Kidney Allograft Fibrosis: Diagnostic and Therapeutic Strategies.

Interstitial fibrosis with tubule atrophy (IF/TA) is the response to virtually any sustained kidney injury and correlates inversely with kidney function and allograft survival. IF/TA is driven by various pathways that include hypoxia, renin-angiotensin-aldosterone system, transforming growth factor-ß signaling, cellular rejection, inflammation, and others. In this review, we will focus on key pathways in the progress of renal fibrosis, diagnosis and therapy of allograft fibrosis. This review discusses the role and origin of myofibroblasts as matrix producing cells and therapeutic targets in renal fibrosis with a particular focus on renal allografts. We summarize current trends to use multiomic approaches to identify new biomarkers for IF/TA detection and to predict allograft survival. Furthermore, we review current imaging strategies that might help to identify and follow-up IF/TA complementary or as alternative to invasive biopsies. We further discuss current clinical trials and therapeutic strategies to treat kidney fibrosis.

The Use of Genomics to Drive Kidney Disease Drug Discovery and Development.

As opposed to diseases such as cancer, autoimmune disease, and diabetes, identifying drugs to treat CKD has proven significantly more challenging. Over the past 2 decades, new potential therapeutic targets have been identified as genetically altered proteins involved in rare monogenetic kidney diseases. Other possible target genes have been implicated through common genetic polymorphisms associated with CKD in the general population. Significant challenges remain before translating these genetic insights into clinical therapies for CKD. This paper will discuss how genetic variants may be leveraged to develop drugs and will especially focus on those genes associated with CKD to exemplify the value and challenges in including genetic information in the drug development pipeline.

Metabolic Reprogramming in Autosomal Dominant Polycystic Kidney Disease: Evidence and Therapeutic Potential.

Autosomal dominant polycystic kidney disease is characterized by progressive development and enlargement of kidney cysts, leading to ESKD. Because the kidneys are under high metabolic demand, it is not surprising that mounting evidence suggests that a metabolic defect exists in in vitro and animal models of autosomal dominant polycystic kidney disease, which likely contributes to cystic epithelial proliferation and subsequent cyst growth. Alterations include defective glucose metabolism (reprogramming to favor aerobic glycolysis), dysregulated lipid and amino acid metabolism, impaired autophagy, and mitochondrial dysfunction. Limited evidence supports that cellular kidney metabolism is also dysregulated in humans with autosomal dominant polycystic kidney disease. There are notable overlapping features and pathways among metabolism, obesity, and/or autosomal dominant polycystic kidney disease. Both dietary and pharmacologic-based strategies targeting metabolic abnormalities are being considered as therapies to slow autosomal dominant polycystic kidney disease progression and are attractive, particularly given the slowly progressive nature of the disease. Dietary strategies include daily caloric restriction, intermittent fasting, time-restricted feeding, a ketogenic diet, and 2-deoxy-glucose as well as alterations to nutrient availability. Pharmacologic-based strategies include AMP-activated kinase activators, sodium glucose cotransporter-2 inhibitors, niacinamide, and thiazolidenediones. The results from initial clinical trials targeting metabolism are upcoming and anxiously awaited within the scientific and polycystic kidney disease communities. There continues to be a need for additional mechanistic studies to better understand the role of dysregulated metabolism in autosomal dominant polycystic kidney disease and for subsequent translation to clinical trials. Beyond single-intervention trials focused on metabolic reprograming in autosomal dominant polycystic kidney disease, great potential also exists by combining metabolic-focused therapeutic approaches with compounds targeting other signaling cascades altered in autosomal dominant polycystic kidney disease, such as tolvaptan.

[Bardoxolone: a new potential therapeutic agent in the treatment of autosomal dominant polycystic kidney disease?]

