Alessia Scatena

High-volume online haemodiafiltration improves erythropoiesis-stimulating agent (ESA) resistance in comparison with low-flux bicarbonate dialysis: results of the REDERT study

BACKGROUND In haemodialysis (HD) patients, anaemia is associated with reduced survival. Despite treatment with erythropoiesis-stimulating agents (ESAs), a large number of patients with chronic kidney disease show resistance to this therapy and require much higher than usual doses of ESAs in order to maintain the recommended haemoglobin (Hb) target, and recent studies suggest that hepcidin (HEP) may mediate the ESA resistance index (ERI). High-volume online haemodiafiltration (HV-OL-HDF) has been shown to improve anaemia and to reduce the need for ESAs in HD patients; this effect is associated with a reduced inflammatory state in these patients. The aim of the REDERT study (role of haemodiafiltration on ERI) was to investigate the effect of different dialysis techniques on ERI and HEP levels in chronic dialysis patients. METHODS A single cross-over, randomized, multicentre study (A-B or B-A) was designed. Forty stable HD patients from seven different dialysis units (male 65%, mean age 67.6 ± 14.7 years and mean dialytic age 48 ± 10 months) were enrolled. Patients were randomized to the standard bicarbonate dialysis (BHD) with low-flux polysulfone (PS) membrane group or to the HV-OL-HDF group with high-flux PS membranes and exchange volume of >20 L/session. After 6 months, patients were shifted to the other dialytic group for a further 6 months. Clinical data, Hb, ESA doses and iron metabolism were recorded every month. HEP, beta2-microglobulin (b2MG) and C-reactive protein (CRP) were determined every 3 months, and ERI was calculated monthly as the weekly ESA dose per kilogram of body weight divided by Hb level. Data were analysed using paired-samples t-test, Wilcoxon signed-rank test and Spearmans correlation coefficient. RESULTS Dialysis efficiency for small molecules assessed as Kt/V was significantly increased in HV-OL-HDF from 1.47 ± 0.24 to 1.49 ± 0.16; P < 0.01. A significant reduction of b2MG was obtained in HV-OL-HDF from month 3 whereas CRP values were not significantly changed during the study period either in BHD or HV-OL-HDF.ERI was significantly reduced in HV-OL-HDF at month 3 and 6 (from 9.1 ± 6.4 UI/weekly/Kg/Hb to 6.7 ± 5.3 UI/weekly/Kg/Hb; P < 0.05) due to a higher ESA consumption in BHD in spite of similar Hb levels. HEP levels were reduced in HV-OL-HDF with respect to BHD after 3 and 6 months. Iron consumption was not significantly different during BHD or HV-OL-HDF treatment as well as transferrin, ferritin and TSAT levels. A significant positive linear correlation between HEP and ERI (r(2) = 0.258, P < 0.001) was observed. CONCLUSIONS In a uraemic patient population with low-grade inflammation treated with HV-OL-HDF, we observed a significant reduction of ERI values as well as HEP levels. The positive correlation between these two parameters supports a role for HEP in the development of ERI in the dialytic population. Moreover, the lower b2MG and the higher Kt/V achieved in HV-OL-HDF confirms the better depurative effect of this technique in comparison with BHD with respect to middle molecules and small-molecular-weight molecules.

Effectiveness and Safety of a Novel Gel Dressing in the Management of Neuropathic Leg Ulcers in Diabetic Patients: A Prospective Double-Blind Randomized Trial

Neuropathic leg ulcers (NLUs) affect more than 10% of diabetic patients with peripheral neuropathy and represent the most common cause of ulceration of the leg in these patients. Though their pathogenesis is well known, related to the chronic neuropathic edema, the management of NLUs, mainly based on elastocompression, is still controversial, with lower healing rates than nondiabetic venous leg ulcers. The authors tested if a novel gel formulation, containing amino acids and hyaluronic acid (Vulnamin® gel; Errekappa, Milan, Italy), will improve the outcomes of NLUs when used together with elastocompression. Thirty patients affected by NLU were randomized into 2 groups, both treated with 4-layer elastocompressive bandaging: patients in group A were topically treated with the application of Vulnamin® gel, whereas patients in group B received only the inert gel vehicle. The healing rate at 3 months was evaluated as the primary endpoint, whereas the secondary endpoints were healing time, reduction in ulcer area and ulceration score in 4 weeks, number of infective complications, and overall satisfaction of patients. Healing rate was significantly (P < .05) higher in patients in group A when compared with those in group B; healing time, patients’ satisfaction, and reduction in ulcer area and ulceration score in 4 weeks were also higher in patients in group A. However, no significant differences were found in the prevalence of infections and other adverse events. The use of Vulnamin ® gel with elastocompression is safe and effective in the management of NLUs of diabetic patients.

