Search

Supplemental Digital Content is available in the text., Background. Data on severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) seroprevalence in kidney transplant recipients (KTRs) remain rare. We sought to shed further light on this issue by conducting a single-center study in a kidney transplant center located in one of the France’s highest risk zone (Grand Est) for coronavirus disease 2019 (Covid-19) during the initial disease outbreak. Methods. To this aim, we used a survey approach coupled with systematic investigation of SARS-CoV-2 serology in a cohort of 1390 KTRs. Results. SARS-CoV-2 serologies were available for 780 survey respondents, among whom 48 had anti-SARS-CoV-2 antibodies (total seroprevalence: 6.2%). Thirty-five of the 48 seropositive KTRs had previously received a diagnosis of Covid-19, whereas the remaining 13 patients were not known to be infected (8 asymptomatic cases). Specifically, 18.7% of seropositive KTRs and 1.1% of the entire cohort were asymptomatic. Household exposure was found to markedly increase the risk of SARS-CoV-2 transmission. Conclusions. Our findings demonstrate that the overall SARS-CoV-2 seroprevalence in KTRs living in one of the France’s highest risk zone for Covid-19 during the first French lockdown was as low as 6.3%. Rapid and strict implementation of protective measures could have significantly mitigated virus spread even in an area of high virus circulation.

ObjectiveThis single-center retrospective study evaluated the use of tixagevimab-cilgavimab as an early treatment for COVID-19 in kidney transplant recipients (KTRs) during the omicron wave.MethodsKTRs were deemed at high risk for moderate-to-severe COVID-19 in presence of at least one comorbidity (age >60 years, diabetes, obesity, or cardiovascular disease) associated with a weak humoral response (ResultsOf the 61 KTRs at high risk, 26 received tixagevimab-cilgavimab. COVID-19-related hospitalizations (3.8% versus 34%, p=0.006) and oxygen need (3.8% versus 23%, p=0.04) were significantly less frequent in patients who received tixagevimab-cilgavimab. In addition, non-significant trends towards a lower number of ICU admissions (3.8% versus 14.3% p=0.17) and deaths (0 versus 3, p=0.13) were observed after administration of tixagevimab-cilgavimab. Ten of the 73 low-risk KTRs received tixagevimab-cilgavimab, and no significant clinical benefit was observed in this subgroup.ConclusionEarly administration of tixagevimab-cilgavimab may be clinically useful in high-risk KTRs with COVID-19; however, no major benefit was observed for low-risk patients.

Transplant recipients, who receive therapeutic immunosuppression to prevent graft rejection, are characterized by high coronavirus disease 2019 (COVID-19)–related mortality and defective response to vaccines. We observed that previous infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), but not the standard two-dose regimen of vaccination, provided protection against symptomatic COVID-19 in kidney transplant recipients. We therefore compared the cellular and humoral immune responses of these two groups of patients. Neutralizing anti–receptor-binding domain (RBD) immunoglobulin G (IgG) antibodies were identified as the primary correlate of protection for transplant recipients. Analysis of virus-specific B and T cell responses suggested that the generation of neutralizing anti-RBD IgG may have depended on cognate T-B cell interactions that took place in germinal center, potentially acting as a limiting checkpoint. High-dose mycophenolate mofetil, an immunosuppressive drug, was associated with fewer antigen-specific B and T follicular helper (TFH) cells after vaccination; this was not observed in patients recently infected with SARS-CoV-2. Last, we observed that, in two independent prospective cohorts, administration of a third dose of SARS-CoV-2 mRNA vaccine restored neutralizing titers of anti-RBD IgG in about 40% of individuals who had not previously responded to two doses of vaccine. Together, these findings suggest that a third dose of SARS-CoV-2 mRNA vaccine improves the RBD-specific responses of transplant patients treated with immunosuppressive drugs.

A recent study demonstrated that a single dose of a severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) mRNA-based vaccine is sufficient to mount a robust immunological response in immunocompetent subjects with a previous history of coronavirus disease 2019 (COVID-19).1,2 While research has suggested that immunocompromised kidney transplant recipients (KTRs) who received mRNA-based vaccines show low immunization rates,3-5 the question as to whether this also applies to KTRs with a past history of COVID-19 remains unanswered. The aim of this study was to describe the results of immunization after one dose of the mRNA-1273 SARS-CoV-2 vaccine in KTRs who were already seropositive at baseline because of previous exposure to SARS-CoV-2.

