Therapeutic monoclonal antibodies have been successful in protecting vulnerable populations against SARS-CoV-2. However, their effectiveness has been hampered by the emergence of new variants. To adapt the therapeutic landscape, health authorities have based their recommendations mostly on in vitro neutralization tests. However, these do not provide a reliable understanding of the changes in the dose-effect relationship and how they may translate into clinical efficacy. Taking the example of EvusheldTM (AZD7442), we aimed to investigate how in vivo data can provide critical quantitative results and project clinical effectiveness. We used the Golden Syrian hamster model to estimate 90â¯% effective concentrations (EC90) of AZD7442 in vivo against SARS-CoV-2 Omicron BA.1, BA.2 and BA.5 variants. While our in vivo results confirmed the partial loss of AZD7442 activity for BA.1 and BA.2, they showed a much greater loss of efficacy against BA.5 than that obtained in vitro. We analyzed in vivo EC90s in perspective with antibody levels measured in a cohort of immunocompromised patients who received 300â¯mg of AZD7442. We found that a substantial proportion of patients had serum levels of anti-SARS-CoV-2 spike protein IgG above the estimated in vivo EC90 for BA.1 and BA.2 (21â¯% and 92â¯% after 1 month, respectively), but not for BA.5. These findings suggest that AZD7442 is likely to retain clinical efficacy against BA.2 and BA.1, but not against BA.5. Overall, the present study illustrates the importance of complementing in vitro investigations by preclinical studies in animal models to help predict the efficacy of monoclonal antibodies in humans.
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.
Introduction: Pre-emptive access to the kidney transplant (KT) waiting list remains limited in France, with only 3.9% of patients on pre-emptive KT and 5.6% of patients registered at the time of initiation of dialysis. A similar trend was observed in Aquitaine. The aim of this study was to assess the impact of a regional program in terms of access to the waiting list for patients initiating a kidney replacement therapy (KRT). Methods: We included all patients assessed for registration on the list between 2017 and 2020, 2017 being the reference year and 2018 the beginning of the program. Using the CRISTAL and REIN registries, we assessed changes in the number of patients on the list at the time of initiation of dialysis or transplantation. Results: The number of new assessed candidates increased gradually each year from 255 in 2017 to 352 in 2020 (+38%). The number of patients on the list sharply increased in 2018 from 229 in 2017 to 319 in 2018 (+39.3%) and then remained stable. At the initiation of KRT, the proportion of patients registered on the waiting list increased gradually from 7.1% in 2017 to 18.2% in 2020. The proportion of pre-emptive KT remained stable between 2017 and 2021 (around 7%) with a decrease in 2020 (4.6%). Approximately 60% of patients had a contraindication to transplantation throughout the study. Conclusion: This study showed that a regional program aimed at providing better information to healthcare professionals and patients and encouraging rapid assessment of transplant candidates could increase the rate of pre-emptive registration on the KT waiting list for eligible patients over 4 years.
Introduction: L'accès préemptif à la liste d'attente de transplantation rénale (TR) reste limité en France, avec seulement 3,9 % de TR préemptives et 5,6 % de patients inscrits lors de l'initiation de la dialyse. Une tendance similaire était observée en Aquitaine. L'objectif de cette étude était d'évaluer l'impact d'un programme régional en termes d'accès à la liste d'attente chez les patients débutant un traitement de suppléance. Méthodes: Nous avons inclus l'ensemble des patients évalués pour une inscription sur liste entre 2017 et 2020, 2017 étant l'année de référence et 2018 l'année de début du programme régional. Nous avons évalué de façon annuelle, grâce aux registres CRISTAL et REIN, l'évolution du nombre de patients inscrits sur liste lors de l'initiation du traitement de suppléance par dialyse ou transplantation. Résultats: Le nombre de nouveaux candidats évalués a augmenté graduellement chaque année, passant de 255 en 2017 à 352 en 2020 (+ 38 %). Le nombre de patients inscrits sur la liste a fortement augmenté en 2018 passant de 229 en 2017 à 319 en 2018 (+39,3 %), puis est resté stable. À l'initiation du traitement de suppléance, la proportion de patients inscrits a augmenté graduellement passant de 7,1 % en 2017 à 18,2 % en 2020. La proportion de TR préemptive est restée stable entre 2017 et 2021 (environ 7 %) avec une baisse en 2020 (4,6 %). Environ 60 % des patients présentaient une contre-indication à la transplantation tout au long de cette étude. Conclusion: Cette étude a montré qu'un programme régional visant à mieux informer les professionnels de santé et les patients et favorisant l'évaluation rapide des candidats à la greffe permet d'augmenter en 4 ans le taux d'inscription préemptive sur liste d'attente de TR chez les patients éligibles.
