Toward an optimization of empirical antibiotic therapy in acute graft pyelonephritis: A retrospective multicenter study

OBJECTIVE

Acute graft pyelonephritis (AGPN) is the most frequent infectious complication in kidney transplant recipients (KTR). The treatment of acute community-acquired (CA) pyelonephritis is based on third-generation cephalosporins (3GC) and fluoroquinolones. Cefepime or a piperacillin-tazobactam combination are more often used in healthcare-associated (HCA) infections. However, these recommendations do not consider the resistance observed in KTRs. The objective of our study was to define the most appropriate empirical antibiotherapy for AGPN in KTRs according to the CA and HCA settings. To answer this question, we assessed the prevalence of resistance to different antibiotics usually recommended for urinary tract infections (UTIs) in the general population.

METHODS

Observational, retrospective, multicenter study covering all episodes of AGPN occurring in hospitalized KTRs in 2019.

RESULTS

A total of 210 patients were included in 7 centers and 244 episodes of AGPN were analyzed (158 CA-AGPN and 86 HCA-AGPN). The prevalence of 3GC and fluoroquinolone resistance was 23 % (n = 36) and 30 % (n = 50) in CA infections (n = 158), and 47 % (n = 40) and 31 % (n = 27) in HCA infections (n = 86), respectively. Cefepime resistance rate was 19 % (n = 30) in CA-AGPN and 29 % (n = 25) in HCA-AGPN. Piperacillin-tazobactam combination had resistance rates > 15 % in both CA and HCA infections. The only antimicrobials with resistance rates < 10 % were aminoglycosides and carbapenems.

CONCLUSION

None of the antibiotics recommended in empirical treatment in UTIs has shown a resistance rate of less than 10% with regard to AGPN. Therefore, none of them should be used as monotherapy. A combination therapy including amikacin could be an appropriate strategy in this setting.

Primary Graft Function and 5 Year Insulin Independence After Pancreas and Islet Transplantation for Type 1 Diabetes: A Retrospective Parallel Cohort Study

In islet transplantation (ITx), primary graft function (PGF) or beta cell function measured early after last infusion is closely associated with long term clinical outcomes. We investigated the association between PGF and 5 year insulin independence rate in ITx and pancreas transplantation (PTx) recipients. This retrospective multicenter study included type 1 diabetes patients who underwent ITx in Lille and PTx in Nantes from 2000 to 2022. PGF was assessed using the validated Beta2-score and compared to normoglycemic control subjects. Subsequently, the 5 year insulin independence rates, as predicted by a validated PGF-based model, were compared to the actual rates observed in ITx and PTx patients. The study enrolled 39 ITx (23 ITA, 16 IAK), 209 PTx recipients (23 PTA, 14 PAK, 172 SPK), and 56 normoglycemic controls. Mean[SD] PGF was lower after ITx (ITA 22.3[5.2], IAK 24.8[6.4], than after PTx (PTA 38.9[15.3], PAK 36.8[9.0], SPK 38.7[10.5]), and lower than mean beta-cell function measured in normoglycemic control: 36.6[4.3]. The insulin independence rates observed at 5 years after PTA and PAK aligned with PGF predictions, and was higher after SPK. Our results indicate a similar relation between PGF and 5 year insulin independence in ITx and solitary PTx, shedding new light on long-term transplantation outcomes.

Impact of Preformed Donor-Specific Anti-HLA-Cw and Anti-HLA-DP Antibodies on Acute Antibody-Mediated Rejection in Kidney Transplantation

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.

KiT-GENIE, the French genetic biobank of kidney transplantation

KiT-GENIE is a monocentric DNA biobank set up to consolidate the very rich and homogeneous DIVAT French cohort of kidney donors and recipients (D/R) in order to explore the molecular factors involved in kidney transplantation outcomes. We collected DNA samples for kidney transplantations performed in Nantes, and we leveraged GWAS genotyping data for securing high-quality genetic data with deep SNP and HLA annotations through imputations and for inferring D/R genetic ancestry. Overall, the biobank included 4217 individuals (n = 1945 D + 2,272 R, including 1969 D/R pairs), 7.4 M SNPs and over 200 clinical variables. KiT-GENIE represents an accurate snapshot of kidney transplantation clinical practice in Nantes between 2002 and 2018, with an enrichment in living kidney donors (17%) and recipients with focal segmental glomerulosclerosis (4%). Recipients were predominantly male (63%), of European ancestry (93%), with a mean age of 51yo and 86% experienced their first graft over the study period. D/R pairs were 93% from European ancestry, and 95% pairs exhibited at least one HLA allelic mismatch. The mean follow-up time was 6.7 years with a hindsight up to 25 years. Recipients experienced biopsy-proven rejection and graft loss for 16.6% and 21.3%, respectively. KiT-GENIE constitutes one of the largest kidney transplantation genetic cohorts worldwide to date. It includes homogeneous high-quality clinical and genetic data for donors and recipients, hence offering a unique opportunity to investigate immunogenetic and genetic factors, as well as donor-recipient interactions and mismatches involved in rejection, graft survival, primary disease recurrence and other comorbidities.

[Surgical outcomes and complications following third kidney transplantation]

BACKGROUND

After two consecutive kidney transplant failures, a third kidney transplantation improves survival for patients on the waiting list. The surgical outcomes and complications of third kidney transplantations remain poorly known.

