The possible role of physical activity in the modulation of gut microbiota in chronic kidney disease and its impact on cardiovascular risk: a narrative review.

Chronic degenerative non-communicable diseases (CDNCDs), in particular chronic kidney disease, induce gut microbiota (GM) dysbiosis, which, in turn, worsens the progression of CDNCDs and patients' quality of life. We analyzed literature studies to discuss the possible positive and beneficial impact of physical activity on GM composition and CV risk in CKD patients. Regular physical activity seems to be able to positively modulate the GM, reducing the systemic inflammation and consequently the production of uremic gut-derived toxins, which are directly correlated with the increase of cardiovascular risk. In particular, the accumulation of indoxyl sulphate (IS) seems to be able to induce vascular calcifications, vascular stiffness and cardiac calcifications, while p-Cresyl sulphate (p-CS) seems to be able to exert a cardiotoxic action through metabolic pathways, capable of inducing oxidative stress. In addition, trimethylamine N-oxide (TMAO) can alter lipid metabolism, inducing the production of foam cells and causing an accelerated atherosclerosis process. In this context, a regular physical activity program seems to represent an adjuvant non-pharmacological approach to the clinical management of CKD patients.

Screening of Fabry Disease of patients in renal replacement therapy in a population from Lazio (Italy).

OBJECTIVE: Fabry's disease (FD) is a genetic disorder of lysosomal storage characterized by the intralysosomal accumulation of globotriaosylceramide (Gb3). This genetic mutation causes a total or partial deficit of the α-galactosidase (GAL) enzyme activity. FD has an incidence of 1:40000-60000 born alive. Its prevalence is higher in specific pathological conditions like chronic kidney disease (CKD). The aim of this study was to evaluate the FD prevalence in Italian renal replacement therapy (RRT) patients from Lazio region. PATIENTS AND METHODS: 485 patients in RRT (hemodialysis, peritoneal dialysis, and kidney transplantation) were recruited. The screening test was performed on venous blood sample. The latter was analyzed using specific FD diagnostic kit, based on the analysis of dried blood spots on filter paper. RESULTS: We found 3 cases of positivity to FD (1 female and 2 males). In addition, 1 male patient was identified with biochemical alteration indicative of GAL enzyme deficiency with a genetic variant of the GLA gene of unknown clinical significance. The FD prevalence in our population was 0.60% (1 case out 163), it rises to 0.80% (1 case out of 122) if the genetic variant of unknown clinical significance is considered. Comparing the three subpopulations, we observed a statistically significant difference in GAL activity in transplanted patients compared to dialysis patients (p<0.001). CONCLUSIONS: Considering the presence of an enzyme replacement therapy able to modify FD clinical history, it is essential to try to implement FD early diagnoses. However, the screening is too expensive to be extended on large scale, due to the low prevalence of the pathology. The screening should be performed on high-risk populations.

Novel therapeutic approaches based on the pathological role of gut dysbiosis on the link between nonalcoholic fatty liver disease and insulin resistance.

The growing global epidemic of obesity and type 2 diabetes mellitus has determined an increased prevalence of NAFLD (non-alcoholic fatty liver disease), making it the most common chronic liver disease in the Western world and a leading cause of liver transplantation. In the last few years, a rising number of studies conducted both on animal and human models have shown the existence of a close association between insulin resistance (IR), dysbiosis, and steatosis. However, all the mechanisms that lead to impaired permeability, inflammation, and fibrosis have not been fully clarified. Recently, new possible treatment modalities have received much attention. To reach the review purpose, a broad-ranging literature search on multidisciplinary research databases was performed using the following terms alone or in combination: "NAFLD", "gut dysbiosis", "insulin resistance", "inflammation", "probiotics", "Chinese herbs". The use of probiotics, prebiotics, symbiotics, postbiotics, fecal microbiota transplant (FMT), Chinese herbal medicine, antibiotics, diet (polyphenols and fasting diets), and minor therapies such as carbon nanoparticles, the MCJ protein, water rich in molecular hydrogen, seems to be able to improve the phenotypic pattern in NAFLD patients. In this review, we provide an overview of how IR and dysbiosis contribute to the development and progression of NAFLD, as well as the therapeutic strategies currently in use.

