Circulating alternative pathway complement cleavage factor Bb is associated with vascular lesions and outcomes in IgA nephropathy

BACKGROUND

Complement alternative pathway (AP) activation is linked to immunoglobulin A nephropathy (IgAN) prognosis severity, but Bb fragment's role is unclear. We examined the relationship between serum Bb fragment concentration at IgAN diagnosis and disease activity and outcomes.

METHODS

This retrospective study included 125 biopsy-proven IgAN patients [age 39.9 years, 75% male, estimated glomerular filtration rate (eGFR) 82 ml/min, proteinuria 0.5 g/day] enrolled from 1984 to 2010 and followed for a minimum of 18 months. Monitoring continued until the last follow-up, end-stage kidney disease (ESKD) or death. Serum Bb fragment was measured using an enzyme-linked immunosorbent assay at diagnosis. Oxford classification and global optical score (GOS) were utilized for pathology assessment.

RESULTS

Patients were followed for a median of 16 years; 42% developed chronic kidney disease stage ≥3, 19% reached ESKD and 9% died. Serum Bb fragment concentration negatively correlated with eGFR values at the last follow-up and positively with vascular and tubular histopathological indices. In univariate Cox regression analyses, higher Bb fragment concentration was associated with ESKD alongside older age, increased body mass index, arterial hypertension, lower eGFR, higher proteinuria, E1, S1, T1-2, GOS and corticotherapy. Patients with Bb levels ≥14.3 μg/ml had shorter mean kidney survival time (19.5 versus 22.7 years, P = .07); after adjusting for progression risk factors, the association persisted [hazard ratio 4.76 (95% confidence interval 1.56-14.43)].

CONCLUSIONS

Serum Bb fragment concentration at diagnosis may predict long-term IgAN outcomes, potentially due to AP activation at the endothelial surface. Further research is needed to confirm these results and evaluate Bb fragment's role in IgAN management.

Validation of the international IgA nephropathy prediction tool in a French cohort beyond 10 years after diagnosis

INTRODUCTION

The International IgA Nephropathy Network developed a tool (IINN-PT) for predicting the risk of end-stage renal disease (ESRD) or a 50% decline in the estimated glomerular filtration rate (eGFR). We aimed to validate this tool in a French cohort with longer follow-up than previously published validation studies.

METHODS

The predicted survival of patients with biopsy-proven immunoglobulin A nephropathy (IgAN) from the Saint Etienne University Hospital cohort was computed with IINN-PT models with or without ethnicity. The primary outcome was the occurrence of either ESRD or a 50% decline in eGFR. The models' performances were evaluated through c-statistics, discrimination and calibration analysis.

RESULTS

There were 473 patients with biopsy-proven IgAN, with a median follow-up of 12.4 years. Models with and without ethnicity showed areas under the curve (95% confidence interval) of 0.817 (0.765; 0.869) and 0.833 (0.791; 0.875) and R2D of 0.28 and 0.29, respectively, and an excellent discrimination of groups of increasing predicted risk (P < .001). The calibration analysis was good for both models up to 15 years after diagnosis. The model without ethnicity exhibited a mathematical issue of survival function after 15 years.

DISCUSSION

The IINN-PT provided good performances even after 10 years post-biopsy as showed by our study based on a cohort with a longer follow-up than previous cohorts (12.4 versus <6 years). The model without ethnicity exhibited better performances up to 15 years but became aberrant beyond this point due to a mathematical issue affecting the survival function. Our study sheds light on the usefulness of integrating ethnicity as a covariable for prediction of IgAN course.

Nonskeletal and skeletal effects of high doses versus low doses of vitamin D3 in renal transplant recipients: Results of the VITALE (VITamin D supplementation in renAL transplant recipients) study, a randomized clinical trial

Vitamin D sufficiency is associated with a reduced risk of fractures, diabetes mellitus, cardiovascular events, and cancers, which are frequent complications after renal transplantation. The VITALE (VITamin D supplementation in renAL transplant recipients) study is a multicenter double-blind randomized trial, including nondiabetic adult renal transplant recipients with serum 25-hydroxy vitamin D (25(OH) vitamin D) levels of <30 ng/mL, which is randomized 12 to 48 months after transplantation to receive high (100 000 IU) or low doses (12 000 IU) of cholecalciferol every 2 weeks for 2 months and then monthly for 22 months. The primary outcome was a composite endpoint, including diabetes mellitus, major cardiovascular events, cancer, and death. Of 536 inclusions (50.8 [13.7] years, 335 men), 269 and 267 inclusions were in the high-dose and low-dose groups, respectively. The serum 25(OH) vitamin D levels increased by 23 versus 6 ng/mL in the high-dose and low-dose groups, respectively (P < .0001). In the intent-to-treat analysis, 15% versus 16% of the patients in the high-dose and low-dose groups, respectively, experienced a first event of the composite endpoint (hazard ratio, 0.94 [0.60-1.48]; P = .78), whereas 1% and 4% of patients in the high-dose and low-dose groups, respectively, experienced an incident symptomatic fracture (odds ratio, 0.24 [0.07-0.86], P = .03). The incidence of adverse events was similar between the groups. After renal transplantation, high doses of cholecalciferol are safe but do not reduce extraskeletal complications (trial registration: ClinicalTrials.gov; identifier: NCT01431430).

