Prognostic Biomarkers in Kidney Transplantation: A Systematic Review and Critical Appraisal.

SIGNIFICANCE STATEMENT: Why are there so few biomarkers accepted by health authorities and implemented in clinical practice, despite the high and growing number of biomaker studies in medical research ? In this meta-epidemiological study, including 804 studies that were critically appraised by expert reviewers, the authors have identified all prognostic kidney transplant biomarkers and showed overall suboptimal study designs, methods, results, interpretation, reproducible research standards, and transparency. The authors also demonstrated for the first time that the limited number of studies challenged the added value of their candidate biomarkers against standard-of-care routine patient monitoring parameters. Most biomarker studies tended to be single-center, retrospective studies with a small number of patients and clinical events. Less than 5% of the studies performed an external validation. The authors also showed the poor transparency reporting and identified a data beautification phenomenon. These findings suggest that there is much wasted research effort in transplant biomarker medical research and highlight the need to produce more rigorous studies so that more biomarkers may be validated and successfully implemented in clinical practice. BACKGROUND: Despite the increasing number of biomarker studies published in the transplant literature over the past 20 years, demonstrations of their clinical benefit and their implementation in routine clinical practice are lacking. We hypothesized that suboptimal design, data, methodology, and reporting might contribute to this phenomenon. METHODS: We formed a consortium of experts in systematic reviews, nephrologists, methodologists, and epidemiologists. A systematic literature search was performed in PubMed, Embase, Scopus, Web of Science, and Cochrane Library between January 1, 2005, and November 12, 2022 (PROSPERO ID: CRD42020154747). All English language, original studies investigating the association between a biomarker and kidney allograft outcome were included. The final set of publications was assessed by expert reviewers. After data collection, two independent reviewers randomly evaluated the inconsistencies for 30% of the references for each reviewer. If more than 5% of inconsistencies were observed for one given reviewer, a re-evaluation was conducted for all the references of the reviewer. The biomarkers were categorized according to their type and the biological milieu from which they were measured. The study characteristics related to the design, methods, results, and their interpretation were assessed, as well as reproducible research practices and transparency indicators. RESULTS: A total of 7372 publications were screened and 804 studies met the inclusion criteria. A total of 1143 biomarkers were assessed among the included studies from blood ( n =821, 71.8%), intragraft ( n =169, 14.8%), or urine ( n =81, 7.1%) compartments. The number of studies significantly increased, with a median, yearly number of 31.5 studies (interquartile range [IQR], 23.8-35.5) between 2005 and 2012 and 57.5 (IQR, 53.3-59.8) between 2013 and 2022 ( P < 0.001). A total of 655 studies (81.5%) were retrospective, while 595 (74.0%) used data from a single center. The median number of patients included was 232 (IQR, 96-629) with a median follow-up post-transplant of 4.8 years (IQR, 3.0-6.2). Only 4.7% of studies were externally validated. A total of 346 studies (43.0%) did not adjust their biomarker for key prognostic factors, while only 3.1% of studies adjusted the biomarker for standard-of-care patient monitoring factors. Data sharing, code sharing, and registration occurred in 8.8%, 1.1%, and 4.6% of studies, respectively. A total of 158 studies (20.0%) emphasized the clinical relevance of the biomarker, despite the reported nonsignificant association of the biomarker with the outcome measure. A total of 288 studies assessed rejection as an outcome. We showed that these rejection studies shared the same characteristics as other studies. CONCLUSIONS: Biomarker studies in kidney transplantation lack validation, rigorous design and methodology, accurate interpretation, and transparency. Higher standards are needed in biomarker research to prove the clinical utility and support clinical use.

Identification of liver transplant biopsy phenotypes associated with distinct liver biological markers and allograft survival.

