kidney injury directly or indirectly and is associated with high mortality in severe cases. Outcomes of COVID-19-associated kidney disease were not equitable globally owing to a lack of health infrastructure, challenges in diagnostic testing, and management of COVID-19 in low-income settings. COVID-19 also significantly impacted kidney transplant rates and mortality among kidney transplant recipients. Vaccine availability and uptake remains a significant challenge in low- and lower-middle-income countries compared with high-income countries. In this review, we explore the inequities in low- and lower-middle-income countries and highlight the progress made in the prevention, diagnosis, and management of patients with COVID-19 and kidney disease. We recommend further studies into the challenges, lessons learned, and progress made in the diagnosis, management, and treatment of patients with COVID-19-related kidney diseases and suggest ways to improve the care and management of patients with COVID-19 and kidney disease.

Our Pediatric Liver and Kidney Transplant Activities in 2021.

OBJECTIVES: In children with end-stage renal disease, chronic liver failure, or acute liver failure, liver transplant and kidney transplant are the most effective modalities for better clinical outcomes compared with other therapies. However, children are particularly susceptible to surgical complications, so pediatric solid-organ transplants should be reserved for centers with substantial experience and multidisciplinary expertise. Here, we assessed liver and kidney transplants performed at our center in 2021. MATERIALS AND METHODS: From November 3, 1975, to December 31, 2021, we performed 701 liver transplants and 3290 kidney transplants. From January 1, 2021, to December 31, 2021, we performed 21 liver transplants (19 in children) and 114 kidney transplants (12 in children). We recorded age, sex, body mass index, comorbidities, etiologies, laboratory values, and clinical outcomes. RESULTS: For the year 2021, we performed 19 pediatric liver transplants and 12 pediatric kidney transplants. Mean age of liver recipients was 3.4 years, and 8 were male patients. The most common etiology was biliary atresia (n = 7). All liver grafts were from living related donors who were first-degree (n = 16) or second- degree (n = 3) relatives of the recipients. Mean hospital stay was 17.6 days. All but 2 liver transplant recipients were discharged successfully (2 died from sepsis in the early postoperative period). Mean age of kidney transplant recipients was 14.1 years, and 4 were male patients. The most common etiology was vesicoureteral reflux (n = 3). One kidney graft was from a deceased donor, with the rest from living related donors who were first-degree relatives of the recipients (n = 11; mother for 8 recipients and father for 3 recipients). Mean hospital stay was 4.3 days. All kidney transplant recipients were discharged successfully. CONCLUSIONS: Solid-organ transplants for young children are often complex but can be performed successfully at experienced transplant centers.

Development and implementation of telehealth for peritoneal dialysis and kidney transplant patients monitoring during the COVID-19 pandemic.

The coronavirus (Sars-Cov-2) pandemic raised the need for social distance to reduce its spread. Chronic kidney disease patients on renal replacement therapy are especially susceptible to developing the most severe form of COVID-19, and, at the same time, require regular medical and multidisciplinary periodic follow-up. On an emergency basis, Brazil's professional regulatory bodies authorized telehealth assistance, which made possible to migrate from face-to-face to distance appointments in health services across the country, when necessary. This article's main objective is to describe the process of developing and implementing telehealth for monitoring renal transplant patients and patients on peritoneal dialysis during the COVID-19 pandemic.

Serologic response to COVID-19 infection or vaccination in pediatric kidney transplant recipients compared to healthy children.

BACKGROUND: Differences in serologic response to COVID-19 infection or vaccination were reported in adult kidney transplant recipients (KTR) compared to non-immunocompromised patients. This study aims to compare the serologic response of naturally infected or vaccinated pediatric KTR to that of controls. METHODS: Thirty-eight KTR and 42 healthy children were included; aged ≤18 years, with a previously confirmed COVID-19 infection or post COVID-19 vaccination. Serological response was measured by anti-spike protein IgG antibody titers. Response post third vaccine was additionally assessed in KTR. RESULTS: Fourteen children in each group had previously confirmed infection. KTR were significantly older and developed a 2-fold higher antibody titer post-infection compared to controls [median (interquartile range [IQR]) age: 14.9 (7.8, 17.5) vs. 6.3 (4.5, 11.5) years, p = 0.02; median (IQR) titer: 1695 (982, 3520) vs. 716 (368, 976) AU/mL, p = 0.03]. Twenty-four KTR and 28 controls were vaccinated. Antibody titer was lower in KTR than in controls [median (IQR): 803 (206, 1744) vs. 8023 (3032, 30,052) AU/mL, p < 0.001]. Fourteen KTR received third vaccine. Antibody titer post booster in KTR reached similar levels to those of controls post two doses [median (IQR) 5923 (2295, 12,278) vs. 8023 (3034, 30,052) AU/mL, p = 0.37] and to KTR post natural infection [5282 AU/mL (2583, 13,257) p = 0.8]. CONCLUSION: Serologic response to COVID-19 infection was significantly higher in KTR than in controls. Antibody level in KTR was higher in response to infection vs. vaccination, contrary to reports in the general population. Response to vaccination in KTR reached levels comparable to controls only after third vaccine.