METHODS

We analyzed the last 100 third kidney transplantations performed in our center between January 2000 and August 2018. The data, relating to donors and recipients, were extracted retrospectively from medical records and from the prospective DIVAT database (computerized and validated data in transplantation). Continuous variables are expressed as means, medians, first and third quartiles (median, [Q1;Q3]). Categorical variables are expressed as percentages. Patient and transplant survivals were calculated using the Kaplan-Meier method.

RESULTS

Mean age of recipients was 46.4 years (47, [36;53]). Thirty-five percent had kidney failure due to urinary tract malformations. Mean age of donors was 48.2 years (52, [39.75; 58]) with 63% of donors with standard criteria. Mean cold ischemia time was 22.4hours (21, [16.5; 29.2]). Surgical mortality rate was 2% and surgical complication rate was 45%. Third kidney transplants survival was 73.1% and 58.8% at 5 years and 10 years. Mortality rate with a functioning transplant was 18%.

CONCLUSION

A third kidney transplant offers satisfactory functional outcomes but remains associated with high morbi-mortality and a significant death rate with a functioning transplant.

LEVEL OF EVIDENCE: 4

A Phase I/IIa study of autologous tolerogenic dendritic cells immunotherapy in kidney transplant recipients

Kidney transplant survival is shortened by chronic rejection and side effects of standard immunosuppressive drugs. Cell-based immunotherapy with tolerogenic dendritic cells has long been recognized as a promising approach to reduce general immunosuppression. Published trials report the safety and the absence of therapy-related adverse reactions in patients treated with tolerogenic dendritic cells suffering from several inflammatory diseases. Here, we present the first phase I clinical trial results using human autologous tolerogenic dendritic cells (ATDC) in kidney transplantation. Eight patients received ATDC the day before transplantation in conjunction with standard steroids, mycophenolate mofetil and tacrolimus immunosuppression with an option to taper mycophenolate mofetil. ATDC preparations were manufactured in a Good Manufacturing Practice-compliant facility and fulfilled cell count, viability, purity and identity criteria for release. A control group of nine patients received the same standard immunosuppression, except basiliximab induction replaced ATDC therapy and mycophenolate tapering was not allowed. During the three-year follow-up, no deaths occurred and there was 100% graft survival. No significant increase of adverse events was associated with ATDC infusion. Episodes of rejection were observed in two patients from the ATDC group and one patient from the control group. However, all rejections were successfully treated by glucocorticoids. Mycophenolate was successfully reduced/stopped in five patients from the ATDC group, allowing tacrolimus monotherapy for two of them. Regarding immune monitoring, reduced CD8 T cell activation markers and increased Foxp3 expression were observed in the ATDC group. Thus, our results demonstrate ATDC administration safety in kidney-transplant recipients.

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

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

Very Low Dose Anti-Thymocyte Globulins Versus Basiliximab in Non-Immunized Kidney Transplant Recipients

The choice between Basiliximab (BSX) or Anti-Thymocyte Globulin (ATG) as induction therapy in non-immunized kidney transplant recipients remains uncertain. Whilst ATG may allow steroid withdrawal and a decrease in tacrolimus, it also increases infectious complications. We investigated outcomes in non-immunized patients receiving a very low dosage of ATG versus BSX as induction. Study outcomes were patient/graft survival, cumulative probabilities of biopsy proven acute rejection (BPAR), infectious episode including CMV and post-transplant diabetes (PTD). Cox, logistic or linear statistical models were used depending on the studied outcome and models were weighted on propensity scores. 100 patients received ATG (mean total dose of 2.0 mg/kg) and 83 received BSX. Maintenance therapy was comparable. Patient and graft survival did not differ between groups, nor did infectious complications. There was a trend for a higher occurrence of a first BPAR in the BSX group (HR at 1.92; 95%CI: [0.77; 4.78]; p = 0.15) with a significantly higher BPAR episodes (17% vs 7.3%, p = 0.01). PTD occurrence was significantly higher in the BSX group (HR at 2.44; 95%CI: [1.09; 5.46]; p = 0.03). Induction with a very low dose of ATG in non-immunized recipients was safe and associated with a lower rate of BPAR and PTD without increasing infectious complications.

Kidney allograft rejection is associated with an imbalance of B cells, regulatory T cells and differentiated CD28-CD8+ T cells: analysis of a cohort of 1095 graft biopsies

Introduction

The human immune system contains cells with either effector/memory or regulatory functions. Besides the well-established CD4+CD25hiCD127lo regulatory T cells (Tregs), we and others have shown that B cells can also have regulatory functions since their frequency and number are increased in kidney graft tolerance and B cell depletion as induction therapy may lead to acute rejection. On the other hand, we have shown that CD28-CD8+ T cells represent a subpopulation with potent effector/memory functions. In the current study, we tested the hypothesis that kidney allograft rejection may be linked to an imbalance of effector/memory and regulatory immune cells.

Methods

Based on a large cohort of more than 1000 kidney graft biopsies with concomitant peripheral blood lymphocyte phenotyping, we investigated the association between kidney graft rejection and the percentage and absolute number of circulating B cells, Tregs, as well as the ratio of B cells to CD28-CD8+ T cells and the ratio of CD28-CD8+ T cells to Tregs. Kidney graft biopsies were interpreted according to the Banff classification and divided into 5 biopsies groups: 1) normal/subnormal, 2) interstitial fibrosis and tubular atrophy grade 2/3 (IFTA), 3) antibody-mediated rejection (ABMR), 4) T cell mediated-rejection (TCMR), and 5) borderline rejection. We compared group 1 with the other groups as well as with a combined group 3, 4, and 5 (rejection of all types) using multivariable linear mixed models.