Results from part A of the multi-center, double-blind, randomized, placebo-controlled NefIgArd trial, which evaluated targeted-release formulation of budesonide for the treatment of primary immunoglobulin A nephropathy

The therapeutic potential of a novel, targeted-release formulation of oral budesonide (Nefecon) for the treatment of IgA nephropathy (IgAN) was first demonstrated by the phase 2b NEFIGAN trial. To verify these findings, the phase 3 NefigArd trial tested the efficacy and safety of nine months of treatment with Nefecon (16 mg/d) versus placebo in adult patients with primary IgAN at risk of progressing to kidney failure (ClinicalTrials.gov: NCT03643965). NefIgArd was a multicenter, randomized, double-blind, placebo-controlled two-part trial. In Part A, 199 patients with IgAN were treated with Nefecon or placebo for nine months and observed for an additional three months. The primary endpoint for Part A was 24-hour urine protein-to-creatinine ratio (UPCR) after nine months. Secondary efficacy outcomes evaluated included estimated glomerular filtration rate (eGFR) at nine and 12 months and the UPCR at 12 months. At nine months, UPCR was 27% lower in the Nefecon group compared with placebo, along with a benefit in eGFR preservation corresponding to a 3.87 ml/min/1.73 m2 difference versus placebo (both significant). Nefecon was well-tolerated, and treatment-emergent adverse events were mostly mild to moderate in severity and reversible. Part B is ongoing and will be reported on later. Thus, NefIgArd is the first phase 3 IgA nephropathy trial to show clinically important improvements in UPCR and eGFR and confirms the findings from the phase 2b NEFIGAN study.

MO955: Serum Cystatin C in Renal Transplantation: Beyond GFR Estimation, A Prognosis Marker?

BACKGROUND AND AIMS

In renal transplantation, death with a functioning graft remains one of the main causes of graft loss. In the general population, renal function impairment is strongly associated with cardiovascular and all-cause mortality. Whether this association holds true for kidney transplant recipients (KTR) is unclear. This uncertainty is likely to be due, in part, to the fact that glomerular filtration rate (GFR) estimation based on serum creatinine (SCr) does not always provide an accurate evaluation of the graft function in KTR. As compared to SCr, we have previously shown in a large cohort of KTR that serum cystatin C (SCysC) is a much better marker of GFR.

Herein, we sought to study the ability of the 1-year-post-transplant renal function to predict all-cause mortality according to the methods used to assess GFR.

METHOD

Four hundred and ten consecutive KTR for whom a measurement of GFR by inulin clearance was available at 1 year post-transplant were included. SCr and ScysC were measured with standardized methods. The association of the 1-year inulin clearance value the 1-year MDRD Study equation value and the 1-year CKD-EPI ScysC equation value with all-cause mortality was studied by ROC analysis and Cox model.

RESULTS

During a median follow-up of 17 years, 131 KTR died. Mean (±SD) inulin clearance at 1-year-post-transplant was 47 (±13) mL/min/1.73 m2. Areas under the ROC curves were similar for inulin and CKD-EPI ScysC equation values (0.62 for both), and were both significantly superior to that of the MDRD equation (0.54, P  &lt; 0.01). In Cox analysis, while all types of GFR evaluations were significantly associated to graft loss, only an inulin and a CKD-EPI ScysC equation values below 45 mL/min/1.73 m2 were associated with an excess risk of mortality (HR of 1.55, 1.45 and 1.01 for inulin, CKD-EPI ScysC and MDRD, respectively).

CONCLUSION

We conclude that ScysC-based GFR estimation might better predict KTR outcome as compared with a traditional SCr-based estimation. The one year-post transplant GFR value given by the CKD-EPI ScysC equation should be further evaluated as a potential surrogate marker for both graft and patient survival.

MO989: Ap'tx: Preliminary Results of A Randomized Controlled Trial on Telemedicine Implementation in Kidney Transplantation

BACKGROUND AND AIMS

Telemedecine is a matter of growing interest in transplantation. However, its real added value is uncertain. In 2018, we have started to study the medico-economic impact of a less stringent on-site follow-up of our kidney transplant recipients (KTR) using Ap'Telecare®. We present here the first report focusing on KTR with a 2 years follow-up.

METHOD

The Ap'Tx study (NCT03750331) is a prospective controlled randomized trial testing the hypothesis that monitoring stable KTR (at least 3 months after transplantation) with Ap'Telecare® is non inferior as compared to a conventional follow-up in terms of the occurrence of graft dysfonction (defined as a decrease in eGFR of 20% or more). On-site consultation scheduling was two times less frequent for KTR followed by Ap'Telecare®. Secondary endpoints are the impact of a remote follow-up by Ap'Telecare® on medical workload, economic saving and quality of life.

