[Renal xenotransplantation : state of the art]

Xenotransplantation could be an inexhaustible source of organs and change the life of end-stage kidney disease patients with reduction of morbidity and mortality. Through genetic engineering it is now possible to reduce the risk of hyperacute and acute graft rejection and improve the overall immune compatibility between two different species. Some experiments have already brought promising perspectives. Nevertheless, there are still difficulties to overcome. The risk of animal-related infectious diseases, ethnic limitations, safety, and applicability of large-scale xenotransplantation should be assessed. We still need to improve the technical aspects and define the purpose of these procedures: definitive replacement or temporary solution?

[Kidney disease in antiphospholipid antibody syndrome]

Antiphospholipid syndrome (APS) is a rare autoimmune disease characterized by recurrent arterial and venous thromboembolic events. Renal complications occur in 3 % of patients. Renal artery stenosis is the most common, and APS-related nephropathy is the predominant microvascular complication. APS nephropathy has heterogeneous manifestations ranging from hematuria and non-nephrotic range proteinuria to hypertension and multi-organ failure caused by catastrophic antiphospholipid antibody syndrome. Anticoagulation and thromboprophylaxis are key to management. Immunosuppression has been used with some success but lacks randomized controlled trial validation for their use.

[Nephrology: what's new in 2023]

Molecules such as sparsentan and budesonide look promising to treat proteinuric IGA nephropathy. SLGT2 inhibitors have a prominent place in nephroprotection and could be used in the treatment of acute kidney injury due to heart failure as well. High volume hemodiafiltration compared to hemodialysis improves survival in dialysis patients. Lessening dialysate temperature does not improve hemodynamic stability during the dialysis session. Sodium bicarbonate does not seem to protect renal function in renal transplant patients. SGLT2 inhibitors may have a beneficial effect in these patients in terms of nephroprotection.

Association between urinary oxytocin secretion and natriuresis after transsphenoidal pituitary surgery

OBJECTIVE

Oxytocin (OXT) secretion has been shown to be abnormally elevated in patients who develop syndrome of inappropriate secretion of antidiuretic hormone (SIADH)-related hyponatremia after transsphenoidal pituitary surgery (TPS). While OXT was previously reported to increase natriuresis in the kidney, a potential role for this hormone in postoperative sodium balance and dysnatremias has not been studied. The objective of this study was to analyze the correlation between patients' urinary output of OXT and natremia and natriuresis after TPS.

METHODS

The authors measured and correlated the urinary output of OXT with natriuresis and natremia in 20 consecutive patients who underwent TPS.

RESULTS

The ratio of urinary secretion of OXT between days 1 and 4 showed a strong, significant correlation with patient natriuresis at day 7 after pituitary surgery. Concomitantly, patient natremia showed a moderate, inverted correlation with OXT secretion in the urine.

CONCLUSIONS

Together, these results show for the first time that urinary OXT secretion correlates with patient natriuresis and natremia after pituitary surgery. This observation suggests a notable role for this hormone in sodium balance.

[Management of genetic renal disorders: local experience and importance of the network]

In nephrology, rare disorders are frequently encountered. In children, about 60% of the renal disorders are rare, with congenital abnormalities of the kidney and urinary tract disorders (CAKUT), being highly prevalent. In adults, about 22% of the disorders leading to renal replacement therapies are rare and include glomerulonephritis and genetic disorders. Rarity may preclude the rapid and extensive access to care for patients suffering of renal disorders, especially in Switzerland, which is small and fragmented. Only collaborative network and access to databases, shared resources and to specific competence may help patient management. Lausanne and Geneva University Hospitals have started specialized outpatient clinics for rare renal disorders several years ago and are part of national and international networks.

Renal involvement in systemic sclerosis

Systemic sclerosis is a rare autoimmune vasculopathy associated with dysregulated innate and adaptive immunity that leads to generalized systemic fibrosis. Renal involvement occurs in a significant proportion of systemic sclerosis patients, and is associated with worse outcome. Scleroderma renal crisis (SRC) is the most studied and feared renal complication described in systemic sclerosis. However, with the emergence of ACE inhibitors and better management, the mortality rate of SRC has significantly decreased. Renal disease in systemic sclerosis offers a wide array of differential diagnoses that may be challenging for the clinician. The spectrum of renal manifestations in systemic sclerosis ranges from an isolated decrease in glomerular filtration rate, increased intrarenal arterial stiffness, and isolated proteinuria due to SRC to more rare manifestations such as association with antiphospholipid antibody nephropathy and ANCA-associated vasculitis. The changes observed in the kidneys in systemic sclerosis are thought to be due to a complex interplay of various factors, including renal vasculopathy, as well as the involvement of the complement system, vasoactive mediators such as endothelin-1, autoimmunity, prothrombotic and profibrotic cytokines, among others. This literature review aims to provide an overview of the main renal manifestations in systemic sclerosis by discussing the most recent epidemiological and pathophysiological data available and the challenges for clinicians in making a diagnosis of renal disease in patients with systemic sclerosis.