Results and discussion

We found that compared to normal/subnormal biopsies, rejection of all types was marginally associated with a decrease in the percentage of circulating B cells (p=0.06) and significantly associated with an increase in the ratio of CD28-CD8+ T cells to Tregs (p=0.01). Moreover, ABMR, TCMR (p=0.007), and rejection of all types (p=0.0003) were significantly associated with a decrease in the ratio of B cells to CD28-CD8+ T cells compared to normal/subnormal biopsies. Taken together, our results show that kidney allograft rejection is associated with an imbalance between immune cells with effector/memory functions and those with regulatory properties.

Development and validation of multivariable prediction models of serological response to SARS-CoV-2 vaccination in kidney transplant recipients

Repeated vaccination against SARS-CoV-2 increases serological response in kidney transplant recipients (KTR) with high interindividual variability. No decision support tool exists to predict SARS-CoV-2 vaccination response to third or fourth vaccination in KTR. We developed, internally and externally validated five different multivariable prediction models of serological response after the third and fourth vaccine dose against SARS-CoV-2 in previously seronegative, COVID-19-naïve KTR. Using 20 candidate predictor variables, we applied statistical and machine learning approaches including logistic regression (LR), least absolute shrinkage and selection operator (LASSO)-regularized LR, random forest, and gradient boosted regression trees. For development and internal validation, data from 590 vaccinations were used. External validation was performed in four independent, international validation cohorts comprising 191, 184, 254, and 323 vaccinations, respectively. LASSO-regularized LR performed on the whole development dataset yielded a 20- and 10-variable model, respectively. External validation showed AUC-ROC of 0.840, 0.741, 0.816, and 0.783 for the sparser 10-variable model, yielding an overall performance 0.812. A 10-variable LASSO-regularized LR model predicts vaccination response in KTR with good overall accuracy. Implemented as an online tool, it can guide decisions whether to modulate immunosuppressive therapy before additional active vaccination, or to perform passive immunization to improve protection against COVID-19 in previously seronegative, COVID-19-naïve KTR.

Impact of parathyroidectomy on kidney graft function in post-transplant tertiary hyperparathyroidism: a comparative study

PURPOSE

Parathyroidectomy to treat tertiary hyperparathyroidism (THPT) is now on a par with calcimimetic treatment. The effects of cinacalcet and parathyroidectomy on kidney transplant function remain controversial. The aim of this study was to evaluate kidney transplant function in THPT patients treated either by parathyroidectomy, cinacalcet, or not treated.

METHODS

Between 2009 and 2019, 231 patients with functional grafts presenting THPT, defined either by calcaemia superior to 2.5 mmol/L with elevated PTH level or hypercalcaemia with non-adapted PTH level 1 year after kidney transplantation, were included. Hyperparathyroid patients treated by cinacalcet and parathyroidectomy were matched for age, sex, graft rank, and baseline eGFR with cinacalcet-only and untreated patients. Conditional logistic regression models were used to compare eGFR variations 1 year after parathyroidectomy between operated patients and matched controls. Five-year survivals were compared with the Mantel-Cox test.

RESULTS

Eleven patients treated with parathyroidectomy and cinacalcet were matched with 16 patients treated by cinacalcet-only and 29 untreated patients. Demographic characteristics were comparable between groups. Estimated odds ratios for eGFR evolution in operated patients compared with cinacalcet-only and untreated patients were 0.92 [95%CI 0.83-1.02] and 0.99 [0.89-1.10] respectively, indicating no significant impairment of eGFR 1 year after surgery. Five-year allograft survival was not significantly impaired in operated patients.

CONCLUSIONS

Parathyroidectomy did not appear to substantially alter or improve graft function 1 year after surgery or 5-year allograft survival. It could be hypothesized that in addition to its known benefits, parathyroidectomy can be safely performed vis-à-vis graft function in tertiary hyperparathyroidism.

Impact of Late and Recurrent Acute Graft Pyelonephritis on Long-Term Kidney Graft Outcomes

Background

While Urinary tract infections are the most common infections in kidney transplant recipients, the impact of late acute graft pyelonephritis (AGPN) on graft outcomes remains unknown. Our study was performed to more precisely evaluate the long-term impact of AGPN.

Methods

We included 9052 kidney and combined kidney-pancreas recipients who underwent transplantation between 2008 and 2018 from a French multicenter cohort. The relationships between AGPN and patient and graft survival were analyzed with a time-dependent multivariate Cox model.

Results

The cumulative incidence of AGPN was 20.9%. A first episode of early AGPN is associated with a non-significant increase in the risk of graft failure (hazard ratio [HR], 1.27; 95% confidence interval [95% CI], 0.90 to 1.79). Though, cumulative number of AGPN episodes (HR = 1.51; 95% CI, 0.89 to 2.57 for two episodes and HR = 2.08; 95% CI, 1.17 to 3.69 for three or more episodes) is associated with an increased risk of graft failure. In contrast, when the first episode of AGPN occurred late (i.e., 6 months post transplantation), the risk of graft failure is significantly increased (HR = 2.25; 95% CI, 1.65 to 3.07), and this risk remains relatively stable with the recurrence of late AGPN episodes. The onset of late AGPN were also associated with a higher risk of patient death.

Conclusion

This analysis shows that late AGPN and recurrent AGPN are both risk factors for a poor long-term graft outcome and mortality. Late AGPN should not be considered benign infections in post-transplantation follow-up.

