Kidney Transplantation in Patients With AA Amyloidosis: Outcomes in a French Multicenter Cohort.

RATIONALE & OBJECTIVE: Outcomes of kidney transplantation for patients with renal AA amyloidosis are uncertain, with reports of poor survival and high rates of disease recurrence. However, the data are inconclusive and mostly based on studies from the early 2000s and earlier. STUDY DESIGN: Retrospective multicenter cohort study. SETTING & PARTICIPANTS: We searched the French national transplant database to identify all patients with renal AA amyloidosis who underwent kidney transplantation between 2008 and 2018. EXPOSURES: Age, cause of amyloidosis, use of biotherapies, and C-reactive protein levels. OUTCOMES: Outcomes were all-cause mortality and allograft loss. We also reported amyloidosis allograft recurrence, occurrence of acute rejection episodes, as well as infectious, cardiovascular, and neoplastic disease events. ANALYTICAL APPROACH: Kaplan-Meier estimator for mortality and cumulative incidence function method for allograft loss. Factors associated with patient and allograft survival were investigated using a Cox proportional hazards model and a cause-specific hazards model, respectively. RESULTS: 86 patients who received kidney transplants for AA amyloidosis at 26 French centers were included. The median age was 49.4 years (IQR, 39.7-61.1). The main cause of amyloidosis was familial Mediterranean fever (37 cases; 43%). 16 (18.6%) patients received biotherapy after transplantation. Patient survival rates were 94.0% (95% CI, 89.1-99.2) at 1 year and 85.5% (77.8-94.0) at 5 years after transplantation. Cumulative incidences of allograft loss were 10.5% (4.0-17.0) at 1 year and 13.0% (5.8-20.1) at 5 years after transplantation. Histologically proven AA amyloidosis recurrence occurred in 5 transplants (5.8%). An infection requiring hospitalization developed in 55.8% of cases, and there was a 27.9% incidence of acute allograft rejection. Multivariable analysis showed that C-reactive protein concentration at the time of transplantation was associated with patient survival (HR, 1.01; 95% CI, 1.00-1.02; P=0.01) and allograft survival (HR, 1.68; 95% CI, 1.10-2.57; P=0.02). LIMITATIONS: The study lacked a control group, and the effect of biotherapies on transplantation outcomes could not be explored. CONCLUSIONS: This relatively contemporary cohort of patients who received a kidney transplant for AA amyloidosis experienced favorable rates of survival and lower recurrence rates than previously reported. These data support the practice of treating these patients with kidney transplantation for end-stage kidney disease. PLAIN-LANGUAGE SUMMARY: AA amyloidosis is a severe and rare disease. Kidney involvement is frequent and leads to end-stage kidney disease. Because of the involvement of other organs, these patients are often frail, which has raised concerns about their suitability for kidney transplantation. We reviewed all patients with AA amyloidosis nephropathy who underwent kidney transplantation in France in the recent era (2008-2018) and found that the outcomes after kidney transplantation were favorable, with 85.5% of patients still alive 5 years after transplantation, a survival rate that is comparable to the outcomes of patients receiving a transplant for other forms of kidney diseases. Recurrence of amyloidosis in the transplanted kidney was infrequent (5.8%). These data support the practice of kidney transplantation for patients with AA amyloidosis who experience kidney failure.

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.

AgeR deletion decreases soluble fms-like tyrosine kinase 1 production and improves post-ischemic angiogenesis in uremic mice.

Peripheral arterial disease occurs more frequently and has a worse prognosis in patients with chronic kidney disease (CKD). The receptor for advanced glycation end products (RAGE) is involved in multiple aspects of uremia-associated vasculopathy. Previous data suggest that the RAGE pathway may promote soluble fms-like tyrosine kinase 1 (sFlt1) production, an anti-angiogenic molecule. Thus, we tested the hypothesis that the deletion of AgeR would decrease sFlt1 production and improve post-ischemic revascularization in uremic condition. We used a well-established CKD model (5/6 nephrectomy) in WT and AgeR-/- C57/Bl6 mice. Hindlimb ischemia was induced by femoral artery ligation. Revascularization was evaluated by complementary approaches: ischemic limb retraction, LASCA imagery, and capillary density. The production of sFlt1 was assessed at both RNA and protein levels. After hindlimb ischemia, uremic mice showed slower functional recovery (p < 0.01), decreased reperfusion (p < 0.01), lower capillary density (p = 0.02), and increased circulating sFlt1 levels (p = 0.03). AgeR deletion restored post-ischemic angiogenesis and was protective from sFlt1 increase in uremic mice. These findings show the main role of RAGE in post-ischemic angiogenesis impairment associated with CKD. RAGE may represent a key target for building new therapeutic approaches to improve the outcome of CKD patients with PAD.