[Collaboration in nephrology between Geneva and Yaoundé: a convincing example]

Chronic kidney disease (CKD) has a high prevalence in Cameroon and will become an important public health problem. Its management must be comprehensive, starting with CKD prevention to the implementation of renal replacement therapies best suited to the needs of patients and resources available in Cameroon. Practical interventions involving nephrology departments in both Africa and Europe can contribute to an improved management of CKD in Africa. The current collaboration between the Geneva University Hospitals and the Yaoundé teaching hospitals is a convincing example. It includes a clinical trial on the treatment of metabolic acidosis linked to CKD, assistance with the placement of hemodialysis catheters by sonography and the initiation of a kidney transplantation program with living donors.

[Nephrology: what's new in 2022]

Severe cases of IGA nephropathy might benefit from corticosteroid therapy. Inflimidase may be a promising treatment of Goodpasture disease. SGLT2 inhibitors and acetazolamide act synergistically with loop diuretics in the treatment of acute cardiac failure. In hemodialysis, use of lung ultrasound to determine the ultrafiltration seems to decrease hospitalizations due to acute heart failure but does not reduce patient-centered outcomes. Icodextrin may mitigate the loss of ultrafiltration in PD patients who are carriers of the Aquaporin I promotor TT genotype. MICA-antibodies have an impact on the risk of graft rejection. Xenotransplantation may become a reality.

Shorter versus longer corticosteroid duration and recurrent immune checkpoint inhibitor-associated AKI

BACKGROUND

Corticosteroids are the mainstay of treatment for immune checkpoint inhibitor-associated acute kidney injury (ICPi-AKI), but the optimal duration of therapy has not been established. Prolonged use of corticosteroids can cause numerous adverse effects and may decrease progression-free survival among patients treated with ICPis. We sought to determine whether a shorter duration of corticosteroids was equally efficacious and safe as compared with a longer duration.

METHODS

We used data from an international multicenter cohort study of patients diagnosed with ICPi-AKI from 29 centers across nine countries. We examined whether a shorter duration of corticosteroids (28 days or less) was associated with a higher rate of recurrent ICPi-AKI or death within 30 days following completion of corticosteroid treatment as compared with a longer duration (29-84 days).

RESULTS

Of 165 patients treated with corticosteroids, 56 (34%) received a shorter duration of treatment and 109 (66%) received a longer duration. Patients in the shorter versus longer duration groups were similar with respect to baseline and ICPi-AKI characteristics. Five of 56 patients (8.9%) in the shorter duration group and 12 of 109 (11%) in the longer duration group developed recurrent ICPi-AKI or died (p=0.90). Nadir serum creatinine in the first 14, 28, and 90 days following completion of corticosteroid treatment was similar between groups (p=0.40, p=0.56, and p=0.89, respectively).

CONCLUSION

A shorter duration of corticosteroids (28 days or less) may be safe for patients with ICPi-AKI. However, the findings may be susceptible to unmeasured confounding and further research from randomized clinical trials is needed.

[Finerenone: a new step on the way to nephroprotection]

Finerenone is a new mineralocorticoid receptor antagonist with a different structure, volume of distribution and half-life compared to spironolactone. This drug has been tested in two large, randomized trials including diabetic patients with chronic kidney disease (in terms of glomerular filtration rate and albuminuria) and already treated by renin-angiotensin system blockade. Results are positive on hard renal- and cardiac endpoints. Risk of hyperkalaemia is higher than with placebo but is considered as acceptable. An open question that will be tested in further studies is the role of finerenone in the context of a treatment by gliflozins, drugs that also showed cardiorenal protection.

Outcomes of incident patients treated with incremental haemodialysis as compared with standard haemodialysis and peritoneal dialysis

BACKGROUND

Residual kidney function is considered better preserved with incremental haemodialysis (I-HD) or peritoneal dialysis (PD) as compared with conventional thrice-weekly HD (TW-HD) and is associated with improved survival. We aimed to describe outcomes of patients initiating dialysis with I-HD, TW-HD or PD.