A literature review of hypertensive retinopathy: systemic correlations and new technologies.

OBJECTIVE: Hypertensive retinopathy (HR) is the most common ocular manifestation of systemic arterial hypertension. This paper aims to summarize the current knowledge of HR, reviewing its classical features, such as epidemiology, pathophysiology, clinical manifestations, classifications, management and the most significant systemic correlations. We also provide an update on the latest advances in new technologies focusing on novel instrumental classifications. MATERIALS AND METHODS: A literature search was performed to identify articles regarding HR listed in Embase, PubMed, Medline (Ovid) and Scopus database up to 1 December 2021. The reference lists of the analyzed articles were also considered a source of literature information. The following keywords were used in various combinations: hypertensive retinopathy, hypertension and eye, hypertensive retinopathy and systemic correlations, optical coherence tomography (OCT) and hypertensive retinopathy, optical coherence tomography angiography (OCTA) and hypertensive retinopathy, adaptive optics (AO) and hypertensive retinopathy. The authors analyzed all English articles found using the aforementioned keywords. All the publications were thoroughly reviewed to create a detailed overview of this issue. RESULTS: HR signs have a significative association with cardiovascular, cerebrovascular and other systemic diseases. Patients with arteriosclerotic changes and, at the same time, severe HR, are at increased risk for coronary disease, peripheral vascular disease, stroke and dementia. HR is even now diagnosed and classified by its clinical appearance on a fundoscopic exam that is limited by interobserver variability. New technologies, like OCT, OCTA, AO and artificial intelligence may be used to develop a new instrumental classification that could become an objective and quantitative method for the evaluation of this disease. They could be useful to evaluate the subclinical retinal microvascular changes due to hypertension that may reflect the involvement of other vital organs. CONCLUSIONS: The eye is the only organ in the human body where changes in the blood vessels due to systemic hypertension can be studied in vivo. All doctors should be familiar with this disease because it has been largely demonstrated that signs of HR are correlated to patient's health and mortality. Researchers should develop a new common, standardized, and objective method to assess hypertensive retinal changes; new technologies may have a significant role in this field. This review takes most of the literature published so far, including the OCTA studies in order to stimulate new points of reference to standardize parameters and new diagnostic markers of this disease.

Link between gut microbiota dysbiosis and chronic kidney disease.

During chronic kidney disease (CKD), typical alterations in the gut microbiota are observed. The kidney no longer plays the role of the main excretory organ as this function is performed by the intestine. In CKD patients, an alteration of intestinal permeability and a degradation of the protective mucous layer are observed. These changes in the intestinal barrier allow the passage of bacterial material from the intestine to the bloodstream through the intestinal wall. This phenomenon contributes to the induction of the chronic inflammatory state, typical of CKD. In nephropathic patients, there is an increase in circulation of p-cresyl sulfate (p-CS), indoxyl sulphate (IS), indole-3 acetic acid (IAA) and trimethylamine-N-oxide (TMAO), all gut-derived uremic toxins. The changes in gut microbiota composition are related to CKD stage and this phenomenon is exacerbated in hemodialysis (HD) adult and pediatric patients. Interestingly, it is observed a positive shift in gut microbiota composition after renal transplantation and at the same time a reduction of circulating gut-derived uremic toxins. Either gut dysbiosis or uremic toxins accumulation contribute to the CKD onset and progression.

Risk factors for diabetic foot ulcers: an Albanian retrospective study of inpatients with type 2 diabetes.

