Tacrolimus Exposure Before and After a Switch From Twice-Daily Immediate-Release to Once-Daily Prolonged Release Tacrolimus: The ENVARSWITCH Study.

LCP-tacrolimus displays enhanced oral bioavailability compared to immediate-release (IR-) tacrolimus. The ENVARSWITCH study aimed to compare tacrolimus AUC0-24 h in stable kidney (KTR) and liver transplant recipients (LTR) on IR-tacrolimus converted to LCP-tacrolimus, in order to re-evaluate the 1:0.7 dose ratio recommended in the context of a switch and the efficiency of the subsequent dose adjustment. Tacrolimus AUC0-24 h was obtained by Bayesian estimation based on three concentrations measured in dried blood spots before (V2), after the switch (V3), and after LCP-tacrolimus dose adjustment intended to reach the pre-switch AUC0-24 h (V4). AUC0-24 h estimates and distributions were compared using the bioequivalence rule for narrow therapeutic range drugs (Westlake 90% CI within 0.90-1.11). Fifty-three KTR and 48 LTR completed the study with no major deviation. AUC0-24 h bioequivalence was met in the entire population and in KTR between V2 and V4 and between V2 and V3. In LTR, the Westlake 90% CI was close to the acceptance limits between V2 and V4 (90% CI = [0.96-1.14]) and between V2 and V3 (90% CI = [0.96-1.15]). The 1:0.7 dose ratio is convenient for KTR but may be adjusted individually for LTR. The combination of DBS and Bayesian estimation for tacrolimus dose adjustment may help with reaching appropriate exposure to tacrolimus rapidly after a switch.

Torque teno virus viremia and QuantiFERON®-CMV assay in prediction of cytomegalovirus reactivation in R+ kidney transplant recipients.

Introduction: Cytomegalovirus (CMV) is the most frequent infectious complication following solid organ transplantation. Torque teno viruses (TTV) viremia has been proposed as a biomarker of functional immunity in the management of kidney transplant recipients (KTR). The QuantiFERON®-CMV (QF-CMV) is a commercially available assay that allows the assessment of CD8+ T-cell responses in routine diagnostic laboratories. Methods: In a prospective national multicenter cohort of 64 CMV-seropositive (R+) KTR, we analyzed the value of TTV load and the two markers of the QF-CMV assay [QF-Ag (CMV-specific T-cell responses) and QF-Mg (overall T-cell responses)], alone and in combination, in prediction of CMV reactivation (≥3 log10 IU/ ml) in the first post-transplant year. We compared previously published cut-offs and specific cut-offs optimized from ROC curves for our population. Results: Using the conventional cut-off (3.45 log10 copies/ml), TTV load at D0 [inclusion visit on the day of transplantation before induction (D0)], or at M1 (1-month post-transplant visit) perform better in predicting CMV viremia control than CMV reactivation. Survival analyses suggest a better performance of our optimized TTV cut-offs (3.78 log10 copies/ml at D0 and 4.23 log10 copies/ml at M1) for risk stratification of CMV reactivation in our R+ KTR cohort. The QF-CMV (QF-Ag = 0.2 IU/ml, and QF-Mg = 0.5 IU/ml) also appears to better predict CMV viremia control than CMV reactivation. Moreover, survival analyses suggest that the QF-Mg would perform better than the QF-Ag in stratifying the risk of CMV reactivation. The use of our optimized QF-Mg cut-off (1.27 IU/ml) at M1 further improved risk stratification of CMV reactivation. Using conventional cut-offs, the combination of TTV load and QF-Ag or TTV load and QF-Mg did not improve prediction of CMV viremia control compared to separate analysis of each marker but resulted in an increase of positive predictive values. The use of our cut-offs slightly improved risk prediction of CMV reactivation. Conclusion: The combination of TTV load and QF-Ag or TTV load and QF-Mg could be useful in stratifying the risk of CMV reactivation in R+ KTR during the first post-transplant year and thereby have an impact on the duration of prophylaxis in these patients. Clinical trial registration: ClinicalTrials.gov registry, identifier NCT02064699.

Evaluation of the efficacy of HEMO2life®, a marine OXYgen carrier for Organ Preservation (OxyOp2) in renal transplantation: study protocol for a multicenter randomized trial.

