Acute kidney injury (AKI) is a complex disorder for which currently there is no accepted definition. Having a uniform standard for diagnosing and classifying AKI would enhance our ability to manage these patients. Future clinical and translational research in AKI will require collaborative networks of investigators drawn from various disciplines, dissemination of information via multidisciplinary joint conferences and publications, and improved translation of knowledge from pre-clinical research. We describe an initiative to develop uniform standards for defining and classifying AKI and to establish a forum for multidisciplinary interaction to improve care for patients with or at risk for AKI. Members representing key societies in critical care and nephrology along with additional experts in adult and pediatric AKI participated in a two day conference in Amsterdam, The Netherlands, in September 2005 and were assigned to one of three workgroups. Each group's discussions formed the basis for draft recommendations that were later refined and improved during discussion with the larger group. Dissenting opinions were also noted. The final draft recommendations were circulated to all participants and subsequently agreed upon as the consensus recommendations for this report. Participating societies endorsed the recommendations and agreed to help disseminate the results. The term AKI is proposed to represent the entire spectrum of acute renal failure. Diagnostic criteria for AKI are proposed based on acute alterations in serum creatinine or urine output. A staging system for AKI which reflects quantitative changes in serum creatinine and urine output has been developed. We describe the formation of a multidisciplinary collaborative network focused on AKI. We have proposed uniform standards for diagnosing and classifying AKI which will need to be validated in future studies. The Acute Kidney Injury Network offers a mechanism for proceeding with efforts to improve patient outcomes.

Acute Kidney Injury Network: report of an initiative to improve outcomes in acute kidney injury

Polyomavirus-associated nephropathy (PVAN) is an emerging cause of kidney transplant failure affecting 1-10% of patients. As uncertainty exists regarding risk factors, diagnosis, and intervention, an independent panel of experts reviewed the currently available evidence and prepared this report. Most cases of PVAN are elicited by BK virus (BKV) in the context of intense immunosuppression. No specific immunosuppressive drug is exclusively associated with PVAN, but most cases reported to date arise while the patient is on triple immunosuppressive combinations, often comprising tacrolimus and/or mycophenolate mofetil plus corticosteroids. Immunologic control of polyomavirus replication can be achieved by reducing, switching, and/or discontinuing components of the immunosuppressive regimen, but the individual's risk of rejection should be considered. The success rate of this intervention is increased with earlier diagnosis. Therefore, it is recommended that all renal transplant recipients should be screened for BKV replication in the urine: 1) every three months during the first two years posttransplant; 2) when allograft dysfunction is noted; and 3) when allograft biopsy is performed. A positive screening result should be confirmed in <4 weeks and assessed by quantitative assays (e.g. BKV DNA or RNA load in plasma or urine). Definitive diagnosis of PVAN requires allograft biopsy. If PVAN and concurrent acute rejection is diagnosed, antirejection treatment should be considered, coupled with subsequently reducing immunosuppression. The antiviral cidofovir is not approved for PVAN, but investigational use at low doses (0.25-0.33 mg/kg intravenously biweekly) without probenicid should be considered for refractory cases. Retransplantation after renal allograft loss to PVAN remains a treatment option for patients clearing polyomavirus replication.

Polyomavirus-Associated Nephropathy in Renal Transplantation: Interdisciplinary Analyses and Recommendations

Hyponatraemia, defined as a serum sodium concentration !135 mmol/l, is the most common disorder of body fluid and electrolyte balance encountered in clinical practice. It can lead to a wide spectrum of clinical symptoms, from subtle to severe or even life threatening, and is associated with increased mortality, morbidity and length of hospital stay in patients presenting with a range of conditions. Despite this, the management of patients remains problematic. The prevalence of hyponatraemia in widely different conditions and the fact that hyponatraemia is managed by clinicians with a broad variety of backgrounds have fostered diverse institution- and speciality-based approaches to diagnosis and treatment. To obtain a common and holistic view, the European Society of Intensive Care Medicine (ESICM), the European Society of Endocrinology (ESE) and the European Renal Association – European Dialysis and Transplant Association (ERA–EDTA), represented by European Renal Best Practice (ERBP), have developed the Clinical Practice Guideline on the diagnostic approach and treatment of hyponatraemia as a joint venture of three societies representing specialists with a natural interest in hyponatraemia. In addition to a rigorous approach to methodology and evaluation, we were keen to ensure that the document focused on patient-important outcomes and included utility for clinicians involved in everyday practice.

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Clinical practice guideline on diagnosis and treatment of hyponatraemia

https://www.kidney-international.org/article/S0085-2538(15)52823-8/pdf

Association between obesity and kidney disease: a systematic review and meta-analysis.

This article updates the Heart Failure Association of the European Society of Cardiology (ESC) 2007 classification of advanced heart failure and describes new diagnostic and treatment options for these patients. Recognizing the patient with advanced heart failure is critical to facilitate timely referral to advanced heart failure centres. Unplanned visits for heart failure decompensation, malignant arrhythmias, co-morbidities, and the 2016 ESC guidelines criteria for the diagnosis of heart failure with preserved ejection fraction are included in this updated definition. Standard treatment is, by definition, insufficient in these patients. Inotropic therapy may be used as a bridge strategy, but it is only a palliative measure when used on its own, because of the lack of outcomes data. Major progress has occurred with short-term mechanical circulatory support devices for immediate management of cardiogenic shock and long-term mechanical circulatory support for either a bridge to transplantation or as destination therapy. Heart transplantation remains the treatment of choice for patients without contraindications. Some patients will not be candidates for advanced heart failure therapies. For these patients, who are often elderly with multiple co-morbidities, management of advanced heart failure to reduce symptoms and improve quality of life should be emphasized. Robust evidence from prospective studies is lacking for most therapies for advanced heart failure. There is an urgent need to develop evidence-based treatment algorithms to prolong life when possible and in accordance with patient preferences, increase life quality, and reduce the burden of hospitalization in this vulnerable patient population.