Urinary metabolomic profiling from spontaneous tolerant kidney transplanted recipients shows enrichment in tryptophan-derived metabolites

Background

Operational tolerance is the holy grail in solid organ transplantation. Previous reports showed that the urinary compartment of operationally tolerant recipients harbor a specific and unique profile. We hypothesized that spontaneous tolerant kidney transplanted recipients (KTR) would have a specific urinary metabolomic profile associated to operational tolerance.

Methods

We performed metabolomic profiling on urine samples from healthy volunteers, stable KTR under standard and minimal immunosuppression and spontaneous tolerant KTR using liquid chromatography in tandem with mass spectrometry. Supervised and unsupervised multivariate computational analyses were used to highlight urinary metabolomic profile and metabolite identification thanks to workflow4metabolomic platform.

Findings

The urinary metabolome was composed of approximately 2700 metabolites. Raw unsupervised clustering allowed us to separate healthy volunteers and tolerant KTR from others. We confirmed by two methods a specific urinary metabolomic signature in tolerant KTR mainly driven by kynurenic acid independent of immunosuppressive drugs, serum creatinine and gender.

Interpretation

Kynurenic acid and tryptamine enrichment allowed the identification of putative pathways and metabolites associated with operational tolerance like IDO, GRP35 and AhR and indole alkaloids.

Funding

This study was supported by the ANR, IRSRPL and CHU de Nantes.

Incidence, risk factors and outcomes of kidney and liver cyst infection in kidney transplant recipient with autosomal dominant polycystic kidney disease

Introduction

Methods

Results

Conclusion

Occurrence of de novo Donor Specific Antibodies after Covid-19 in kidney transplant recipients is low despite immunosuppression modulation

Introduction

Methods

Results

Conclusion

Timing of Kidney Clamping and Deceased Donor Kidney Transplant Outcomes

BACKGROUND AND OBJECTIVES

The fact that metabolism and immune function are regulated by an endogenous molecular clock that generates circadian rhythms suggests that the magnitude of ischemia reperfusion, and subsequent inflammation on kidney transplantation, could be affected by the time of the day.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

We evaluated 5026 individuals who received their first kidney transplant from deceased heart-beating donors. In a cause-specific multivariable analysis, we compared delayed graft function and graft survival according to the time of kidney clamping and declamping. Participants were divided into those clamped between midnight and noon (ante meridiem [am] clamping group; 65%) or clamped between noon and midnight (post meridiem [pm] clamping group; 35%), and, similarly, those who underwent am declamping (25%) or pm declamping (75%).

RESULTS

Delayed graft function occurred among 550 participants (27%) with am clamping and 339 (34%) with pm clamping (adjusted odds ratio, 0.81; 95% confidence interval, 0.67 to 0.98; P=0.03). No significant association was observed between clamping time and overall death-censored graft survival (hazard ratio, 0.92; 95% confidence interval, 0.77 to 1.10; P=0.37). No significant association of declamping time with delayed graft function or graft survival was observed.

CONCLUSIONS

Clamping between midnight and noon was associated with a lower incidence of delayed graft function, whereas declamping time was not associated with kidney graft outcomes.

Time-dependent blood eosinophilia count increases the risk of kidney allograft rejection

Background

Growing evidence suggest that type 2 immune effectors play a role in solid organ transplantation. The aim of this study was to evaluate the impact of blood count eosinophils (BCEo) on immunological outcomes in kidney transplant recipients with stable graft function after 3 months post-transplant.

Method

We performed cause-specific Cox model considering BCEo, the use of calcineurin inhibitors and systemic corticoids as time-dependent explicative variables on a prospective cohort of 1013 kidney transplant patients who experienced kidney allograft rejection and/or the appearance of de novo donor specific antibodies after excluding common causes of increased BCEo..

Findings

BCEo ≥ 0.3 G/L was associated with a 3-fold increased risk of rejection independent of immunosuppressive regimen after 3 months post-transplant in patients without pre-transplant DSAs and with CNI-based immunosuppression. No association between BCEo either with donor specific antibodies or graft survival was noticed.

Interpretation

These observations in this large cohort support the hypothesis of eosinophils in allo-immunity in human and claim for further mechanistic research.

Funding

This study was supported by the French National Research Agency, The “Institut de Recherche en Santé Respiratoire des Pays de la Loire” and the University hospital of Nantes.

Kidney transplantation from expanded criteria donors: an increased risk of urinary complications - the UriNary Complications Of Renal Transplant (UNyCORT) study

OBJECTIVES

To assess the impact of expanded criteria donors (ECD) on urinary complications in kidney transplantation.

PATIENTS AND METHODS

The UriNary Complications Of Renal Transplant (UNyCORT) is a cohort study based on the French prospective Données Informatisées et VAlidées en Transplantation/Computerized and VAlidated Data in Transplantation (DIVAT) cohort. Data were extracted between 1 January 2002 and 1 January 2018 with 1-year minimum follow-up, in relation to 44 pre- and postoperative variables. ECD status was included according to United Network for Organ Sharing (UNOS) definition. The primary outcome of the UNyCORT study was the association between the donor's ECD/standard criteria donors (SCD) status and urinary complications at 1 year in uni- and multivariate analysis. Sub-group analysis, stratified analysis on ECD/SCD donor's status and transplant failure analysis were then conducted.