Data concerning the anti-SARS-CoV-2 antibody response after mRNA COVID-19 vaccine in kidney transplant recipients (KTRs) are currently lacking. Here, we sought to examine this issue by analyzing the serological response observed in 241 KTRs after a first vaccine injection. Our results indicate that KTRs have a weak anti-SARS-CoV-2 antibody response, ultimately resulting in a low seroconversion rate (26/241, 10.8%). This phenomenon likely stems from a high immunosuppression burden in this clinical population.

The aim of this study was to estimate the incidence of COVID-19 disease in the French national population of dialysis patients, their course of illness and to identify the risk factors associated with mortality. Our study included all patients on dialysis recorded in the French REIN Registry in April 2020. Clinical characteristics at last follow-up and the evolution of COVID-19 illness severity over time were recorded for diagnosed cases (either suspicious clinical symptoms, characteristic signs on the chest scan or a positive reverse transcription polymerase chain reaction) for SARS-CoV-2. A total of 1,621 infected patients were reported on the REIN registry from March 16th, 2020 to May 4th, 2020. Of these, 344 died. The prevalence of COVID-19 patients varied from less than 1% to 10% between regions. The probability of being a case was higher in males, patients with diabetes, those in need of assistance for transfer or treated at a self-care unit. Dialysis at home was associated with a lower probability of being infected as was being a smoker, a former smoker, having an active malignancy, or peripheral vascular disease. Mortality in diagnosed cases (21%) was associated with the same causes as in the general population. Higher age, hypoalbuminemia and the presence of an ischemic heart disease were statistically independently associated with a higher risk of death. Being treated at a selfcare unit was associated with a lower risk. Thus, our study showed a relatively low frequency of COVID-19 among dialysis patients contrary to what might have been assumed., Graphical abstract

BACKGROUND Data on coronavirus disease 2019 (COVID-19) in immunocompromised kidney transplant recipients (KTR) remain scanty. Although markers of inflammation, cardiac injury, and coagulopathy have been previously associated with mortality in the general population of patients with COVID-19, their prognostic impact amongst KTR with severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection has not been specifically investigated. METHODS We conducted a cohort study of 49 KTR who presented with COVID-19. Clinical and laboratory risk factors for severe disease and mortality were prospectively collected and analyzed with respect to outcomes. The study participants were divided into 3 groups: (1) mild disease manageable in an outpatient setting (n = 8), (2) nonsevere disease requiring hospitalization (n = 21), and (3) severe disease (n = 20). RESULTS Gastrointestinal manifestations were common at diagnosis. The 30-day mortality rate in hospitalized patients was 19.5%. Early elevations of C-reactive protein (>100 mg/L) and interleukin-6 (>65 ng/L) followed by increases in high-sensitivity troponin I (>30 ng/L) and D-dimer (>960 ng/mL) were significantly associated with severe disease and mortality. Viral load did not have prognostic significance in our sample, suggesting that outcomes were chiefly driven by a cytokine release syndrome (CRS). CONCLUSIONS Regular monitoring of CRS biomarkers in KTR with COVID-19 is paramount to improve clinical outcomes.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has spread widely, causing coronavirus disease 2019 (COVID-19) and significant mortality. However, data on viral loads and antibody kinetics in immunocompromised populations are lacking. We aimed to determine nasopharyngeal and plasma viral loads via reverse transcription-polymerase chain reaction and SARS-CoV-2 serology via enzyme-linked immunosorbent assay and study their association with severe forms of COVID-19 and death in kidney transplant recipients. In this study, we examined hospitalized kidney transplant recipients with nonsevere (n = 21) and severe (n = 19) COVID-19. SARS-CoV-2 nasopharyngeal and plasma viral load and serological response were evaluated based on outcomes and disease severity. Ten recipients (25%) displayed persistent viral shedding 30 days after symptom onset. The SARS-CoV-2 viral load of the upper respiratory tract was not associated with severe COVID-19, whereas the plasma viral load was associated with COVID-19 severity (P = .010) and mortality (P = .010). All patients harbored antibodies during the second week after symptom onset that persisted for 2 months. We conclude that plasma viral load is associated with COVID-19 morbidity and mortality, whereas nasopharyngeal viral load is not. SARS-CoV-2 shedding is prolonged in kidney transplant recipients and the humoral response to SARS-CoV-2 does not show significant impairment in this series of transplant recipients.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has spread widely, causing coronavirus disease 2019 (COVID-19) and significant mortality. However, data on viral loads and antibody kinetics in immunocompromised populations are lacking. We aimed to determine nasopharyngeal and plasma viral loads via RT-PCR and SARS-CoV-2 serology via ELISA and study their association with severe forms of COVID-19 and death in kidney transplant recipients. In this study we examined hospitalized kidney transplant recipients with non-severe (n = 21) and severe (n =19) COVID-19. SARS-CoV-2 nasopharyngeal and plasma viral load and serological response were evaluated based on outcomes and disease severity. Ten recipients (25%) displayed persistent viral shedding 30 days after symptom onset. The SARS-CoV-2 viral load of the upper respiratory tract was not associated with severe COVID-19, whereas the plasma viral load was associated with COVID-19 severity (p=0.0087) and mortality (p=0.024). All patients harbored antibodies the second week after symptom onset that persisted for two months. We conclude that plasma viral load is associated with COVID-19 morbidity and mortality, whereas nasopharyngeal viral load is not. SARS-CoV-2 shedding is prolonged in kidney transplant recipients and the humoral response to SARS-CoV-2 does not show significant impairment in this series of transplant recipients.