Abdominal Organ Transplantation: Noteworthy Literature in 2022.

This review highlights noteworthy literature published in 2022 pertinent to anesthesiologists and critical care physicians caring for patients undergoing abdominal organ transplantation. We begin by exploring the impacts that the COVID-19 pandemic has had across the field of abdominal organ transplantation, including the successful use of grafts procured from COVID-19-infected donors. In pancreatic transplantation, we highlight several studies on dexmedetomidine and ischemia-reperfusion injury, equity in transplantation, and medical management, as well as studies comparing pancreatic transplantation to islet cell transplantation. In our section on intestinal transplantation, we explore donor selection. Kidney transplantation topics include cardiovascular risk management, obesity, and intraoperative management, including fluid resuscitation, dexmedetomidine, and sugammadex. The liver transplantation section focuses on clinical trials, systematic reviews, and meta-analyses published in 2022 and covers a wide range of topics, including machine perfusion, cardiovascular issues, renal issues, and coagulation/transfusion.

Kidney Transplantation from a Deceased Donor with COVID-19 Ad26.COV2-S Vaccine-Induced Thrombotic Thrombocytopenia.

BACKGROUND Vaccine-induced thrombosis and thrombocytopenia is a rare immune disorder documented after adenoviral vector ChAdOx1 nCOV-19 (AstraZeneca) and Ad26.COV2-S (Janssen) vaccine administration against severe acute respiratory syndrome coronavirus 2. It is a rare adverse effect with an incidence of 1 case per 100 000 exposures. The disorder represents altered immune response with proliferation of antibodies that bind to platelet factor 4 (PF4), leading to formation of thrombi and consumptive coagulopathy. Thrombosis combined with thrombocytopenia generally occurs in the first month following vaccination and can lead to fatal outcome, even in young, previously healthy individuals. These young adults ultimately may become solid organ donors. The main concerns with vaccine-induced thrombosis and thrombocytopenia solid organ donors are anti-PF4 antibodies transmission potential, risk of early major graft thrombosis, and serious bleeding. CASE REPORT In our center, 2 kidney transplantations were performed from a single brain-dead vaccine-induced thrombosis and thrombocytopenia donor following Ad26.COV2-S COVID-19 (Janssen) vaccine in October 2021, which represents the first 2 cases of kidney transplantation from a deceased vaccine-induced thrombosis and thrombocytopenia donor after immunization with Ad26.COV2-S (Janssen) vaccine. Both recipients were closely monitored in the early post-transplantation period and after discharge from the hospital. To date, both recipients have a good functioning allograft, without any evidence of vaccine-induced thrombosis and thrombocytopenia transmission. CONCLUSIONS Our results are consistent with those of previously published cases of successful vaccine-induced thrombosis and thrombocytopenia donor solid organ transplantation. Kidney allografts transplanted from vaccine-induced thrombosis and thrombocytopenia donors can have a good overall function with favorable outcomes.

Comparable cellular and humoral immunity upon homologous and heterologous COVID-19 vaccination regimens in kidney transplant recipients.

Background: Kidney transplant recipients (KTRs) are at high risk for a severe course of coronavirus disease 2019 (COVID-19); thus, effective vaccination is critical. However, the achievement of protective immunogenicity is hampered by immunosuppressive therapies. We assessed cellular and humoral immunity and breakthrough infection rates in KTRs vaccinated with homologous and heterologous COVID-19 vaccination regimens. Method: We performed a comparative in-depth analysis of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-specific T-cell responses using multiplex Fluorospot assays and SARS-CoV-2-specific neutralizing antibodies (NAbs) between three-times homologously (n = 18) and heterologously (n = 8) vaccinated KTRs. Results: We detected SARS-CoV-2-reactive T cells in 100% of KTRs upon third vaccination, with comparable frequencies, T-cell expression profiles, and relative interferon γ and interleukin 2 production per single cell between homologously and heterologously vaccinated KTRs. SARS-CoV-2-specific NAb positivity rates were significantly higher in heterologously (87.5%) compared to homologously vaccinated (50.0%) KTRs (P < 0.0001), whereas the magnitudes of NAb titers were comparable between both subcohorts after third vaccination. SARS-CoV-2 breakthrough infections occurred in equal numbers in homologously (38.9%) and heterologously (37.5%) vaccinated KTRs with mild-to-moderate courses of COVID-19. Conclusion: Our data support a more comprehensive assessment of not only humoral but also cellular SARS-CoV-2-specific immunity in KTRs to provide an in-depth understanding about the COVID-19 vaccine-induced immune response in a transplant setting.