RESULTS

Between 1 January 2002 and 1 January 2018, 10 279 kidney transplants in adult recipients were recorded within the DIVAT network. A total of 8559 (83.4%) donors were deceased donors and 1699 (16.6%) were living donors (LD). Among donation after circulatory death (DCD) donors, 224 (2.85%) were uncontrolled DCD and 93 (1.09%) were controlled DCD donors. A total of 3617 (43.9%) deceased donors were ECD. The overall urological complication rate was 16.26%. The donor's ECD status was significantly associated with an increased risk of urological complications at 1 year in multivariate analysis (odds ratio: 1.50, 95% CI 1.31-1.71; P < 0.001) and especially with stenosis and ureteric fistulae at 1 year. There is no association with LD, uncontrolled and controlled DCD. The placement of an endo-ureteric stent was beneficial in preventing urinary complications in all donors and particularly in ECD donors.

CONCLUSION

The donor's ECD status is associated with a higher likelihood of stenosis and ureteric fistulae at 1 year. Recipients of grafts from ECD donors should probably be considered for closer urological monitoring and systematic preventive measures.

Clinical utility of C-peptide measurement after pancreas transplantation with especial focus on early graft thrombosis

Since the beginning of our pancreas transplant programme, plasma C-peptide was routinely measured daily during the postoperative period. We aimed to evaluate the clinical interest of the C-peptide in the follow-up of pancreas transplantation with a particular look on early graft failure. From 2000 to 2016, 384 pancreas transplantations were evaluated. We collected and compared C-peptide, glycaemia and adjusted C-peptide (aCP; calculated based on C-peptide, glycaemia and creatininaemia) in patients with and without pancreas failure within 30 days after surgery. Variations of glycaemia, C-peptide and aCP between the day before and the day of failure were also recorded. The difference of aCP was significant during the first week after transplantation between patients with thrombosis and those with functional allograft: 63.2 vs. 26.7 on day 1, P = 0.0003; 61.4 vs. 26.7 on day 3, P < 0.0001; 64.8 vs. 5.7 on day 7, P < 0.0001, respectively. Glycaemia had a median increase of 8% on the day of failure, whereas C-peptide and aCP had, respectively, a median decrease of 88% and 83%. C-peptide monitoring after pancreas transplantation may help to identify graft function and early failure. This sensitive biomarker could allow pre-emptive diagnosis of an early thrombotic event allowing the possibility of rescue interventions.

Parathyroidectomy or cinacalcet: Do we still not know the best option for graft function in kidney-transplanted patients? A meta-analysis

BACKGROUND

Tertiary hyperparathyroidism occurs in 25% to 50% of kidney-transplanted patients. Indication of parathyroidectomy is now discussed, since the calcimimetic agent, cinacalcet, is an alternate option. The effects of either of these treatments on graft function remain controversial, studied only in small cohorts showing either decrease or absence of modification. We performed a meta-analysis to evaluate the evolution of graft function after surgical or medical treatment.

METHODS

Studies assessing graft function in tertiary hyperparathyroidism after parathyroidectomy or cinacalcet introduction were enrolled into quantitative analysis using Pubmed, Embase, and Cochrane databases following the Preferred Reporting Items for Systematic Reviews and Meta-Analysis reporting guidelines. Among 68 screened studies, 18 had no missing data and were included for statistical analyses. We performed random effect meta-analysis to determine changes in serum creatinine and estimated glomerular filtration rate.

RESULTS

Seven studies assessing the evolution of graft function 6 and/or 12 months after parathyroidectomy and 13 after administration of cinacalcet were included. Meta-analysis found no significant variations after parathyroidectomy in serum creatinine (6 studies, 314 patients) and estimated glomerular filtration rate (2 studies, 105 patients). No significant variation was found after administration of cinacalcet in serum creatinine (10 studies, 404 patients) and estimated glomerular filtration rate (6 studies, 149 patients). A significant heterogeneity between the studies (P < .01, Cochran's Q) was found.

CONCLUSION

Meta-analysis shows that parathyroidectomy and cinacalcet do not significantly impair graft function in patients with tertiary hyperparathyroidism. However, the significant heterogeneity between selected studies, partially explained by the lack of consensual definition of tertiary hyperparathyroidism, limits the conclusions of all previously published series.

Higher mortality risk among kidney transplant recipients than among estimated glomerular filtration rate-matched patients with CKD-preliminary results

BACKGROUND

Although kidney transplantation prolongs survival relative to dialysis, it is associated with a higher death rate than in the general population. The objective of the present study was to assess and compare the risk of mortality and frequency of non-lethal cardiovascular (CV) events in kidney transplant recipients (KTRs) beyond 1 year after successful transplantation versus patients with chronic kidney disease (CKD) using propensity score-matched analysis of estimated glomerular filtration rate (eGFR) and other parameters.

METHODS

After propensity score matching, we studied 340 KTRs from the French Données Informatisées et Validées en Transplantation cohort and 605 non-transplant patients with CKD (CKDps) from the French Chronic Kidney Disease-Renal Epidemiology and Information Network cohort. The mean ± standard deviation eGFR was 42 ± 13 and 41 ± 12 mL/min/  1.73 m2, respectively (P = 0.649). Descriptive data were completed by a survival analysis with Cox regression models.

RESULTS

After a median follow-up period of 2.8 years (KTRs 2.0 years, CKDp 2.9 years), 71 deaths were recorded (31 and 40 in the KTR and CKD groups, respectively). Univariate analysis showed that KTRs had a significantly greater risk of mortality than CKDps. In multivariable analysis, KTRs were found to have a 2.7-fold greater risk of mortality [hazard ratio 2.7 (95% confidence interval 1.6-4.7); P = 0.005]. There was no between-group difference concerning the risk of CV events (P = 0.448). CV death rates in KTRs (29.0%) approximated those of CKDps (22.5%), whereas death rates due to infections were higher in KTRs (19.4% versus 10.0%).