OBJECTIVE: The aim of this study was to assess the impact of glucose control, diabetes-related complications and cardiometabolic risk factors on the risk of diabetic foot ulcers (DFUs) and DFU complications in Albanian adult inpatients with T2D. PATIENTS AND METHODS: We conducted a retrospective case-control study on 482 Albanian adult inpatients with T2D. DFU was defined as a full-thickness skin lesion requiring ≥14 days for healing and was classified at the time of hospital admission. Demographic and biochemical parameters of the study participants, the presence of comorbidities and diabetes-related complications at the time of hospital admission were evaluated through a retrospective chart review. RESULTS: Mean age of study participants was 54.8±10.7 years. Participants (284 males and 198 females) were divided into two groups: DFU (cases; n=104) and non-DFU (controls; n=378). Multivariate analysis (performed by a logistic regression model) revealed that the most relevant independent variables associated with DFU were BMI [OR=0.62; p=0.007], HDL-cholesterol [OR=0.00; p<0.0001], triglycerides [OR=7.48; p=0.0004], cigarette smoking [OR=26.46; p=0.005], duration of diabetes [OR=1.53; p<0.0001], fasting plasma glucose (FPG) [OR=1.06; p<0.0001], systolic blood pressure (SBP) [OR=1.13; p=0.0004] and insulin therapy alone [OR=0.11; p=0.02]. ROC curve analysis showed that FPG (AUC=0.83), glycated hemoglobin (HbA1c) (AUC=0.75), triglycerides (AUC=0.78) and HDL-cholesterol (AUC=0.82) were the most reliable biomarkers able to detect DFU. In the DFU group, the most relevant independent variables associated with previous minor lower-extremity amputations (LEAs) were represented by HbA1c [OR=1.47; p=0.03], age <55 years [OR=0.12; p=0.05] and female sex [OR=4.18; p=0.03]; whereas the most relevant independent variables associated with diabetic peripheral neuropathy (DPN) were HbA1c [OR=1.70; p=0.006], SBP [OR=1.08; p=0.05], BMI [OR=1.20; p=0.03] and lack of cigarette smoking [OR=0.07; p=0.01]. Correlation analysis (performed through the nonparametric Spearman's rank correlation test or through the parametric Pearson test, as appropriate) revealed a significant positive relationship between HbA1c and FPG (r=0.58; p<0.0001), ulcer surface area (r=0.50; p<0.0001), ulcer grade (r=0.23; p=0.02), minor LEAs (r=0.20; p=0.04), DPN (r=0.41; p<0.0001), and metformin therapy alone (r=0.72; p<0.0001). There was a significant inverse correlation between HbA1c and insulin therapy alone (r=-0.31; p=0.01) and combined metformin and insulin therapy (r=-0.60; p<0.0001). Both DFU and non-DFU groups exhibited suboptimal mean LDL-cholesterol levels (>100 mg/dl) and mean HbA1c values >7.5%. Moreover, in DFU group HbA1c values were markedly elevated (≥10%) particularly in patients with a grade 3 ulcer and an ulcer surface area ≥4 cm2, as well as in patients with history of minor LEAs and in patients affected by DPN. CONCLUSIONS: The present study suggested that longer duration of diabetes, cigarette smoking, lower HDL-cholesterol levels, poor glucose control, and elevated triglyceride and SBP values may all represent major risk factors for the development of DFU in Albanian patients with T2D. Thus, community interventions and health policies aimed to improve the management of diabetes and related cardiometabolic risk factors should be urgently implemented in Albania, in order to prevent DFUs and other diabetes complications in patients with T2D.

Free-amino acid metabolic profiling of visceral adipose tissue from obese subjects.

Interest in adipose tissue pathophysiology and biochemistry have expanded considerably in the past two decades due to the ever increasing and alarming rates of global obesity and its critical outcome defined as metabolic syndrome (MS). This obesity-linked systemic dysfunction generates high risk factors of developing perilous diseases like type 2 diabetes, cardiovascular disease or cancer. Amino acids could play a crucial role in the pathophysiology of the MS onset. Focus of this study was to fully characterize amino acids metabolome modulations in visceral adipose tissues (VAT) from three adult cohorts: (i) obese patients (BMI 43-48) with metabolic syndrome (PO), (ii) obese subjects metabolically well (O), and (iii) non obese individuals (H). 128 metabolites identified as 20 protein amino acids, 85 related compounds and 13 dipeptides were measured by ultrahigh performance liquid chromatography-tandem mass spectroscopy (UPLC-MS/MS) and gas chromatography-/mass spectrometry GC/MS, in visceral fat samples from a total of 53 patients. Our analysis indicates a probable enhanced BCAA (leucine, isoleucine, valine) degradation in both VAT from O and PO subjects, while levels of their oxidation products are increased. Also PO and O VAT samples were characterized by: elevated levels of kynurenine, a catabolic product of tryptophan and precursor of diabetogenic substances, a significant increase of cysteine sulfinic acid levels, a decrease of 1-methylhistidine, and an up regulating trend of 3-methylhistidine levels. We hope this profiling can aid in novel clinical strategies development against the progression from obesity to metabolic syndrome.