Living kidney donor evaluation for all candidates with normal estimated GFR for age.

Multiple days assessments are frequent for the evaluation of candidates to living kidney donation, combined with an early GFR estimation (eGFR). Living kidney donation is questionable when eGFR is <90 ml/min/1.73 m2 (KDIGO guidelines) or 80 ml/min/1.73 m2 (most US centres). However, age-related GFR decline results in a lower eGFR for older candidates. That may limit the number of older kidney donors. Yet, continuing the screening with a GFR measure increases the number of eligible donors. We hypothesized that in-depth screening should be proposed to all candidates with a normal eGFR for age. We compared the evolution of eGFR after donation between three groups of predonation eGFR: normal for age (Sage ) higher than 90 or 80 ml/min/1.73 m2 (S90 and S80, respectively); across three age groups (<45, 45-55, >55 years) in a population of 1825 French living kidney donors with a median follow-up of 5.9 years. In donors younger than 45, postdonation eGFR, absolute- and relative-eGFR variation were not different between the three groups. For older donors, postdonation eGFR was higher in S90 than in S80 or Sage but other comparators were identical. Postdonation eGFR slope was comparable between all groups. Our results are in favour of in-depth screening for all candidates to donation with a normal eGFR for age.

Efficacy of rituximab in thymoma associated minimal change disease: case report.

BACKGROUND: Thymomas have been associated with a broad spectrum of autoimmune diseases. Minimal change disease (MCD) is the most frequent pathological lesion reported. Pathophysiological mechanisms involved in secondary MCD, and linking MCD to thymoma are not yet fully explained, although the hypothesis of T cell dysfunction has been suggested. The fundamental therapeutic principles are steroids and surgical treatment of thymoma, but failures and relapses often require immunosuppressant combinations. CASE PRESENTATION: A 62-year-old female was admitted in our unit for a nephrotic syndrome associated with a thymoma. The diagnosis of thymoma associated MCD was confirmed by kidney biopsy. After surgical resection of the thymoma and steroid therapy, no remission was observed. Immunosuppressive therapy was then intensified with introduction of rituximab. Here, we report a steroid-resistant nephrotic syndrome secondary to MCD associated thymoma, which achieved complete remission after rituximab therapy. To the best of our knowledge, this is the first report of the use and efficacy of rituximab therapy in this pathology. CONCLUSIONS: Our case report suggests that primary and secondary MCD may share similar pathophysiological mechanisms. It does not allow us to draw any conclusions about the mechanism of action of rituximab, but we believe this report argues for the safety and efficacy of rituximab use in thymoma-associated MCD, and therefore constitutes a rationale for future studies.

Unilateral nephrectomy versus renal arterial embolization and technique survival in peritoneal dialysis patients with autosomal dominant polycystic kidney disease.

BACKGROUND: Autosomal dominant polycystic kidney disease (ADPKD) is a common genetic disorder associated with progressive enlargement of the kidneys and liver. ADPKD patients may require renal volume reduction, especially before renal transplantation. The standard treatment is unilateral nephrectomy. However, surgery incurs a risk of blood transfusion and alloimmunization. Furthermore, when patients are treated with peritoneal dialysis (PD), surgery is associated with an increased risk of temporary or definitive switch to haemodialysis (HD). Unilateral renal arterial embolization can be used as an alternative approach to nephrectomy. METHODS: We performed a multicentre retrospective study to compare the technique of survival of PD after transcatheter renal artery embolization with that of nephrectomy in an ADPKD population. We included ADPKD patients treated with PD submitted to renal volume reduction by either surgery or arterial embolization. Secondary objectives were to compare the frequency and duration of a temporary switch to HD in both groups and the impact of the procedure on PD adequacy parameters. RESULTS: More than 700 patient files from 12 centres were screened. Only 37 patients met the inclusion criteria (i.e. treated with PD at the time of renal volume reduction) and were included in the study (21 embolized and 16 nephrectomized). Permanent switch to HD was observed in 6 embolized patients (28.6%) versus 11 nephrectomized patients (68.8%) (P = 0.0001). Renal artery embolization was associated with better technique survival: subdistribution hazard ratio (SHR) 0.29 [95% confidence interval (CI) 0.12-0.75; P = 0.01]. By multivariate analysis, renal volume reduction by embolization and male gender were associated with a decreased risk of switching to HD. After embolization, a decrease in PD adequacy parameters was observed but no embolized patients required temporary HD; the duration of hospitalization was significantly lower [5 days [interquartile range (IQR) 4.0-6.0] in the embolization group versus 8.5 days (IQR 6.0-11.0) in the surgery group. CONCLUSIONS: Transcatheter renal artery embolization yields better technique survival of PD in ADPKD patients requiring renal volume reduction.