The intricate association between histologic lesions and circulating antihuman leucocyte antigen donor-specific antibodies (DSA) in liver transplantation (LT) requires further clarification. We conducted a probabilistic, unsupervised approach in a comprehensively well-annotated LT cohort to identify clinically relevant archetypes. We evaluated 490 pairs of LT biopsies with DSA testing from 325 recipients transplanted between 2010 and 2020 across 3 French centers and an external cohort of 202 biopsies from 128 recipients. Unsupervised archetypal analysis integrated all clinico-immuno-histologic parameters of each biopsy to identify biopsy archetypes. The median time after LT was 1.17 (interquartile range, 0.38-2.38) years. We identified 7 archetypes distinguished by clinico-immuno-histologic parameters: archetype #1: severe T cell-mediated rejection (15.9%); #2: chronic rejection with ductopenia (1.8%); #3: architectural and microvascular damages (3.5%); #4: (sub)normal (55.9%); #5: mild T cell-mediated rejection (4.9%); #6: acute antibody-mediated rejection (6.5%); and #7: chronic rejection with DSA (11.4%). Cell infiltrates vary in the archetype. These archetypes were associated with distinct liver biological markers and allograft outcomes. These findings remained consistent when stratified using the patient's age or indications for LT, with good performance in the external cohort (mean highest probability assignment = 0.58, standard deviation ± 0.17). In conclusion, we have identified clinically meaningful archetypes, providing valuable insights into the intricate DSA-histology association, which may help standardize liver allograft pathology classification.

Banff 2022 Liver Group Meeting report: Monitoring long-term allograft health.

The Banff Working Group on Liver Allograft Pathology met in September 2022. Participants included hepatologists, surgeons, pathologists, immunologists, and histocompatibility specialists. Presentations and discussions focused on the evaluation of long-term allograft health, including noninvasive and tissue monitoring, immunosuppression optimization, and long-term structural changes. Potential revision of the rejection classification scheme to better accommodate and communicate late T cell-mediated rejection patterns and related structural changes, such as nodular regenerative hyperplasia, were discussed. Improved stratification of long-term maintenance immunosuppression to match the heterogeneity of patient settings will be central to improving long-term patient survival. Such personalized therapeutics are in turn contingent on a better understanding and monitoring of allograft status within a rational decision-making approach, likely to be facilitated in implementation with emerging decision-support tools. Proposed revisions to rejection classification emerging from the meeting include the incorporation of interface hepatitis and fibrosis staging. These will be opened to online testing, modified accordingly, and subject to consensus discussion leading up to the next Banff conference.

Progressive Multifocal Leukoencephalopathy Treated by Immune Checkpoint Inhibitors.

OBJECTIVE: Our aim was to assess the real-world effectiveness of immune checkpoint inhibitors for treatment of patients with progressive multifocal leukoencephalopathy (PML). METHODS: We conducted a multicenter survey compiling retrospective data from 79 PML patients, including 38 published cases and 41 unpublished cases, who received immune checkpoint inhibitors as add-on to standard of care. One-year follow-up data were analyzed to determine clinical outcomes and safety profile. Logistic regression was used to identify variables associated with 1-year survival. RESULTS: Predisposing conditions included hematological malignancy (n = 38, 48.1%), primary immunodeficiency (n = 14, 17.7%), human immunodeficiency virus/acquired immunodeficiency syndrome (n = 12, 15.2%), inflammatory disease (n = 8, 10.1%), neoplasm (n = 5, 6.3%), and transplantation (n = 2, 2.5%). Pembrolizumab was most commonly used (n = 53, 67.1%). One-year survival was 51.9% (41/79). PML-immune reconstitution inflammatory syndrome (IRIS) was reported in 15 of 79 patients (19%). Pretreatment expression of programmed cell death-1 on circulating T cells did not differ between survivors and nonsurvivors. Development of contrast enhancement on follow-up magnetic resonance imaging at least once during follow-up (OR = 3.16, 95% confidence interval = 1.20-8.72, p = 0.02) was associated with 1-year survival. Cerebrospinal fluid JC polyomavirus DNA load decreased significantly by 1-month follow-up in survivors compared to nonsurvivors (p < 0.0001). Thirty-two adverse events occurred among 24 of 79 patients (30.4%), and led to treatment discontinuation in 7 of 24 patients (29.1%). INTERPRETATION: In this noncontrolled retrospective study of patients with PML who were treated with immune checkpoint inhibitors, mortality remains high. Development of inflammatory features or overt PML-IRIS was commonly observed. This study highlights that use of immune checkpoint inhibitors should be strictly personalized toward characteristics of the individual PML patient. ANN NEUROL 2023;93:257-270.