Arterial ageing: from endothelial dysfunction to vascular calcification.

Complex structural and functional changes occur in the arterial system with advancing age. The aged artery is characterized by changes in microRNA expression patterns, autophagy, smooth muscle cell migration and proliferation, and arterial calcification with progressively increased mechanical vessel rigidity and stiffness. With age the vascular smooth muscle cells modify their phenotype from contractile to 'synthetic' determining the development of intimal thickening as early as the second decade of life as an adaptive response to forces acting on the arterial wall. The increased permeability observed in intimal thickening could represent the substrate on which low-level atherosclerotic stimuli can promote the development of advanced atherosclerotic lesions. In elderly patients the atherosclerotic plaques tend to be larger with increased vascular stenosis. In these plaques there is a progressive accumulation of both lipids and collagen and a decrease of inflammation. Similarly the plaques from elderly patients show more calcification as compared with those from younger patients. The coronary artery calcium score is a well-established marker of adverse cardiovascular outcomes. The presence of diffuse calcification in a severely stenotic segment probably induces changes in mechanical properties and shear stress of the arterial wall favouring the rupture of a vulnerable lesion in a less stenotic adjacent segment. Oxidative stress and inflammation appear to be the two primary pathological mechanisms of ageing-related endothelial dysfunction even in the absence of clinical disease. Arterial ageing is no longer considered an inexorable process. Only a better understanding of the link between ageing and vascular dysfunction can lead to significant advances in both preventative and therapeutic treatments with the aim that in the future vascular ageing may be halted or even reversed.

Is low-protein diet a possible risk factor of malnutrition in chronic kidney disease patients?

Chronic kidney disease (CKD) is becoming increasingly widespread in the world. Slowing its progression means to prevent uremic complications and improve quality of life of patients. Currently, a low-protein diet (LPD) is one of the tools most used in renal conservative therapy but a possible risk connected to LPD is protein-energy wasting. The aim of this study is evaluate the possible correlation between LPD and malnutrition onset. We enrolled 41 CKD patients, stages IIIb/IV according to K-DIGO guidelines, who followed for 6 weeks a diet with controlled protein intake (recommended dietary allowance 0.7 g per kilogram Ideal Body Weight per day of protein). Our patients showed a significant decrease of serum albumin values after 6 weeks of LDP (T2) compared with baseline values (T0) (P=0.039), whereas C-reactive protein increased significantly (T0 versus T2; P=0.131). From body composition analysis, a significant impairment of fat-free mass percentage at the end of the study was demonstrated (T0 versus T2; P=0.0489), probably related to total body water increase. The muscular mass, body cell mass and body cell mass index are significantly decreased after 6 weeks of LDP (T2). The phase angle is significantly reduced at the end of the study compared with basal values (T0 versus T2; P=0.0001, and T1 versus T2; P=0.0015). This study indicated that LPD slows down the progression of kidney disease but worsens patients' nutritional state.

Obesity and kidney disease: Beyond the hyperfiltration.

In industrialized countries, overweight and obesity account for approximately 13.8% and 24.9% of the kidney disease observed in men and women, respectively. Moreover, obesity-associated glomerulopathy is now considered as "an emerging epidemic." Kidney function can be negatively impacted by obesity through several mechanisms, either direct or indirect. While it is well established that obesity represents the leading risk factor for type 2 diabetes and hypertension, awareness that obesity is associated with direct kidney damage independently of hypertension and diabetes is still not widespread. In this paper we will discuss the emerging role of adipose tissue, particularly in the visceral depot, in obesity-induced chronic kidney damage.

SGK-1 protects kidney cells against apoptosis induced by ceramide and TNF-α.