Nirmatrelvir/ritonavir is a promising option for preventing severe COVID-19 in solid organ transplant recipients with SARS-CoV-2 infection. However, concerns have arisen regarding potential drug interactions with calcineurin inhibitors (CNI). This two-phase multicentre retrospective study, involving 113 patients on tacrolimus and 13 on cyclosporine A, aimed to assess the feasibility and outcomes of recommendations issued by The French societies of transplantation (SFT) and pharmacology (SFPT) for CNI management in this context. The study first evaluated adherence to recommendations, CNI exposure, and clinical outcomes. Notably, 96.5% of patients on tacrolimus adhered to the recommendations, maintaining stable tacrolimus trough concentrations (C0) during nirmatrelvir/ritonavir treatment. After reintroduction, most patients experienced increased C0, with 42.9% surpassing 15 ng/mL, including three patients exceeding 40 ng/mL. Similar trends were observed in cyclosporine A patients, with no COVID-19-related hospitalizations. Moreover, data from 22 patients were used to refine the reintroduction strategy. Modelling analyses suggested reintroducing tacrolimus at 50% of the initial dose on day 8, and then at 100% from day 9 as the optimal approach. In conclusion, the current strategy effectively maintains consistent tacrolimus exposure during nirmatrelvir/ritonavir treatment, and a stepwise reintroduction of tacrolimus may be better suited to the low CYP3A recovery.
COVID-19 , Lactams , Leucine , Nitriles , Organ Transplantation , Proline , Humans , Tacrolimus , Cyclosporine/therapeutic use , Ritonavir/therapeutic use , Ritonavir/pharmacology , Retrospective Studies , COVID-19 Drug Treatment , SARS-CoV-2 , Immunosuppressive Agents , Calcineurin Inhibitors/therapeutic use , Transplant Recipients , Antiviral Agents/therapeutic use
There is an unmet need for robust and clinically validated biomarkers of kidney allograft rejection. Here we present the KTD-Innov study (ClinicalTrials.gov, NCT03582436), an unselected deeply phenotyped cohort of kidney transplant recipients with a holistic approach to validate the clinical utility of precision diagnostic biomarkers. In 2018-2019, we prospectively enrolled consecutive adult patients who received a kidney allograft at seven French centers and followed them for a year. We performed multimodal phenotyping at follow-up visits, by collecting clinical, biological, immunological, and histological parameters, and analyzing a panel of 147 blood, urinary and kidney tissue biomarkers. The primary outcome was allograft rejection, assessed at each visit according to the international Banff 2019 classification. We evaluated the representativeness of participants by comparing them with patients from French, European, and American transplant programs transplanted during the same period. A total of 733 kidney transplant recipients (64.1% male and 35.9% female) were included during the study. The median follow-up after transplantation was 12.3 months (interquartile range, 11.9-13.1 months). The cumulative incidence of rejection was 9.7% at one year post-transplant. We developed a distributed and secured data repository in compliance with the general data protection regulation. We established a multimodal biomarker biobank of 16,736 samples, including 9331 blood, 4425 urinary and 2980 kidney tissue samples, managed and secured in a collaborative network involving 7 clinical centers, 4 analytical platforms and 2 industrial partners. Patients' characteristics, immune profiles and treatments closely resembled those of 41,238 French, European and American kidney transplant recipients. The KTD-Innov study is a unique holistic and multidimensional biomarker validation cohort of kidney transplant recipients representative of the real-world transplant population. Future findings from this cohort are likely to be robust and generalizable.