Prophylactic treatment of FSGS recurrence in patients who relapsed in a previous kidney graft.

BACKGROUND AND HYPOTHESIS: Recurrence of focal segmental glomerulosclerosis (FSGS) is common after kidney transplantation and is classically associated with a significant decrease in graft survival. A major risk factor is a prior history of FSGS recurrence on a previous graft. This analysis reports the impact of a prophylactic treatment of FSGS recurrence in very high-risk patients who experienced a recurrence on a previous graft. METHODS: We performed a retrospective multicentre observational study in 25 French transplantation centres. The inclusion criteria were patients aged more than 18 years who had undergone kidney transplant between December 31, 2004, and December 31, 2020, and who had a history of FSGS recurrence on a previous graft. RESULTS: We identified 66 patients: 40 received prophylactic treatment (PT+), including intravenous cyclosporine and/or rituximab and/or plasmapheresis, and 26 did not receive any prophylactic treatment (PT-). The time to progression to end-stage kidney disease was similar between groups. The PT + group was younger at FSGS diagnosis and at the time of kidney retransplantation and lost their previous graft faster. The overall recurrence rate was 72.7% (76.9% in the PT- group and 70.0% in the PT + group, P = 0.54). At least partial remission was achieved in 87.5% of patients. The 5-year graft survival was 67.7% (95% CI: 53.4 to 78.4%): 65.1% (95%CI: 48.7 to 77.4%) in patients with FSGS recurrence vs. 77.3% (95% CI: 43.8 to 92.3%) in patients without recurrence (P = 0.48). CONCLUSION: Our study suggests that prophylactic treatment should not be used routinely in patients receiving a second transplantation after recurrence of FSGS on a previous graft. The recurrence rate is high regardless of the use of prophylactic treatment. However, the 5-year graft survival remains satisfactory.

Effect of steroid pulses in severe BK virus allograft nephropathy with extensive interstitial inflammation.

INTRODUCTION: As there is no specific antiviral treatment currently available for BK polyomavirus associated nephropathy (BKVAN), its management relies on immunosuppression reduction in kidney transplant patients. Data on efficacy of steroid pulses in this indication are lacking. METHODS: We performed a retrospective monocenter study on 64 patients diagnosed with biopsy-proven BKVAN. Patients within the "pulse group" (n = 37) received IV methylprednisolone 10 mg/kg 3 days consecutively. In the "low dose" steroid group (n = 27), patients were continued oral prednisone 5 mg daily. RESULTS: Mean follow up was 78 months in the steroid pulse group and 56 months in the low dose group (p = 0.15). Mean eGFR values at diagnosis were comparable, as well as other demographic characteristics. Mean BK plasma viral load was higher in "pulse" than in "low dose" steroid group. Pulse group had higher inflammation and tubulitis (p < 0.05). Graft loss reached 57% in the "pulse" group versus 41% in the "low dose" group, p = 0.20. Rejection events were similar. No major adverse event was statistically associated with steroid pulse, including infections, cancer, and de novo diabetes. CONCLUSION: No significant differences were found in the evolution of both groups of patients, despite patients receiving "pulse" steroids were identified as the most severe sharing higher BK viral load and more frequent active lesions on histology.

Subclinical rejection-free diagnostic after kidney transplantation using blood gene expression.

We previously established a six-gene-based blood score associated with operational tolerance in kidney transplantation which was decreased in patients developing anti-HLA donor-specific antibodies (DSA). Herein, we aimed to confirm that this score is associated with immunological events and risk of rejection. We measured this using quantitative PCR (qPCR) and NanoString methods from an independent multicenter cohort of 588 kidney transplant recipients with paired blood samples and biopsies at one year after transplantation validating its association with pre-existing and de novo DSA. From 441 patients with protocol biopsy, there was a significant decrease of the score of tolerance in 45 patients with biopsy-proven subclinical rejection (SCR), a major threat associated with pejorative allograft outcomes that prompted an SCR score refinement. This refinement used only two genes, AKR1C3 and TCL1A, and four clinical parameters (previous experience of rejection, previous transplantation, sex of recipient and tacrolimus uptake). This refined SCR score was able to identify patients unlikely to develop SCR with a C-statistic of 0.864 and a negative predictive value of 98.3%. The SCR score was validated in an external laboratory, with two methods (qPCR and NanoString), and on 447 patients from an independent and multicenter cohort. Moreover, this score allowed reclassifying patients with discrepancies between the DSA presence and the histological diagnosis of antibody mediated rejection unlike kidney function. Thus, our refined SCR score could improve detection of SCR for closer and noninvasive monitoring, allowing early treatment of SCR lesions notably for patients DSA-positive and during lowering of immunosuppressive treatment.