RESULTS

Five hundred and ninety KTR have been randomized so far with 256 of them having a follow-up of 2 years. Among all KTR approached to participate in the study, 37% were not included mainly due to the impossibility to access internet (44%) or to mastered the app (36%). After randomization, 11% of KTR were considered as noncompliant in adequately using Ap'Telecare®. Over the 2-year study duration, graft dysfunction occurred in 8.5% and 12% of KTR in the Ap'telecare® and conventional arm, respectively (not significant). Medical time dedicated to handling daily lab results was decreased by a factor 3 for KTR using Ap'Telecare®.

CONCLUSION

This preliminary report of Ap'Tx suggest that a partial and reasonable remote follow-up of selected KTR is both feasible and safe. Determining the nature of factors associated with a wider implementation of Ap'Telecare® is important.

Impact of targeted hypothermia in expanded-criteria organ donors on recipient kidney-graft function: study protocol for a multicentre randomised controlled trial (HYPOREME)

INTRODUCTION

Expanded-criteria donors (ECDs) are used to reduce the shortage of kidneys for transplantation. However, kidneys from ECDs are associated with an increased risk of delayed graft function (DGF), a risk factor for allograft loss and mortality. HYPOREME will be a multicentre randomised controlled trial (RCT) comparing targeted hypothermia to normothermia in ECDs, in a country where the use of machine perfusion for organ storage is the standard of care. We hypothesise that hypothermia will decrease the incidence of DGF.

METHODS AND ANALYSIS

HYPOREME is a multicentre RCT comparing the effect on kidney function in recipients of targeted hypothermia (34°C-35°C) and normothermia (36.5°C-37.5°C) in the ECDs. The temperature intervention starts from randomisation and is maintained until aortic clamping in the operating room. We aim to enrol 289 ECDs in order to analyse the kidney function of 516 recipients in the 53 participating centres. The primary outcome is the occurrence of DGF in kidney recipients, defined as a requirement for renal replacement therapy within 7 days after transplantation (not counting a single session for hyperkalemia during the first 24 hours). Secondary outcomes include the proportion of patients with individual organs transplanted in each group; the number of organs transplanted from each ECD and the vital status and kidney function of the recipients 7 days, 28 days, 3 months and 1 year after transplantation. An interim analysis is planned after the enrolment of 258 kidney recipients.

ETHICS AND DISSEMINATION

The trial was approved by the ethics committee of the French Intensive Care Society (CE-SRLF-16-07) on 26 April 2016 and by the competent French authorities on 20 April 2016 (Comité de Protection des Personnes-TOURS-Région Centre-Ouest 1, registration #2016-S3). Findings will be published in peer-reviewed journals and presented during national and international scientific meetings.

TRIAL REGISTRATION NUMBER

NCT03098706.

MO275RARE VARIANTS OF COMPLEMENT FACTOR H AND THROMBOMODULIN ARE OVER-REPRESENTED IN A COHORT OF SEVERE IGA NEPHROPATHY PATIENTS

Background and Aims

IgA nephropathy is the most frequent primary glomerulonephritis leading to end stage renal disease (ESRD) in about 30% of cases within 20 years after diagnosis. Complement activation through alternative and lectin pathways has been described to impact the pathogeny of the disease. We hypothesized in this study that rare variants of alternative pathways regulatory genes could be overrepresented and could play a role at initiating the disease and could harm the prognosis of IgA Nephropathy.

Method

Patients with biopsy proven IgA nephropathy with markers of severity comprising an evolution through ESRD and/or a proteinuria &gt;0.5g/day with available DNA sample were included. All coding sequences of CFH, CFI, MCP, C3, Factor B THBD and CFHR5 genes were analyzed by next generation sequencing. We defined a variant as rare when its minor allele frequency was below 0.1% in the general population. Frequencies were compared to a French volonteers cohort (n=80) and a European large cohort (n=503)

Results

We screened 128 patients with IgA N, with following characteristics at diagnosis: median age 42.4 yo, proteinuria (median) 1.4g/day, hypertension 66%, median eGFR 48.7 mL/min/1.73m². The median follow-up was 99 months and 58% of patients progressed to ESRD.

We identified rare variants with MAF&lt;0.1% in 10.2 % (n=13) including 1 patient with two rare variants. The functional consequences of the 12 out the 14 variants are unknown. Two variants in CFH are located in function domains and are pathogenic.

Patients with IgA N have high rates of rare variants in CFH (n=9/128 ; 7 %) versus normal controls (n=9/503 ; 1.8%) (p=0.004); Pathogenic Variants with minor allele frequency &lt;0.1% in CFH were found in 2 IgA N (2 out of 128, 1.5%) versus 1 European controls (1 out of 503)

In total, 11 % (14/128), 3.8 % (5/128) and 0.8 % (1/128) of the 128 patients were homozygous for the at-risk haplotype MCP ggaac, CFH tgtgt or both, respectively (versus 6.2 % (5/80), 3.8 % (3/80) and 0% in the controls)

6 patients carried the pathogenic variant in THDM gene p.Ala43Thr (6/128) versus 5 in 508 controls population (p=0.01).