CONCLUSION

Beyond 1 year after transplantation, KTRs, who possibly had a longer CKD history, had a significantly greater mortality risk than eGFR-matched CKDps. The excess risk was not associated with CV events.

Renal transplantation outcomes in obese patients: a French cohort-based study

Background

Whilst there are a number of publications comparing the relationship between body mass index (BMI) of kidney transplant recipients and graft/patient survival, no study has assessed this for a French patient cohort.

Methods

In this study, cause-specific Cox models were used to study patient and graft survival and several other time-to-event measures. Logistic regressions were performed to study surgical complications at 30 days post-transplantation as well as delayed graft function.

Results

Among the 4691 included patients, 747 patients were considered obese with a BMI level greater than 30 kg/m². We observed a higher mortality for obese recipients (HR = 1.37, p = 0.0086) and higher risks of serious bacterial infections (HR = 1.24, p = 0.0006) and cardiac complications (HR = 1.45, p < 0.0001). We observed a trend towards death censored graft survival (HR = 1.22, p = 0.0666) and no significant increased risk of early surgical complications.

Conclusions

We showed that obesity increased the risk of death and serious bacterial infections and cardiac complications in obese French kidney transplant recipients. Further epidemiologic studies aiming to compare obese recipients versus obese candidates remaining on dialysis are needed to improve the guidelines for obese patient transplant allocation.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12882-021-02278-1.

[Acute renal failure of the donor in encephalic death: A real contraindication to kidney transplantation?]

INTRODUCTION

The shortage of kidney transplants encourages the expansion of the limits of eligibility criteria for donation. Many donors who are brain dead display acute renal failure at the time of death; is this a real contraindication to harvesting? The aim of this study was to assess kidney graft survival from donors after brain death with confirmed acute renal failure, with or without anuria previous donation.

MATERIALS AND METHODS

All of the transplants performed in two university hospitals between 2010 and 2017 were analyzed retrospectively. All patients who underwent single kidney transplant from a brain-dead donor with acute renal failure (ARF) were included in this study. ARI was defined here by a decrease over 50 % of glomerular filtration rate (GFR) to a threshold below 45mL/min/1.73 m² at the time of kidney procurement. Kidney graft survival, incidence of delayed graft function (DGF) and the GFR at 12 months were analyzed. Analysis of kidney transplant survival based on pre-implantation biopsies was additionally done.

RESULTS

One hundred and sixty four patients were transplanted with a kidney from donor with ARF during the selected period. At the admission in ICU the average GFR was 67,7±19mL/min/1,73m². At the time of donation, the average age of donors was 56.4±17.7 years, the GFR was 33.7±8.0mL/min/1.73 m² 16 % of donors were anuric. Cold ischemia time (CIT) was 16.8±5.0hours. The average age of recipients was 55.6±14.1 years. 81 % of the cases were primary transplants. Graft function took place within 7.8±9.4 days after transplantation. There were two non-primary functions (PNF). One hundred and fifty two patients (93 %) had a functional graft at 12 months. The mean GFR at 12 months was 46.8±20.1mL/min/1.73 m² and 122 patients (73 %) had a GFR greater than 30mL/min/1.73 m². Seventy-one percent of preimplantation biopsies revealed acute tubular necrosis (ATU); no cortical necrosis was observed. Survival of theses grafts was 85 %, comparable to the total population of study (P=0,21) CONCLUSION: The acute renal failure of the brain-dead donor should not alone be systematically a contraindication to harvesting and kidney transplantation.

Association between Use of Hydrochlorothiazide and Risk of Keratinocyte Cancers in Kidney Transplant Recipients

BACKGROUND AND OBJECTIVES

Keratinocyte cancers, which primarily comprise squamous cell carcinomas and basal cell carcinomas, represent a major concern and potential risk for kidney transplant recipients. Hydrochlorothiazide, a diuretic widely used to treat hypertension, has been implicated in skin photosensitivity reaction. Recent studies conducted in the general population have found that hydrochlorothiazide use is associated with a higher risk of keratinocyte cancer, especially squamous cell carcinomas. High-risk groups, however, including transplant recipients were excluded from these. Our aim was to investigate whether hydrochlorothiazide use was associated with keratinocyte cancer in kidney transplant recipients on immunosuppressive therapy.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

In a single-center cohort of kidney (n=2155), combined kidney-pancreas (n=282), and pancreas (n=59) transplant recipients from the Données Informatisées VAlidées Transplantation (DIVAT) database transplanted between 2000 and 2017 in Nantes, France, we evaluated the association between hydrochlorothiazide exposure and keratinocyte cancers. Multivariable cause-specific, time-varying Cox models were used to estimate the relationship between hydrochlorothiazide exposure and the hazard of squamous cell carcinoma and basal cell carcinoma, with hydrochlorothiazide designated as the time-dependent variable.

RESULTS

Among the participants, 279 of 2496 (11%) were exposed to hydrochlorothiazide after the transplantation. Cumulative incidence rates of keratinocyte cancer by 10 and 15 years were 7% and 9% for squamous cell carcinomas, respectively, and 8% and 11% for basal cell carcinomas, respectively. We found a relationship between exposure to hydrochlorothiazide and the risk of squamous cell carcinomas (hazard ratio, 2.04; 95% confidence interval, 1.27 to 3.28). In contrast, we found no association between hydrochlorothiazide exposure and basal cell carcinomas (hazard ratio, 0.63; 95% confidence interval, 0.35 to 1.15).