Receptor for advanced glycation end products: a key molecule in the genesis of chronic kidney disease vascular calcification and a potential modulator of sodium phosphate co-transporter PIT-1 expression.

BACKGROUND: Chronic kidney disease (CKD) is associated with increased cardiovascular mortality, frequent vascular calcification (VC) and accumulation of uraemic toxins. Advanced glycation end products and S100 proteins interact with the receptor for advanced glycation end products (RAGE). In the present work, we aimed to investigate the role(s) of RAGE in the CKD-VC process. METHODS: Apoe-/- or Apoe-/-Ager (RAGE)-/- male mice were assigned to CKD or sham-operated groups. A high-phosphate diet was given to a subgroup of Apoe-/-and Apoe-/-Ager-/- CKD mice. Primary cultures of Ager+/+ and Ager-/- vascular smooth muscle cells (VSMCs) were established and stimulated with either vehicle, inorganic phosphate (Pi) or RAGE ligands (S100A12; 20 µM). RESULTS: After 12 weeks of CKD we observed a significant increase in RAGE ligand (AGE and S100 proteins) concentrations in the serum of CKD Apoe-/- mice. Ager messenger RNA (mRNA) levels were 4-fold higher in CKD vessels of Apoe-/- mice. CKD Apoe-/- but not CKD Apoe-/- or Ager-/- mice displayed a marked increase in the VC surface area. Similar trends were found in the high-phosphate diet condition. mRNA levels of Runx2 significantly increased in the Apoe-/- CKD group. In vitro, stimulation of Ager+/+VSMCs with Pi or S100A12 induced mineralization and osteoblast transformation, and this was inhibited by phosphonoformic acid (Pi co-transporters inhibitor) and Ager deletion. In vivo and in vitro RAGE was necessary for regulation of the expression of Pit-1, at least in part through production of reactive oxygen species. CONCLUSION: RAGE, through the modulation of Pit-1 expression, is a key molecule in the genesis of VC.

Outcome of autosomal dominant polycystic kidney disease patients on peritoneal dialysis: a national retrospective study based on two French registries (the French Language Peritoneal Dialysis Registry and the French Renal Epidemiology and Information Network).

Background: Pathological features of autosomal dominant polycystic kidney disease (ADPKD) include enlarged kidney volume, higher frequency of digestive diverticulitis and abdominal wall hernias. Therefore, many nephrologists have concerns about the use of peritoneal dialysis (PD) in ADPKD patients. We aimed to analyse survival and technique failure in ADPKD patients treated with PD. Methods: We conducted two retrospective studies on patients starting dialysis between 2000 and 2010. We used two French registries: the French Renal Epidemiology and Information Network (REIN) and the French language Peritoneal Dialysis Registry (RDPLF). Using the REIN registry, we compared the clinical features and outcomes of ADPKD patients on PD (n = 638) with those of ADPKD patients on haemodialysis (HD) (n = 4653); with the RDPLF registry, those same parameters were determined for ADPKD patients on PD (n = 797) and compared with those of non-ADPKD patients on PD (n = 12 059). Results: A total of 5291 ADPKD patients and 12 059 non-ADPKD patients were included. Analysis of the REIN registry found that ADPKD patients treated with PD represented 10.91% of the ADPKD population. During the study period, PD was used for 11.2% of the non-ADPKD population. Compared with ADPKD patients on HD, ADPKD patients on PD had higher serum albumin levels (38.8 ± 5.3 versus 36.8 ± 5.7 g/dL, P < 0.0001) and were less frequently diabetic (5.31 versus 7.71%, P < 0.03). The use of PD in ADPKD patients was positively associated with the occurrence of a kidney transplantation but not with death [hazard ratio 1.15 (95% confidence interval 0.84-1.58)]. Analysis of the RDPLF registry found that compared with non-ADPKD patients on PD, ADPKD patients on PD were younger and had fewer comorbidities and better survival. ADPKD status was not associated with an increased risk of technique failure or an increased risk of peritonitis. Conclusions: According to our results, PD is proposed to a selected population of ADPKD patients, PD does not have a negative impact on ADPKD patients' overall survival and PD technique failure is not influenced by ADPKD status. Therefore PD is a reasonable option for ADPKD patients.