METHODS

We conducted a retrospective analysis of a prospectively assembled cohort in a single university centre including all adults initiating dialysis from January 2013 to December 2020. Primary and secondary endpoints were overall survival and hospitalization days at 1 year, respectively.

RESULTS

We included 313 patients with 234 starting on HD (166 TW-HD and 68 I-HD) and 79 on PD. At the end of the study, 10 were still on I-HD while 45 transitioned to TW-HD after a mean duration of 9.8 ± 9.1 months. Patients who stayed on I-HD were less frequently diabetics (P = .007). Mean follow-up was 33.1 ± 30.8 months during which 124 (39.6%) patients died. Compared with patients on TW-HD, those on I-HD had improved survival (hazard ratio 0.49, 95% confidence interval 0.26-0.93, P = .029), while those on PD had similar survival. Initial kidney replacement therapy modality was not significantly associated with hospitalization days at 1 year.

CONCLUSIONS

I-HD is suitable for selected patients starting dialysis and can be maintained for a significant amount of time before transition to TW-HD, with diabetes being a risk factor. Although hospitalization days at 1 year are similar, initiation with I-HD is associated with improved survival as compared with TW-HD or PD. Results of randomized controlled trials are awaited prior to large-scale implementation of I-HD programmes.

[Acute interstitial nephritis: clinical presentation and diagnosis]

Acute interstitial nephritis is characterized by renal inflammation and interstitial edema. The clinical presentation is pauci-symptomatic and often non-specific. Acute interstitial nephritis typically presents with acute renal failure, alone or with fever, eosinophilia, hematuria, sterile pyuria and small range proteinuria. An early diagnosis is crucial to prevent the morbidity and mortality associated with renal function decline. The most frequent etiology of this disease is drug-induced. A kidney biopsy is not systematically required to establish the diagnosis. It should be considered in the absence of renal function improvement 5 to 7 days after withdrawal of the causal agent. Although the benefits of glucocorticoid treatment have not been proven to date, its use may be associated with a better kidney function recovery.

Kidney disease in antiphospholipid antibody syndrome: Risk factors, pathophysiology and management

Antiphospholipid antibody syndrome (APLS) is a rare autoimmune disease characterized by recurrent arterial and venous thromboembolic events, pregnancy related complications as well as the persistent detection of antiphospholipid antibodies at a 12 week interval. Renal complications tend to occur in 3% of APLS patients, with renal artery stenosis being the most common kidney related complication. Renal pathology may be subdivided into macro as well as microvascular thrombotic complications with stenosis, thrombosis and infarction representing the principle macrovascular events and APLS nephropathy representing the predominant microvascular complication. APLS related kidney disease may present with an array of heterogenous manifestations ranging from hematuria and non-nephrotic range proteinuria to hypertension or as part of a severe, life threatening and fulminant multiorgan failure disorder known as catastrophic antiphospholipid antibody syndrome (CAPS). Management of APLS related renal complications depends on the site of vascular injury, the thromboembolic risk profile based on the subtype, isotype and titer of the autoantibodies as well as the severity of the injury. Primary prophylaxis in these patients primarily revolves around the use of low dose aspirin, with prophylactic anticoagulation during events that increase thromboembolic like surgery and hospitalization. Anticoagulation is the cornerstone of treatment of APLS related kidney disease with INR targets varying depending on the associated venous or arterial thrombosis. Immunosuppression with the likes of rituximab, mTOR inhibitors, eculizumab and belimumab have been used with some success, but lack randomized control trial validation for their use. Pulsed corticosteroids with Plasmapheresis and intravenous immunoglobulins is the recommended treatment for CAPS.

[Nephrology: what's new in 2021?]

Major advances in the treatment of nondiabetic chronic nephropathy and ANCA associated-renal vasculitis were published within the past two years. A new formula for assessing GFR was developed that does not take ethnicity into account. For hemodialysis patients, hemodiafiltration does not diminish uremic neuropathy. In hemodialysis patients, DOACs induce less bleeding than K vitamin antagonists. Weaning of steroids should be more rapid in some transplant patients. COVID-19 vaccination is less effective in dialysis and transplant patients and will necessitate a third dose.

OUP accepted manuscript

Background

Hyperkalaemia is frequent in haemodialysis (HD) patients and associated with increased cardiovascular mortality. Despite routine clinical use, evidence regarding the efficacy of potassium (K⁺) binders in HD is scant. We wished to compare the efficacy of patiromer (PAT) and sodium polystyrene sulfonate (SPS) on K⁺ levels in this setting.