CONCLUSIONS

In a single-center cohort of kidney, combined kidney-pancreas, and pancreas transplant recipients, exposure to hydrochlorothiazide was associated with a two-fold higher risk of squamous cell carcinoma and no higher risk of basal cell carcinoma.

Clinical and immunological follow-up of very long-term kidney transplant recipients treated with calcineurin inhibitors indicates dual phenotypes

Operationally tolerant kidney transplant recipients harbor an immunological signature, associated with low rejection risk, and focused on B lymphocytes. Here, we investigated whether patients with long-term transplantation and still on immunosuppressive therapy would present such a signature of low immunological rejection risk, compared to more recently transplanted patients. Of 114 kidney transplant recipients enrolled, 38 with more than 25 years of graft survival and stable graft function under calcineurin inhibitors, were matched with two different groups of transplanted patients (10-15 and 5-7 years after transplantation). Three phenotypes associated with low immunological rejection risk (Tfh, B and regulatory T cells), initially found in operationally tolerant kidney transplant recipients, and the composite score of tolerance (combination of six transcriptomic markers, age at transplantation and age at sampling) were analyzed. We found that very long-term patients were characterized by a significantly lower percentage of total B cells, a significantly higher proportion of CD24^HiCD38^Lo memory B cells, significantly fewer CD24^LoCD38^Lo naive B cells, and a significantly lower proportion of PD1^HiCCR7^Lo Tfh lymphocytes than more recently transplanted patients. This phenotype is associated with a positive composite score of tolerance in patients transplanted for more than 25 years. Thus, our study suggests a dual phenotype in very long-term kidney transplanted patients with an immunological profile associated with low rejection risk.

Time-dependent lymphocyte count after transplantation is associated with higher risk of graft failure and death

The transplantation field requires the identification of specific risk factors associated with the level of immunosuppression. Here, our aim was to analyze the association between the number of circulating lymphocytes, monitored routinely by complete blood cell counts during outpatient visits, and patient and graft survival. In total, 2,999 kidney or combined kidney-pancreas recipients transplanted between 2000 and 2016, from two University hospitals, were enrolled. We investigated the etiological relationship between time-dependent lymphocyte count beyond one year after transplantation and patient and graft survival, viral infection and cancer risk using time-dependent multivariate Cox models. Model 1 considered kidney function at one year and model 2 as time-dependent variable. At the time of inclusion (one year after transplantation), 584 patients (19.4%) had deep lymphopenia (under 750 /mm³) and 1,072 (35.7%) had a normal count (over 1,500 /mm³). A patient with deep lymphopenia at a given follow-up time had significantly higher risks of graft failure, death and viral infection than comparable patients with a normal lymphocyte count at the same time point. Thus, after the first year of transplantation, the occurrence of deep lymphopenia within a patient's follow-up is a risk factor for long-term graft failure, death and viral infection.

The weekend effect in kidney transplantation outcomes: a French cohort-based study

Numerous studies have reported a weekend effect on outcomes for diseases treated at hospitals. No study has been conducted in France for kidney transplantation. We therefore performed a cohort-based study to evaluate whether outcomes of kidney transplant recipients display a weekend effect. Data were extracted from the French DIVAT cohort. Patients aged 18 years and older, transplanted with a single kidney from deceased donors between 2005 and 2017 were studied. Linear regression, logistic regression, and cause-specific Cox model were used. Among the 6652 studied patients, 4653 patients were transplanted during weekdays (69.9%) versus 1999 during weekends (30.1%). The only statistically significant difference was the percentage of patients with vascular surgical complication(s) at 30 days: 13.3% in the weekend group versus 16.2% in the weekday group 0.79 (95% CI: 0.68; 0.92). We did not observe other significant differences for the other outcomes: patient or graft survival, the risk of acute rejection episodes, the 30-day percentage of urological complications, and the 1-year estimated glomerular filtration rate. Our study highlights a small protective weekend effect with less post-surgery vascular complications compared to weekdays. This paradox might be explained by a different handling of weekend transplantations.

CXCR5+PD1+ICOS+ Circulating T Follicular Helpers Are Associated With de novo Donor-Specific Antibodies After Renal Transplantation

Donor-specific anti-HLA antibodies (DSAs) are a major risk factor associated with renal allograft outcomes. As a trigger of B cell antibody production, T follicular helper cells (Tfhs) promote DSA appearance. Herein, we evaluated whether circulating Tfhs (cTfhs) are associated with the genesis of antibody-mediated rejection. We measured cTfh levels on the day of transplantation and 1 year after transplantation in blood from a prospective cohort of 237 renal transplantation patients without DSA during the first year post-transplantation. Total cTfhs were characterized as CD4⁺CD45RA⁻CXCR5⁺, and the three following subsets of activated cTfh were analyzed: CXCR5⁺PD1⁺, CXCR5⁺PD1⁺ICOS⁺, an CXCR5⁺PD1⁺CXCR3⁻. Immunizing events (previous blood transfusion and/or pregnancy) and the presence of class II anti-HLA antibodies were associated with increased frequencies of activated CXCR5⁺PD1⁺, CXCR5⁺PD1⁺ICOS⁺, and CXCR5⁺PD1⁺CXCR3⁻ cTfh subsets. In addition, ATG-depleting induction and calcineurin inhibitor treatments were associated with a relative increase of activated cTfh subsets frequencies at 1 year post-transplantation. In multivariate survival analysis, we reported that a decrease in activated CXCR5⁺PD1⁺ICOS⁺ at 1 year after transplantation in the blood of DSA-free patients was significantly associated with the risk of developing de novo DSA after the first year (p = 0.018, HR = 0.39), independently of HLA mismatches (p = 0.003, HR = 3.79). These results highlight the importance of monitoring activated Tfhs in patients early after transplantation and show that current treatments cannot provide early, efficient prevention of Tfh activation and migration. These findings indicate the need to develop innovative treatments to specifically target Tfhs to prevent DSA appearance in renal transplantation.