BACKGROUND: Preventing ischemia‒reperfusion injury (IRI) is a major issue in kidney transplantation, particularly for transplant recipients receiving a kidney from extended criteria donors (ECD). The main consequence of IRI is delayed graft function (DGF). Hypoxia is one of the key factors in IRI, suggesting that the use of an oxygen carrier as an additive to preservation solution may be useful. In the OxyOp trial, we showed that the organs preserved using the oxygen carrier HEMO2life® displayed significantly less DGF. In the OxyOp2 trial, we aim to definitively test and quantify the efficacy of HEMO2life® for organ preservation in a large population of kidney grafts. METHODS: OxyOp2 is a prospective, multicenter, randomized, comparative, single-blinded, parallel-group study versus standard of care in renal transplantation. After the selection of a suitable donor according to the inclusion/exclusion criteria, both kidneys will be used in the study. Depending on the characteristics of the donor, both kidneys will be preserved either in static cold storage (standard donors) or on machine perfusion (for ECD and deceased-after-cardiac-death donors (DCD)). The kidneys resulting from one donor will be randomized: one to the standard-of-care arm (organ preserved in preservation solution routinely used according to the local practice) and the other to the active treatment arm (HEMO2life® on top of routinely used preservation solution). HEMO2life® will be used for ex vivo graft preservation at a dose of 1 g/l preservation solution. The primary outcome is the occurrence of DGF, defined as the need for renal replacement therapy during the first week after transplantation. DISCUSSION: The use of HEMO2life® in preservation solutions is a novel approach allowing, for the first time, the delivery of oxygen to organs. Improving graft survival by limiting ischemic lesions is a major public-health goal in the field of organ transplantation. TRIAL REGISTRATION: ClinicalTrials.gov, ID: NCT04181710 . registered on November 29, 2019.

New perspectives for the therapeutic drug monitoring of tacrolimus: Quantification in volumetric DBS based on an automated extraction and LC-MS/MS analysis.

Volumetric microsampling devices have been developed for home-based capillary blood sampling and are now increasingly proposed for the therapeutic drug monitoring (TDM) of immunosuppressive drugs. Our objective was to validate a LC-MS/MS method for tacrolimus quantification based on both a manual and an automated extraction of dried blood spots (DBS) collected with a volumetric microsampling device. DBS collection was performed by placing a drop of whole blood (WB) pre-spiked with tacrolimus onto a sealing film and placing the hemaPEN® device (Trajan Scientific and Medical, Melbourne, Australia) into the drop according to the device specifications. Tacrolimus was quantified using a fully automatic preparation module connected to a LCMS system (CLAM-3020® and LCMS-8060®, Shimadzu, Marne-la-Vallée, France). The method was validated analytically and clinically in accordance with the EMA and IATDMCT guidelines. The method was linear from 1 to 100 µg/L. Within- and between-run accuracy and precision fulfilled the validation criteria (biases and imprecision <15% or 20% for the lower limit of quantification). No hematocrit effect, matrix effect or carry-over was observed. No selectivity issue was identified and dilution integrity was confirmed. Tacrolimus in DBS was stable for 14 days at room temperature and +4°C, and for 72h at +60°C. There was a good correlation between tacrolimus concentrations measured in WB and in DBS of 20 kidney and liver transplant recipients (r=0.93 and 0.87, for manual and automated extraction respectively). A method for tacrolimus measurement in DBS collected with volumetric micro-sampling device, based on a fully automated process from pre-treatment to LC-MS/MS analysis was developed and validated according to analytical and clinical criteria. This performing sampling and analytical procedure opens the perspective of an easier, faster and more efficient TDM of tacrolimus for patients, clinicians and laboratories.

Absence of Mortality Differences Between the First and Second COVID-19 Waves in Kidney Transplant Recipients.