No difference in term of hypertension, proteinuria, eGFR, Oxford classification, vascular score at diagnosis was noticed between patients without any rare variant compared to patients with at least one rare variant. The progression through ESRD was not different between groups.

Conclusion

In this cohort of Caucasian IgA nephropathy patients, rare variants of CFH and THBD were found significantly overrepresented compared to a French and European control cohort. Rare variants of alternative pathway regulatory genes were not associated with particular severity or prognosis.

FC 031LARGE SCALE VALIDATION OF THE NEW INTERNATIONAL PROGNOSTIC SCORE OF IGA NEPHROPATHY ON A FRENCH COHORT WITH PROLONGED FOLLOW-UP

Background and Aims

IgA Nephropathy is the most frequent primary glomerulonephritis worldwide, with a progression to End Stage Renal Disease in up to 30% of cases within 20 years after diagnosis. The severity of this disease is nevertheless extremely heterogenous with a majority of slow progression to late stages of Chronic Kidney Disease. The early stratification of risk to progress to ESRD is crucial. In this aim, International IgA Nephropathy Network recently developped a risk prediction tool (IINN tool) to allow an estimation of the probability to progress. The objective of our study was to validate this prediction tool (i) in our French Caucasien retrospective cohort (ii) on long term prognosis.

Method

All biopsy-proven IgA Nephropathy patients from Saint Etienne retrospective cohort for whom proteinuria, mean arterial pressure, CKD-EPI based GFR estimate and adequate Oxford classification at diagnosis were available have been included for analysis. For each patient the estimate of risk to progress to ESRD and/or 50% GFR decline was computed at 5, 10 and 15 years according to the IINN tool. For each time of follow-up, risks were grouped and ranked by deciles, and the median observed rate of event was compared to the median of predicted risk by decile, at 5, 10 and 15 years of follow-up. Correlation between observed and predicted risk was expressed as a Pearson correlation coefficient. A R²&gt;0.8 was considered adequate to validate the prognosis tool.

Results

A total of 468 patients have been included for analysis, with a median age of 38.9 years old, a median proteinuria of 0.5g/day, a mean CKD-EPI of 81,6 mL/min/1,73m² and mean arterial pressure of 96.9mmHg at diagnosis. The cumulative number of events at 5,10, 15 years were respectively of 34, 54, 68. The median follow-up was 12 years. The correlations between observed/predicted risks were R² =0,990 [0,959 ; 0,998] at 5 years, R² = 0,984 [0,930 ;0,996] at 10 years and 0,964 [0,851 ;0,992] at 15 years after diagnosis.

Conclusion

In our study we validated the IINN tool to predict the risk to progress to ESRD and/or 50% eGFR decline (i) in a French Caucasian cohort and (ii) even after 5, 10 and 15 years after diagnosis, allowed by a particularly long follow-up.

Relationship between decline in estimated or measured glomerular filtration rate and 16-year postrenal transplant outcome

Background

Glomerular filtration rate (GFR) decline ≥30% over 2 years can substitute for the conventional ‘doubling of serum creatinine’ to predict end-stage renal disease in patients with native kidneys. While chronic kidney disease trajectory is less predictable in transplanted patients, recent data have suggested that similar GFR decline might be an acceptable surrogate for long-term transplant outcome. We sought (i) to confirm the prognostic value of an early GFR decline in kidney transplant recipients and (ii) to determine whether using direct measurement of GFR with inulin improves the performance of this surrogate.

Methods

We retrospectively analysed all recipients transplanted between 1989 and 2000 in our centre, with inulin-measured and Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI)-estimated GFR at 1 and 5 years post-transplant, and evaluated the performance [time-dependent area under the receiver operating characteristic curve (ROC AUC) and subdistribution hazard ratio (sdHR) with competing risk model] of GFR change to predict graft failure and all-cause mortality.

Results

Out of 417 kidney transplant recipients, 116 patients had lost their graft and 77 had died 16 years after transplantation. While being significantly associated with graft failure [sdHR = 2.37 (95% confidence interval 1.47–3.83)], CKD-EPI-GFR decline ≥30% failed to appropriately predict long-term graft survival (C-statistics of 0.63). Concordance between inulin-GFR and CKD-EPI-GFR to detect similar GFR change was only 53%. Inulin-GFR change was, however, not a better predictor (C-statistics of 0.59). Comparable results were observed for mortality.

Conclusions

Our data suggest that early GFR decline is a poor surrogate for long-term transplant outcome, even when change in GFR is directly measured by a reference method.

Repeat renal biopsy improves the Oxford classification-based prediction of immunoglobulin A nephropathy outcome

BACKGROUND

The prognosis of IgA nephropathy (IgAN) is very heterogeneous. Predicting the nature and the rate of the disease progression is crucial for refining patient treatment. The aim of this study was to evaluate the prognostic impact of an Oxford classification-based repeat kidney tissue evaluation to predict end-stage renal disease (ESRD).