Dynamic predictions of long-term kidney graft failure: an information tool promoting patient-centred care

Background

Informing kidney transplant recipients of their prognosis and disease progression is of primary importance in a patient-centred vision of care. By participating in decisions from the outset, transplant recipients may be more adherent to complex medical regimens due to their enhanced understanding.

Methods

We proposed to include repeated measurements of serum creatinine (SCr), in addition to baseline characteristics, in order to obtain dynamic predictions of the graft failure risk that could be updated continuously during patient follow-up. Adult recipients from the French Données Informatisées et VAlidées en Transplantation (DIVAT) cohort transplanted for the first or second time from a heart-beating or living donor and alive with a functioning graft at 1 year post-transplantation were included.

Results

The model was composed of six baseline parameters, in addition to the SCr evolution. We validated the dynamic predictions by evaluating both discrimination and calibration accuracy. The area under the receiver operating characteristic curve varied from 0.72 to 0.76 for prediction times at 1 and 6 years post-transplantation, respectively, while calibration plots showed correct accuracy. We also provided an online application tool (https://shiny.idbc.fr/DynPG).

Conclusion

We have created a tool that, for the first time in kidney transplantation, predicts graft failure risk both at an individual patient level and dynamically. We believe that this tool would encourage willing patients into participative medicine.

Association of Long-Term Diet Quality with Hippocampal Volume: Longitudinal Cohort Study

BACKGROUND

Diet quality is associated with brain aging outcomes. However, few studies have explored in humans the brain structures potentially affected by long-term diet quality. We examined whether cumulative average of the Alternative Healthy Eating Index 2010 (AHEI-2010) score during adult life (an 11-year exposure period) is associated with hippocampal volume.

METHODS

Analyses were based on data from 459 participants of the Whitehall II imaging sub-study (mean age [standard deviation] (SD) = 59.6 [5.3] years in 2002-2004, 19.2% women). Multimodal magnetic resonance imaging examination was performed at the end of follow-up (2015-2016). Structural images were acquired using a high-resolution 3-dimensional T1-weighted sequence and processed with Functional Magnetic Resonance Imaging of the Brain Software Library (FSL) tools. An automated model-based segmentation and registration tool was applied to extract hippocampal volumes.

RESULTS

Higher AHEI-2010 cumulative average score (reflecting long-term healthy diet quality) was associated with a larger total hippocampal volume. For each 1 SD (SD = 8.7 points) increment in AHEI-2010 score, an increase of 92.5 mm³ (standard error = 42.0 mm³) in total hippocampal volume was observed. This association was independent of sociodemographic factors, smoking habits, physical activity, cardiometabolic health factors, cognitive impairment, and depressive symptoms, and was more pronounced in the left hippocampus than in the right hippocampus. Of the AHEI-2010 components, no or light alcohol consumption was independently associated with larger hippocampal volume.

CONCLUSIONS

Higher long-term AHEI-2010 scores were associated with larger hippocampal volume. Accounting for the importance of hippocampal structures in several neuropsychiatric diseases, our findings reaffirm the need to consider adherence to healthy dietary recommendation in multi-interventional programs to promote healthy brain aging.

Long-term quality of life among localised prostate cancer survivors: QALIPRO population-based study

BACKGROUND

To evaluate quality of life (QoL) 10 years after treatments for localised prostate cancer (LPCa) patients in comparison with aged-matched healthy controls.

METHODS

LPCa patients diagnosed in 2001 were obtained from 11 French cancer registries. Controls were recruited among the general population and were matched to patients on age and geographic area. EORTC Quality of Life Questionnaire - Core 30 items, Expanded Prostate Cancer Index Composite, Hospital Anxiety and Depression Scale and Multidimensional Fatigue Inventory self-reported questionnaires were used to measure QoL, anxiety and fatigue. Patients were classified in three groups according to previous treatments: radical prostatectomy (RP), radiotherapy (RT) and radical prostatectomy and radiotherapy (RP+RT). The differences in QoL between patients and controls and according to treatment groups were evaluated.

RESULTS

There were 287 patients and 287 controls. There was no socio-demographic difference between patients and controls. Treatments were: RP (143), RT (78), PR+RT (33), baseline hormone therapy (49) and hormone therapy at the time of the study (34). Patients had similar levels of global QoL, anxiety, depression and fatigue as controls. They reported more urinary troubles (urinary function and incontinence) (p < 0.0001) and more sexual dysfunctions (p < 0.0001) than controls, whatever the treatment group. Worse bowel dysfunction was reported in patients treated by RT and RP+RT (p < 0.002). According to the treatments, RP groups had the worst urinary function and incontinence (p < 0.01), and reported more bowel bother when the treatment was combined with RT.

CONCLUSIONS

Even though patients reported similar global QoL as control 10 years after treatment, patients reported numerous urinary and sexual dysfunctions. Patients treated with RP+RT reported cumulative sequelae of both treatments.