Introduction: SARS-CoV-2 pandemic evolved in 2 consecutive waves during 2020. Improvements in the management of COVID-19 led to a reduction in mortality rates among hospitalized patients during the second wave. Whether this progress benefited kidney transplant recipients (KTRs), a population particularly vulnerable to severe COVID-19, remained unclear. Methods: In France, 957 KTRs were hospitalized for COVID-19 in 2020 and their data were prospectively collected into the French Solid Organ Transplant (SOT) COVID registry. The presentation, management, and outcomes of the 359 KTRs diagnosed during the first wave were compared to those of the 598 of the second wave. Results: Baseline comorbidities were similar between KTRs of the 2 waves. Maintenance immunosuppression was reduced in most patients but withdrawal of antimetabolite (73.7% vs. 58.4%, P < 0.001) or calcineurin inhibitor (32.1% vs. 16.6%, P < 0.001) was less frequent during the second wave. Hydroxychloroquine and azithromycin that were commonly used during the first wave (21.7% and 30.9%, respectively) but were almost abandoned during the second wave. In contrast, the use of high dose corticosteroids doubled (19.5% vs. 41.6%, P < 0.001). Despite these changing trends in COVID-19 management, 60-day mortality was not statistically different between the 2 waves (25.3% vs. 23.9%; Log Rank, P = 0.48) and COVID-19 hospitalization period was not associated with death due to COVID-19 in multivariate analysis (Hazard ratio 0.89, 95% confidence interval 0.67-1.17, P = 0.4). Conclusion: We conclude that changing of therapeutic trends during 2020 did not reduce COVID-19 related mortality among KTRs. Our data indirectly support the importance of vaccination and neutralizing monoclonal anti-SARS-CoV-2 antibodies to protect KTRS from severe COVID-19.

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.

HEMO2 life® improves renal function independent of cold ischemia time in kidney recipients: A comparison with a large multicenter prospective cohort study.

BACKGROUND: M101 is an extracellular hemoglobin isolated from a marine lugworm and is present in the medical device HEMO2 life®. The clinical investigation OXYOP was a paired kidney analysis (n = 60) designed to evaluate the safety and performance of HEMO2 life® used as an additive to preservation solution in renal transplantation. The secondary efficacy endpoints showed less delayed graft function (DGF) and better renal function in the HEMO2 life® group but due to the study design cold ischemia time (CIT) was longer in the contralateral kidneys. METHODS: An additional analysis was conducted including OXYOP patients and patients from the ASTRE database (n = 6584) to verify that the decrease in DGF rates observed in the HEMO2 life® group may not be due solely to the shorter CIT but also to HEMO2 life® performance. Kaplan-Meier estimate curves of cumulative probability of achieving a creatinine level below 250 µmol/L were generated and compared in both groups. A Cox model was used to test the effect of the explanatory variables (use of HEMO2 life® and CIT). Finally, a bootstrap strategy was used to randomly select smaller samples of patients and test them for statistical comparison in the ASTRE database. RESULTS: Kaplan-Meier estimate curves confirmed the existence of a relation between DGF and CIT and Cox analysis showed a benefit in the HEMO2 life® group regardless of the associated CIT. Boostrap analysis confirmed these results. CONCLUSIONS: The present study suggested that the better recovery of renal function observed among kidneys preserved with HEMO2 life® in the OXYOP study is a therapeutic benefit of this breakthrough innovative medical device.

Humoral Response after SARS-CoV-2 mRNA Vaccination in a Cohort of Hemodialysis Patients and Kidney Transplant Recipients.

BACKGROUND: Kidney transplant recipients and patients receiving hemodialysis are immunocompromised populations that are prioritized for COVID-19 vaccination but were excluded from clinical trials of SARS-CoV-2 mRNA vaccines. Antibody titers and rates of seroconversion after vaccination are lower among patients with CKD and those taking immunosuppressants compared with controls. Data are lacking regarding their humoral response to vaccination to prevent COVID-19. METHODS: This investigation of early serological response after COVID-19 vaccination with the Pfizer/BioNTech (BNT162b2) mRNA vaccine included 78 patients undergoing hemodialysis, 74 kidney transplant recipients, and seven healthy controls. We recorded data from the medical file for various clinical parameters, including response to hepatitis B vaccination, and measured antibody titers against SARS-CoV-2 at 0, 14, 28, 36, and 58 days after the first injection. RESULTS: In controls, we detected antibodies at a positive level (>13 arbitrary units per ml; AU/ml) at day 14 postinjection, which increased progressively to peak at day 36 (1082 AU/ml; interquartile range [IQR], 735.0-1662.0). Patients undergoing hemodialysis had lower titers that peaked at day 58 (276 AU/ml; IQR, 83.4-526.0). We detected a positive antibody level in only three transplant recipients at day 36. In patients on hemodialysis, those aged <75 years had a higher antibody response versus those aged >75 years, and serum albumin and Kt/V were positively correlated with serological response (P<0.04 and P<0.0, respectively); nonresponders to HBV vaccine had the lowest anti-SARS-CoV-2 antibody titers. CONCLUSIONS: Our results suggest that the postvaccination humoral response is strongly inhibited by immunosuppressant therapy in kidney transplant recipients, and is reduced by the uremic condition in patients undergoing hemodialysis.