Methods

We screened patients in three HD centres with pre-HD K⁺ value between 5.0 and 6.4 mmol/L, after an initial 2-week washout period for those previously on K⁺ binders. We included patients in an unblinded two-arm crossover trial comparing SPS 15 g before each meal on non-dialysis days with PAT 16.8 g once daily on non-dialysis days with randomized attribution order and a 2-week intermediate washout period. The primary outcome was the mean weekly K⁺ value.

Results

We included 51 patients and analysed 48 with mean age of 66.4 ± 19.4 years, 72.9% men and 43.4% diabetics. Mean weekly K⁺ values were 5.00 ± 0.54 mmol/L, 4.55 ± 0.75 mmol/L and 5.17 ± 0.64 mmol/L under PAT (P = .003), SPS (P < .001) and washout, respectively. In direct comparison, K⁺ values and prevalence of hyperkalaemia were lower under SPS as compared with PAT (P < .001). While the incidence of gastrointestinal side effects was similar between treatments, SPS showed lower subjective tolerability score (6.0 ± 2.4 and 6.9 ± 1.9) and compliance (10.8 ± 20.4% and 2.4 ± 7.3% missed doses) as compared with PAT (P < .001 for both).

Conclusion

Both PAT and SPS are effective in decreasing K⁺ levels in chronic HD patients. However, at the tested doses, SPS was significantly more effective in doing so as compared with PAT, despite lower tolerability and compliance. Larger randomized controlled trials should be conducted in order to confirm our findings and determine whether they would impact clinical outcomes.

Acute kidney injury in patients treated with immune checkpoint inhibitors

Background

Immune checkpoint inhibitor-associated acute kidney injury (ICPi-AKI) has emerged as an important toxicity among patients with cancer.

Methods

We collected data on 429 patients with ICPi-AKI and 429 control patients who received ICPis contemporaneously but who did not develop ICPi-AKI from 30 sites in 10 countries. Multivariable logistic regression was used to identify predictors of ICPi-AKI and its recovery. A multivariable Cox model was used to estimate the effect of ICPi rechallenge versus no rechallenge on survival following ICPi-AKI.

Results

ICPi-AKI occurred at a median of 16 weeks (IQR 8–32) following ICPi initiation. Lower baseline estimated glomerular filtration rate, proton pump inhibitor (PPI) use, and extrarenal immune-related adverse events (irAEs) were each associated with a higher risk of ICPi-AKI. Acute tubulointerstitial nephritis was the most common lesion on kidney biopsy (125/151 biopsied patients [82.7%]). Renal recovery occurred in 276 patients (64.3%) at a median of 7 weeks (IQR 3–10) following ICPi-AKI. Treatment with corticosteroids within 14 days following ICPi-AKI diagnosis was associated with higher odds of renal recovery (adjusted OR 2.64; 95% CI 1.58 to 4.41). Among patients treated with corticosteroids, early initiation of corticosteroids (within 3 days of ICPi-AKI) was associated with a higher odds of renal recovery compared with later initiation (more than 3 days following ICPi-AKI) (adjusted OR 2.09; 95% CI 1.16 to 3.79). Of 121 patients rechallenged, 20 (16.5%) developed recurrent ICPi-AKI. There was no difference in survival among patients rechallenged versus those not rechallenged following ICPi-AKI.

Conclusions

Patients who developed ICPi-AKI were more likely to have impaired renal function at baseline, use a PPI, and have extrarenal irAEs. Two-thirds of patients had renal recovery following ICPi-AKI. Treatment with corticosteroids was associated with improved renal recovery.

[SGLT2 inhibitors in diabetic and non-diabetic nephropathies]

SGLT2 inhibitors (SGLT2i) will change the clinical practice of nephrology with their therapeutic cardiorenal and antidiabetic properties. By inhibiting proximal tubular sodium and glucose reabsorption, these new drugs decrease intraglomerular pressures. Over the last 5 years several breakthrough studies have demonstrated the SGLT2i protective effects on outcomes such as cardiovascular mortality, hospital admission for heart failure, sustained decreases in eGFR in patients with diabetic nephropathy and the development of ESKD. With the new DAPA-CKD study revealing protective effects of SGLT2i in CKD patients without diabetes, therapeutic recommendations will now have to evolve towards including these drugs in the chronic management of all most proteinuric CKD patients.

[IgA nephropathy : update]

IgA nephropathy is the most common primary glomerulopathy worldwide. However, it remains underdiagnosed because of its clinical heterogeneity. Its diagnosis is currently based on kidney biopsy and there are no clinically validated serological tests. Its pathogenesis is based on an anomaly in the glycosylation of type A immunoglobulins and a progression punctuated by multiple triggering events (hits). The conservative approach of using corticosteroid therapy and/or more selective immunosuppression in certain clinical situations remains the state-of-the-art treatment. New therapeutic perspectives seem promising but must be validated.