Introduction Determiner les criteres pertinents a prendre en compte pour inscrire un patient de plus de 70 ans sur liste d’attente de transplantation renale est un probleme croissant dans la vie quotidienne du nephrologue. L’extrapolation des resultats de la litterature est difficile a l’echelle individuelle. Une evaluation geriatrique pourrait apporter de nouveaux criteres d’evaluation pre-transplantation utiles a la decision. Description Cent douze patients âges de 70 ans ou plus, adresses pour une evaluation pre-transplantation, ont ete inclus dans notre etude observationnelle monocentrique. Une evaluation geriatrique complete a ete realisee pour tous les patients. Les conclusions des geriatres et des nephrologues ont ete comparees. Les patients transplantes ont ete suivis. Methode Les parametres pre-transplantation associes a la duree d’hospitalisation initiale et a la duree totale d’hospitalisation pendant la premiere annee post-transplantation ont ete recherches en analyses uni- et multivariee, avec courbes ROC pour les parametres identifies. Resultats Cent patients ont termine l’evaluation pre-transplantation. Soixante-huit patients (68 %) ont ete inscrits sur liste d’attente. Les avis des geriatres et des nephrologues etaient similaires pour 74 patients (74 %). Les divergences etaient dues a des appreciations differentes entre geriatres et nephrologues. A la fin de l’etude, 22 patients inscrits (32 %) ont ete transplantes et 13 patients (11,6 %) sont decedes. La duree d’hospitalisation initiale etait associee a la SPPB (Short Physical Performance Battery) et a un score pronostique de survie en dialyse. La duree totale d’hospitalisation etait associee a l’âge et a un score de comorbidites. Conclusion L’acces a la transplantation dans cette population reste mediocre. L’expertise des geriatres apporte de precieuses informations dans l’evaluation pre-transplantation des personnes âgees. Nous avons identifie plusieurs scores geriatriques pertinents pour l’evaluation pre-transplantation. Ceux-ci pourraient permettre une meilleure objectivite et aider les nephrologues a selectionner plus objectivement les patients âges.

The management of chronic kidney disease-mineral and bone disorders has recently changed. We investigated the modifications of chronic kidney disease-mineral and bone disorder with a special focus on the incidence of fractures in the first year after kidney transplantation (KT).We retrospectively compared 2 groups of patients who consecutively underwent transplantation at our center 5 years from each other. Group 1 consisted of patients (n = 152) transplanted between 2004 and 2006, whereas patients in group 2 (n = 137) underwent KT between 2009 and 2011.During the end-stage renal disease phase at the time of transplant, cinacalcet, and native vitamin D were used significantly more frequently in group 2. Median intact parathyroid hormone levels were lower and severe hyperparathyroidism decreased significantly. Vitamin D deficiency dropped from 64% to 20%. After transplantation, persistent hyperparathyroidism (parathyroid hormone130 ng/L) and bone turnover markers were significantly reduced in group 2. Native vitamin D supplementation increased over time, whereas the use of active vitamin D was unchanged. The 25-hydroxyvitamin D and 1,25-dihydroxyvitamin D levels were significantly higher. The fracture incidence at 1 year decreased significantly (3.1% vs 9.1%; P = 0.047). No steroid sparing was observed in group 2. Bisphosphonates after KT were more frequently used in group 2.Recent changes in clinical practice are associated with reductions in pretransplant and posttransplant hyperparathyroidism, vitamin D deficiency, and fracture risk after KT.