OBJECTIVE: Frailty has been extensively studied in end-stage kidney disease (ESKD) and kidney transplant (KT) patients. The identification of frailty is useful to predict adverse outcomes among ESKD and KT patients. The recent concept of intrinsic capacity (IC) appears as a good and easy-to-understand tool to screen for and monitor frailty in older adults with ESKD. This study aims to assess the relationships between frailty and IC in older adults with ESKD awaiting KT. DESIGN: Cross-sectional study SETTING AND PARTICIPANTS: 236 patients from a day-care geriatric unit undergoing pre-KT geriatric assessment between 2017 and 2022 were included in the main sample, and 151 patients in an independent multicentric replication sample. MEASUREMENTS: Frailty was evaluated using the physical frailty phenotype (PFP) and IC measures using the World Health Organization's screening (step 1) and diagnostic (step 2) tools for five IC domains (vitality, locomotion, audition, cognition, psychology). Multivariate regressions were run to assess relationships between PFP and IC domains, adjusted for age, sex, and comorbidities. Analyses were replicated using another independent multicenter cohort including 151 patients with ESKD to confirm the results. RESULTS: Impairments in the locomotion, psychology, and vitality IC domains according to WHO screening tools were associated with frailty (odds ratio 9.62 [95% CI 4.09-24.99], 3.19 [95% CI 1.11-8.88], and 3.11 [95% CI 1.32-7.29], respectively). When IC were measured linearly with z-scores, all IC domains except hearing were inversely associated with frailty. In the replication cohort, results were overall similar, with a greater association between psychology domain and frailty. CONCLUSION: This study highlights the relationship between frailty and IC in ESKD patients. We assume that IC may be assessed and monitored in ESKD patients, to predict and prevent future frailty, and post-KT adverse outcomes.
Frailty , Geriatric Assessment , Kidney Failure, Chronic , Kidney Transplantation , Humans , Male , Female , Kidney Failure, Chronic/surgery , Kidney Failure, Chronic/complications , Aged , Frailty/complications , Cross-Sectional Studies , Geriatric Assessment/methods , Frail Elderly , Middle Aged , Aged, 80 and over
Cytomegalovirus (CMV) infection is associated with poor kidney transplant outcomes. While innate and adaptive immune cells have been implicated in its prevention, an in-depth characterization of the in vivo kinetics of multiple cell subsets and their role in protecting against CMV infection has not been achieved. Here, we performed high-dimensional immune phenotyping by mass cytometry, and functional assays, on 112 serially collected samples from CMV seropositive kidney transplant recipients. Advanced unsupervised deep learning analysis was used to assess immune cell populations that significantly correlated with prevention against CMV infection and anti-viral immune function. Prior to infection, kidney transplant recipients who developed CMV infection showed significantly lower CMV-specific cell-mediated immune (CMI) frequencies than those that did not. A broad diversity of circulating cell subsets within innate and adaptive immune compartments were associated with CMV infection or protective CMV-specific CMI. While percentages of CMV (tetramer-stained)-specific T cells associated with high CMI responses and clinical protection, circulating CD3+CD8midCD56+ NK-T cells overall strongly associated with low CMI and subsequent infection. However, three NK-T cell subsets sharing the CD11b surface marker associated with CMV protection and correlated with strong anti-viral CMI frequencies in vitro. These data were validated in two external independent cohorts of kidney transplant recipients. Thus, we newly describe the kinetics of a novel NK-T cell subset that may have a protective role in post-transplantation CMV infection. Our findings pave the way to more mechanistic studies aimed at understanding the function of these cells in protection against CMV infection.
The clinical impact of individual dose adjustment of mycophenolate mofetil is still debated, due to conflicting results from randomized clinical trials. This retrospective study aimed to compare 3-year rejection-free survival and adverse effects between adult kidney transplant recipients (KTRs) with or without mycophenolate mofetil model-informed precision dosing (MIPD). MIPD is defined here as mycophenolic acid area under the curve (AUC0-12h ) estimation using a limited sampling strategy, pharmacokinetic models and Bayesian estimators; dose recommendation to reach AUC0-12h = 45 mg.h/L; using a widely used online expert system. The study, nested in two multicenter prospective cohort studies, focused on patients who received a mycophenolate drug and were followed up for 1-3 years. Mycophenolate mofetil MIPD was prescribed as per local practice, on a regular basis, when deemed necessary, or not at all. The MIPD group included 341 KTRs and the control group 392. At 3 years, rejection-free survival was respectively 91.2% and 80.6% (P < 0.001) and the cumulative incidence of rejection 5.08% vs. 12.7% per patient × year (hazard ratio = 0.49 (0.34, 0.71), P < 0.001), corresponding to a 2.5-fold reduction. Significant association with rejection-free survival was confirmed in patients at low or high risk of rejection (P = 0.017 and 0.013) and in patients on tacrolimus, but not on cyclosporine (P < 0.001 and 0.205). The mycophenolate mofetil MIPD group had significantly more adverse effects, but most occurred before the first AUC0-12h , suggesting some may be the reason why MIPD was ordered.