Treatment of donor-specific anti-HLA antibodies-mediated rejection after liver transplantation: A French nationwide retrospective study.

The deleterious effect of donor-specific anti-HLA antibodies (DSA) after liver transplantation (LT) has been increasingly recognized during the past decade. Antibody-mediated rejection (AMR) represents a rare but severe complication in the presence of DSA. However, little is known concerning the treatment of AMR after LT. The nationwide French study aimed to describe LT recipients who received specific treatment of AMR. We performed a multicenter retrospective study on 44 patients who were treated with B-cell targeting agents from January 2008 to December 2020. Median patient age at the time of AMR treatment was 51.6 years (range: 17.9-68.0). AMR was classified as acute (n = 19) or chronic (n = 25). The diagnosis of AMR was made after a median time of 16.8 months (range: 0.4-274.2) after LT. The main therapeutic combination was plasma exchange/rituximab/IVIG (n = 25, 56.8%). The median follow-up after the treatment of AMR was 32 months (range: 1-115). After the treatment, 1-, 5- and 10-year patient and graft survivals were 77%, 55.9%, and 55.9%, and 69.5%, 47.0%, and 47.0%, respectively. Initial total bilirubin (Q1-Q3 vs. Q4) was significantly associated with patient survival (log-rank test, p = 0.005) and graft survival (log-rank test, p = 0.002). After a median follow-up of 21 months (range: 12-107), DSA became undetectable in 15/38 patients (39.5%) with available DSA monitoring. In conclusion, specific treatment of AMR in LT recipients has slowly emerged in France during the past decade and has probably been considered in the most severe patients; this explains the global poor outcome, even if the outcome was favorable in some cases.

Anti-SARS-CoV-2 spike protein and neutralizing antibodies at 1 and 3 months after three doses of SARS-CoV-2 vaccine in a large cohort of solid organ transplant patients.

The immunogenicity of the severe acute respiratory syndrome-coronavirus 2 (SARS-CoV-2) vaccine was improved by the administration of a third dose. The aim of our retrospective study was to assess the evolution of binding and neutralizing antibody concentration until 3 months after the third dose in a large cohort of solid organ transplant (SOT) patients (n = 872). At 1 month after the third dose, anti-SARS-CoV-2 antibodies were detected by means of enzyme-linked immunosorbent assay tests in 578 patients (66.3%). In a subgroup of patients, 70% (180 out of 257) had anti-SARS-CoV-2 antibody concentrations ranging from 1.2 to 18 411 binding antibody units (BAU)/ml and 48.5% (115 out of 239) had a neutralizing antibodies titer that can confer clinical protection against SARS-CoV-2. Three-hundred ninety-three patients out of the 416 (94.5%) who were seropositive at month 1 and were tested at 3 months after vaccination remained seropositive. Between months 1 and 3 after vaccination, binding and neutralizing antibodies concentrations decreased significantly. The proportion of protected patients against the SARS-CoV-2 also slightly decreased. In conclusion, this study shows that although two-third of SOT develop anti-SARS-CoV-2 antibodies after three doses, one-third of them remain weak or non-protected. It is important to measure anti-SARS-CoV-2 antibodies to define the strategy that can optimize SOT protection against SARS-CoV-2.

Incidence of cytomegalovirus infection in seropositive kidney transplant recipients treated with everolimus: A randomized, open-label, multicenter phase 4 trial.