Donor-specific antibodies (DSA) increase the risk of allograft rejection and graft failure. They may be present before transplant or develop de novo after transplantation. Here, we studied the evolution of preformed DSA and their impact on graft outcome in kidney transplant recipients. Using the Luminex Single Antigen assay, we analyzed the sera on the day of transplantation of 239 patients who received a kidney transplant. Thirty-seven patients (15.5%) had pre-existing DSA detected the day of transplantation. After 5 years, the pre-existing DSA disappeared in 22 patients whereas they persisted in 12. Variables associated with DSA persistence were age50 years (P = 0.009), a history of previous transplantation (P = 0.039), the presence of class II DSA (P = 0.009), an MFI of preformed DSA3500 (P 0.001), and the presence of two or more DSA (P 0.001). DSA persistence was associated with a higher risk of graft loss and antibody-mediated rejection. Previously undetected preformed DSA are deleterious to graft survival only when they persist after transplantation.

IntroductionSeveral studies have indicated that impaired GFR is an important predictor factor associated with impaired platelet inhibition by clopidogrel. In chronic kidney disease, the presence of low platelet inhibition by clopidogrel is associated with adverse outcome following PCI and stenting. In the present study, we sought to determine if renal transplantation per se alters clopidogrel pharmacodynamics.Patients and methods36 patients with kidney transplantation were enrolled in one single center (Nephrology Department, Hôpitaux Universitaires de Strasbourg). Control patients were 126 patients with different degrees of chronic renal failure, tested in the same conditions. Inclusion criteria were patients under clopidogrel treatment of 75mg per day for at least 8 days. Unstable patients or those presenting with any conditions that could account for reduced platelet inhibition by clopidogrel (heart failure, shock) were excluded. Treatment and medical history were collected at inclusion. Clopidogrel pharmacodynamics was studied using the VASP assay.ResultsPatients with kidney transplantation were younger (58.3 vs 72.6 years, p

BACKGROUND Overimmunosuppression is a widely recognized risk factor for BK virus (BKV) infection, particularly with the combination of tacrolimus, mycophenolate mofetil (MMF), and steroids. Nevertheless, the exact impact of exposure to tacrolimus and MMF is not well understood. METHODS We examined 240 kidney recipients between 2006 and 2008. BKV was monitored every 2 months in the urine or blood. A kidney biopsy was performed when viremia exceeded 10 copies/mL. RESULTS Ninety-five (40%) patients had sustained viruria, 48 (20%) sustained viremia, and 17 (7%) biopsy-proven polyomavirus-associated nephropathy. The mean time-to-occurrence was 7.6, 7.9, and 9.7 months for viruria, viremia, and polyomavirus-associated nephropathy. Risk factors associated with BKV infection in univariate analyses were retransplantation, panel-reactive antibody more than 0%, cytomegalovirus D+/R-, cold ischemia time, delayed graft function, induction with antithymocyte globulins, acute rejection before month 3 (M3), tacrolimus trough levels more than 10 ng/mL, and M3 AUC0-12 hr more than 50 hr mg/L. Multivariate analyses showed that cytomegalovirus D+/R- (adjusted hazard ratio [AHR], 2.03; P=0.05), acute rejection (AHR, 5.4; P

The risk of fractures after kidney transplantation is high. Hyperparathyroidism frequently persists after successful kidney transplantation and contributes to bone loss, but its impact on fracture has not been demonstrated. This longitudinal study was designed to evaluate hyperparathyroidism and its associations with mineral disorders and fractures in the 5 posttransplant years. We retrospectively analyzed 143 consecutive patients who underwent kidney transplantation between August 2004 and April 2006. The biochemical parameters were determined at transplantation and at 3, 12 and 60 months posttransplantation, and fractures were recorded. The median intact parathyroid hormone (PTH) level was 334 ng/L (interquartile 151-642) at the time of transplantation and 123 ng/L (interquartile 75-224) at 3 months. Thirty fractures occurred in 22 patients. The receiver operating characteristic (ROC) curve analysis for PTH at 3 months (area under the ROC curve = 0.711, p = 0.002) showed that a good threshold for predicting fractures was 130 ng/L (sensitivity = 81%, specificity = 57%). In a multivariable analysis, independent risk factors for fracture were PTH >130 ng/L at 3 months (adjusted hazard ratio [AHR] = 7.5, 95% CI 2.18-25.50), and pretransplant osteopenia (AHR = 2.7, 95% CI 1.07-7.26). In summary, this study demonstrates for the first time that persistent hyperparathyroidism is an independent risk factor for fractures after kidney transplantation.