Autosomal dominant polycystic kidney disease (ADPKD) is the most common genetic cause of chronic renal failure. The natural history of ADPKD is characterized by development of multiple bilateral renal cysts that progressively destroy the architecture of the parenchyma and lead to an enlargement in the total kidney volume (TKV) and to the decline of the renal function. Cyst growth activates the immune system response causing interstitial inflammation and fibrosis that contribute to disease progression. In recent years, the therapeutic toolkit available to the nephrologist in the treatment of ADPKD has been enriched with new tools, and in this context bardoxolone is classified as a potential therapeutic agent. It is a semisynthetic derivative of triterpenoids, a family of compounds widely used in traditional Asian medicine for their multiple effects. Bardoxolone exerts antioxidant activity by promoting the activation of Nrf2 (Nuclear factor erythroid2-derivative - 2) and the downregulation of the proinflammatory NF-kB (Nuclear factor kappa-light-chain-enhancer of activated B cells) signaling. Several pieces of evidence support the use of bardoxolone in the treatment of chronic kidney disease (CKD) documenting an effect on the increase of glomerular filtration rate (GFR). However, its use is limited to patients at risk of heart failure. The FALCON study will clarify the efficacy and safety of bardoxolone in the treatment of ADPKD.

Effect of Alprostadil on the Prevention of Contrast-Induced Nephropathy: A Meta-Analysis of 36 Randomized Controlled Trials.

Contrast-induced nephropathy (CIN) is the third leading cause of acquired acute renal injury in hospitalized patients. Alprostadil plays a role in the maintenance and redistribution of intrarenal blood flow and the excretion of electrolytes and water. However, the effectiveness of alprostadil in preventing CIN remains controversial. Thirty-six articles with a total of 5495 patients were included in this study. Both groups (experimental group and control group) received standard hydration therapy. In the experimental group, patients received different doses of alprostadil. Serum creatinine (SCr), blood urea nitrogen (BUN), estimated glomerular filtration rate (eGFR), cystatin C, creatinine clearance rate (CCr), and ß2-microglobulin (ß2-MG) were measured at 24, 48, and 72 hours after contrast media injection. The incidence of CIN in the experimental group was significantly lower than that in the control group (6.56% vs 16.74%). The level of SCr, cystatin C, BUN, and ß2-MG in the experimental group was lower than those in the control group; CCr and eGFR in the experimental group were higher than those in the control group. This study demonstrated that alprostadil may reduce the incidence of CIN in patients undergoing coronary angiogram and/or percutaneous coronary intervention.

Long-Term Mortality and Bone Safety in Patients with End-Stage Renal Disease Receiving Lanthanum Carbonate.

BACKGROUND/AIMS: This post-marketing observational study assessed the long-term safety of lanthanum carbonate (LaC) in US patients with end-stage renal disease (NCT00567723). METHODS: Patients (≥18 years old) undergoing dialysis, who had Medicare as their primary healthcare payer, and records in the United States Renal Data System were followed-up for 5 years. Patients who had received LaC for at least 12 consecutive weeks formed the exposed cohort. During the same time period, patients who had undergone dialysis for at least 12 consecutive weeks and had been treated with any other phosphate binder formed the primary comparator cohort. A historical cohort was also evaluated. Primary outcomes were all-cause mortality, and time to and incidence of first bone-fracture event requiring hospitalization. Secondary outcomes were time to first occurrence of and incidence of specific gastrointestinal (GI) disease, liver disease, malignancy, and major infectious episode requiring hospitalization. -Results: 2,026 and 8,094 patients were included in the exposed and primary comparator cohorts, respectively. A Cox proportional hazards model showed that patients receiving LaC were not at increased risk of all-cause mortality (adjusted hazard ratio 0.94; 95% CI 0.88-1.01; p = 0.078), bone fractures (0.86; 0.71-1.05; p = 0.130), specific GI disease (0.86; 0.76-0.97; p = 0.015), liver disease (0.88; 0.70-1.09; p = 0.236), malignancy (0.85; 0.54-1.34; p = 0.496), or major infectious episodes (0.87; 0.80-0.94; p < 0.001) requiring hospitalization compared with primary comparator patients. CONCLUSIONS: LaC was not associated with increased risk of mortality, bone fractures, or any secondary outcome.

The mechanistic insight of polyphenols in calcium oxalate urolithiasis mitigation.