Characteristics of T- and NK-cell Lymphomas After Renal Transplantation: A French National Multicentric Cohort Study.

BACKGROUND: Posttransplant lymphoproliferative disorders (PTLDs) encompass a spectrum of heterogeneous entities. Because the vast majority of cases PTLD arise from B cells, available data on PTLD of T or NK phenotype (T/NK-cell PTLD) are scarce, which limits the quality of the management of these patients. METHODS: All adult cases of PTLD diagnosed in France were prospectively recorded in the national registry between 1998 and 2007. Crosschecking the registry data with 2 other independent national databases identified 58 cases of T/NK-cell PTLD. This cohort was then compared with (i) the 395 cases of B-cell PTLD from the registry, and of (ii) a cohort of 148 T/NK-cell lymphomas diagnosed in nontransplanted patients. RESULTS: T/NK-cell PTLD occurred significantly later after transplantation and had a worse overall survival than B-cell PTLD. Two subtypes of T/NK-cell PTLD were distinguished: (i) cutaneous (28%) and (ii) systemic (72%), the latter being associated with a worse prognosis. Compared with T/NK-cell lymphomas of nontransplanted patients, overall survival of systemic T/NK-cell PTLD was worse (hazard ratio: 2.64 [1.76-3.94]; P < 0.00001). CONCLUSIONS: This difference, which persisted after adjustment on tumoral mass, histological subtype, and extension of the disease at diagnosis could be explained by the fact that transplanted patients were less intensively treated and responded less to chemotherapy.

Clinical Pharmacokinetics and Bayesian Estimators for the Individual Dose Adjustment of a Generic Formulation of Tacrolimus in Adult Kidney Transplant Recipients.

BACKGROUND: Tacrolimus has a narrow therapeutic range and requires dose adjustment, usually based on the trough blood concentration but preferably on the area under the concentration-time curve over 12 h post-dose (AUC0-12h). The single-arm, multicentre, clinical study IMPAKT aimed: (i) to develop, in de novo kidney transplant recipients, pharmacokinetic models and maximum a-posteriori Bayesian estimators for a generic, immediate-release, oral formulation of tacrolimus to estimate tacrolimus AUC0-12h at different post-transplant periods using a limited sampling strategy, and considering the CYP3A5*3 polymorphism as a covariate and (ii) to compare the performance of these Bayesian estimators to those previously developed for the original formulation. METHODS: Thirty patients were enrolled and 29 provided nine blood samples over 9 h at day 7 and months 1 and 3 post-transplant. Tacrolimus blood profiles measured with liquid chromatography-tandem mass spectrometry were modelled using one-compartment, double gamma absorption, linear elimination models developed in-house. Different limited sampling strategies of three time-points within 4 h post-dose were tested for the maximum a-posteriori Bayesian estimator of tacrolimus AUC0-12h. The models and estimators were validated internally and their performance compared to that of models previously developed for the original formulation. RESULTS: The concentration-time curves, AUC0-12h/dose and trough blood concentration/dose exhibited wide inter-individual variability. The covariate-free pharmacokinetic models developed for the three post-transplant periods closely fitted the individual profiles. Maximum a-posteriori Bayesian estimators based on three different limited sampling strategies and no covariate yielded accurate AUC0-12h estimates, including for the five cytochrome P450 3A5 expressers and for the four patients without corticosteroids. The 0-1 h-3 h strategy finally chosen had very low bias (- 4.0 to - 2.5%) and imprecision (root mean square error 5.5-9.2%). The maximum a-posteriori Bayesian estimators previously developed for the reference product fitted the generic profiles with similar performance. CONCLUSIONS: We developed original pharmacokinetic models and accurate maximum a-posteriori Bayesian estimators to estimate patient exposure and adjust the dose of generic tacrolimus, and confirmed that the robust tools previously developed for the original formulation can be applied to this generic.