Introduction Les patients qui presentent une insuffisance renale ont un sur-risque de thrombose et d’hemorragie. Les indications d’anticoagulation orale (ACO) dans cette population sont plus frequentes que dans la population generale en raison de l’incidence accrue de fibrillation atriale et autres complications cardiovasculaires. Nous avons evalue dans une population de transplantes renaux le risque hemorragique grâce a des scores extrapoles de la population generale et revu les evenements hemorragiques survenus. Patients et methodes Nous avons identifie 146 patients (12 % de la cohorte) traites par ACO dont nous avons compile les donnees de biologie, comorbidites, et habitus necessaires au calcul des scores CHA2DS2 VASc, mOBRI, HAS-BLED et HEMORR2HAGES [1] , [2] . Les accidents hemorragiques severes (necessitant une hospitalisation ou une transfusion) ont ete releves. Les caracteristiques des patients transplantes a haut risque de saignement ont ete identifiees. Resultats Un accident hemorragique est survenu chez 45 % des patients sous ACO, 34 % concernaient le site de la transplantation en postoperatoire, 22 % etaient digestifs, et 8 % intracrâniens. Quatorze pour cent des patients avec ACO avaient un score CHA2DS2 VASc Discussion Les saignements sont un accident frequent en post-transplantation. Le score predictif HEMORR2HAGES parait le plus adapte a notre population. Un groupe particulier de patients a haut risque de saignement peut etre identifie qui beneficierait d’adaptations therapeutiques personnalisees. Conclusion Les saignements sous ACO sont une complication frequente apres transplantation renale necessitant une evaluation benefice–risque a chaque introduction de traitement.

Introduction La mortalite cardiovasculaire est la principale cause de deces chez les patients ayant eu une transplantation renale. Parmi les facteurs de risque de cardiopathie, les effets hemodynamiques de la fistule arterioveineuse (FAV) notamment en condition d’hyperdebit ont ete peu etudies. L’objectif de notre travail a ete de determiner la prevalence des FAV en hyperdebit un an apres transplantation et les modifications echocardiographiques associees. Patients et methodes Au total, 41 patients ayant eu une transplantation renale (29H et 12F, âge 57 ± 12 ans), hemodialyses sur FAV avant la transplantation ont ete etudies prospectivement entre fevrier 2014 et avril 2015 a 1 an de leur transplantation. 95 % des patients etaient traites par anticalcineurines (11 CsA ; 28 FK). La creatininemie etait de 142 ± 49 μmol/L et l’hemoglobine de 12,7 ± 1,7 g/dL. Une mesure du debit de FAV et une ETT ont ete realisees dans le meme temps. L’hyperdebit absolu etait defini par un debit dans la FAV > 2 L/min et l’hyperdebit relatif par un debit dans la FAV > 1 L/min associe a un ratio debit FAV sur debit cardiaque > 20 %. Resultats Dans notre population, le debit moyen dans la FAV etait de 1622 ± 807 mL/min, le debit cardiaque de 5,9 ± 1,1 L/min, la FEVG de 69 ± 7 % et le score NYHA de 2 ± 1. 70,7 % des patients avaient une hypertrophie ventriculaire gauche (HVG). Un hyperdebit de FAV a ete mis en evidence chez 66 % des patients (debit moyen 2016 ± 786 mL/min). Dans 32 % des cas, il s’agissait d’un hyperdebit absolu et dans 34 % d’un hyperdebit relatif. Trois patients avaient une insuffisance cardiaque a haut debit dont 2 cas secondaires a un hyperdebit de FAV. Seuls les diametres telesystoliques ( p = 0,01) et telediastoliques du ventricule gauche (DTDVG) ( p = 0,02) etaient significativement plus eleves dans le groupe hyperdebit. Discussion La prevalence particulierement elevee d’un hyperdebit de FAV a 1 an de la transplantation renale suggere l’importance du suivi hemodynamique de ces patients, de determiner les indications de la ligature de FAV et d’en evaluer les eventuels benefices en termes de regression des anomalies cardiaques par un travail ulterieur. Conclusion La ligature de la FAV pourrait permettre une diminution de la dilatation ventriculaire gauche chez les transplantes renaux comme cela vient d’etre recemment suggere [1] .

