Search

BACKGROUND: Kidney transplant recipients (KTRs) with COVID-19 have poor outcomes compared to non-KTRs. To provide insight into management of immunosuppression during acute illness, we studied immune signatures from the peripheral blood during and after COVID-19 infection from a multicenter KTR cohort.□ METHODS: Clinical data were collected by chart review. PAXgene blood RNA was poly-A selected and RNA sequencing was performed to evaluate transcriptome changes. RESULTS: A total of 64 cases of COVID-19 in KTRs were enrolled, including 31 acute cases (< 4 weeks from diagnosis) and 33 post-acute cases (>4 weeks). In the blood transcriptome of acute cases, we identified differentially expressed genes (DEGs) in positive or negative association COVID-19 severity scores. Functional enrichment analyses showed upregulation of neutrophil and innate immune pathways, but downregulation of T-cell and adaptive immune-activation pathways proportional to severity score. This finding was independent of lymphocyte count and despite reduction in immunosuppression (IS) in most KTRs. Comparison with post-acute cases showed “normalization” of these enriched pathways after >4 weeks, suggesting recovery of adaptive immune system activation despite reinstitution of IS. The latter analysis was adjusted for COVID-19 severity score and lymphocyte count. DEGs associated with worsening disease severity in a non-KTR cohort with COVID-19 (GSE152418) showed significant overlap with KTRs in these identified enriched pathways. CONCLUSION: Blood transcriptome of KTRs affected by COVID-19 shows decrease in T-cell and adaptive immune activation pathways during acute disease that associate with severity despite IS reduction and show recovery after acute illness. SIGNIFICANCE STATEMENT: Kidney transplant recipients (KTRs) are reported to have worse outcomes with COVID-19, and empiric reduction of maintenance immunosuppression is pursued. Surprisingly, reported rates of acute rejection have been low despite reduced immunosuppression. We evaluated the peripheral blood transcriptome of 64 KTRs either during or after acute COVID-19. We identified transcriptomic signatures consistent with suppression of adaptive T-cell responses which significantly associated with disease severity and showed evidence of recovery after acute disease, even after adjustment for lymphocyte number. Our transcriptomic findings of immune-insufficiency during acute COVID-19 provide an explanation for the low rates of acute rejection in KTRs despite reduced immunosuppression. Our data support the approach of temporarily reducing T –cell-directed immunosuppression in KTRs with acute COVID-19.

Introduction: Belatacept has demonstrated effectiveness for preventing rejection in kidney transplant and has a favorable side effect profile. Studies assessing long-term infectious complications with belatacept compared to tacrolimus are limited. Project Aims: The purpose of this program evaluation was to determine the proportion of patients who developed an infection when converted to belatacept compared to those on tacrolimus. Design: In this retrospective evaluation, kidney transplant recipients receiving belatacept were matched 1:1 to those receiving tacrolimus, based on transplant date, age, induction immunosuppression, and cytomegalovirus risk. Data collection was initiated in tacrolimus patients on the date of belatacept conversion in the belatacept-matched patients. Data were extracted until study conclusion, death, or discontinuation of belatacept. Patients were stratified into 3 groups based on time of conversion posttransplant, which included early, late, and very late conversion. The primary outcome was the proportion of patients with an infection in belatacept compared to tacrolimus. Outcome data were calculated using chi-square, Fisher's exact test, student's t-test or Mann-Whitney U test where appropriate. Results: A total of 328 matched patients were included in the analysis. More patients on belatacept developed an infection compared to tacrolimus (42.7% vs 29.9%, P = 0.02), which was primarily driven by pneumonia (6.1% vs 0.5%; P = 0.01). Higher incidences of infections were identified in those converted within 6 months from transplant. Conclusions: Belatacept was associated with a higher proportion of patients with infections compared to tacrolimus, particularly in those converted within 6 months from time of transplant.