Advanced heart failure : a position statement of the Heart Failure Association of the European Society of Cardiology

Enhanced removal of sodium has often been cited as an advantage of ultrafiltration (UF) therapy over diuretic-based medical treatment in the management of acute decompensated heart failure. However, so far clinical studies have rarely evaluated the precise magnitude of sodium removal, and this assumption is largely based on the physiologic mechanisms and anecdotal observations that predate the contemporary management of heart failure. Recent data suggest that patients treated with UF experience substantial reduction in urinary sodium excretion possibly due to prolonged intravascular volume contraction. Consequently, the efficient sodium extraction through production of isotonic ultrafiltrate can be offset by urine hypotonicity. Based on the limited currently available data, it seems unlikely that the persistent benefits of UF could be solely explained by its greater efficiency in sodium removal. The design of the future studies should include frequent measurements of urine sodium to precisely compare the impact of UF and diuretics on sodium balance.

/pdf/more-efficient-sodium-removal-by-ultrafiltration-compared-to-44ifrkvfir.pdf

More Efficient Sodium Removal by Ultrafiltration Compared to Diuretics in Acute Heart Failure; Underexplored and Overstated.

Ultrafiltration therapy for acute decompensated heart failure: lessons learned from 2 major trials.

Low serum sodium concentration has long been recognized as an established marker of short- and long-term morbidity and mortality in patients with heart failure (HF), and is commonly included in various risk prediction models. Mechanisms leading to hyponatremia (e.g. maladaptive neurohormonal activation) could also lead to concurrent decline in serum chloride levels. Besides, chloride has distinct biological roles (e.g. modulation of renal tubular sodium transporters) that are relevant to the pathophysiology and therapy of HF, making it a potent cardiorenal connector. Several clinical studies have recently reported on a potentially overlooked link between low serum chloride levels and adverse outcomes in patients with a wide variety of HF syndromes, which could indeed be stronger than that of sodium. While evidence on predictive value of chloride is accumulating in various patient populations and settings, the limited available interventional studies have so far yielded conflicting results. It remains to be elucidated whether hypochloremia represents a marker of disease severity and prognosis, or it is an actual pathogenetic mechanism, hence being a potential novel target of therapy. Current ongoing studies are designed to better understand the mechanistic aspects of the role of hypochloremia in HF and shed light on its clinical applicability.

The dynamic relationship between serum chloride and cardiorenal syndrome.

While fibromuscular dysplasia (FMD) is an established cause of secondary hypertension, its association with renal infarction is less well recognized. We report a middle-aged man who presented with complaints of loin pain and severe hypertension. Computed tomography angiography of the abdomen revealed bilateral renal infarction with multiple short-segment arterial dissection compatible with FMD in the absence of systemic vasculitis and other risk factors for thromboembolic events. Bilateral renal infarction complicating FMD is extremely rare and has so far been reported only in a handful of cases. Physicians encountering cases of otherwise unexplained renal infarction/ischemia need to be aware of this complication.

/pdf/bilateral-renal-infarction-an-uncommon-presentation-of-1abqygno1z.pdf

Bilateral renal infarction: an uncommon presentation of fibromuscular dysplasia

Sir, The paper by Suliman et al ‘The reverse epidemiology of plasma total homocysteine as mortality risk factor is related to the impact of wasting and inflammation’ [1] tries to address the very important issue of the strange opposite clinical behaviour of some well-recognized mortality risk factors [in the paper, total homocysteine (tHcy) levels] in the haemodialysis population as compared to the general population. The authors suspect that this ‘reverse relationship’ between tHcy and outcome could be due to the effect of certain confounding factors such as age, gender, GFR, plasma folate, serum cholesterol, mean arterial BP, cardiovascular disease and diabetes. The inclusion of all these parameters in the Cox proportional hazards model, either for all cause and CVD adjusted mortality, did not change the ‘reverse’ nature of the relationship, in fact not significant, between tHcy and mortality. Inclusion in the model of nutritional and inflammatory markers, was associated with a ‘normalization’ of the relationship between tHcy and mortality, and this is taken by the authors as strong support of the effect of wasting and inflammation on tHcy, when evaluating this parameter as a risk factor for morbidity and mortality in haemodialysis (HD) patients. However, this statement lacks any support, since the supposed relationship between tHcy levels and mortality after adjustment for all variables plus nutritional and inflammation markers is not statistically significant (HR of low tHcy for all cause mortality was 0.73; CI: 0.33–1.60. HR for cardiovascular mortality was 0.78; CI: 0.34–1.76). Moreover, the very wide range of CI limits indicates the extreme weakness of the suggested association. For this reason, the message of the paper, also reported in the title: ‘The reverse epidemiology of plasma total homocysteine as mortality risk factor is related to the impact of wasting and inflammation’, although theoretically plausible, is not supported by the data.

Amir Kazory

Papers

More Efficient Sodium Removal by Ultrafiltration Compared to Diuretics in Acute Heart Failure; Underexplored and Overstated.

Ultrafiltration therapy for acute decompensated heart failure: lessons learned from 2 major trials.

The dynamic relationship between serum chloride and cardiorenal syndrome.

Bilateral renal infarction: an uncommon presentation of fibromuscular dysplasia

Removal of BNP and inflammatory cytokines by haemodiafiltration in refractory heart failure. Authors' reply