Cytomegalovirus (CMV) persists as the most frequent opportunistic infection among solid organ transplant recipients. This multicenter trial aimed to test whether treatment with everolimus (EVR) could decrease the incidence of CMV DNAemia and disease. We randomized 186 CMV seropositive kidney transplant recipients in a 1:1 ratio to receive EVR or mycophenolic acid (MPA) in association with basiliximab, cyclosporin, and steroids and 87 in each group were analyzed. No universal prophylaxis was administered to either group. The composite primary endpoint was the presence of CMV DNAemia, CMV treatment, graft loss, death, and discontinuation of the study at 6 months posttransplant. In the modified intent-to-treat analysis, 42 (48.3%) and 70 (80.5%) patients in the EVR and MPA groups reached the primary endpoint (OR = 0.21, 95% CI: 0.11-0.43, p < .0001). Fewer patients of the EVR group received treatment for CMV (21.8% vs. 47.1%, p = .0007). EVR was discontinued in 31 (35.6%) patients. Among the 56 patients with ongoing EVR treatment, only 7.4% received treatment for CMV. In conclusion, EVR prevents CMV DNAemia requiring treatment in seropositive recipients as long as it is tolerated and maintained.

Impact of calcineurin inhibitor-free immunosuppression on de novo donor-specific antibody formation in liver transplant recipients.

BACKGROUND & AIMS: Low calcineurin inhibitor (CNI) levels expose liver transplant recipients to rejection episodes and potentially to antibody-mediated rejection. There are little data on the impact of CNI-free immunosuppression on de novo donor-specific HLA antibody (dnDSA) development. Here we evaluated the prevalence of dnDSA in liver transplant recipients on CNI-free maintenance regimens and their associations with histopathological abnormalities of allografts. METHODS: Seven hundred and twenty-seven liver transplant recipients underwent a first liver transplant between 2000 and 2018 in three French transplant centres and had protocolized follow-up with dnDSA screening and allograft biopsy 1, 5 and 10 years after transplantation. RESULTS: CNIs were withdrawn in 166 (22.8%) patients with or without conversion to mammalian target of rapamycin inhibitors and/or maintenance with mycophenolic acid. DSA were present after withdrawal in 30.1% (50/166) patients on CNI-free immunosuppression compared with 16% (90/561) on CNI maintenance therapy (p < 0.001). The cumulative incidence of dnDSA 10 years after transplant was 20% in the CNI group versus 28% in the CNI-free group (p < 0.01). dnDSAs were associated with histological graft abnormalities (significant allograft fibrosis or rejection) (HR 2.24, 95% CI 1.2-4.1; p = 0.01). In univariate Cox regression analysis, being on a CNI-free regimen did not impact graft histology. CONCLUSIONS: Patients on a CNI-free IS regimen have a higher prevalence of dnDSA than patients on a standard IS regimen. dnDSAs but not CNI-free immunosuppression were associated with abnormal allograft histology.

Identification of Predictive Markers and Outcomes of Late-onset Pneumocystis jirovecii Pneumonia in Kidney Transplant Recipients.

BACKGROUND: In the era of prophylaxis, Pneumocystis pneumonia (PCP) has become a late-onset opportunistic infection requiring indications for prolonged prophylaxis to be defined. The primary objective of our study was therefore to evaluate risk factors associated with late-onset PCP. The secondary objective was to assess the impact of this infection on graft and patient survival. METHODS: We conducted a French case-control study in Bordeaux and Toulouse center by matching 1 case to 1-2 controls from the same center based on the transplant date and the type of induction treatment. RESULTS: Seventy cases and 134 controls were included. PCP occurred at a median of 3 years after transplantation. The total lymphocyte count and CD4+ and CD8+ T-lymphocyte values were lower in the cases than in their matched controls on the day of infection and annually up to 4 years earlier. The covariables independently associated with PCP were the total lymphocyte count 1 year before Pneumocystis, mTOR inhibitors used as maintenance immunosuppressive drugs, and the administration of corticosteroid boluses used in acute rejection. A total lymphocyte count threshold <1000/µL offered the best predictive value for infection occurrence. PCP was associated with high incidence of graft loss and patient death (30% and 17% respectively, 3 years after PCP). CONCLUSIONS: Pneumocystis pneumonia has dramatic consequences in kidney transplant recipients; a targeted prophylaxis based on simple criteria, such as chronic lymphopenia and/or history of corticosteroid boluses, could be useful to avoid life-threatening complications.