Ceramide regulates several different cellular responses including mechanisms leading to apoptosis. Serum- and glucocorticoid-inducible protein kinase (SGK)-1 is a serine threonine kinase, which activates survival pathways in response to stress stimuli. Recently, we demonstrated an anti-apoptotic role of SGK-1 in human umbilical endothelial cells treated with high glucose. In the present study, since ceramide induces apoptosis by multiple mechanisms in diabetes and its complication such as nephropathy, we aimed to investigate whether SGK-1 may protect even against apoptosis induced by ceramide in kidney cells. Human embryonic kidney (HEK)-293 cells stable transfected with SGK-1 wild type (SGK-1wt) and its dominant negative gene (SGK-1dn) have been used in this study. Apoptotic stimuli were induced by C2-ceramide and TNF-α to increase endogenous synthesis of ceramide. Upon activation with these stimuli, SGK-1wt transfected cells have a statistically significant reduction of apoptosis compared with SGK-1dn cells (P<0.001). This protection was dependent on activation of caspase-3 and Poly-ADP-ribose-polymerase-1 (PARP-1) cleavage. SGK-1 and AKT-1 two highly homologous kinases differently reacted to ceramide treatment, since SGK-1 increases in response to apoptotic stimulus while AKT-1 decreases. This enhancement of SGK-1 was dependent on p38-mitogen-activated-protein kinases (p38MAPK), cyclic-adenosine-monophosphate/protein kinase A (cAMP/PKA) and phosphoinositide-3-kinase (PI3K) pathways. Especially, by using selective LY294002 inhibitor, we demonstrated that the most involved pathway in the SGK-1 mediated process of protection was PI3K. Treatment with inhibitor of SGK-1 (GSK650394) significantly enhanced TNF-α-dependent apoptosis in HEK-293 cells overexpressing SGK-1wt. Caspase-3, -8 and -9 selective inhibitors confirmed that SGK-1 reduced the activation of caspase-dependent apoptosis, probably by both intrinsic and extrinsic pathways. In conclusion, we demonstrated that in kidney cells, overexpression of SGK-1 is protective against ceramide-induced apoptosis and the role of SGK-1 can be potentially explored as a therapeutic target in conditions like diabetes, where ceramide levels are increased.

Role of Serum and Glucocorticoid-Inducible Kinase (SGK)-1 in Senescence: A Novel Molecular Target Against Age-Related Diseases.

Senescence is a phenomenon characterized by a progressive decline of body homeostasis. Premature senescence acts when the cellular system is not able to adequately respond to noxious stimuli by synthesis of stressor molecules. Among those, serum-and-glucocorticoidinducible kinase-1 (SGK-1) dramatically increases under typical physiopathological conditions, such as glucocorticoid or mineralcorticoids exposure, inflammation, hyperglycemia, and ischemia. SGK-1 has been implicated in mechanism regulating oxidative stress, apoptosis, and DNA damage, which are all leading to a state of accelerating aging. Moreover, SGK-1-sensitive ion channels participate in the regulation of renal Na(+)/K(+) regulation, blood pressure, gastric acid secretion, cardiac action potential, and neuroexcitability. Recently, we demonstrated in endothelial cells as an increase in SGK-1 activity and expression reduces oxidative stress, improves cell survival and restores insulin-mediated nitric oxide production after hyperglycemia. Moreover, we showed as SGK-1 delays the onset of senescence by increasing telomerase activity, significantly decreasing reactive oxygen species (ROS) production, and by directly interacting with hTERT. Therefore, SGK-1 may represent a specific target to further develop novel therapeutic options against chronic diseases such as diabetes typical of aging. SGK-1 has been also associated with cancer, neurodegenerative diseases, and cardiovascular disease, among other age-related diseases. However, to date, the data available on SGK-1 and aging, are sparse, controversial, and only from C. elegans experimental models. In this review we sought to discuss the possible implication of SGK-1 in mechanisms regulating senescence and age-related diseases. Moreover, we aimed to discuss and identify the possible role of SGK-1 as possible molecular target to counteract and prevent aging.

The possible role of glutathione-S-transferase activity in diabetic nephropathy.