Signaling of Serum Amyloid A Through Receptor for Advanced Glycation End Products as a Possible Mechanism for Uremia-Related Atherosclerosis.

OBJECTIVE: Cardiovascular disease is the leading cause of death in patients with end-stage renal disease. Serum amyloid A (SAA) is an acute phase protein and a binding partner for the multiligand receptor for advanced glycation end products (RAGE). We investigated the role of the interaction between SAA and RAGE in uremia-related atherogenesis. APPROACH AND RESULTS: We used a mouse model of uremic vasculopathy, induced by 5 of 6 nephrectomy in the Apoe(-/-) background. Sham-operated mice were used as controls. Primary cultures of Ager(+/+) and Ager(-/-) vascular smooth muscle cells (VSMCs) were stimulated with recombinant SAA, S100B, or vehicle alone. Relevance to human disease was assessed with human VSMCs. The surface area of atherosclerotic lesions at the aortic roots was larger in uremic Apoe(-/-) than in sham-operated Apoe(-/-) mice (P<0.001). Furthermore, atherosclerotic lesions displayed intense immunostaining for RAGE and SAA, with a pattern similar to that of α-SMA. Ager transcript levels in the aorta were 6× higher in uremic animals than in controls (P<0.0001). Serum SAA concentrations were higher in uremic mice, not only after 4 weeks of uremia but also at 8 and 12 weeks of uremia, than in sham-operated animals. We investigated the functional role of RAGE in uremia-induced atherosclerosis further, in animals lacking RAGE. We found that the induction of uremia in Apoe(-/-) Ager(-/-) mice did not accelerate atherosclerosis. In vitro, the stimulation of Ager(+/+) but not of Ager(-/-) VSMCs with SAA or S100B significantly induced the production of reactive oxygen species, the phosphorylation of AKT and mitogen-activated protein kinase-extracellular signal-regulated kinases and cell migration. Reactive oxygen species inhibition with N-acetyl cysteine significantly inhibited both the phosphorylation of AKT and the migration of VSMCs. Similar results were obtained for human VSMCs, except that the phosphorylation of mitogen-activated protein kinase-extracellular signal-regulated kinases, rather than of AKT, was subject to specific redox-regulation by SAA and S100B. Furthermore, human aortic atherosclerotic sections were positively stained for RAGE and SAA. CONCLUSIONS: Uremia upregulates SAA and RAGE expression in the aortic wall and in atherosclerotic lesions in mice. Ager(-/-) animals are protected against the uremia-induced acceleration of atherosclerosis. SAA modulates the functions of murine and human VSMCs in vitro in a RAGE-dependent manner. This study, therefore, identifies SAA as a potential new uremic toxin involved in uremia-related atherosclerosis through interaction with RAGE.

Deletion of receptor for advanced glycation end products exacerbates lymphoproliferative syndrome and lupus nephritis in B6-MRL Fas lpr/j mice.