[Nephrology : what's new in 2020 ?]

Impact of gliflozines in the treatment of non-diabetic nephropathies and cardiac failure has lately been demonstrated. Tolvaptan has now been recognized in Switzerland as a treatment of hyponatremia. In hemodialysis, some progress has been made in the management of dysfunctional arterio-venous fistulas. A glimmer of hope in the treatment of uremic pruritus? Conservative management of a stable coronary heart disease is also advocated in patients with end-stage kidney disease. Therapy with immune cells may either minimize or remove the need for immunosuppression in renal transplant patients. A new predictive score combining several markers can predict long-term graft failure.

[Nephrology : what's new in 2019 ?]

Impact of gliflozines and rituximab in the treatments of diabetic and membranous nephropathies respectively has been confirmed. Roxadustat may be the new promising treatment of renal anemia. Long-acting erythropoietins may be associated with a higher death rate than short-acting ones in hemodialysis patients. Kidneys of HCV-seropositive donors can be proposed to any wait-listed patient for renal transplantation. Immunosupression minimizing the use of calcineurin inhibitors may be achieved with an everolimus-based protocol.

[Volemic resuscitation in acute care setting : which intravenous fluid ?]

Crystalloid-type solutions are currently recommended for volume resuscitation. Although historically considered as « physiological saline », NaCl 0.9 % has a high concentration of sodium and chloride that can lead to metabolic acidosis and impaired renal function when large volumes are used. Recent evidence confirms that use of low-chloride crystalloids (so-called balanced solutions) could reduce the occurrence of renal failure and should be preferred during high volume resuscitation.

[Chronic kidney disease and new antidiabetic drugs : an overview in 2019]

Diabetic nephropathy is a leading cause of chronic kidney disease and dialysis. We know that a good diabetes control slows the progression of kidney disease, but the risk of hypoglycemia is greater in patients with chronic kidney disease and contributes to their mortality. Chronic kidney disease and diabetes are major cardiovascular risk factors with additive effects. Decreasing cardiovascular mortality is a major aim in chronic kidney disease. The ideal antidiabetic molecule in these patients should reduce the risk of dialysis, reduce cardiovascular mortality and carry no risk of hypoglycaemia. This article aims to summarize for the general practician the nephrological implications of new antidiabetic drugs and their use in chronic kidney disease patients.

Clinical Pharmacology in HIV Therapy

The success of combination antiretroviral therapy in the treatment of HIV-1-positive individuals has shifted clinical attention toward combination antiretroviral drug regimens that optimize tolerability, long-term safety, and durable efficacy. Wherever patients have access to treatment, morbidity and mortality are increasingly driven by non-HIV-associated comorbidities, which may be observed earlier than in age-matched controls and despite the best available combination antiretroviral therapy. Similarly, HIV-1-positive individuals are now diagnosed and treated earlier with anticipated lifelong therapy. The contribution of specific antiretroviral agents to long-term morbidity and mortality is dependent on the pharmacologic characteristics of these agents, and it is increasingly important in this context.

[Metformin-associated lactic acidosis : myth or reality ?]

Metformin is the first line therapy for patients with diabete type 2. However, the molecule is known to be responsible for lactic acidosis through its inhibition of the mitochondrial respiratory chain complex, a pathology called MALA (metformin associated lactic acidosis). This complication has been widely discussed in the literature because its development is usually the result of a multifactorial and complex process. As the mortality of MALA is potentially high, a good knowledge of the physiopathology, existing treatments and predisposing factors is necessary for the primary care physician.

[Nephrology : what's new in 2018 ?]

Major advances in the treatment of ANCA associated-renal vasculitides, IGA nephropathy and renal autosomal dominant polycystic disease were published within the past year. There is neither clear benefit of early initiation of renal replacement therapy in the intensive care unit nor with the use of chloride-poor solutions to prevent kidney failure. Maintenance parenteral iron supplementation in hemodialysis patients is neither associated with infectious nor cardiovascular risks. Cognitive decline may be more associated with hemodialysis than peritoneal dialysis. In transplantation, the persistence of complement-binding donor-specific antibodies after treatment is predictor of graft loss. Tocilizumab is a promising treatment for chronic antibody-mediated rejection.