METHODS

Patients with biopsy-proven primary IgAN who underwent two renal biopsies at our centre were analyzed retrospectively. Renal biopsies were scored by two pathologists blinded to the clinical data and according to the updated Oxford classification. Cox models were generated to evaluate the prognostic impact considering the Oxford classification elementary lesions from the first (Model 1) or the second (Model 2) biopsy, adjusted on clinical data at time of reevaluation. The prognostic impacts of the dynamic evolution of each elementary lesion between biopsies were also assessed through univariate and multivariate evaluation.

RESULTS

A total of 168 adult patients were included, with a median follow-up duration of 18 (range 11-24) years. The second biopsy was performed either systematically (n = 112) of for-cause (n = 56), after a median time of 5.4 years. The prognostic performances of Model 2 (second biopsy) were significantly better than Model 1 (first biopsy, analysis of deviance P < 0.0001). The dynamic changes of C and T lesions were significantly associated with the progression toward ESRD after adjustment on variables from Model 2.

CONCLUSION

Both static and dynamic Oxford-based histological evaluation offered by a repeat biopsy improves the prediction of ESRD in patients with IgAN.

Cholesterol-Lowering Treatment in Chronic Kidney Disease: Multistage Pairwise and Network Meta-Analyses

Pairwise and network meta-analyses on the relationship between the efficacy of the use of statins with or without ezetimibe and reductions in low-density lipoprotein cholesterol (LDLc) and C-reactive protein (CRP) in patients with chronic kidney disease (CKD) are presented. In the pairwise meta-analysis, statins with or without ezetimibe were shown to be efficacious in reducing major adverse cardiovascular events (MACE) in patients with CKD and an estimated glomerular filtration rate (eGFR) of less than 60 ml/min/1.73 m², in the context of both primary prevention [odds ratio (OR)/95% confidence interval (95% CI)/I²/number of studies (n): 0.50/0.40–0.64/0%/6] and primary/secondary prevention (0.66/0.57–0.76/57%/18). However, in the Bayesian network meta-analysis, compared to the placebo, only atorvastatin 80 mg daily and atorvastatin and rosuvastatin at doses equivalent to simvastatin 20 mg daily reduced the odds of MACEs in this patient population. The network meta-analysis for LDLc and CRP treatment objectives also showed that, regardless of eGFR and excluding dialysis patients, the number of MACEs decreased in patients with CKD, with reductions in both LDLc and CRP of less than 50% (surface under the cumulative ranking (SUCRA)/heterogeneity (vague)/n: 0.77/0.14/3). The evaluation of the benefits of drugs may lead to individualized therapy for CKD patients: Cholesterol-lowering treatment for CKD patients with high levels of both LDLc and CRP is suggested.

Correction of Hyponatremia May Be a Treatment Stratification Biomarker: A Two-Stage Systematic Review and Meta-Analysis

Changes in serum sodium concentration ([Na⁺]_serum) can permit evaluation of the treatment effect of vasopressin antagonists (vaptans) in patients with worsening heart failure (HF) or cirrhotic ascites; that is, they may act as a treatment stratification biomarker. A two-stage systematic review and meta-analysis were carried out and contextualized by experts in fluid resuscitation and translational pharmacology (registration ID in the International Prospective Register of Systematic Reviews (PROSPERO): CRD42017051440). Meta-analysis of aggregated dichotomous outcomes was performed. Pooled estimates for correction of hyponatremia (normalization or an increase in [Na⁺]_serum of at least 3–5 mEq/L) under treatment with vaptans (Stage 1) and for clinical outcomes in both worsening HF (rehospitalization and/or death) and cirrhotic ascites (ascites worsening) when correction of hyponatremia is achieved (Stage 2) were calculated. The body of evidence was assessed. Correction of hyponatremia was achieved under vaptans (odds ratio (OR)/95% confidence interval (95% CI)/I²/number of studies (n): 7.48/4.95–11.30/58%/15). Clinical outcomes in both worsening HF and cirrhotic ascites improved when correction of hyponatremia was achieved (OR/95% CI/I²/n: 0.51/0.26–0.99/52%/3). Despite the appropriateness of the study design, however, there are too few trials to consider that correction of hyponatremia is a treatment stratification biomarker. Patients with worsening HF or with cirrhotic ascites needing treatment with vaptans, have better clinical outcomes when correction of hyponatremia is achieved. However, the evidence base needs to be enlarged to propose formally correction of hyponatremia as a new treatment stratification biomarker. Markers for use with drugs are needed to improve outcomes related to the use of medicines.

Effect of High-Cutoff Hemodialysis vs Conventional Hemodialysis on Hemodialysis Independence Among Patients With Myeloma Cast Nephropathy: A Randomized Clinical Trial

Importance

Cast nephropathy is the main cause of acute kidney injury in multiple myeloma and persistent reduction in kidney function strongly affects prognosis. Strategies to rapidly remove nephrotoxic serum-free light chains combined with novel antimyeloma agents have not been evaluated prospectively.