Introduction La distinction histologique entre le rejet humoral aigu tardif (RHAT) et le rejet humoral chronique (RHC) a ete revisee recemment dans la classification de Banff 2013. Le pronostic de ces deux diagnostics et surtout leur prise en charge restent a preciser. Patients et methodes Nous avons analyse les patients avec un diagnostic de rejet humoral (aigu ou chronique) survenu apres 1 an de greffe prouve par biopsie et un anticorps contre le greffon (DSA) mis en evidence par technique Luminex, entre 2008 et 2014. Nous avons releve les traitements mis en œuvre, l’evolution des valeurs de fluorescence des DSA, et le pronostic renal de ces patients avec au moins un an de recul. Resultats Un diagnostic de rejet humoral a ete pose chez 89 patients (RHAT : n = 36, RHC : n = 53). L’âge moyen etait de 51,2 ans et il y avait 55 % d’hommes. Les DSA mis en evidence etaient le plus souvent de classe II (82 %) et de novo (81 %). Les patients ayant un RHC avaient un debit de filtration glomerulaire estime (DFGe) plus bas au moment de la biopsie (35 vs 45 mL/min/1,73 m 2 , p = 0,008), ainsi qu’un an apres le diagnostic ( p = 0,001). La proteinurie etait plus elevee dans le groupe RHC (1,7 versus 0,9 g/j, p = 0,13). Cinquante et un pour cent des patients ont perdu leur greffon dans le groupe RHC vs 33 % dans le groupe RHAT ( p = 0,10) dans un delai moyen de 2,5 ans. La MFI des DSA etait plus elevee dans le groupe RHC a j0, et significativement a 3 et 6 mois apres le diagnostic de rejet ( p = 0,002 et 0,005, respectivement). Les patients avec RHC ont ete moins traites (45 vs 89 %, p p 2 au diagnostic, l’arterite inflammatoire et le delai entre la detection du DSA et le diagnostic de rejet. Discussion Le RHC est associe a un mauvais pronostic de survie du greffon et la mise en route d’un traitement n’influence pas l’evolution de la fonction renale dans notre etude. Conclusion Il est important de bien identifier les lesions histologiques caracteristiques lorsqu’un rejet humoral survient apres la 1 re annee afin de bien differencier RHAT et RHC.

Introduction Une augmentation de la morbidite et de la mortalite apres revascularisation coronaire est observee chez les patients insuffisants renaux. Une double antiagregation plaquettaire est consideree comme la strategie de reference pour prevenir les complications thrombotiques post-revascularisation apres mise en place de stent. Le taux d’inhibition plaquettaire est tres variable en cas de baisse du debit de filtration glomerulaire (DFG) exposant les patients insuffisants renaux a un mauvais pronostic cardiovasculaire. Les traitements immunosuppresseurs augmentent l’activation plaquettaire et favorisent la dysfonction endotheliale. Nous avons voulu preciser le degre de reponse au clopidogrel des patients transplantes. Patients et methodes Trente-six patients transplantes renaux traites par clopidogrel 75 mg/j depuis au minimum une semaine ont ete inclus. Le test VASP (mesurant l’activation plaquettaire) a ete realise (inhibition plaquettaire insuffisante si > 61 %). Un groupe controle de 126 patients insuffisants renaux a ete constitue. Resultats Les patients transplantes etaient significativement plus jeunes (58,3 vs 72,6 ans, p p = 0,12), avec un IMC moindre (25,2 vs 27,2, p = 0,05). Le VASP etait superieur a 61 % chez 20/36 patients transplantes. La transplantation majore le risque de reactivite plaquettaire residuelle : OR 3,5 [1,35–6,43], p = 0,011. Cette difference persiste meme apres ajustement sur le DFG ( p = 0,006). Discussion et conclusion La ciclosporine et le tacrolimus sont associes a une activation plaquettaire accrue. Plusieurs mecanismes pourraient etre impliques, comme une competition de ces molecules au niveau du cytochrome P450, une augmentation de molecules pro-inflammatoires, ou encore une augmentation du calcium intra-plaquettaire et dans le cardiomyocyte. Les patients transplantes renaux presentent une reponse plaquettaire inadaptee. Il reste a evaluer l’implication des immunosuppresseurs dans ces anomalies plaquettaires.