Opportunistic Infections and Efficacy Following Conversion to Belatacept-Based Therapy after Kidney Transplantation: A French Multicenter Cohort.

Conversion from calcineurin-inhibitors (CNIs) to belatacept can help kidney-transplant (KT) recipients avoid CNI-related nephrotoxicity. The risk of associated opportunistic infections (OPIs) is ill-defined. We conducted a multicentric cohort study across 15 French KT-centers in a real-life setting. Between 07-2010 and 07-2019, 453 KT recipients were converted from CNI- to belatacept-based therapy at 19 [0.13-431] months post-transplantation. Most patients, i.e., 332 (79.3%), were converted after 6-months post-transplantation. Follow-up time after conversion was 20.1 +/- 13 months. OPIs developed in 42(9.3%) patients after 14 +/- 12 months post-conversion. Eight patients (19%) had two OPI episodes during follow-up. Incidences of CMV DNAemia and CMV disease were significantly higher in patients converted before 6-months post-KT compared to those converted later (i.e., 31.6% vs. 11.5%; p < 0.001; and 11.6% vs. 2.4%, p < 0.001, respectively). Cumulative incidence of OPIs was 6.5 OPIs/100 person-years. Incidence of CMV disease was 2.8/100 person-years, of pneumocystis pneumonia 1.6/100 person-years, and of aspergillosis 0.2/100 person-years. Multivariate analyses showed that estimated glomerular filtration (eGFR) < 25 mL/min/1.73 m2 at conversion was independently associated with OPIs (HR = 4.7 (2.2 - 10.3), p < 0.001). The incidence of EBV DNAemia was 17.3 events /100 person-years. At 1-year post-conversion, mean eGFR had significantly increased from 32.0 +/- 18 mL/min/1.73 m2 to 42.2 +/- 18 mL/min/1.73 m2 (p < 0.0001). Conversion to belatacept is an effective strategy with a low infectious risk.

Chronic Hepatitis C Virus Infection After Kidney Transplantation With or Without Direct-Acting Antivirals in a Real-Life Setting: A French Multicenter Experience.

PURPOSE: Kidney transplant recipients (KTRs) are frequently infected with chronic hepatitis C virus (HCV), which can increase the risk of graft loss. Active HCV infections among KTRs are associated with shorter survival times. The emergence of very efficient interferon-free treatments (direct-acting antivirals [DAAs]) has revolutionized prognoses for chronic viral hepatitis. We performed a multicenter study where HCV (+)/RNA (+) KTRs were followed up and either received DAAs (group A) or not (group B) according to the transplant center. The aim was to assess, in a real-life setting, the impact of DAA therapy and to compare these results with those from HCV RNA (+) KTRs where HCV infection was not treated during the same period. METHODS: This study included 66 patients from 11 centers: 44 patients (66.7%; group A) received DAAs, whereas 22 patients did not (group B); the 2 groups were comparable according to baseline data. Most patients (88.6%) received sofosbuvir, 50% received ledipasvir, and 34.7% received daclatasvir. The duration of treatments ranged from 8 to 24 weeks. RESULTS: HCV RNA clearance (ie, a sustained virologic response) was observed in 95.4% of treated patients. Eradication of HCV led to a significant decrease in liver enzymes (50% reduction for alanine aminotransferase [P ≤ .001] and 41% for gamma glutamyl transpeptidase [P < .001]). Conversely, liver enzymes did not decrease in group B. Death occurred significantly more frequently in nontreated than treated patients (3 in group B vs none in group A, P = .003). Of the 10 treated patients with severe renal impairment before DAA therapy, 6 experienced graft loss. CONCLUSION: DAAs are very effective at treating chronic HCV and have an excellent tolerance profile.

New clinical forms of hereditary apoA-I amyloidosis entail both glomerular and retinal amyloidosis.