Objective

To compare the hemodialysis independence rate among patients newly diagnosed with myeloma cast nephropathy treated with hemodialysis using a high-cutoff dialyzer (with very large membrane pores and high permeability to immunoglobulin light chains) or a conventional high-flux dialyzer (with small pores and lower permeability).

Design, Setting, and Participants

Randomized clinical trial involving 98 patients with biopsy-proven myeloma cast nephropathy requiring hemodialysis treated at 48 French centers between July 2011 and June 2016; the final date of follow-up was June 29, 2016.

Interventions

Intensive hemodialysis (eight 5-hour sessions over 10 days) with either a high-cutoff dialyzer (46 patients) or a conventional high-flux dialyzer (48 patients). All patients received the same chemotherapy regimen of bortezomib and dexamethasone.

Main Outcomes and Measures

Primary end point was hemodialysis independence at 3 months; secondary end points: hemodialysis independence rates at 6 and 12 months, hemodialysis- and chemotherapy-related adverse events, and death.

Results

Among 98 randomized patients, 94 (96%) (median age, 68.8 years [interquartile range, 61.2-75.3 years]; 45% women) were included in the modified intent-to-treat analysis. The hemodialysis independence rate at 3 months was 41.3% (n = 19) in the high-cutoff hemodialysis group vs 33.3% (n = 16) in the conventional hemodialysis group (between-group difference, 8.0% [95% CI, -12.0% to 27.9%], P = .42); at 6 months, the rate was 56.5% (n = 26) vs 35.4% (n = 17), respectively (between-group difference, 21.1% [95% CI, 0.9% to 41.3%], P = .04); and at 12 months, the rate was 60.9% (n = 28) vs 37.5% (n = 18) (between-group difference, 23.4% [95% CI, 3.2% to 43.5%], P = .02). The incidence of hemodialysis-related adverse events was 43% in the high-cutoff hemodialysis group vs 39% in the conventional hemodialysis group; chemotherapy-related serious adverse events, 39% vs 37%, respectively; and at 12 months, 9 patients vs 10 patients died.

Conclusions and Relevance

Among patients with myeloma cast nephropathy treated with a bortezomib-based chemotherapy regimen, the use of high-cutoff hemodialysis compared with conventional hemodialysis did not result in a statistically significant difference in hemodialysis independence at 3 months. However, the study may have been underpowered to identify an early clinically important difference.

Trial Registration

clinicaltrials.gov Identifier: NCT01208818.

Deletion Variants of CFHR1 and CFHR3 Associate with Mesangial Immune Deposits but Not with Progression of IgA Nephropathy

Activation of complement through the alternative pathway has a key role in the pathogenesis of IgA nephropathy (IgAN). Large, international, genome-wide association studies have shown that deletion of complement factor H-related genes 1 and 3 (CFHR3,1Δ) is associated with a reduced risk of developing IgAN, although the prognostic value of these deletions in IgAN remains unknown. Here, we compared the renal outcomes of patients with IgAN according to their CFHR3,1Δ genotype. This retrospective, monocentric cohort study included 639 white patients with biopsy-proven IgAN since 1979 (mean age at diagnosis, 40.1 years; median follow-up, 132 months). We determined the number of CFHR3 and CFHR1 gene copies by quantitative PCR and collected clinical and biologic data by reviewing the patients' medical records. In all, 30.5% of the patients were heterozygous and 4% were homozygous for CFHR3,1Δ We did not detect an association between CFHR3,1Δ and age, eGFR, urinary protein excretion rate, or the presence of hypertension or hematuria at the time of diagnosis. The mean intensities of immune IgA, IgG, and C3 deposits were lower in the group with heterozygous or homozygous gene deletions than in those with no deletion. However, CFHR3,1Δ did not associate with progression to stage 3 CKD or renal death. In conclusion, the CFHR3,1Δ genotype did not associate with progression toward CKD stages 3 and 5 in our white population of patients with IgAN, although it did associate with a reduced level of glomerular immune deposits.

A French Cohort Study of Kidney Retransplantation after Post-Transplant Lymphoproliferative Disorders

BACKGROUND AND OBJECTIVES

Post-transplant lymphoproliferative disorders arising after kidney transplantation portend an increased risk of morbidity and mortality. Retransplantation of patients who had developed post-transplant lymphoproliferative disorder remains questionable owing to the potential risks of recurrence when immunosuppression is reintroduced. Here, we investigated the feasibility of kidney retransplantation after the development of post-transplant lymphoproliferative disorder.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

We reviewed the data from all patients who underwent kidney retransplantation after post-transplant lymphoproliferative disorder in all adult kidney transplantation centers in France between 1998 and 2015.