Allograft biopsies with lesions of Antibody-Mediated Rejection (ABMR) with Microvascular Inflammation (MVI) have shown heterogeneous etiologies and outcomes.To examine factors associated with outcomes in biopsies that meet histologic ABMR criteria, we retrospectively evaluated for-cause biopsies at our center between 2011 and 2017. We included biopsies that met the diagnosis of ABMR by histology, along with simultaneous evaluation for anti-Human Leukocyte Antigen (HLA) donor-specific antibodies (DSA). We evaluated death-censored graft loss (DCGL) and used a principal component analysis (PCA) approach to identify key predictors of outcomes.Out of the histologic ABMR cohort (n = 118), 70 were DSA-positive ABMR, while 48 had no DSA. DSA(+)ABMR were younger and more often female recipients. DSA(+)ABMR occurred significantly later post-transplant than DSA(-)ABMR suggesting time-dependence. DSA(+)ABMR had higher inflammatory scores (i,t), chronicity scores (ci, ct) and tended to have higher MVI scores. Immunodominance of DQ-DSA in DSA(+)ABMR was associated with higher i+t scores. Clinical/histologic factors significantly associated with DCGL after biopsy were inputted into the PCA. Principal component-1 (PC-1), which contributed 34.8% of the variance, significantly correlated with time from transplantation to biopsy, ci/ct scores and DCGL. In the PCA analyses, i, t scores, DQ-DSA, and creatinine at biopsy retained significant correlations with GL-associated PCs.Time from transplantation to biopsy plays a major role in the prognosis of biopsies with histologic ABMR and MVI, likely due to ongoing chronic allograft injury over time.

There is a paucity of data on the impact of cytomegalovirus (CMV) serostatus and CMV infection on outcomes in facial vascularized composite allotransplantation.This international, multicenter, retrospective cohort study presents data on CMV and basic transplant-related demographics, including pretransplant viral D/R serostatus, and duration of antiviral prophylaxis. CMV-related complications (viremia, disease), allograft-related complications (rejection episodes, loss), and mortality were analyzed.We included 19 patients, 4 of whom received CMV high-risk transplants (D+/R-). CMV viremia was noted in 6 patients (all 4 D+/R- patients and 2 D-/R+), mostly within the first-year posttransplant, shortly after discontinuation of antiviral prophylaxis (median 2 mo). CMV disease occurred in 2 D+/R- patients. The high-risk group experienced relatively more rejection episodes per month follow-up. None of D+/R- patients suffered allograft loss due to rejection (longest follow-up: 121 mo).D+/R- patients were at increased risk of CMV-related complications. Although a higher number of rejections was noted in this group, none of the D+/R- patients lost their allograft or died because of CMV or rejection. Thus, CMV D+/R- face transplantation can likely be safely performed with prophylaxis, active surveillance, and prompt treatment.

BackgroundKidney transplant recipients (KTRs) with COVID-19 have poor outcomes compared to non-KTRs. To provide insight into management of immunosuppression during acute illness, we studied immune signatures from the peripheral blood during and after COVID-19 infection from a multicenter KTR cohort.□MethodsClinical data were collected by chart review. PAXgene blood RNA was poly-A selected and RNA sequencing was performed to evaluate transcriptome changes.ResultsA total of 64 cases of COVID-19 in KTRs were enrolled, including 31 acute cases (< 4 weeks from diagnosis) and 33 post-acute cases (>4 weeks). In the blood transcriptome of acute cases, we identified differentially expressed genes (DEGs) in positive or negative association COVID-19 severity scores. Functional enrichment analyses showed upregulation of neutrophil and innate immune pathways, but downregulation of T-cell and adaptive immune-activation pathways proportional to severity score. This finding was independent of lymphocyte count and despite reduction in immunosuppression (IS) in most KTRs. Comparison with post-acute cases showed “normalization” of these enriched pathways after >4 weeks, suggesting recovery of adaptive immune system activation despite reinstitution of IS. The latter analysis was adjusted for COVID-19 severity score and lymphocyte count. DEGs associated with worsening disease severity in a non-KTR cohort with COVID-19 (GSE152418) showed significant overlap with KTRs in these identified enriched pathways.ConclusionBlood transcriptome of KTRs affected by COVID-19 shows decrease in T-cell and adaptive immune activation pathways during acute disease that associate with severity despite IS reduction and show recovery after acute illness.Significance statementKidney transplant recipients (KTRs) are reported to have worse outcomes with COVID-19, and empiric reduction of maintenance immunosuppression is pursued. Surprisingly, reported rates of acute rejection have been low despite reduced immunosuppression. We evaluated the peripheral blood transcriptome of 64 KTRs either during or after acute COVID-19. We identified transcriptomic signatures consistent with suppression of adaptive T-cell responses which significantly associated with disease severity and showed evidence of recovery after acute disease, even after adjustment for lymphocyte number. Our transcriptomic findings of immune-insufficiency during acute COVID-19 provide an explanation for the low rates of acute rejection in KTRs despite reduced immunosuppression. Our data support the approach of temporarily reducing T –cell-directed immunosuppression in KTRs with acute COVID-19.