The receptor for advanced glycation end products (RAGE) is a pattern recognition receptor that interacts with advanced glycation end products, but also with C3a, CpG DNA oligonucleotides, and alarmin molecules such as HMGB1 to initiate a proinflammatory reaction. Systemic lupus erythematosus is an autoimmune disorder associated with the accumulation of RAGE ligands. We generated mice invalidated for RAGE in the lupus-prone B6-MRL Fas lpr/j background to determine the role of RAGE in the pathogenesis of systemic lupus erythematosus. We compared the phenotype of these mice with that of their wild-type and B6-MRL Fas lpr/j littermates. Lymphoproliferative syndrome, production of anti-dsDNA Abs, lupus nephritis, and accumulation of CD3(+)B220(+)CD4(-)CD8(-) autoreactive T cells (in the peripheral blood and the spleen) were significantly increased in B6-MRL Fas lpr/j RAGE(-/-) mice compared with B6-MRL Fas lpr/j mice (respectively p < 0.005, p < 0.05, p < 0.001, and p < 0.001). A large proportion of autoreactive T cells from B6-MRL Fas lpr/j mice expressed RAGE at their surface. Time course studies of annexin V expression revealed that autoreactive T cells in the spleen of B6-MRL Fas lpr/j-RAGE(-/-) mice exhibited a delay in apoptosis and expressed significantly less activated caspase 3 (39.5 ± 4.3%) than T cells in B6-MRL Fas lpr/j mice (65.5 ± 5.2%) or wild-type mice (75.3 ± 2.64%) (p = 0.02). We conclude that the deletion of RAGE in B6-MRL Fas lpr/j mice promotes the accumulation of autoreactive CD3(+)B220(+)CD4(-)CD8(-) T cells, therefore exacerbating lymphoproliferative syndrome, autoimmunity, and organ injury. This suggests that RAGE rescues the apoptosis of T lymphocytes when the death receptor Fas/CD95 is dysfunctional.

Reconsidering the Lack of Urea Toxicity in Dialysis Patients.

Urea is an old uremic toxin which has been used for many years as a global biomarker of CKD severity and dialysis adequacy. Old studies were not in favor of its role as a causal factor in the pathogenesis of complications associated with the uremic state. However, recent experimental and clinical evidence is compatible with both direct and indirect toxicity of urea, particularly via the deleterious actions of urea-derived carbamylated molecules. Further studies are clearly needed to explore the potential relevance of urea-related CKD complications for patient management, in particular the place of new therapeutic strategies to prevent urea toxicity.

Recurrent IgA nephropathy is predicted by altered glycosylated IgA, autoantibodies and soluble CD89 complexes.

IgA nephropathy (IgAN), the most common primary glomerulonephritis worldwide, frequently leads to end-stage renal disease and kidney transplantation. However, disease recurrence often occurs after transplantation. Here we evaluated the predictive value of three markers for IgAN recurrence: the presence of galactose-deficient IgA1, IgG anti-IgA autoantibodies, and IgA-soluble (s) CD89 complexes. This was analyzed in 38 kidney transplant recipients with IgAN recurrence and compared with 22 patients transplanted for IgAN but without recurrence and with 17 healthy controls. Pre-transplantation galactose-deficient IgA1 serum levels were significantly higher in the recurrence compared with the no recurrence or control groups. IgA-IgG complexes were significantly elevated in the recurrence group. Both the recurrence and no recurrence groups had increased values of IgA-sCD89 complexes compared with healthy controls, but values were significantly lower in patients with recurrence compared with no recurrence. Areas under the receiver operating curve of the markers in pre-transplantation sera were 0.86 for galactose-deficient-IgA, 0.82 for IgA-IgG, and 0.78 for sCD89-IgA; all significant. Disease recurrence was associated with decreased serum galactose-deficient IgA1 and appearance of mesangial-galactose-deficient IgA1 deposits, whereas increased serum IgA-sCD89 complexes were associated with mesangial sCD89 deposits. Thus, galactose-deficient-IgA1, IgG autoantibodies, and IgA-sCD89 complexes are valuable biomarkers to predict disease recurrence, highlighting major pathogenic mechanisms in IgAN.

Formin mDia1 mediates vascular remodeling via integration of oxidative and signal transduction pathways.

RATIONALE: The mammalian diaphanous-related formin (mDia1), governs microtubule and microfilament dynamics while functioning as an effector for Rho small GTP-binding proteins during key cellular processes such as adhesion, cytokinesis, cell polarity, and morphogenesis. The cytoplasmic domain of the receptor for advanced glycation endproducts binds to the formin homology 1 domain of mDia1; mDia1 is required for receptor for advanced glycation endproducts ligand-induced cellular migration in transformed cells. OBJECTIVE: Because a key mechanism in vascular remodeling is the induction of smooth muscle cell migration, we tested the role of mDia1 in this process. METHODS AND RESULTS: We report that endothelial denudation injury to the murine femoral artery significantly upregulates mDia1 mRNA transcripts and protein in the injured vessel, particularly in vascular smooth muscle cells within the expanding neointima. Loss of mDia1 expression significantly reduces pathological neointimal expansion consequent to injury. In primary murine aortic smooth muscle cells, mDia1 is required for receptor for advanced glycation endproducts ligand-induced membrane translocation of c-Src, which leads to Rac1 activation, redox phosphorylation of AKT/glycogen synthase kinase 3ß, and consequent smooth muscle cell migration. CONCLUSIONS: We conclude that mDia1 integrates oxidative and signal transduction pathways triggered, at least in part, by receptor for advanced glycation endproducts ligands, thereby regulating pathological neointimal expansion.