In 2023, significant advances were made in various areas of kidney transplantation. Firstly, the use of a balanced crystalloid solution in the recipient appears to prevent the delay in graft function, unlike hypothermia in the donor and normothermic pulsatile perfusion. Understanding the pathophysiology of humoral rejection has progressed, highlighting the major role of HLA class II molecules and innate immune cells (NK and monocytes expressing FCGR3A). An automatic Banff classification algorithm has been developed to better categorize biopsies in currently known diagnoses. CXCL10, combined with other variables, seems effective in ruling out rejection, but its role in routine care is yet to be defined. Regarding cytomegalovirus (CMV), letermovir has been proven effective in preventing CMV disease in D+R- patients, with fewer hematological side effects. For R+ patients, monitoring CMV-specific T-cell immunity is suggested to reduce the duration of antiviral prophylaxis. The only innovation in immunosuppression is imlifidase for highly sensitized patients, guided by French recommendations. A new equation for glomerular filtration rate measurement has been developed for kidney transplant recipients, performing well across various analyzed stratifications. Finally, xenotransplantation is making a comeback this year, generating hope. However, the description of early humoral rejections involving innate immune cells indicates that adjustments are still needed before considering its widespread deployment.
L'année 2023 a connu des avancées significatives dans plusieurs domaines en transplantation rénale. En premier lieu, l'utilisation d'une solution cristalloïde balancée chez le receveur semble jouer un rôle préventif sur le retard de reprise de fonction contrairement à l'hypothermie chez le donneur et la perfusion pulsatile normothermique. La compréhension de la physiopathologie du rejet humoral a aussi progressé : l'expression des molécules HLA de classe II semble jouer un rôle majeur, ainsi que les cellules immunitaires innées (NK et monocytes exprimant le FCGR3A). Un algorithme de classification automatique de Banff a été mis au point pour aider à mieux classer les biopsies dans les diagnostics actuellement connus. Le CXCL10 couplé à d'autres variables d'intérêt semble être performant pour écarter un diagnostic de rejet, mais sa place dans le soin courant reste à définir. En ce qui concerne le cytomégalovirus (CMV), le letermovir a fait la preuve de son efficacité dans la prévention de la maladie chez les patients D+R-, avec moins d'effets indésirables hématologiques. Chez les R+, la surveillance de l'immunité cellulaire T spécifique du CMV est proposée pour diminuer la durée de la prophylaxie antivirale. La seule nouveauté en immunosuppression est l'imlifidase pour les patients hyperimmunisés, avec une utilisation encadrée par des recommandations françaises. Une nouvelle équation de mesure du débit de filtration glomérulaire (DFG) a été développée chez le transplanté rénal, fonctionnant bien quelles que soient les stratifications analysées. Enfin, la xénotransplantation revient sur le devant de la scène cette année en suscitant beaucoup d'espoir. Néanmoins, la description de rejets humoraux précoces impliquant des cellules innées montre que des ajustements sont encore nécessaires avant d'envisager son déploiement.