The most common cause of end stage renal disease is diabetic nephropathy. An early diagnosis may allow an intervention to slow down disease progression. Recently, it has been hypothesized that glutathione-S-transferase (GST) activity may be a marker of severity of chronic kidney disease. In particular, a lower GST activity is present in healthy subjects compared to patients with nephropathy. In the present review we illustrate the scientific evidence underlying the possible role of GST activity in the development of diabetic nephropathy and we analyze its usefulness as a possible early biomarker of this diabetic complication.

Essential versus accessory aspects of cell death: recommendations of the NCCD 2015.

Cells exposed to extreme physicochemical or mechanical stimuli die in an uncontrollable manner, as a result of their immediate structural breakdown. Such an unavoidable variant of cellular demise is generally referred to as 'accidental cell death' (ACD). In most settings, however, cell death is initiated by a genetically encoded apparatus, correlating with the fact that its course can be altered by pharmacologic or genetic interventions. 'Regulated cell death' (RCD) can occur as part of physiologic programs or can be activated once adaptive responses to perturbations of the extracellular or intracellular microenvironment fail. The biochemical phenomena that accompany RCD may be harnessed to classify it into a few subtypes, which often (but not always) exhibit stereotyped morphologic features. Nonetheless, efficiently inhibiting the processes that are commonly thought to cause RCD, such as the activation of executioner caspases in the course of apoptosis, does not exert true cytoprotective effects in the mammalian system, but simply alters the kinetics of cellular demise as it shifts its morphologic and biochemical correlates. Conversely, bona fide cytoprotection can be achieved by inhibiting the transduction of lethal signals in the early phases of the process, when adaptive responses are still operational. Thus, the mechanisms that truly execute RCD may be less understood, less inhibitable and perhaps more homogeneous than previously thought. Here, the Nomenclature Committee on Cell Death formulates a set of recommendations to help scientists and researchers to discriminate between essential and accessory aspects of cell death.

Gut hormones and endothelial dysfunction in patients with obesity and diabetes.

Overweight and obesity are the fifth leading risk for global deaths and its prevalence has doubled since 1980. At least 2.8 million adults, worldwide, die each year as a result of being overweight or obese. The deleterious effects of obesity are tightly related to diabetes, as they are often clinically present in combination to confer increased cardiovascular mortality. Thus, patients with diabetes and obesity are known to develop accelerated atherosclerosis characterized by a dysfunctional endothelium and decreased nitric oxide bioavailability. Recent clinical studies support, indeed, the use of incretin-based antidiabetic therapies for vascular protection. Thus, attention has been focusing on gut hormones and their role, not only in the regulation of appetite but also in vascular health. Intervention directed at modulating these molecules has the potential to decrease mortality of patients with diabetes and obesity. This review will cover part of the ongoing research to understand the role of gut hormones on endothelial function and vascular health.

Obesity, inflammation and endothelial dysfunction.

Cardiovascular disease is the leading cause of morbidity and mortality in obese individuals. Obesity dramatically increases the risk of development of metabolic and cardiovascular disease. This risk appears to originate from disruption in adipose tissue function leading to a chronic inflammatory state and to dysregulation of the endocrine and paracrine actions of adipocyte-derived factors. These, in turn, impair vascular homeostasis and lead to endothelial dysfunction. An altered endothelial cell phenotype and endothelial dysfunction are common among all obesity-related complications. A crucial aspect of endothelial dysfunction is reduced nitric oxide (NO) bioavailability. A systemic pro-inflammatory state in combination with hyperglycemia, insulin resistance, oxidative stress and activation of the renin angiotensin system are systemic disturbances in obese individuals that contribute independently and synergistically to decreasing NO bioavailability. On the other hand, pro-inflammatory cytokines are locally produced by perivascular fat and act through a paracrine mechanism to independently contribute to endothelial dysfunction and smooth muscle cell dysfunction and to the pathogenesis of vascular disease in obese individuals. The promising discovery that obesity-induced vascular dysfunction is, at least in part, reversible, with weight loss strategies and drugs that promote vascular health, has not been sufficiently proved to prevent the cardiovascular complication of obesity on a large scale. In this review we discuss the pathophysiological mechanisms underlying inflammation and vascular damage in obese patients.