Is social deprivation associated with the peritoneal dialysis outcomes? A cohort study with REIN registry data.

BACKGROUND: Social deprivation is associated with lower peritoneal dialysis (PD) uptake. This study was carried out to evaluate the role of social deprivation on the outcome of PD. METHODS: This was a retrospective study of data extracted from the Renal Epidemiology and Information Network registry for patients older than 18 years who started PD in metropolitan France between 1 January 2017 and 30 June 2018. The end of the observation period was 31 December 2020. The exposure was the European Deprivation Index calculated using the patient's address. The events of interest were death, transfer to haemodialysis (HD), transplantation and the composite event of death or transfer to HD. A Cox model and Fine and Gray model were used for the analysis. RESULTS: A total of 1581 patients were included, of whom 418 (26.5%) belonged to Quintile 5 of the European Deprivation Index (the most deprived patients). In the Cox model, the most deprived subjects did not have a greater risk of death (cause-specific hazard ratio (cs-HR): 0.76 [95% confidence interval (CI): 0.53-1.10], transfer to HD (cs-HR 1.37 [95% CI: 0.95-1.98]) or the composite event of death or transfer to HD (cs-HR: 1.08 [95% CI: 0.84-1.38]) or a lower risk of kidney transplantation (cs-HR: 0.73 [95% CI: 0.48-1.10]). In the competing risk analysis, the most deprived subjects had a higher risk of transfer to HD (subdistribution hazard ratio (sd-HR): 1.54 [95% CI: 1.08-2.19]) and lower access to kidney transplantation (sd-HR: 0.68 [0.46-0.99]). CONCLUSION: In PD patients, social deprivation was not associated with death or the composite event of death or transfer to HD. Socially deprived individuals had a greater risk of transfer to HD and lower access to kidney transplantation in the competing risk analysis.

Legionnaires Disease in Solid Organ Transplant Recipients: A Decade-Long Nationwide Study in France.

BACKGROUND: Legionnaires disease (LD) is a rare, life-threatening opportunistic bacterial infection that poses a significant risk to patients with impaired cell-mediated immunity such as solid organ transplant recipients. However, the epidemiologic features, clinical presentation, and outcomes of LD in this population are poorly described. RESEARCH QUESTION: What are the clinical manifestations, radiologic presentation, risk factors for severity, treatment, and outcome of LD in solid organ transplant recipients? STUDY DESIGN AND METHODS: In this 10-year multicenter retrospective cohort study in France, where LD notification is mandatory, patients were identified by hospital discharge databases. Diagnosis of LD relied on positive culture findings from any respiratory sample, positive urinary antigen test (UAT) results, positive specific serologic findings, or a combination thereof. Severe LD was defined as admission to the ICU. RESULTS: One hundred one patients from 51 transplantation centers were eligible; 64 patients (63.4%) were kidney transplant recipients. Median time between transplantation and LD was 5.6 years (interquartile range, 1.5-12 years). UAT results were positive in 92% of patients (89/97). Among 31 patients with positive culture findings in respiratory samples, Legionella pneumophila serogroup 1 was identified in 90%. Chest CT imaging showed alveolar consolidation in 98% of patients (54 of 57), ground-glass opacity in 63% of patients (36 of 57), macronodules in 21% of patients (12 of 57), and cavitation in 8.8% of patients (5 of 57). Fifty-seven patients (56%) were hospitalized in the ICU. In multivariate analysis, severe LD was associated with negative UAT findings at presentation (P = .047), lymphopenia (P = .014), respiratory symptoms (P = .010), and pleural effusion (P = .039). The 30-day and 12-month mortality rates were 8% (8 of 101) and 20% (19 of 97), respectively. In multivariate analysis, diabetes mellitus was the only factor associated with 12-month mortality (hazard ratio, 3.2; 95% OR, 1.19-8.64; P = .022). INTERPRETATION: LD is a late and severe complication occurring in solid organ transplant recipients that may present as pulmonary nodules on which diabetes impacts its long-term prognosis.