Procurement biopsies suffer from challenges with quality and reproducibility and are linked to kidney discard. Nonetheless, procurement biopsies are obtained for the majority of kidneys in the United States, and biopsy findings are commonly relied upon in kidney acceptance decisions.We conducted in-depth, semistructured interviews with 30 surgeons, nephrologists, nurse coordinators, and organ procurement organization (OPO) staff and directors to assess perceptions of factors contributing to kidney discard and strategies to reduce kidney discard, with a focus on the role of procurement biopsies. Thematic analysis was used to analyze qualitative data.Three main themes emerged: (1) participants emphasized the importance of biopsy findings in making acceptance decisions but expressed concerns about a lack of standardization and quality control; (2) participants reported large variations in the level of importance placed on biopsy findings, the level of reliance on glomerulosclerosis in particular, and the cutoffs used; and (3) participants disagreed about how often procurement biopsies should be taken, with some supporting stricter limits on which kidneys are biopsied and others preferring a biopsy for most kidney offers.These findings support the development of standard practices for which kidneys require biopsy, how the biopsy material is prepared, and how the biopsy is interpreted. Variability in kidney acceptance practices across centers and the use of biopsy findings in guiding recipient selection also lend support to policies to allocate kidneys with suboptimal histological findings to the centers that are willing to use such kidneys and the patients who could most benefit from such offers.

Supplemental Digital Content is available in the text., Background. Although the impact of the kidney donor profile index (KDPI) on kidney discard is well researched, less is known about how patients make decisions about whether to give consent for KDPI > 85 kidney offers. Methods. We conducted in-depth, semistructured interviews with 16 transplant recipients, 15 transplant candidates, and 23 clinicians (transplant surgeons, nephrologists, and nurse coordinators) to assess and compare perceptions of transplant education, informed consent for KDPI > 85 kidneys‚ and the decision-making process for accepting kidney offers. Thematic analysis was used to analyze qualitative data. Results. Four themes emerged: (1) patients reported uncertainty about the meaning of KDPI or could not recall information about KDPI; (2) patients reported uncertainty about their KDPI > 85 consent status and a limited role in KDPI > 85 consent decision making; (3) patients’ reported willingness to consider KDPI > 85 kidneys depended on their age, health status, and experiences with dialysis, and thus it changed over time; (4) patients’ underestimated the survival benefit of transplantation compared with dialysis, which could affect their KDPI > 85 consent decision making. Conclusions. To better support patients’ informed decision making about accepting KDPI > 85 kidneys, centers must ensure that all patients receive education about the trade-offs between accepting a KDPI > 85 kidney and remaining on dialysis. Additionally, education about KDPI and discussions about informed consent for KDPI > 85 kidneys must be repeated at multiple time points while patients are on the waiting list.