Apolipoprotein A1 amyloidosis (ApoAI) results from specific mutations in the APOA1 gene causing abnormal accumulation of amyloid fibrils in diverse tissues. The kidney is a prominent target tissue in ApoAI amyloidosis with a remarkable selectivity for the renal medulla. Here, we investigated six French families with ApoAI Glu34Lys, p.His179Profs∗47, and a novel p.Thr185Alafs∗41 variant revealing unprecedented clinical association of a glomerular with a retinal disease. Comprehensive clinicopathological, molecular and proteomics studies of numerous affected tissues ensured the correlation between clinical manifestations, including novel unrecognized phenotypes, and apoA-I amyloid deposition. These ophthalmic manifestations stemmed from apoA-I amyloid deposition, highlighting that the retina is a previously unrecognized tissue affected by ApoAI amyloidosis. Our study provides the first molecular evidence that a significant fraction of ApoAI amyloidosis cases with no family history result from spontaneous neomutations rather than variable disease penetrance. Finally, successful hepatorenal transplantation resulted in a life- and vision-saving measure for a 32-year-old man with a hitherto unreported severe ApoAI amyloidosis caused by the very rare Glu34Lys variant. Our findings reveal new modes of occurrence and expand the clinical spectrum of ApoAI amyloidosis. The awareness of glomerular and ocular manifestations in ApoAI amyloidosis should enable earlier diagnosis and avoid misdiagnosis with other forms of renal amyloidosis. Thus, documented apoA-I amyloid deposition in the retina offers new biological information about this disease and may change organ transplantation practice to reduce retinal damage in patients with ApoAI amyloidosis.

Population pharmacokinetics of gentamicin in haemodialysis patients: modelling, simulations and recommendations.

PURPOSE: The usual recommended dose for gentamicin is 3 to 7 mg/kg/day for patients with a normal renal function while 1.7 mg/kg/day is recommended for patients undergoing chronic haemodialysis. The objectives of this study were to develop a population pharmacokinetics model (POPPK) for gentamicin, designed for patients undergoing dialysis, and to investigate the best dosing scheme for different MIC clinical breakpoints using Monte Carlo simulations. METHODS: In this monocentric prospective interventional open clinical study, 23 patients (141 gentamicin samples) were included. The covariates investigated were weight, creatinine, dialysis (yes/no), dialysis flow and dialysis duration. The POPPK model was developed in Pmetrics and 1000 time-concentration profiles were simulated for 9 doses between 2 and 10 mg/kg/day, with an inter-dose period of 24, 48 or 96 h to predict the probability of having both a serum peak > 8*MIC and a trough < 1 mg/L for MIC values between 0.25 and 4 mg/L. RESULTS: A two-compartment model including the dialysis on the elimination constant and bodyweight on the volume of distribution best described the data. A 30-min gentamicin infusion of 2 mg/kg/day (for MIC = 1 mg/L) or 8 mg/kg/day (for MIC = 4 mg/L) just before dialysis eliminated by two dialysis sessions before the next administration (dose interval of at least 96 h) led to a peak > 8*MIC for > 90% of the simulations and a trough concentration < 1 mg/L at 96 h for 92% and 34% respectively. CONCLUSION: The gentamicin dose generally used to treat infections in dialysis patients is insufficient and might be increased to 3-8 mg/kg/day just before dialysis, taking into account the type of infection.

Opportunistic infections after conversion to belatacept in kidney transplantation.

BACKGROUND: Belatacept (bela) rescue therapy seems to be a valuable option for calcineurin inhibitor chronic toxicity in kidney transplantation. Nevertheless, the risk of infection associated with bela is not well reported. METHODS: We report the rate of opportunistic infections (OPI) after a switch to bela in a multicentric cohort of 280 kidney transplant patients. RESULTS: Forty-two OPI occurred in 34 patients (12.1%), on average 10.8 ± 11.3 months after the switch. With a cumulative exposure of 5128 months of bela treatment, we found an incidence of 0.008 OPI/month of exposure, and 9.8 OPI/100 person-years. The most common OPI was cytomegalovirus (CMV) disease in 18/42 OPI (42.9%) and pneumocystis pneumonia in 12/42 OPI (28.6%). Two patients presented a progressive multifocal leucoencephalopathy and two patients developed a cerebral Epstein-Barr virus-induced post-transplant lymphoproliferative disease. OPI led to death in 9/34 patients (26.5%) and graft failure in 4/34 patients (11.8%). In multivariate analysis, estimated glomerular filtration rate <25/mL/min/1.73 m2 on the day of the switch and the use of immunosuppressive agents before transplantation were associated with the occurrence of OPI. We found a higher rate of infection-related hospitalization (24.1 versus 12.3/100 person-years, P = 0.0007) and also a higher rate of OPI (13.2 versus 6.7/100 person-years, P = 0.005) in the early conversion group (within 6 months). CONCLUSIONS: The risk of OPI is significant post-conversion to bela and may require additional monitoring and prophylactic therapy, particularly regarding pneumocystis pneumonia and CMV disease. These data need to be confirmed in a larger case-control study.