About 12% of world population is affected by different forms of urolithiasis of which the recurrence rate in female is 47-60% and in male is 70-80%. Standard therapeutic agents (allopurinol, citrate, cystone and thiazide diuretics) are used to prevent and treat urolithiasis but these are not universally-effective due to common kidney stone relapse and other side effects. Surgical treatment causes long-term renal damage, hypertension and stone recurrence. Polyphenols, the plant-derived bioactive molecules, have showed protection against cancers, cardiovascular diseases, diabetes, osteoporosis and neurodegenerative diseases, among a number of other ailments. The role of these phytochemicals in urolithiasis management is emerging. Hence, the present review discusses peer-reviewed published literature till date on this aspect and highlights that polyphenols could effectively inhibit the formation of calcium oxalate urinary stones (most common renal stone), correlating with their antioxidant, anti-inflammatory, diuretic and angiotensin-converting enzyme (ACE) inhibition. Further, we have proposed the prospects and challenges in developing the plant polyphenols into drugs against kidney stone prevention. This review might be a stepping stone for further investigation into the clinical implications of the polyphenols in urolithiasis remediation.

Available and incoming therapies for idiopathic focal and segmental glomerulosclerosis in adults.

Focal and segmental glomerulosclerosis (FSGS) is a histological pattern clinically characterized by nephrotic proteinuria, hypoalbuminemia, edema and dyslipidemia. Approximately 50% of patients progress to end-stage renal disease within 5-10 years, particularly those not responding to the therapies. FSGS pathogenesis is largely unknown and therapy is symptomatic and unspecific. The podocyte is considered as the pathogenetic main target and FSGS is now categorized as a podocytopathy together with minimal change disease, diffuse mesangial proliferation and collapsing glomerulonephritis. This paper provides an overview on the treatment of idiopathic FSGS in adults, citing the latest published trials and the most reliable pathogenetic hypotheses of the disease. A large part of the review then focuses on emerging therapies, specifying for each new drug the assumed mechanism of action and the data available in the literature on the drug's use in experimental animals and humans.

Effectiveness of Treatment Modalities on Kidney Stone Recurrence.

Nephrolithiasis is highly prevalent across all demographic groups in the Western world and beyond, and its incidence rates are rising. In addition to the morbidity of the acute event, stone disease often becomes a lifelong problem that requires preventative therapy to diminish ongoing morbidity. Across the majority of stone types, increased fluid intake and targeted dietary modifications are mainstays of therapy. Specific dietary interventions associated with reduced calcium stone risk include adequate dietary calcium intake and restriction of sodium, protein, and oxalate intake, among others. Pharmaceutical therapy may be required if lifestyle changes are insufficient to minimize risk of stone recurrence, and must be targeted to the specific metabolic abnormalities portending risk for a given patient. Therapeutic options for idiopathic calcium stone disease include thiazides, citrate salts, and uric acid-lowering agents. Alkali salts are also the treatment of choice for uric acid stone disease. Management of struvite stone disease is largely surgical, but acetohydroxamic acid is a proven second line therapy. Cystinuria requires lifestyle modifications and may call for thiol-binding agents. Significant heterogeneity of the clinical population with stone disease has previously limited opportunities for large randomized controlled trials. However, as clinical phenotypes and genotypes are increasingly clarified, there are mounting opportunities for targeted randomized controlled trials in stone prevention. In the meantime, the currently available evidence for both lifestyle and pharmacologic interventions is reviewed herein.

Defective glycolysis and the use of 2-deoxy-D-glucose in polycystic kidney disease: from animal models to humans.