Introduction Depuis plusieurs annees, la prise en charge des troubles mineraux et osseux (TMO) de la maladie renale chronique a evolue. L’impact de ces changements sur les TMO au moment et apres la transplantation renale (TR), et particulierement sur l’incidence fracturaire n’a pas ete evalue. L’hyperparathyroidie persistante apres la TR est un facteur de risque fracturaire important. Patients et methodes Les TMO et leurs traitements ont ete analyses lors de la premiere annee de TR chez 141 patients adultes transplantes successivement en 2009–2011 dans notre centre et compares a 152 patients transplantes cinq annees plus tot (2004–2006). Resultats Au moment de la TR, les concentrations de PTH intacte etaient significativement plus basses (medianes : 334 vs 239 ng/L) et plus souvent dans les cibles KDIGO dans la cohorte recente ; la prevalence de l’insuffisance en vitamine D native etait reduite (60 vs 94 %). Le groupe recent etait plus souvent traite par cinacalcet (33 vs 4 %) et par vitamine D native (39 vs 10 %). La premiere annee, la prevalence de l’hyperparathyroidie persistante (PTH > 130 ng/L) etait diminuee (25 % vs 38 % a un an, p = 0,023) avec des marqueurs du remodelage moins eleves et une concentration en 25 OH-vitamine D deux fois plus elevee et proche de 30 μg/L. L’incidence fracturaire a un an etait trois fois plus basse (3,3 % vs 9,1 %, p = 0,036). Les patients avec une osteoporose pregreffe avaient ete trois fois plus traites par bisphosphonates. Le risque fracturaire semble plus important chez les patients avec une osteopenie pregreffe ( p = 0,064). Discussion et conclusion L’evolution de la prise en charge des TMO-MRC est associee a une amelioration des resultats la premiere annee de transplantation renale avec une reduction de l’incidence fracturaire, de l’hyperparathyroidie persistante et de l’insuffisance en vitamine D native. Un traitement precoce par bisphosphonate doit etre considere dans cette periode chez les patients a risque fracturaire eleve traites par corticoides.

Introduction La survenue d’un syndrome nephrotique (SN) apres transplantation renale chez les patients greffes pour hyalinose segmentaire et focale (HSF) est frequente. Cette recidive resiste souvent aux therapeutiques classiques. Dans cette situation, l’abatacept, dont l’efficacite a ete recemment rapportee [1] , est tente en derniers recours chez un patient. Patients et methodes Monsieur C, 50 ans, greffe pour HSF en 2003, presente une recidive postoperatoire, partiellement controlee a m1 par ciclosporine intraveineuse (IV) et 13 plasmaphereses (EP), puis retourne en dialyse en 2011. Une seconde transplantation est effectuee en 2012, avec plasmapherese preoperatoire, ciclosporine IV et trandolapril. Une recidive a m1 est traitee par ciclosporine IV et EP pluri-hebdomadaires. Le SN recidivera des espacement des EP, a m3 malgre l’association au rituximab, a m6 malgre la reprise de la ciclosporine IV, a m12 apres 12 seances d’immuno-adsorption. A m15, apres 3 mois supplementaires d’EP pluri-hebdomadaires, 2 perfusions d’abatacept (10 mg/kg), espacees de 15 jours, sont realisees. Resultats La tolerance est bonne mais sans efficacite sur la proteinurie qui reste elevee (> 10 g/j). Un EP hebdomadaire est maintenu au long cours. Discussion et conclusion L’abatacept inhibe la costimulation, en ciblant B7-1, dont l’expression podocytaire est activee dans divers modeles animaux de nephropathie proteinurique, et chez des patients atteints notamment de HSF. A la difference des remissions d’HSF constatees chez 5 patients (dont 4 transplantes) dans la recente serie de Boston, ce traitement reste inefficace chez notre patient, soulignant la necessite d’etudes supplementaires. La limite de notre approche concerne l’absence de recherche de l’expression de B7-1 sur les biopsies de greffon.