Cytomegalovirus Infections , Kidney Transplantation , Humans , Kidney Transplantation/adverse effects , Antiviral Agents/therapeutic use , Cytomegalovirus Infections/drug therapy , Cytomegalovirus , Immunosuppressive Agents/therapeutic use , Graft Rejection/prevention & control
BACKGROUND: While opportunistic infections are a frequent and challenging problem in kidney transplant recipients, their long-term epidemiology remains hardly known. METHODS: Opportunistic infections were recorded in 1144 recipients transplanted in our center between 2004 and 2015. Incidence rates and baseline risk factors were determined using joint frailty models. RESULTS: After a median follow-up of 5.6 years, 544 opportunistic infections occurred in 373/1144 (33%) patients, dominated by viral infections (396/544, 72%), especially cytomegalovirus (CMV) syndromes and diseases (213/544, 39%). One-third of the infected patients experienced at least two opportunistic infections. The incidence of opportunistic infections was 10 times higher during the first year post-transplantation than after that (34.7 infections for 100 patient-years vs 3.64). Opportunistic infections associated with the age of the donor (P = .032), the age of the recipient (P = .049), the CMV serostatus (P < 10-6), a higher class II HLA mismatch (P = .032) and an induction treatment including rabbit anti-thymocyte globulins (P = .026). Repeated opportunistic infections associated with each other (P < 10-6) and with renal death (P < 10-6). CONCLUSION: Opportunistic infections occur with a two-period incidence pattern and many susceptible patients suffer from repeated episodes. This knowledge may help tailor new prevention and follow-up strategies to reduce the burden of opportunistic infections and their impact on transplantation outcome.
Cytomegalovirus Infections , Kidney Transplantation , Opportunistic Infections , Humans , Cytomegalovirus Infections/drug therapy , Antiviral Agents/therapeutic use , Kidney Transplantation/adverse effects , Retrospective Studies , Risk Factors , Cytomegalovirus , Opportunistic Infections/etiology , Transplant Recipients
T-cell mediated rejection (TCMR), de novo anti-HLA donor-specific antibodies (dnDSAs) and ensuing antibody-mediated rejection (ABMR) reduce kidney transplantation (KT) survival. The immunomodulatory effects of 25-hydroxyvitamin D [25(OH)D] could be beneficial for KT outcomes. We aimed to evaluating the association between 25(OH)D levels, the development of dnDSAs, clinical TCMR and ABMR, and graft survival. This single center retrospective study included 253 KT recipients (KTRs) transplanted without preformed DSA between 2010 and 2013. We measured 25(OH)D in successive serum samples: at KT (M0) and M12 for the entire cohort, and additionally at M24 and/or M36 when sera were available. We assessed graft outcomes up to 5 years post-KT. The proportion of KTRs having sufficient 25(OH)D at KT (M0) was high (81.4%) and then dropped at M12 (71.1%). KTRs with sufficient 25(OH)D at M0 experienced less clinical TCMR (HR, 0.41; 95% CI, 0.19-0.88 in multivariate analysis). A sufficient 25(OH)D at M12 was independently associated with a longer dnDSA-free survival (HR, 0.34; 95% CI, 0.17-0.69). There was no association between 25(OH)D and clinical AMBR. Studying the KTRs with 25(OH)D measurements at M12, M24 and M36 (n = 203), we showed that 25(OH)D sufficiency over the 3 first-years post-KT was associated with a longer graft survival in multivariate analyses (HR, 0.39; 95% CI, 0.22-0.70). To our knowledge, this study is the first showing an association between 25(OH)D sufficiency post-KT and dnDSA occurrence in KTRs. Moreover, we reinforce previously published data showing an association between 25(OH)D, TCMR and graft survival in KT.
Kidney Transplantation , Vitamin D/analogs & derivatives , Humans , Retrospective Studies , Risk Factors , HLA Antigens , Alleles , Antibodies , Graft Rejection , Isoantibodies
Bariatric surgery is routinely proposed to patients suffering from obesity including kidney transplant recipients. In this specific population, bariatric surgery has a positive impact in long-term outcomes in terms of patient and graft survival. We report here the cases of 4 patients with five post-kidney transplantation bariatric surgeries who experimented acute renal injury early after surgery. Creatinine rising occurred between day 14 and day 20 after surgery. In all cases, it was due to dehydration leading to a pre-renal acute renal failure. The specific care of kidney transplanted patients is discussed: single kidney associated with pre-existing altered kidney function associated with concomitant use of nephrotoxic drugs. Specific education intervention before surgery associated with careful early management of hydration after surgery is mandatory for these patients.