Ethicists and guidelines have suggested that potential living kidney donors who withdraw from evaluation be offered an 'alibi.' We sought to determine what potential living kidney donors are told about their ability to opt out, alibi availability and postwithdrawal confidentiality. We reviewed 148 consent forms for living kidney donor evaluation from US transplant centres that performed5 living kidney transplants in 2010-2011 (response rate 87%). We found that while 98% of centres used evaluation consent forms that indicated that the donor could withdraw, only 21% of these documents offered an alibi. Another 23% of centres' consent forms indicated that the transplant team would be willing to inform the intended recipient that an individual was not a potential donor. Relatively few consent documents explicitly addressed the confidentiality of the donor's health information (31%), candidacy status (18%), decision (24%) or reasons (23%) following withdrawal. To preserve potential donors' autonomy and relationships, we advocate that all transplant centres offer general alibis in their evaluation consent forms. We conclude by offering recommendations for evaluation consent discussions of opting out, alibis and postwithdrawal confidentiality.

Epstein-Barr virus (EBV)–specific CD8 T lymphocytes are present at remarkably high frequencies in healthy EBV+individuals and provide protection from EBV-associated lymphoproliferative diseases. Allogeneic peripheral blood stem cell transplantation (allo-PBSCT) is a commonly used therapy in which T-cell surveillance for EBV is temporarily disrupted. Herein, human leukocyte antigen (HLA) class I tetramers were used to investigate the reestablishment of the EBV-specific CD8 T-cell repertoire in patients following allo-PBSCT. CD8+ T cells specific for lytic and latent cycle–derived EBV peptides rapidly repopulate the periphery of matched sibling allo-PBSCT patients. The relative frequencies of T cells specific for different EBV peptides in transplantation recipients closely reflect those of their respective donors. Investigation of patients at monthly intervals following unmanipulated allo-PBSCT demonstrated that the frequency of EBV-specific T cells correlates with the number of EBV genome copies in the peripheral blood and that expansion of EBV-specific T-cell populations occurs even in the setting of immunosuppressive therapy. In contrast, patients undergoing T-cell–depleted or unrelated cord blood transplantation have undetectable EBV-specific T cells, even in the presence of Epstein-Barr viremia. The protective shield provided by EBV-specific CD8 T cells is rapidly established following unmanipulated matched sibling allo-PBSCT and demonstrates that HLA class I tetramers complexed with viral peptides can provide direct and rapid assessment of pathogen-specific immunity in this and other vulnerable patient populations.

Despite a trend toward patient autonomy in clinical practice, the decision whether or not to accept a kidney for transplantation is made predominantly by the transplant surgeon. The purpose of this study is to examine how patients and surgeons prioritize relevant factors when deciding to accept or decline an available kidney.We elicited patient and surgeon rankings for a list of factors involved in the decision using a validated computer survey. We computed the relative importance of each factor and examined associations between patient characteristics and priorities using Spearman's correlation coefficient and the Mann-Whitney U-test for continuous and categorical variables, respectively.Patients placed the greatest value on kidney quality and predictors of transplant outcome. Patients who were on the waiting list longer gave less importance to kidney quality and function. Surgeons placed the greatest value on kidney quality, difficulty for the patient to be matched to a kidney, and the age of the donor.The results of this study suggest that decision support tools can be used to improve the understanding of patient priorities in the decision to accept a donor kidney.

Two groups of rats were given preconditioning CS (PCS) exposures in an operant box after learning to bar press for food. One-half of two other groups were given similar PCS exposures in a holding cage, but otherwise were treated identically. One group that got PCS in the operant box and one that did not were given 10 CS-US (buzzer-shock) pairings in the operant chamber while the other two were identically conditioned in a cylindrical chamber. A fifth group got only the US. CS presentations following conditioning produced the most suppression of bar pressing for Ss that got no PCS, intermediate suppression if the PCS was given in the holding cage, and no suppression if preexposures occurred in the operant chamber. These effects were independent of place of conditioning.