Diffusion-weighted magnetic resonance imaging to assess diffuse renal pathology: a systematic review and statement paper

Diffusion-weighted magnetic resonance imaging (DWI) is a non-invasive method sensitive to local water motion in the tissue. As a tool to probe the microstructure, including the presence and potentially the degree of renal fibrosis, DWI has the potential to become an effective imaging biomarker. The aim of this review is to discuss the current status of renal DWI in diffuse renal diseases. DWI biomarkers can be classified in the following three main categories: (i) the apparent diffusion coefficient-an overall measure of water diffusion and microcirculation in the tissue; (ii) true diffusion, pseudodiffusion and flowing fraction-providing separate information on diffusion and perfusion or tubular flow; and (iii) fractional anisotropy-measuring the microstructural orientation. An overview of human studies applying renal DWI in diffuse pathologies is given, demonstrating not only the feasibility and intra-study reproducibility of DWI but also highlighting the need for standardization of methods, additional validation and qualification. The current and future role of renal DWI in clinical practice is reviewed, emphasizing its potential as a surrogate and monitoring biomarker for interstitial fibrosis in chronic kidney disease, as well as a surrogate biomarker for the inflammation in acute kidney diseases that may impact patient selection for renal biopsy in acute graft rejection. As part of the international COST (European Cooperation in Science and Technology) action PARENCHIMA (Magnetic Resonance Imaging Biomarkers for Chronic Kidney Disease), aimed at eliminating the barriers to the clinical use of functional renal magnetic resonance imaging, this article provides practical recommendations for future design of clinical studies and the use of renal DWI in clinical practice.

Immunogenicity of Anti-HLA Antibodies in Pancreas and Islet Transplantation

The aim of the current study was to characterize the anti-HLA antibodies before and after pancreatic islet or pancreas transplantation. We assessed the risk of anti-donor-specific antibody (DSA) sensitization in a single-center, retrospective clinical study at Geneva University Hospital. Data regarding clinical characteristics, graft outcome, HLA mismatch, donor HLA immunogenicity, and anti-HLA antibody characteristics were collected. Between January 2008 and July 2014, 18 patients received islet transplants, and 26 patients received a pancreas transplant. Eleven out of 18 patients (61.1%) in the islet group and 12 out of 26 patients (46.2%) in the pancreas group had anti-HLA antibodies. Six patients (33.3%) developed DSAs against HLA of the islets, and 10 patients (38.4%) developed DSAs against HLA of the pancreas. Most of the DSAs were at a low level. Several parameters such as gender, number of times cells were transplanted, HLA mismatch, eplet mismatch and PIRCHE-II numbers, rejection, and infection were analyzed. Only the number of PIRCHE-II was associated with the development of anti-HLA class II de novo DSAs. Overall, the development of de novo DSAs did not influence graft survival as estimated by insulin independence. Our results indicated that pretransplant DSAs at low levels do not restrict islet or pancreas transplantation [especially islet transplantation (27.8% vs. 15.4.%)]. De novo DSAs do occur at a similar rate in both pancreas and islet transplant recipients (mainly of class II), and the immunogenicity of donor HLA is a parameter that should be taken into consideration. When combined with an immunosuppressive regimen and close follow-up, development of low levels of DSAs was not found to result in reduced graft survival or graft function in the current study.

[Nephrology]

New antidiabetic drugs which slow effectively the course of diabetic nephropathy are now available. There is no benefit of prophylactic hydratation to prevent contrast nephropathy in patients with moderate chronic kidney disease. In elderly hemodialysis patients, hemodiafiltration seems better tolerated than conventional hemodialysis, although there is a similar dialysis-induced myocardial stress with both methods. Role of de novo donor-specific antibodies is better characterized, which may subsequently lead to new treatments of graft rejection.

[Phosphate binders : What are the recent evidences ?]

Hyperphosphatemia is a late complication of chronic kidney disease (CKD). It is a major non-traditional cardiovascular risk factor in CKD. The management of hyperphosphatemia is based on restriction of phosphate intake, phosphate binders and dialysis. Phosphate binders are divided into calcium-based and non-calcium-based binders. Recent evidence suggest restricting the dose of calcium-based phosphate binders because of the associated increased mortality in compared to non-calcic ones. New treatments are under development such as inhibitors of kidney or intestinal phosphate absorption. These therapies could improve patients' compliance.

[Nephrology : What's new in 2016 ?]