Acute Kidney Injury , Bariatric Surgery , Kidney Transplantation , Humans , Kidney Transplantation/adverse effects , Kidney , Bariatric Surgery/adverse effects , Obesity/complications , Acute Kidney Injury/complications
Our objective was to calculate an immunosuppressant possession ratio (IPR) to diagnose non-adherence at the time of antibody-mediated rejection (ABMR). IPR was defined as the ratio of number of pills collected at the pharmacy to the number of pills prescribed over a defined period. In a first cohort of 91 kidney transplant recipients (KTRs), those with an IPR < 90% had more frequently a tacrolimus through level coefficient of variation >30% than patients with an IPR = 100% (66.7% vs. 29.4%, p = 0.05). In a case-control study, 26 KTRs with ABMR had lower 6 months IPRs than 26 controls (76% vs. 99%, p < 0.001). In KTRs with ABMR, non-adherence was more often diagnosed by a 6 months IPR < 90% than by clinical suspicion (73.1% vs 30.8%, p = 0.02). In the multivariable analysis, only de novo DSA and 6 months IPR < 90% were independently associated with ABMR, whereas clinical suspicion was not (odds ratio, 4.73; 95% CI, 1.17-21.88; p = 0.03; and odds ratio, 6.34; 95% CI, 1.73-25.59; p = 0.007, respectively). In summary, IPR < 90% is a quantifiable tool to measure immunosuppressant non-adherence. It is better associated with ABMR than clinical suspicion of non-adherence.
Immunosuppressive Agents , Kidney Transplantation , Humans , Immunosuppressive Agents/therapeutic use , Case-Control Studies , Pharmacists , Antibodies , Graft Rejection/prevention & control , Graft Rejection/diagnosis , Isoantibodies
Given the risk of rejection, the presence of preformed donor specific antibodies (DSA) contraindicates transplantation in most allocation systems. However, HLA-Cw and -DP DSA escape this censorship. We performed a multicentric observational study, in which the objective was to determinate risk factors of acute antibody-mediated rejection (aABMR) in recipients transplanted with preformed isolated Cw- or DP-DSA. Between 2010 and 2019, 183 patients were transplanted with a preformed isolated Cw- or DP-DSA (92 Cw-DSA; 91 DP-DSA). At 2 years, the incidence of aABMR was 12% in the Cw-DSA group, versus 28% in the DP-DSA group. Using multivariable Cox regression model, the presence of a preformed DP-DSA was associated with an increased risk of aABMR (HR = 2.32 [1.21-4.45 (p = 0.001)]) compared with Cw-DSA. We also observed a significant association between the DSA's MFI on the day of transplant and the risk of aABMR (HR = 1.09 [1.08-1.18], p = 0.032), whatever the DSA was. Interaction term analysis found an increased risk of aABMR in the DP-DSA group compared with Cw-DSA, but only for MFI below 3,000. These results may plead for taking these antibodies into account in the allocation algorithms, in the same way as other DSA.
Kidney Transplantation , Humans , Antibodies , Graft Rejection , Graft Survival , Histocompatibility Testing , HLA Antigens , Kidney Transplantation/adverse effects , Tissue Donors
Utilizing assays that assess specific T-cell-mediated immunity against cytomegalovirus (CMV) holds the potential to enhance personalized strategies aimed at preventing and treating CMV in organ transplantation. This includes improved risk stratification during transplantation compared to relying solely on CMV serostatus, as well as determining the optimal duration of antiviral prophylaxis, deciding on antiviral therapy when asymptomatic replication occurs, and estimating the risk of recurrence. In this review, we initially provide an overlook of the current concepts into the immune control of CMV after transplantation. We then summarize the existent literature on the clinical experience of the use of immune monitoring in organ transplantation, with a particular interest on the outcomes of interventional trials. Current evidence indicates that cell-mediated immune assays are helpful in identifying patients at low risk for replication for whom preventive measures against CMV can be safely withheld. As more data accumulates from these and other clinical scenarios, it is foreseeable that these assays will likely become part of the routine clinical practice in organ transplantation.
