Systemic Diseases with Renal Manifestations

Kidney aging process and the management of the elderly patient with renal impairment (Review)

As life expectancy increases, a rise in the number of chronically ill patients is observed due to the aging population. Among the various diseases, chronic kidney disease is at present one of the main causes of morbidity and, due to its typical complications, it is also one of the most important causes of mortality in the general population. For these reasons, the understanding of the kidney aging process, its consequences and its adequate management are essential. The judicious use of certain types of drugs, the prevention of episodes of renal injury either by toxic mechanisms or by dehydration are important aspects and are part of the apropriate approach for elderly patients. The most effective treatment of various types of conditions with a negative impact on renal function and for which an increased incidence is known as we age should also be considered. Thus, in the case of elderly patients, in order to protect the kidneys, an integrative approach is recommended, one that includes both elements of prevention and the appropriate treatment of existing diseases.

Retinal Vascular Density as A Novel Biomarker of Acute Renal Injury after Acute Coronary Syndrome

Iodinated contrast agent (ICA)-induced acute kidney injury (AKI) following acute coronary syndrome (ACS) is a frequent complication, which may lead to chronic kidney disease and increased mortality. Optical coherence tomography angiography (OCT-A) of the retina is new tool delivering a rapid and noninvasive assessment of systemic microvascularization, which is potentially involved in the occurrence of ICA-induced AKI. Between October 2016 and March 2017, 452 ACS patients were admitted to our cardiac intensive care unit. OCT-A was performed within 48 h after the ICA injection. Patients with a history of retinal disease were excluded. The patients included were divided into two groups depending on whether or not AKI occurred after injection of ICA, according to KDIGO criteria. Of the 216 patients included, 21 (10%) presented AKI. AKI was significantly associated with age, Mehran score, GRACE score, and NT-proBNP. AKI patients had significantly lower retinal vascular density (RVD)) and had more frequent low RVD (81% vs 45%, P = 0.002). Adding low RVD to the Mehran score and the NT-proBNP, or to the GRACE score and the NT-proBNP, significantly improved their predictive values, suggesting that systemic microvascular involvement remains incompletely addressed by either standard risk scores or factors known to be associated with ICA-induced AKI.

New insights into molecular mechanisms of sunitinib-associated side effects

The introduction of targeted therapy represents a major advance in the treatment of tumor progression. Targeted agents are a novel therapeutic approach developed to disrupt different cellular signaling pathways. The tyrosine kinase inhibitor sunitinib specifically blocks multiple tyrosine kinase receptors that are involved in the progression of many tumors. Sunitinib is the current standard of care in first-line treatment of advanced renal cell carcinoma, and it is approved in imatinib-intolerant and imatinib-refractory gastrointestinal stromal tumors. However, it is increasingly evident that sunitinib may display collateral effects on other proteins beyond its main target receptors, eliciting undesirable and unexpected adverse events. A better understanding of the molecular mechanisms underlying these undesirable sunitinib-associated side effects will help physicians to maximize efficacy of sunitinib and minimize adverse events. Here, we focus on new insights into molecular mechanisms that may mediate sunitinib-associated adverse events.

Renal function assessment in patients with systemic lupus erythematosus

Few studies have evaluated the glomerular filtration rate (GFR) in patients with systemic lupus erythematosus (SLE). Even though the National Kidney Foundation (NKF) suggests using the equations to estimate GFR, rheumatologists continue using creatinine clearance (CCl). The main objective of our study was the assessment of different equations to estimate GFR in patients with SLE: Simplified MDRD study equation (sMDRD), CCl, Cockcroft Gault (CG), CG calculated with ideal weight (CGi), Mayo Clinic Quadratic (MCQ), and Chronic Kidney Disease Epidemiology Collaboration Equation (CKD-EPI). CKD-EPI was considered as the reference standard, and it was compared with the other equations to evaluate bias, correlation (r), sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), percentage of measurement of GFR between 70-130% of GFR measured through CKD-EPI (P30) and to compute the ROC curves. Adequacy of the 24-h urine collection was evaluated. To classify patients into GFR < 60 ml/min/1.73 m(2), the best sensitivity and NVP were obtained with sMDRD: the best PPV and specificity with MCQ. P30 was 99.3% with sMDRD, 77.5% CCl, 91.7% CG, 96.7% CGi, and 77.2% with MCQ. The lowest bias was for sMDRD and the highest for CCl. Only 159 (52.6%) urine collections were considered adequate, and when these patients were re-evaluated, the statistical results improved for CCl. CGi was better in general than CG. CCl should not be considered as an adequate GFR estimation. Ideal weight is better than real weight to calculate GFR through CG in patients with SLE.

Pharmacokinetics and safety of sunitinib malate in subjects with impaired renal function

This phase I, open-label, single-dose study evaluates the effects of severe renal impairment and end-stage renal disease (ESRD) requiring hemodialysis on the pharmacokinetics, safety, and tolerability of sunitinib and its primary active metabolite, SU12662. Subjects with normal renal function (creatinine clearance > 80 mL/min), severe renal impairment (creatinine clearance < 30 mL/min), and ESRD requiring hemodialysis receive a single dose of sunitinib 50 mg. Serial blood samples are collected for quantification of plasma concentrations using a validated liquid chromatography with tandem mass spectrometry assay. Safety is monitored. Twenty-four subjects complete the study. Pharmacokinetics in subjects with severe renal impairment appear similar to those with normal renal function. Plasma exposure to sunitinib and SU12662 appears lower in subjects with ESRD compared with subjects with normal renal function or severe renal impairment. Single-dose sunitinib 50 mg is well tolerated regardless of renal function. The currently approved starting dose of sunitinib 50 mg on Schedule 4/2 is expected to be appropriate for patients with renal impairment; any subsequent dose modifications should be based on patients' ability to tolerate treatment.

Acute kidney injury in the intensive care unit

Acute kidney injury (AKI) is common among critically ill patients and results in increased mortality in this population. This review focuses on the diagnosis and management of AKI. The authors first explore new aspects of diagnosis, including new criteria that take into account even modest changes in renal function, and the development of novel biomarkers to allow earlier identification and better differential diagnosis of AKI. The authors also explore the available data on choice of dialysis modality and dialysis dose for the treatment of AKI, as well as the breakthrough development of the bioartificial kidney. Last, the authors review co-interventions that may have relevance to prognosis of AKI, such as intensive insulin therapy and the use of erythropoietin.