The first treatment which slows the course of polycystic kidney disease is now available in Switzerland. There is no benefit of immunosuppression when treating IgA nephropathy. Rituximab has been proved effective in the treatment of membranous nephropathy. When to start renal replacement therapy in acute kidney injury ? The debate still continues. In selected patients with end-stage renal failure, starting with twice a week hemodialysis is a desirable option. Peritoneal dialysis can be considered in frail patients. Better being transplanted with a HLA-incompatible living donor than to be on the waiting list. Immunosuppression without a calcineurin inhibitor is a potential immunologic hazard even for stable transplants. Long-term results of belatacept-based immunosuppression instead of cyclosporin showed better graft and patient survival but more acute rejection.

[Genetic kidney diseases: new perspectives on diagnosis]

Suspected renal inherited disorders are regularly evaluated in nephrology consultations both in adults and children. A positive family history and/or a typical phenotype should lead to genetic investigations. A confirmatory diagnosis integrated in a multidisciplinary genetic counseling approach gives patient guidance for further pregnancy. It also allows physician to better stratify disease risk and indicates treatment in some cases. The time to diagnosis and costs have been dramatically reduced thanks to next generation sequencing in several cases of complex inherited nephrologic syndromes.

[Sodium chloride 0.9%: nephrotoxic crystalloid?]

Sodium chloride 0.9%, often incorrectly called physiological saline, contains higher concentration of chloride compared to plasma. It is known that the administration of sodium chloride 0.9% can cause hyperchloremic metabolic acidosis in a reproducible manner. The elevated chloride concentration in 0.9% NaCl solution can also adversely affect renal perfusion. This effect is thought to be induced by hyperchloremia that causes renal artery vasoconstriction. For these reasons, the use of 0.9% NaCl solution is raising attention and some would advocate the use of a more "physiological" solution, such as balanced solutions that contain a level of chloride closer to that of plasma. Few prospective, randomized, controlled trials are available today and most were done in a perioperative setting. Some studies suggest that the chloride excess in 0.9% NaCl solution could have clinical consequences; however, this remains to be established by quality randomized controlled trials.

[Nephrology: what's new in 2015?]

Isotonic saline and buffered crystalloid solutions may carry an equivalent risk of acute kidney injury in critically ill patients. In hemodialyzed patients, highly dialyzable beta-blockers are less cardioprotective than non-dialyzable beta-blockers, cooling the dialyzate may protect their cerebral white matter and too much parenteral iron may be deleterious. A promising treatment for amyloid deposits is underway. A well tolerated treatment for hyperkalemia has emerged. Low serum magnesium and diminished phosphaturia may be associated with an increased risk of chronic kidney disease. Moderate hyponatremia should be considered as a serious public health problem.

N-acetylcysteine does not prevent contrast nephropathy in patients with renal impairment undergoing emergency CT: a randomized study

BACKGROUND

Patients admitted to the emergency room with renal impairment and undergoing a contrast computed tomography (CT) are at high risk of developing contrast nephropathy as emergency precludes sufficient hydration prior to contrast use. The value of an ultra-high dose of intravenous N-acetylcysteine in this setting is unknown.

METHODS

From 2008 to 2010, we randomized 120 consecutive patients admitted to the emergency room with an estimated clearance lower than 60 ml/min/1.73 m2 by MDRD (mean GFR 42 ml/min/1.73 m2) to either placebo or 6000 mg N-acetylcysteine iv one hour before contrast CT in addition to iv saline. Serum cystatin C and creatinine were measured one hour prior to and at day 2, 4 and 10 after contrast injection. Nephrotoxicity was defined either as 25% or 44 μmol/l increase in serum creatinine or cystatin C levels compared to baseline values.

RESULTS

Contrast nephrotoxicity occurred in 22% of patients who received placebo (13/58) and 27% of patients who received N-acetylcysteine (14/52, p = 0.66). Ultra-high dose intravenous N-acetylcysteine did not alter creatinine or cystatin C levels. No secondary effects were noted within the 2 groups during follow-up.

CONCLUSIONS

An ultra-high dose of intravenous N-acetylcysteine is ineffective at preventing nephrotoxicity in patients with renal impairment undergoing emergency contrast CT.

TRIAL REGISTRATION

The study was registered as Clinical trial (NCT01467154).

Determination of the best method to estimate glomerular filtration rate from serum creatinine in adult patients with sickle cell disease: a prospective observational cohort study

BACKGROUND

Sickle cell disease (SCD) leads to tissue hypoxia resulting in chronic organ dysfunction including SCD associated nephropathy. The goal of our study was to determine the best equation to estimate glomerular filtration rate (GFR) in SCD adult patients.