Autosomal dominant polycystic kidney disease (ADPKD) is an inherited renal disease characterized by bilateral renal cyst formation. ADPKD is one of the most common rare disorders, accounting for ~10% of all patients with end-stage renal disease (ESRD). ADPKD is a chronic disorder in which the gradual expansion of cysts that form in a minority of nephrons eventually causes loss of renal function due to the compression and degeneration of the surrounding normal parenchyma. Numerous deranged pathways have been identified in the cyst-lining epithelia, prompting the design of potential therapies. Several of these potential treatments have proved effective in slowing down disease progression in pre-clinical animal studies, while only one has subsequently been proven to effectively slow down disease progression in patients, and it has recently been approved for therapy in Europe, Canada and Japan. Among the affected cellular functions and pathways, recent investigations have described metabolic derangement in ADPKD as a major trait offering additional opportunities for targeted therapies. In particular, increased aerobic glycolysis (the Warburg effect) has been described as a prominent feature of ADPKD kidneys and its inhibition using the glucose analogue 2-deoxy-D-glucose (2DG) proved effective in slowing down disease progression in preclinical models of the disease. At the same time, previous clinical experiences have been reported with 2DG, showing that this compound is well tolerated in humans with minimal and reversible side effects. In this work, we review the literature and speculate that 2DG could be a good candidate for a clinical trial in humans affected by ADPKD.

Diagnosis and Management of Type 2 Diabetic Kidney Disease.

Type 2 diabetic kidney disease (DKD) is the most common cause of CKD and ESRD worldwide, and carries with it enormous human and societal costs. The goal of this review is to provide an update on the diagnosis and management of DKD based on a comprehensive review of the medical literature. Topics addressed include the evolving presentation of DKD, clinical differentiation of DKD from non-DKD, a state-of-the-art evaluation of current treatment strategies, and promising emerging treatments. It is expected that the review will help clinicians to diagnose and manage patients with DKD.

Efficacy of nicorandil treatment for prevention of contrast-induced nephropathy in high-risk patients undergoing cardiac catheterization: A prospective randomized controlled trial.

BACKGROUND: Contrast-induced nephropathy (CIN) remains to be a potentially serious complication of radiographic procedures and is the third leading cause of the acute kidney injury (AKI) among hospitalized patients. This clinical trial was performed to assess the preventive effect of oral nicorandil on CIN in high-risk patients undergoing cardiac catheterization. METHODS: In this prospective, randomized, controlled trial, 128 patients with at least two risk factors for CIN undergoing elective percutaneous coronary intervention (PCI) were randomly assigned to either the nicorandil group or the control group. Patients in the nicorandil group (n = 64) received 10 mg nicorandil, daily from 30 min before and up to 3 days after procedure and intravenous hydration for 2 h before and 6 h after the procedure, whereas patients in the control group (n = 64) just received intravenous hydration. Serum creatinine (SCr) was measured before contrast exposure and at 72 h. CIN was defined as an increase of 25% in SCr or > 0.5 mg/dL 72 h after contrast administration. RESULTS: Contrast-induced nephropathy occurred in 14 out of 64 (21.9%) patients in the control group and in 3 out of 64 (4.7%) patients in the nicorandil group. There was a significant difference in the incidence of CIN between the two groups at 72 h after administering the radiocontrast agent (p = 0.008). Moreover, there were significant differences between the two groups in SCr and estimated glomerular filtration rate 72 h after radiocontrast administration (p < 0.05). CONCLUSIONS: The findings revealed that oral nicorandil had substantial efficacy over hydration protocol for the development of CIN in high-risk patients undergoing cardiac catheterization.

Switching from immediate- to extended-release cysteamine in nephropathic cystinosis patients: a retrospective real-life single-center study.

BACKGROUND: Nephropathic cystinosis is a rare lysosomal storage disease which is characterized by the accumulation of free cystine in lysosomes and subsequent intracellular crystal formation of cystine throughout the body. If not treated with cysteamine, a cystine-depleting agent, end-stage renal disease will develop early, followed by multiple organ failure as the disease progresses. The established cysteamine formulation requires a strict dosing regimen at 6-h intervals. An extended release (ER) twice-daily formulation has recently been developed. The aim of our study was to evaluate the implementation and outcomes of this option in routine care. METHODS: All pediatric cystinosis patients' records in Hannover Medical School were screened, and data on cysteamine therapy, tolerability, dosing, estimated glomerular filtration rates (eGFR), white blood cell cystine levels, and proton pump inhibitor (PPI) use were extracted for the period January 2014 to January 2016. RESULTS: The median age of the 12 patients enrolled in the study was 12.5 (range 1-18) years. At the end of the study period ten of these patients received ER-cysteamine. There were no additional side effects. Halitosis/bad breath was often subjectively judged as improved or eliminated, and PPI use could be stopped in one of three patients. The main reasons for switching to the ER formulation were difficult night-time administration and uncontrolled disease. Mean eGFR values remained stable with a median of 67 ml/min/1.73 m2 before and after the transition. White blood cell (WBC) cystine values remained low after the switch (1 nmol/mg protein before and after transition; p = 0.64). CONCLUSIONS: In this single-center cohort, the switch from IR- to ER-cysteamine was safe and effective over the short term and provided advantages in terms of frequency of administration and less halitosis/bad breath. The long-term benefit of this option needs to be evaluated in future studies.