Ribavirin for Hepatitis E Virus Infection After Organ Transplantation: A Large European Retrospective Multicenter Study.

BACKGROUND: Ribavirin is currently recommended for treating chronic hepatitis E virus (HEV) infection. This retrospective European multicenter study aimed to assess the sustained virological response (SVR) in a large cohort of solid organ transplant (SOT) recipients with chronic HEV infection treated with ribavirin monotherapy (N = 255), to identify the predictive factors for SVR, and to evaluate the impact of HEV RNA mutations on virological response. METHODS: Data from 255 SOT recipients with chronic HEV infection from 30 European centers were analyzed. Ribavirin was given at the median dose of 600 (range, 29-1200) mg/day (mean, 8.6 ± 3.6 mg/kg/day) for a median duration of 3 (range, 0.25-18) months. RESULTS: After a first course of ribavirin, the SVR rate was 81.2%. It increased to 89.8% when some patients were offered a second course of ribavirin. An increased lymphocyte count at the initiation of therapy was a predictive factor for SVR, while poor hematological tolerance of ribavirin requiring its dose reduction (28%) and blood transfusion (15.7%) were associated with more relapse after ribavirin cessation. Pretreatment HEV polymerase mutations and de novo mutations under ribavirin did not have a negative impact on HEV clearance. Anemia was the main adverse event. CONCLUSIONS: This large-scale retrospective study confirms that ribavirin is highly efficient for treating chronic HEV infection in SOT recipients and shows that the predominant HEV RNA polymerase mutations found in this study do not affect the rate of HEV clearance.This large-scale retrospective study that included 255 solid organ transplant recipients confirms that ribavirin is highly efficient for treating chronic hepatitis E virus (HEV) infection and shows that HEV RNA polymerase mutations do not play a role in HEV clearance.

Use of Highly Individualized Complement Blockade Has Revolutionized Clinical Outcomes after Kidney Transplantation and Renal Epidemiology of Atypical Hemolytic Uremic Syndrome.

BACKGROUND: Atypical hemolytic uremic syndrome (HUS) is associated with high recurrence rates after kidney transplant, with devastating outcomes. In late 2011, experts in France recommended the use of highly individualized complement blockade-based prophylaxis with eculizumab to prevent post-transplant atypical HUS recurrence throughout the country. METHODS: To evaluate this strategy's effect on kidney transplant prognosis, we conducted a retrospective multicenter study from a large French nationwide registry, enrolling all adult patients with atypical HUS who had undergone complement analysis and a kidney transplant since January 1, 2007. To assess how atypical HUS epidemiology in France in the eculizumab era evolved, we undertook a population-based cohort study that included all adult patients with atypical HUS (n=397) between 2007 and 2016. RESULTS: The first study included 126 kidney transplants performed in 116 patients, 58.7% and 34.1% of which were considered to be at a high and moderate risk of atypical HUS recurrence, respectively. Eculizumab prophylaxis was used in 52 kidney transplants, including 39 at high risk of recurrence. Atypical HUS recurred after 43 (34.1%) of the transplants; in four cases, patients had received eculizumab prophylaxis and in 39 cases they did not. Use of prophylactic eculizumab was independently associated with a significantly reduced risk of recurrence and with significantly longer graft survival. In the second, population-based cohort study, the proportion of transplant recipients among patients with ESKD and atypical HUS sharply increased between 2012 and 2016, from 46.2% to 72.3%, and showed a close correlation with increasing eculizumab use among the transplant recipients. CONCLUSIONS: Results from this observational study are consistent with benefit from eculizumab prophylaxis based on pretransplant risk stratification and support the need for a rigorous randomized trial.