Cytomegalovirus Infections , Organ Transplantation , Humans , Cytomegalovirus , Cytomegalovirus Infections/drug therapy , Antiviral Agents/therapeutic use , Immunity, Cellular
The impact of immunosuppressive therapy (IS) strategies after kidney transplant failure (KTF) on potential future new grafts is poorly established. We assessed the potential benefit of calcineurin inhibitor (CNI)-based IS maintenance throughout the dialysis period on the outcome of the second kidney transplant (KT). We identified 407 patients who underwent a second KT between January 2008 and December 2018 at four French KT centers. Inverse probability of treatment weighting was used to control for potential confounding. We included 205 patients with similar baseline characteristics at KTF: a total of 53 received at least CNIs on the retransplant day (G-CNI), and 152 did not receive any IS (G-STOP). On the retransplant date, G-STOP patients experienced a longer pretransplant dialysis time, were more often hyperimmunized, and underwent more expanded-criteria donor KTs than G-CNI patients. During the second KT follow-up period, rejection episodes were similar in both groups. The 10-year survival rates without death and dialysis were 98.7% and 59.5% in G-CNI and G-STOP patients, respectively. In the multivariable analysis, CNI-based IS maintenance was associated with better survival (hazard ratio: 0.08; 95% confidence interval: 0.01-0.58, p = 0.01). CNI-based IS maintenance throughout the dialysis period after KTF may improve retransplantation outcomes.
Kidney Diseases , Kidney Transplantation , Humans , Calcineurin Inhibitors/therapeutic use , Immunosuppressive Agents/therapeutic use , Immunosuppressive Agents/pharmacology , Propensity Score , Graft Rejection/prevention & control , Renal Dialysis , Kidney , Immunosuppression Therapy , Graft Survival
Imlifidase recently received early access authorization for highly sensitized adult kidney transplant candidates with a positive crossmatch against an ABO-compatible deceased donor. These French consensus guidelines have been generated by an expert working group, in order to homogenize patient selection, associated treatments and follow-up. This initiative is part of an international effort to analyze properly the benefits and tolerance of this new costly treatment in real-life. Eligible patients must meet the following screening criteria: cPRA ≥ 98%, ≤ 65-year of age, ≥ 3 years on the waiting list, and a low risk of biopsy-related complications. The final decision to use Imlifidase will be based on the two following criteria. First, the results of a virtual crossmatch on recent serum, which shall show a MFI for the immunodominant donor-specific antibodies (DSA) > 6,000 but the value of which does not exceed 5,000 after 1:10 dilution. Second, the post-Imlifidase complement-dependent cytotoxicity crossmatch must be negative. Patients treated with Imlifidase will receive an immunosuppressive regimen based on steroids, rATG, high dose IVIg, rituximab, tacrolimus and mycophenolic acid. Frequent post-transplant testing for DSA and systematic surveillance kidney biopsies are highly recommended to monitor post-transplant DSA rebound and subclinical rejection.
Kidney Transplantation , Adult , Humans , Child, Preschool , Kidney Transplantation/methods , Histocompatibility Testing/methods , HLA Antigens , Graft Rejection/prevention & control , Immunosuppressive Agents/therapeutic use , Antibodies , Isoantibodies
For three decades, the international Banff classification has been the gold standard for kidney allograft rejection diagnosis, but this system has become complex over time with the integration of multimodal data and rules, leading to misclassifications that can have deleterious therapeutic consequences for patients. To improve diagnosis, we developed a decision-support system, based on an algorithm covering all classification rules and diagnostic scenarios, that automatically assigns kidney allograft diagnoses. We then tested its ability to reclassify rejection diagnoses for adult and pediatric kidney transplant recipients in three international multicentric cohorts and two large prospective clinical trials, including 4,409 biopsies from 3,054 patients (62.05% male and 37.95% female) followed in 20 transplant referral centers in Europe and North America. In the adult kidney transplant population, the Banff Automation System reclassified 83 out of 279 (29.75%) antibody-mediated rejection cases and 57 out of 105 (54.29%) T cell-mediated rejection cases, whereas 237 out of 3,239 (7.32%) biopsies diagnosed as non-rejection by pathologists were reclassified as rejection. In the pediatric population, the reclassification rates were 8 out of 26 (30.77%) for antibody-mediated rejection and 12 out of 39 (30.77%) for T cell-mediated rejection. Finally, we found that reclassification of the initial diagnoses by the Banff Automation System was associated with an improved risk stratification of long-term allograft outcomes. This study demonstrates the potential of an automated histological classification to improve transplant patient care by correcting diagnostic errors and standardizing allograft rejection diagnoses.ClinicalTrials.gov registration: NCT05306795 .
Kidney Transplantation , Kidney , Adult , Humans , Male , Female , Child , Prospective Studies , Kidney/pathology , Kidney Transplantation/adverse effects , Transplantation, Homologous , Allografts , Graft Rejection/diagnosis , Biopsy