Combination treatment of nocturnal enuresis with desmopressin and indomethacin.

BACKGROUND: We investigated the effect of combining indomethacin and desmopressin in treating children with monosymptomatic nocturnal enuresis (MNE) and desmopressin-resistant nocturnal polyuria. METHODS: Twenty-three children with MNE, nocturnal polyuria, and partial or no response to desmopressin were recruited from incontinence clinics of our tertiary referral center. We used a randomized single-arm crossover placebo-controlled study design consisting of two 3-week treatment periods with a combination of desmopressin (0.4 mg) and indomethacin (50 mg) or desmopressin and placebo at bedtime. Home recordings at baseline and for the final 2 weeks of each treatment period were performed and included nocturnal urine output measurements. The number of dry nights achieved and reduction in the nocturnal urine output were the main effect parameters. Student's t test and Pearson's correlation coefficient were used for statistical analysis. RESULTS: The addition of indomethacin to desmopressin significantly reduced nocturnal urine output (from 324 ± 14 ml to 258 ± 13 ml, p < 0.001). This did not lead to more dry nights in all children, and we found no statistically significant reduction in enuresis frequency (from 68 % ± 0.1 to 56 % ± 0.1, p = 0.24). CONCLUSIONS: Addition of indomethacin to desmopressin can further reduce nocturnal urine output in children with MNE and desmopressin-resistant nocturnal polyuria. The combination treatment does not, however, improve outcome in terms of frequency of nights with enuresis. The dissociation of antidiuretic and antienuretic effect may reflect nocturnal bladder reservoir dysfunction in children who present with normal daytime bladder function.

[Strategies of age-adapted pharmacotherapy in renal failure]. / Strategien der altersadäquaten Pharmakotherapie bei Niereninsuffizienz.

Many geriatric patients with multimorbidities have an increased risk for impaired renal function due to age and often the presence of comorbidities, such as diabetes mellitus, hypertension and heart failure. This impairment in kidney function in turn necessitates adjustments in drug therapy. A successful strategy for treating these patients includes treatment of the underlying diseases, a comprehensive review of the indications, selection of appropriate pharmacotherapeutic alternatives and for some drugs dose adjustment to the renal function. To achieve therapeutic success many patient individual factors, such as potentially complex medication regimens, polypharmacy, cognitive function and functional disabilities need to be considered when prescribing medications. This article describes the problems associated with drug therapy that is not adjusted to renal function and provides guidelines for assessment of the benefits and risks in patients with kidney failure. The characteristic features of geriatric patients in particular are considered and discussed.

Early results of human atrial natriuretic peptide infusion in non-dialysis patients with chronic kidney disease undergoing isolated coronary artery bypass grafting: the NU-HIT trial for CKD-II.