Adaptive lymphocyte profile analysis discriminates mild and severe forms of COVID-19 after solid organ transplantation.

Solid organ transplant recipients are at high risk for the development of severe forms of COVID-19. However, the role of immunosuppression in the morbidity and mortality of the immune phenotype during COVID-19 in transplant recipients remains unknown. In this retrospective study, we compared peripheral blood T and B cell functional and surface markers, as well as serum antibody development during 29 cases of mild (World Health Organization 9-point Ordinal Scale (WOS) of 3-4) and 22 cases of severe COVID-19 (WOS 5-8) in solid organ transplant (72% kidney transplant) recipients hospitalized in our center. Patients who developed severe forms of COVID-19 presented significantly lower CD3+ (median 344/mm3 (inter quartile range 197; 564) vs. 643/mm3 (397; 1251)) and CD8+ T cell counts (124/mm3 (76; 229) vs. 240/mm3 (119; 435)). However, activated CD4+ T cells were significantly more frequent in severe forms (2.9% (1.37; 5.72) vs. 1.4% (0.68; 2.35)), counterbalanced by a significantly higher proportion of Tregs (3.9% (2.35; 5.87) vs. 2.7% (1.9; 3.45)). A marked decrease in the proportion of NK cells was noted only in severe forms. In the B cell compartment, transitional B cells were significantly lower in severe forms (1.2% (0.7; 4.2) vs. 3.6% (2.1; 6.2)). Nonetheless, a majority of transplant recipients developed antibodies against SARS-CoV-2 (77% and 83% in mild and severe forms, respectively). Thus, our data revealed immunological differences between mild and severe forms of COVID-19 in solid organ transplant recipients, similar to previous reports in the immunocompetent population.

Do anti-IL-6R blockers have a beneficial effect in the treatment of antibody-mediated rejection resistant to standard therapy after kidney transplantation?

Antibody-mediated rejection (AMR) that resists to standard of care (SOC) therapy remains a major challenge after kidney transplantation and leads to graft failure in a majority of cases. The use of anti-IL6 receptor antibodies was suggested to treat chronic antibody-mediated rejection (cAMR) after failure of classical treatments. We treated nine patients with AMR resistant to apheresis, rituximab, and intravenous immunoglobulins, with a monthly infusion of tocilizumab and compared them with a historical cohort of 37 patients with similar clinical, immunological, and histological characteristics. The 1-year graft survival and the decline in renal function did not differ between patients who received tocilizumab and those who did not. Histological follow-up showed that despite a decrease in inflammation and tubulitis scores after tocilizumab, the course of antibody-mediated lesions and chronic glomerulopathy were similar in both groups. In our study, the addition of monthly infusions of tocilizumab did not alter the course of AMR that resist to SOC therapy. Large randomized studies are urgently needed to assess the effect of tocilizumab in this context.

Rituximab for recurrence of primary focal segmental glomerulosclerosis after kidney transplantation: Results of a nationwide study.

Rituximab (RTX) therapy for primary focal segmental glomerulosclerosis recurrence after kidney transplantation (KT) has been extensively debated. We aimed to assess the benefit of adding RTX to plasmapheresis (PP), corticosteroids, and calcineurin inhibitors (standard of care, SOC). We identified 148 adult patients who received KT in 12/2004-12/2018 at 21 French centers: 109 received SOC (Group 1, G1), and 39 received immediate RTX along with SOC (Group 2, G2). In G1, RTX was introduced after 28 days of SOC in the event of failure (G1a, n = 19) or PP withdrawal (G1b, n = 12). Complete remission (CR) was achieved in 46.6% of patients, and partial remission (PR) was achieved in 33.1%. The 10-year graft survival rates were 64.7% and 17.9% in responders and nonresponders, respectively. Propensity score analysis showed no difference in CR+PR rates between G1 (82.6%) and G2 (71.8%) (p = .08). Following the addition of RTX (G1a), 26.3% of patients had CR, and 31.6% had PR. The incidence of severe infections was similar between patients treated with and without RTX. In multivariable analysis, infection episodes were associated with hypogammaglobulinemia <5 g/L. RTX could be used in cases of SOC failure or remission for early discontinuation of PP without increasing the risk of infection.