Regulatory T cells in the immunodiagnosis and outcome of kidney allograft rejection.

Acute rejection (AR) is responsible for up to 12% of graft loss with the highest risk generally occurring during the first six months after transplantation. AR may be broadly classified into humoral as well as cellular rejection. Cellular rejection develops when donor alloantigens, presented by antigen-presenting cells (APCs) through class I or class II HLA molecules, activate the immune response against the allograft, resulting in activation of naive T cells that differentiate into subsets including cytotoxic CD8(+) and helper CD4(+) T cells type 1 (TH1) and TH2 cells or into cytoprotective immunoregulatory T cells (Tregs). The immune reaction directed against a renal allograft has been suggested to be characterized by two major components: a destructive one, mediated by CD4(+) helper and CD8(+) cytotoxic T cells, and a protective response, mediated by Tregs. The balance between these two opposite immune responses can significantly affect the graft survival. Many studies have been performed in order to define the role of Tregs either in the immunodiagnosis of transplant rejection or as predictor of the clinical outcome. However, information available from the literature shows a contradictory picture that deserves further investigation.

Erythrocyte glutathione transferase: a new biomarker for hemodialysis adequacy, overcoming the Kt/V(urea) dogma?

Kt/V(urea) ratio is commonly used to assess the delivered dose of dialysis in maintenance hemodialysis (MHD) patients. This parameter only reflects the efficacy of dialytic treatments in removing small toxins, but not middle and protein-bound toxins. Erythrocyte glutathione transferase (e-GST), an enzyme devoted to cell depuration against a lot of large and small toxins, is overexpressed in uremic patients. Aim of the present study is to verify whether e-GST may represent a novel biomarker to assess the adequacy of different dialytic techniques complementary to Kt/V(urea) parameter. Furthermore, it will be investigated whether e-GST could reflect the 'average' adequacy of multiple dialytic sessions and not of a single one treatment as it occurs for Kt/V(urea). One hundred and three MHD patients and 82 healthy subjects were tested. Fourty four patients were treated with standard bicarbonate hemodialysis (HD) and 59 patients were on online hemodiafiltration (HDF). In all MHD patients e-GST activity was 60% higher than in healthy controls. In HDF, e-GST activity was lower than in HD subgroup (8.2±0.4 versus 10.0±0.4 U/g(Hb), respectively). Single-pool Kt/V(urea) and total weekly Kt/V(urea) were higher in HDF than in HD, but no correlation was found between e-GST activity and Kt/V(urea) data. e-GST, whose level is stable during the erythrocyte life-span, provides information on the long-term depurative efficacy of dialysis treatments.

Endovascular radiofrequency renal denervation in treating refractory arterial hypertension: a preliminary experience.

PURPOSE: This study was done to investigate the efficacy and safety of percutaneous renal denervation with the Symplicity catheter for reducing blood pressure in patients with essential hypertension resistant to medical therapy (systolic blood pressure >160 mmHg despite the use of three or more antihypertensive drugs, including a diuretic). MATERIALS AND METHODS: In September 2010, five patients affected by essential hypertension resistant to medical therapy were treated. All patients were studied by computed tomography angiography (CTA) of the renal arteries before the procedure and underwent follow-up at 30 and 60 days with colour Doppler ultrasound (CDUS) with evaluation of resistive index, glomerular filtration rate (GFR), 24-h blood pressure and serum catecholamine concentration. Student's t test was used to assess the effectiveness of the procedure in lowering blood pressure. RESULTS: In treated patients, mean blood pressure at baseline was 171/100 mmHg [standard deviation (SD) ± 8/10]; mean GFR was 91.6 ml/min/1.73 m(2) (SD ± 15). Blood pressure after the procedure was reduced by -18/-5 and -13/-10 mmHg at 30 and 60 days, respectively, with a mean medication reduction of 3.6. No complications occurred during the intra- or periprocedural period or during short-term follow-up. CONCLUSIONS: The Symplicity system proved to be efficacious and without serious adverse events in reducing blood pressure and antihypertensive medication use in patients affected by essential hypertension resistant to medical therapy. Although encouraging, our data are preliminary and need to be validated by larger prospective randomised studies.