Comparison of four equations for estimation of glomerular filtration rate in predicting cardiovascular events and subclinical vascular disease in patients with type-2 diabetes.

AIMS: Chronic kidney disease (CKD), defined by a low glomerular filtration rate (GFR), is a predictor of cardiovascular disease in patients with type-2 diabetes (T2D). We aimed to compare four GFR equations in predicting future cardiovascular events in T2D and the presence of subclinical vascular disease. METHODS: Four equations were used to estimate GFR in asymptomatic T2D patients consulting our centre for cardiovascular assessment. Follow-up was performed to collect cardiovascular events. Cox proportional hazard ratio (HR) was used to build and compare prediction models, and the incremental value of the addition of GFR with any of the 4 formulas was evaluated. The ability to triage patients with and without CVD events according to GFR were assessed by comparing the receiver operator characteristics (ROC) curves with the 4 models. RESULTS: Among 829 asymptomatic T2D patients, the CKD prevalence was 20.2% for Modification of Diet in Renal Disease (MDRD), 17.3% for Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI), 20.7% for Lund-Malmö Revised (LMR) and 21.4% for Full Age Spectrum (FAS). All the estimated GFRs were well correlated from one formula to another, with stronger agreement to define CKD (GFR <60 mL/min/1.73 m2) between MDRD and CKD-EPI, and between LMR and FAS. The 5-year incidence of cardiovascular events was 8% (n = 63). After adjustment on covariables, CKD was significantly associated with cardiovascular events when defined by MDRD (HR = 2.04; 1.15-3.60) and CKD-EPI (HR = 1.90; 1.05-3.41) but missed statistical significance when using LMR (HR = 1.74; 0.97-3.14) or FAS (HR = 1.71; 0.94-3.14). Only the prediction models including MDRD and CKD-EPI provided a significant incremental information to the predictive model without GFR, but the area under the ROC curves were similar with the 4 models: 0.60 [0.54-0.68] for MDRD, 0.61 [0.49-0.65] for CKD-EPI and 0.62 [0.55-0.69] for LMR and FAS, without any significant difference among formulas. CONCLUSION: In asymptomatic T2D patients, MDRD and CKD-EPI may be preferable when more specificity is desired (stronger association between GFR and CVD events), while LMR and FAS appear more sensitive by including a higher number of patients with GFR <60 mL/min/1.73 m2.

Effect of social deprivation on peritoneal dialysis uptake: A mediation analysis with the data of the REIN registry.

BACKGROUND: Social deprivation could act as a barrier to peritoneal dialysis (PD). The objective of this study was to assess the association between social deprivation estimated by the European deprivation index (EDI) and PD uptake and to explore the potential mediators of this association. METHODS: From the Renal Epidemiology and Information Network registry, patients who started dialysis in 2017 were included. The EDI was calculated based on the patient's address. The event of interest was the proportion of PD 3 months after dialysis initiation. A mediation analysis with a counterfactual approach was carried out to evaluate the direct and indirect effect of the EDI on the proportion of PD. RESULTS: Among the 9588 patients included, 1116 patients were on PD; 2894 (30.2%) patients belonged to the most deprived quintile (Q5). PD was associated with age >70 years (odds ratio (OR) 0.79 [95% confidence interval (CI): 0.69-0.91]), male gender (0.85 [95% CI: 0.74-0.97]), cardiovascular disease (OR 0.86 [95% CI: 0.86-1.00]), chronic heart failure (OR 1.34 [95% CI: 1.13-1.58]), active cancer (OR 0.67 [95% CI: 0.53-0.85]) and obesity (OR 0.75 [95% CI: 0.63-0.89]). In the mediation analysis, Q5 had a direct effect on PD proportion OR 0.84 [95% CI: 0.73-0.96]. The effect of Q5 on the proportion of PD was mediated by haemoglobin level at dialysis initiation (OR 0.96 [95% CI: 0.94-0.98]) and emergency start (OR 0.98 [95% CI: 0.96-0.99]). CONCLUSION: Social deprivation, estimated by the EDI, was associated with a lower PD uptake. The effect of social deprivation was mediated by haemoglobin level, a proxy of predialysis care and emergency start.

Advanced glycation end product (AGE)-receptor for AGE (RAGE) signaling and up-regulation of Egr-1 in hypoxic macrophages.