Expression of Exhaustion Markers on CD8+ T-Cell Patterns Predict Outcomes in Septic Patients Admitted to the ICU.

RATIONALE: There is an unmet need to improve the description of the state of T-cell exhaustion in patients with sepsis, its reproducibility and correlation with the outcomes before including immunotherapy (like recombinant interleukin-7 or immune checkpoint inhibitors) in the therapeutic armamentarium against sepsis. DESIGN: Observational prospective study. SETTING: Two ICUs in a teaching hospital (France). PATIENTS: Eighty patients with sepsis admitted to the ICU. INTERVENTIONS: Quantification of CD4+ and CD8+ T-cell exhaustion at days 1 and 3. Quantification of the exhaustion markers (programmed death [PD]-1, 2B4, and cluster of differentiation [CD] 160) on T cells, the number of CD4+ regulatory T cells (CD3+ CD4+ CD25hi CD127Lo cells), and the phorbol myristate acetate/ionomycin/ionomycin-induced cytokines production (tumor necrosis factor-α, interleukin-2, and interferon-γ). MEASUREMENTS AND MAIN RESULTS: Using unsupervised clustering analysis, patients could be split in three clusters according to their dominant pattern expression of exhaustion markers on CD8+ T cells (i.e., 2B4lowPD-1lowCD160low, 2B4hiPD-1hiCD160low, and 2B4hiPD-1lowCD160hi) regardless of their underlying morbidities. Only 2B4hiPD-1hiCD160low CD8+ T cells had cytokine production defect, whereas 2B4hi PD-1lowCD160hi pattern correlated with cytokine overproduction. Patients with a predominant "highly activated" 2B4hiPD-1lowCD160hi pattern did not develop secondary bacterial infections. By multivariate analysis, Simplified Acute Physiology Score 2 gravity score at day 1 (p = 0.003) and patterns of exhaustion markers on CD8+ T cells (p = 0.03) were associated with the risk of death. Neither the level of CD4+ regulatory T cells nor the CD4+ exhaustion patterns were associated with the outcomes. CONCLUSIONS: Easy-to-use multicolor flow cytometry assessing 2B4, PD-1, and CD160 expression on CD8+ T cells at day 1 identifies septic patients with poor outcome and discriminates patient subsets in who immunomodulatory drugs should be tested.

High immunogenicity of a messenger RNA-based vaccine against SARS-CoV-2 in chronic dialysis patients.

BACKGROUND: Patients with chronic kidney disease, dialysis patients and kidney transplant patients are at high risk of developing severe coronavirus disease 2019 (COVID-19). Data regarding the immunogenicity of anti-severe acute respiratory syndrome coronavirus 2 messenger RNA (anti-SARS-CoV-2 mRNA) vaccines in dialysis patients were published recently. We assessed the immunogenicity of anti-SARS-CoV-2 mRNA vaccine in dialysis patients. PATIENTS AND METHODS: One hundred and nine patients on haemodialysis (n = 85) or peritoneal dialysis (n = 24) have received two injections of 30-µg doses of BNT162b2 mRNA COVID-19 vaccine (Pfizer-BioNTech) that were administered intramuscularly 28 days apart. Those who were still seronegative after the second dose were given a third dose 1 month later. Anti-SARS-CoV-2 antibodies were tested before and after vaccination. RESULTS: Ninety-one out of the 102 patients who had at least a 1-month follow-up after the second (n = 97) or the third (n = 5) vaccine doses had anti-SARS-CoV-2 antibodies. The seroconversion rate was 88.7% (86 out of 97 patients) among SARS-CoV-2 seronegative patients at the initiation of vaccination. Receiving immunosuppressive therapy was an independent predictive factor for non-response to vaccination. CONCLUSION: Due to high immunogenicity and safety of mRNA vaccines, we strongly recommend prioritizing a two-dose vaccination of dialysis patients. A third dose can be required in non-responders to two doses. When possible, patients waiting for a kidney transplantation should be offered the vaccine before transplantation.

Robotic-assisted kidney transplantation in obese recipients compared to non-obese recipients: the European experience.