RESULTS

We identified a total of 52 patients with kidney transplants who underwent 55 retransplantations after post-transplant lymphoproliferative disorder. The delay from post-transplant lymphoproliferative disorder to retransplantation was 100±44 months (28-224); 98% of patients were Epstein-Barr virus seropositive at the time of retransplantation. Induction therapy for retransplantation was used in 48 patients (i.e., 17 [31%] patients received thymoglobulin, and 31 [57%] patients received IL-2 receptor antagonists). Six patients were also treated with rituximab, and 53% of the patients received an antiviral drug. The association of calcineurin inhibitors, mycophenolate mofetil, and steroids was the most common maintenance immunosuppression regimen. Nine patients were switched from a calcineurin inhibitor to a mammalian target of rapamycin inhibitor. One patient developed post-transplant lymphoproliferative disorder recurrence at 24 months after retransplantation, whereas post-transplant lymphoproliferative disorder did not recur in 51 patients.

CONCLUSIONS

The recurrence of post-transplant lymphoproliferative disorder among patients who underwent retransplantation in France is a rare event.

Anti-phospholipase A2 receptor antibody levels at diagnosis predicts spontaneous remission of idiopathic membranous nephropathy

Background: The diagnostic role of circulating anti-phospholipase A2 receptor antibodies (anti-PLA2R Abs) is now well recognized in idiopathic membranous nephropathy (iMN). These Abs could also be interesting as predictors of clinical outcome. In this study, we explored the prognostic value of anti-PLA2R Abs measured in a cohort of iMN patients, with a special focus on their ability to detect patients achieving spontaneous remission.

Methods: All adult patients with biopsy-proven iMN diagnosed between 1978 and 2007 were retrospectively screened in our centre. Using a validated enzyme-linked immunosorbent assay, levels of anti-PLA2R Abs were measured from serum samples obtained at the time of renal biopsy and stored at −80°C until processing. Clinical data on disease activity, treatments and outcomes were collected by reviewing patients’ medical records. The association between anti-PLA2R Ab titres and clinical activity/outcome was assessed by Cox proportional hazard and Kaplan–Meier methods.

Results: In this retrospective study, 68 patients were included in the final analysis (median follow-up of 81 months). No significant association was found between anti-PLA2R Ab titres at diagnosis with baseline proteinuria, baseline estimated glomerular filtration rate or chronic kidney disease progression. Spontaneous remission was observed in 22% of patients. Ab titres were significantly and gradually correlated in a dose–response manner with the likelihood of spontaneous remission.

Conclusions: While Ab titres measured at diagnosis were not found to predict the activity of iMN, evaluation of anti-PLA2R Ab titres might prove useful in the early identification of patients likely to achieve spontaneous remission.

Relationship between Mean Fluorescence Intensity and C1q/C3d-fixing capacities of anti-HLA antibodies

BACKGROUND

Complement-binding assays are proposed to better stratify the risk of antibody-mediated rejection associated-graft failure. Despite promising clinical results, some have suggested that the MFI of anti-HLA antibodies may influence these tests.

METHODS

We investigated the impact of Abs MFI reduction, induced by plasmapheresis, on C1q- and C3d-binding assays. Sera provided from 7 sensitized kidney transplant patients were analyzed.

RESULTS

Four hundreds and thirty-three SABs were analyzed. Before plasmapheresis, when compared to C1q- SABs, C1q+ SABs had a higher median MFI [17397 (IQR: 14851-18794) vs. 2745 (IQR: 1125-6476), p<0.01]. SABs that remained C1q+ after plasmapheresis had a higher median MFI. Regarding the C3d assay, results were strictly comparable. MFI value was a powerful predictor of both C1q and C3d positivity [AUC 0.97 (CI95% 0.95-0.99) and 0.96, (CI95% 0.93-0.98), respectively].

CONCLUSION

Our data suggest that both C1q- and C3d-binding assays are intimately linked to the MFI of anti-HLA Abs.

Genome-Wide Association Study of Acute Renal Graft Rejection

Acute renal rejection is a major risk factor for chronic allograft dysfunction and long-term graft loss. We performed a genome-wide association study to detect loci associated with biopsy-proven acute T cell-mediated rejection occurring in the first year after renal transplantation. In a discovery cohort of 4127 European renal allograft recipients transplanted in eight European centers, we used a DNA pooling approach to compare 275 cases and 503 controls. In an independent replication cohort of 2765 patients transplanted in two European countries, we identified 313 cases and 531 controls, in whom we genotyped individually the most significant single nucleotide polymorphisms (SNPs) from the discovery cohort. In the discovery cohort, we found five candidate loci tagged by a number of contiguous SNPs (more than five) that was never reached in iterative in silico permutations of our experimental data. In the replication cohort, two loci remained significantly associated with acute rejection in both univariate and multivariate analysis. One locus encompasses PTPRO, coding for a receptor-type tyrosine kinase essential for B cell receptor signaling. The other locus involves ciliary gene CCDC67, in line with the emerging concept of a shared building design between the immune synapse and the primary cilium.