Receptor for advanced glycation end product (RAGE)-dependent signaling has been implicated in ischemia/reperfusion injury in the heart, lung, liver, and brain. Because macrophages contribute to vascular perturbation and tissue injury in hypoxic settings, we tested the hypothesis that RAGE regulates early growth response-1 (Egr-1) expression in hypoxia-exposed macrophages. Molecular analysis, including silencing of RAGE, or blockade of RAGE with sRAGE (the extracellular ligand-binding domain of RAGE), anti-RAGE IgG, or anti-AGE IgG in THP-1 cells, and genetic deletion of RAGE in peritoneal macrophages, revealed that hypoxia-induced up-regulation of Egr-1 is mediated by RAGE signaling. In addition, the observation of increased cellular release of RAGE ligand AGEs in hypoxic THP-1 cells suggests that recruitment of RAGE in hypoxia is stimulated by rapid production of RAGE ligands in this setting. Finally, we show that mDia-1, previously shown to interact with the RAGE cytoplasmic domain, is essential for hypoxia-stimulated regulation of Egr-1, at least in part through protein kinase C betaII, ERK1/2, and c-Jun NH(2)-terminal kinase signaling triggered by RAGE ligands. Our findings highlight a novel mechanism by which an extracellular signal initiated by RAGE ligand AGEs regulates Egr-1 in a manner requiring mDia-1.

High Mortality and Graft Loss after Infective Endocarditis in Kidney Transplant Recipients: A Case-Controlled Study from Two Centers.

Kidney transplant recipients (KTRs) tend to develop infections with characteristic epidemiology, presentation, and outcome. While infective endocarditis (IE) is among such complications in KTRs, the literature is scarce. We describe the presentation, epidemiology, and factors associated with IE in KTRs. We performed a retrospective case/control study which included patients from two centers. First episodes of definite or possible IE (Duke criteria) in adult KTRs from January 2010 to December 2018 were included, as well as two controls per case, and followed until 31 December 2019. Clinical, biological, and microbiological data and the outcome were collected. Survival was studied using the Kaplan-Meier method. Finally, we searched for factors associated with the onset of IE in KTRs by the comparison of cases and controls. Seventeen cases and 34 controls were included. IE was diagnosed after a mean delay of 78 months after KT, mostly on native valves of the left heart only. Pathogens of digestive origin were most frequently involved (six Enterococcus spp, three Streptococcus gallolyticus, and one Escherichia coli), followed by Staphylococci (three cases of S. aureus and S. epidermidis each). Among the risk factors evaluated, age, vascular nephropathy, and elevated calcineurin inhibitor through levels were significantly associated with the occurrence of IE in our study. Patient and death-censored graft survival were greatly diminished five years after IE, compared to controls being 50.3% vs. 80.6% (p < 0.003) and 29.7% vs. 87.5% (p < 0.002), respectively. IE in KTRs is a disease that carries significant risks both for the survival of the patient and the transplant.

Revealing the elasticity of an individual aortic fiber during ageing at nanoscale by in situ atomic force microscopy.

Arterial stiffness is a complex process affecting the aortic tree that significantly contributes to cardiovascular diseases (systolic hypertension, coronary artery disease, heart failure or stroke). This process involves a large extracellular matrix remodeling mainly associated with elastin content decrease and collagen content increase. Additionally, various chemical modifications that accumulate with ageing have been shown to affect long-lived assemblies, such as elastic fibers, that could affect their elasticity. To precisely characterize the fiber changes and the evolution of its elasticity with ageing, high resolution and multimodal techniques are needed for precise insight into the behavior of a single fiber and its surrounding medium. In this study, the latest developments in atomic force microscopy and the related nanomechanical modes are used to investigate the evolution and in a near-physiological environment, the morphology and elasticity of aorta cross sections obtained from mice of different ages with an unprecedented resolution. In correlation with more classical approaches such as pulse wave velocity and fluorescence imaging, we demonstrate that the relative Young's moduli of elastic fibers, as well as those of the surrounding areas, significantly increase with ageing. This nanoscale characterization presents a new view on the stiffness process, showing that, besides the elastin and collagen content changes, elasticity is impaired at the molecular level, allowing a deeper understanding of the ageing process. Such nanomechanical AFM measurements of mouse tissue could easily be applied to studies of diseases in which elastic fibers suffer pathologies such as atherosclerosis and diabetes, where the precise quantification of fiber elasticity could better follow the fiber remodeling and predict plaque rupture.