BACKGROUND: Chronic kidney disease (CKD) is an important risk factor for cardiac surgery. In the most recently reported NU-HIT trial for CKD with CKD patients underwent coronary artery bypass grafting (CABG) as subjects, carperitide was reported to be effective in terms of renal function. In the present study, a subanalysis was performed on patients registered in the NU-HIT trial for CKD from the standpoint of renin-angiotensin system, natriuresis and renal function. METHODS: 303 patients with CKD who underwent isolated CABG were divided into a group that received carperitide infusion and another group without carperitide. The renin activity, angiotensin-II, aldosterone, urine-sodium, urine- creatinine, fractional sodium excretion, renal failure index, and BNP levels. RESULTS: There were significant lower in hANP group than the placebo group, in angiotensin-II at one day postoperatively, and in aldosterone from 0 day to one month postoperatively. FENa was significantly lower in the hANP group at 3 day and one week postoperatively. CONCLUSIONS: In on pump isolated CABG patients with CKD, carperitide showed a potent natriuretic action and inhibited the renin-angiotensin system, suggesting that it prevented deterioration of postoperative renal function. Our findings raise new possibilities for the perioperative and postoperative management of patients undergoing surgery with cardiopulmonary bypass.

Copper deficiency in patients with cystinosis with cysteamine toxicity.

OBJECTIVES: To assess whether copper deficiency plays a role in the recently described cysteamine toxicity in patients with cystinosis, and to examine whether polymorphisms in copper transporters, lysyl oxidase, and/or type I procollagen genes could be responsible for the occurrence of cysteamine toxicity in a small subset of patients with cystinosis. STUDY DESIGN: Thirty-six patients with cystinosis were included: 22 with Fanconi syndrome (including 7 with cysteamine toxicity), 12 after renal transplantation, 1 receiving hemodialysis, and 1 with ocular cystinosis. Serum copper and ceruloplasmin levels and urinary copper/creatinine ratio were measured. Genes ATP7A and CTR1 (encoding copper transporters), LOX (encoding lysyl oxidase), and COL1A1 and COL1A2 (encoding type I procollagen) were analyzed in patients with (n = 6) and without (n = 5) toxicity. Fibroblast (pro)collagen synthesis was compared in patients with (n = 3) and those without (n = 2) cysteamine toxicity. RESULTS: All 22 patients with Fanconi syndrome had increased urinary copper excretion. Serum copper and ceruloplasmin levels were decreased in 9 patients, including all 7 patients with cysteamine toxicity. No specific sequence variations were associated with toxicity. All fibroblasts exhibited normal (pro)collagen synthesis. CONCLUSION: Patients with cystinosis with cysteamine toxicity demonstrate copper deficiency. This can cause decreased activity of lysyl oxidase, the enzyme that generates the aldehydes required for collagen cross-linking. Thus, copper supplementation might prevent cysteamine toxicity.

Long-term outcome of the difficult nephrotic syndrome in children.

To determine the long-term outcome of nephrotic syndrome (NS) in children, we studied 48 patients with the NS aged seven months to 12 years at onset and followed for a long period (3-9 years). Consanguinity was positive in 31.2%. Patients' history of atopy was present in 25%, while family history of allergy was present in 18 (37.5%) patients. Renal impairment at initial presentation was observed in 12.5% of the patients. Among 32 biopsied patients, 11 (34.3%) had focal segmental glomerulosclerosis and eight (25%) revealed mesangial IgM nephropathy. Outcome at two years of presentation showed 41.6% patients as frequent relapsers, 39.5% as steroid dependent and 18.7% as steroid resistant. Forty-three patients were available for follow-up after ten years of presentation, 22 (51%) patients had complete remission, 15 (34.8%) were steroid dependent, two (4.6%) developed chronic renal failure and two (4.6%) died. Two patients (4.6%) developed insulin-dependent diabetes mellitus, two (4.6%) had cataract and one (2.3%) had documented peritonitis. In conclusion, the high incidence of steroid-dependent, frequent relapses and steroid resistance in children can be explained by different factors, including consanguinity, atopy and severe presentation at onset of disease. We suggest longer initial treatment at onset for this group of patients. The low incidence of infection in this group needs to be addressed in future studies.

Desmopressin (dDAVP) incident signals the need for enhanced monitoring protocols.

In this article, the authors highlight the circumstances surrounding the death of a young adult neurosurgical patient, recently reported to ISMP Canada. The incident signals the need for enhanced safeguards for patients receiving desmopressin (also known as dDAVP) and intravenous therapy. The authors present information from a recent ISMP Canada Safety Bulletin relevant to critical care, including an outline of potential contributing factors and suggested recommendations.