METHODS

We conducted a prospective observational cohort study. Since 2007, all adult SCD patients in steady state, followed in two medical departments, have had their GFR measured using iohexol plasma clearance (gold standard). The Cockcroft-Gault, MDRD-v4, CKP-EPI and finally, MDRD and CKD-EPI equations without adjustment for ethnicity were tested to estimate GFR from serum creatinine. Estimated GFRs were compared to measured GFRs according to the graphical Bland and Altman method.

RESULTS

Sixty-four SCD patients (16 men, median age 27.5 years [range 18.0-67.5], 41 with SS-genotype were studied. They were Sub-Saharan Africa and French West Indies natives and predominantly lean (median body mass index: 22 kg/m2 [16-33]). Hyperfiltration (defined as measured GFR >110 mL/min/1.73 m2) was detected in 53.1% of patients. Urinary albumin/creatinine ratio was higher in patients with hyperfiltration than in patients with normal GFR (4.05 mg/mmol [0.14-60] versus 0.4 mg/mmol [0.7-81], p = 0.01). The CKD-EPI equation without adjustment for ethnicity had both the lowest bias and the greatest precision. Differences between estimated GFRs using the CKP-EPI equation and measured GFRs decreased with increasing GFR values, whereas it increased with the Cockcroft-Gault and MDRD-v4 equations.

CONCLUSIONS

We confirm that SCD patients have a high rate of glomerular hyperfiltration, which is frequently associated with microalbuminuria or macroalbuminuria. In non-Afro-American SCD patients, the best method for estimating GFR from serum creatinine is the CKD-EPI equation without adjustment for ethnicity. This equation is particularly accurate to estimate high GFR values, including glomerular hyperfiltration, and thus should be recommended to screen SCD adult patients at high risk for SCD nephropathy.

Rituximab treatment for membranous nephropathy: a French clinical and serological retrospective study of 28 patients

The development of well-tolerated and effective therapies that target the pathogenesis of membranous nephropathy (MN) would be useful. Our objective was to evaluate the efficacy of rituximab in MN. We analyzed the outcome of 28 patients treated with rituximab for idiopathic MN. Anti-PLA₂R antibodies in serum and PLA₂R antigen in kidney biopsy were assessed in 10 and 9 patients, respectively. Proteinuria was significantly decreased by 56, 62 and 87% at 3, 6 and 12 months, respectively. At 6 months, 2 patients achieved complete remission (CR) and 12 partial remission (PR; overall renal response, 50%). At 12 months (n = 23), CR was achieved in 6 patients and PR in 13 patients (overall renal response, 82.6%). Three patients suffered a relapse of nephrotic proteinuria 27–50 months after treatment. Univariate analysis suggested that the degree of renal failure (MDRD estimated glomerular filtration rate <45/ml/min/1.73 m²) is an independent factor that predicts lack of response to rituximab. Anti-PLA₂R antibodies were detected in the serum of 10 patients, and PLA₂R antigen in immune deposits in 8 of 9 patients. Antibodies became negative in all 5 responsive patients with available follow-up sera. In this retrospective study, a high rate of remission was achieved 12 months after treatment.

Aldosterone activates NF-kappaB in the collecting duct

Besides its classical effects on salt homeostasis in renal epithelial cells, aldosterone promotes inflammation and fibrosis and modulates cell proliferation. The proinflammatory transcription factor NF-kappaB has been implicated in cell proliferation, apoptosis, and regulation of transepithelial sodium transport. The effect of aldosterone on the NF-kappaB pathway in principal cells of the cortical collecting duct, a major physiologic target of aldosterone, is unknown. Here, in both cultured cells and freshly isolated rat cortical collecting duct, aldosterone activated the canonical NF-kappaB signaling pathway, leading to increased expression of several NF-kappaB-targeted genes (IkappaBalpha, plasminogen activator inhibitor 1, monocyte chemoattractant protein 1, IL-1beta, and IL-6). Small interfering RNA-mediated knockdown of the serum and glucocorticoid-inducible kinase SGK1, a gene induced early in the response to aldosterone, but not pharmacologic inhibition of extracellular signal-regulated kinase and p38 kinase, attenuated aldosterone-induced NF-kappaB activation. Pharmacologic antagonism or knockdown of the mineralocorticoid receptor prevented aldosterone-induced NF-kappaB activity. In addition, activation of the glucocorticoid receptor inhibited the transactivation of NF-kappaB by aldosterone. In agreement with these in vitro findings, spironolactone prevented NF-kappaB-induced transcriptional activation observed in cortical collecting ducts of salt-restricted rats. In summary, aldosterone activates the canonical NF-kappaB pathway in principal cells of the cortical collecting duct by activating the mineralocorticoid receptor and by inducing SGK1.