PURPOSE: The main objective was to compare minor (Clavien I-II) and major (Clavien ≥ III) intra- and postoperative complications of living donor robotic assisted kidney transplantation (RAKT) in obese (≥ 30 kg/m2 BMI), overweight (< 30/ ≥ 25 kg/m2 BMI) and non-overweight recipients (< 25 kg/m2 BMI). METHODS: For the present retrospective study, we reviewed the multi-institutional ERUS-RAKT database to select consecutive living donor RAKT recipients. Functional outcomes, intra- and postoperative complications were compared between obese, overweight and non-overweight recipients. RESULTS: 169 living donor RAKTs were performed, by 10 surgeons, from July 2015 to September 2018 in the 8 European centers. 32 (18.9%) recipients were obese, 66 (39.1%) were overweight and 71 (42.0%) were non-overweight. Mean follow-up was 1.2 years. There were no major intra-operative complications in either study group. Conversion to open surgery occurred in 1 obese recipient, in 2 overweight recipients and no conversion occurred in non-overweight recipients (p = 0.3). Minor and major postoperative complications rates were similar in the 3 groups. At one-year of follow-up, median eGFR was similar in all groups [54 (45-60) versus 57 (46-70) versus 63 (49-78) ml/min/1.73 m2 in obese, overweight and non-overweight recipient groups, respectively, p = 0.5]. Delayed graft function rate was similar in the 3 groups. Only the number of arteries was an independent predictive factor of suboptimal renal function at post-operative day 30 in the multivariate analysis. CONCLUSION: RAKT in obese recipients is safe, compared to non-overweight recipients and yields very good function, when it performed at high-volume referral centers by highly trained transplant teams.

Comparison of two strategies based on mammalian target of rapamycin inhibitors in secondary prevention of non-melanoma skin cancer after kidney transplantation, a pilot study.

After kidney transplantation, withdrawal of calcineurin inhibitors (CNI) and conversion to sirolimus (SRL) may reduce the occurrence of new non-melanoma skin cancer (NMSC). Conversely, a reduced CNI exposure with everolimus (EVR) is an alternative strategy that has not been thoroughly evaluated. We retrospectively compared the occurrence of newly diagnosed NMSCs in two cohorts of kidney transplant recipients (KTR) with at least one NMSC: 35 patients were converted to EVR with reduced CNI exposure (CNI/EVR group), whereas 46 patients were converted to SRL in association with mycophenolic acid (MPA) (SRL/MPA group). Two years after conversion, survival free of new NMSC was similar between the two cohorts (p = .37), with 19 KTR (54.3%) in the CNI/EVR group and 22 (47.8%) in the SRL/MPA group being diagnosed of at least one new NMSC. Half of the KTR from both groups showed adverse events, leading to mTORi discontinuation for 37.1% of KTR in the CNI/EVR group and 21.7% in the SRL/MPA group (p = .09). The incidence of rejections was similar between the two groups. In a retrospective cohort of KTR with at least one post-transplant NMSC, the outcome of the patients converted to a CNI/EVR regimen was not different from those converted to a SRL/MPA regimen.

Management of anastomotic biliary stricture after liver transplantation and impact on survival.

BACKGROUND: Anastomotic biliary strictures (AS) is the main surgical complication after liver transplantation. The aims of this study are to investigate the risk factors of AS, its management and its impact on overall survival and survival of the graft. METHODS: All patients who had received a liver transplantation with duct-to-duct anastomosis at Toulouse University Hospital between 2010 and 2016 were included. RESULTS: Of 225 included patients, 56 (24.9%) presented with AS. The median time to discovery of AS was 83 days and 69.6% of the AS appeared within 6 months. Transplantation in critically ill patients, with a liver score >800 points, was an independent predictive factor of survival (P = 0.003). The first-line treatment was endoscopic (87.5%), with a success rate of 79.6% and a median of 4 procedures per patient in 12 months. In cases of failure of endoscopic therapy, percutaneous treatment had a high failure rate (50%). AS had no impact in terms of overall survival or in terms of graft survival. CONCLUSION: AS do not have any repercussions on patient or graft survival, requiring long endoscopic treatment with multiple procedures. In the event of failure of this first-line endoscopic treatment, it seems preferable to turn directly towards surgical repair.