Identifying Hemodialysis Patients With the Highest Risk of Staphylococcus aureus Endogenous Infection Through a Simple Nasal Sampling Algorithm

In contrast to Staphylococcus aureus intermittent nasal carriers, persistent ones have the highest risk of infection. This study reports the usefulness of a simple nasal sampling algorithm to identify the S. aureus nasal carriage state of hemodialysis patients (HPs) and their subsequent risk of infection.From a cohort of 85 HPs, 76 were screened for S. aureus nasal carriage once a week during a 10-week period. The S. aureus nasal load was quantified by using either culture on chromogenic medium or fully automated real-time polymerase chain reaction assay. Molecular typing was used to compare strains from carriage and infection.The algorithm based on quantitative cultures was able to determine the status of S. aureus nasal carriage with a sensitivity of 95.8%, a specificity of 94.2%, a positive predictive value of 88.5%, and a negative predictive value of 98.0%. Of note, the determination of the S. aureus carriage state was obtained on the first nasal sample for all the 76 HPs, but 1 (98.7%). The algorithm based on quantitative polymerase chain reaction assay directly from the specimen yielded similar performances. During the 1-year follow-up after the last sampling episode, HPs classified as persistent nasal carriers with the algorithm were found to have a higher risk of S. aureus infection than those classified as nonpersistent carriers (P < 0.05), especially for infections of endogenous origin (P < 0.001).This simple algorithm is reliable for determining the S. aureus nasal carriage status in clinical practice and could contribute to characterize at an early stage of take-up patients with the highest risk of S. aureus infection.

Common hepatic artery as inflow in kidney transplantation

Kidney transplantation originating from the hepatic artery has not previously been reported. Herein, we report a third kidney transplantation with the common hepatic artery as inflow. A 62-year-old male with chronic renal failure due to polycystic kidney disease was proposed to a third kidney transplantation. CT-scan showed diffuse calcification of the aorto-iliac axis and the splenic artery. The common hepatic artery was the only artery suitable for anastomosis and as such was chosen as the inflow for retransplantation. The operation was performed through a right subcostal laparotomy. A saphenous bypass was interposed between the common hepatic artery and the graft, then the renal vein was anastomosed to the suprarenal inferior vena cava. Duration of warm ischemia was 27 min. Postoperative course was complicated with delayed graft function of 17 days and pulmonary infection. Patient was discharged at day 30. With a follow-up of 40 months, serum creatinine level and eGFR are, respectively, 191 µmol/L and 32 mL/min. Hepato-renal bypass technique can be used in kidney retransplantation when patient anatomy is not compatible with other classical options.

Protein A-Based Immunoadsorption Is More Efficient Than Conventional Plasma Exchange to Remove Circulating Anti-HLA Antibodies

We retrospectively evaluated the ability of protein-A immunoadsorption (IA) as compared to that of conventional plasma exchanges (PE) in reducing the mean fluorescence intensity (MFI) of anti-HLA antibodies assessed by the single antigen assay in sensitized renal transplant recipients. Change in MFI of 441 anti-HLA antibodies was measured after 1 single session of IA or after 3 consecutive daily PE sessions. While both strategies were able to significantly lower the amount of anti-HLA antibodies, the relative reduction in MFI was higher after IA as compared to PE (-69 vs. -58%, respectively, p = 0.003). This better efficacy of IA was observed despite a lower total volume of treated plasma (105 ± 6 vs. 160 ± 16 ml/kg after IA and after PE, respectively). Our data suggest a higher efficiency of IA over conventional PE sessions to remove anti-HLA antibodies and call for a larger evaluation of IA to confirm its potential added value in desensitization protocols.

KDIGO Guidelines and Kidney Transplantation: Is the Cystatin-C Based Recommendation Relevant?

The KDIGO guidelines propose a new approach to diagnose chronic kidney disease (CKD) based on estimated glomerular filtration rate (GFR). In patients with a GFR value comprised between 45 and 59 mL/min/1.73 m(2) as estimated by the CKD-EPI creatinine equation (eGFRcreat ), it is suggested to confirm the diagnosis with a second estimation using the CKD-EPI cystatin C-based equations (eGFRcys /eGFRcreat-cys) . We sought to determine whether this new diagnostic strategy might extend to kidney transplant recipients (KTR) and help to identify those with decreased GFR. In 670 KTR for whom a measured GFR was available, we simulated the detection of CKD using the two-steps approach recommended by the guidelines in comparison to the conventional approach relying on creatinine equation. One hundred forty-five patients with no albuminuria had eGFRcreat between 45 and 59 mL/min/1.73 m(2) . Among them, 23% had inulin clearance over 60 mL/min/1.73 m(2) and were thus incorrectly classified as CKD patients. When applying the Kidney Disease: Improving Global Outcomes (KDIGO) strategy, 138 patients were confirmed as having a GFR below 60 mL/min with eGFRcreat-cys . However, 21% of them were misclassified in reference to measured GFR. Our data do no not support the use of cystatin C as a confirmatory test of stage 3 A CKD in KTR.