Anti-Inflammatory Effect of White Wine in CKD Patients and Healthy Volunteers

Background: Mediterranean-style diet has been considered for its important beneficial effects on the progression of CV disease. Wine is an important component of the Mediterranean diet, and moderate wine drinkers have lower mortality rates than nondrinkers and heavy drinkers in epidemiologic studies. The beneficial effects of red wine are thought to be dependent on the polyphenol compounds such as resveratrol that exhibit potent antioxidant activity. However, white wine, although lacking polyphenols, contains simple phenols, such as tyrosol (Tyr) and hydroxytyrosol (OH-Tyr), characteristic also of extra-virgin olive oil, which may share similar antioxidant and inflammatory properties. Patients and Methods: The effect of white wine and extra-virgin olive oil on inflammatory markers was evaluated in 10 healthy volunteers and in 10 patients with CKD (chronic kidney disease) K-DOQI stage III-IV in a prospective, single blind, randomized, cross-over trial. After two weeks of wash-out from alcoholic beverages, subjects were randomized to a cross-over design A-B or B-A of a 2-week treatment with white wine (4 ml/kg body weight, 0.48 g/kg of alcohol 12%, corresponding to 2-3 glasses/daily) and extra-virgin olive oil (treatment A) or extra-virgin olive oil alone (treatment B). The two study periods were separated by a two-week wash-out period. At baseline and at the end of each treatment, plasma levels of inflammatory markers C-reactive protein (CRP), interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF-alpha), and interleukin-8 (IL-8) concentration were determined. Urinary levels of Tyr, OH-Tyr, and their metabolites were measured at the same time. Results: During combined consumption of white wine and extra-virgin olive oil (treatment A), plasma levels of CRP and IL-6 decreased from 4.1 ± 1.8 to 2.4 ± 1.9 mg/l (p < 0.05) and from 5.3 ± 3.2 to 3.4 ± 2.3 mg/l (p < 0.05) in CKD patients. CRP decreased from 2.6 ± 1.2 to 1.9 ± 0.9 mg/l (p < 0.05), and IL-6 decreased from 2.2 ± 1.8 to 1.7 ± 1.3 mg/l (p = ns) in healthy volunteers. No significant variation versus baseline was observed during treatment B. A significant increase in urinary Tyr and OH-Tyr was observed during treatment A (white wine and extra-virgin olive oil). Conclusions: Plasma markers of chronic inflammation were significantly reduced in CKD patients during the combined consumption of white wine and olive oil, suggesting a possible anti-inflammatory effect of this nutritional intervention.

Outcomes of three years of teamwork on critical limb ischemia in patients with diabetes and foot lesions

To evaluate the outcomes of a multidisciplinary team working on diabetic foot (DF) patients with critical limb ischemia (CLI) in a specialized center, the authors retrospectively traced all the patients admitted in their department in 3 consecutive years with a diagnosis of CLI. From January 2006 to December 2008, 245 consecutive DF patients with CLI according the TransAtlantic interSociety Consensus II criteria were included in the study. Treatment strategy was decided by a team of diabetologists, inteventional radiologists, and vascular surgeons. Technical and clinical success, mortality, and ulcer recurrence were evaluated at 6 months and at a mean follow-up of 19.5 ± 13.4 months. Percutaneous transluminal angioplasty (PTA) was performed in 189 (77%) patients, whereas medical treatment, open surgical revascularization (OSR), and primary amputation were performed in 44 (18.3%), 11 (4.3%), and 1 (0.5%) patients, respectively. Revascularization was successful in 227/233 (97.4%) patients. At follow-up, the overall clinical success rate was 60.4%; it was significantly (P = .001) higher after revascularization (75.9%) compared with medical treatment (48.3%). During follow-up, surgical interventions in the foot were 1.5 ± 0.4 in those treated with PTA, 1.6 ± 0.5 in those treated with OSR, and 0.3 ± 0.8 in those receiving medical therapy (P < .05 compared with the others). Ulcer recurrence occurred in 29 (11.8%) patients: 4 (1.6%) in PTA, 2 (0.8%) in OSR, and 23 (9.4%) in the medical therapy group (P < .05). Major amputation rate was 9.3%, being significantly (P = .04) lower after revascularization (5.2%) compared with medical therapy alone (13.8%). Cumulative mortality rate was 10.6%. In conclusion, this study confirms the positive role of a PTA-first approach for revascularizing the complex cases of DF with CLI in a teamwork management strategy.

Caffeic acid, a phenol found in white wine, modulates endothelial nitric oxide production and protects from oxidative stress-associated endothelial cell injury.

Introduction Several studies demonstrated that endothelium dependent vasodilatation is impaired in cardiovascular and chronic kidney diseases because of oxidant stress-induced nitric oxide availability reduction. The Mediterranean diet, which is characterized by food containing phenols, was correlated with a reduced incidence of cardiovascular diseases and delayed progression toward end stage chronic renal failure. Previous studies demonstrated that both red and white wine exert cardioprotective effects. In particular, wine contains Caffeic acid (CAF), an active component with known antioxidant activities. Aim of the study The aim of the present study was to investigate the protective effect of low doses of CAF on oxidative stress-induced endothelial injury. Results CAF increased basal as well as acetylcholine—induced NO release by a mechanism independent from eNOS expression and phosphorylation. In addition, low doses of CAF (100 nM and 1 μM) increased proliferation and angiogenesis and inhibited leukocyte adhesion and endothelial cell apoptosis induced by hypoxia or by the uremic toxins ADMA, p-cresyl sulfate and indoxyl sulfate. The biological effects exerted by CAF on endothelial cells may be at least in part ascribed to modulation of NO release and by decreased ROS production. In an experimental model of kidney ischemia-reperfusion injury in mice, CAF significantly decreased tubular cell apoptosis, intraluminal cast deposition and leukocyte infiltration. Conclusion The results of the present study suggest that CAF, at very low dosages similar to those observed after moderate white wine consumption, may exert a protective effect on endothelial cell function by modulating NO release independently from eNOS expression and phosphorylation. CAF-induced NO modulation may limit cardiovascular and kidney disease progression associated with oxidative stress-mediated endothelial injury.

Clinical Outcomes of Wide Postsurgical Lesions in the Infected Diabetic Foot Managed With 2 Different Local Treatment Regimes Compared Using a Quasi-Experimental Study Design: A Preliminary Communication

The safety and efficacy of a novel superoxidized solution (Dermacyn™ Wound Care [DWC], Oculus Innovative Sciences, Petaluma, Calif) was evaluated for the treatment of wide postsurgical infected ulcers of the diabetic foot. A group (group A,n = 18) of patients with diabetes mellitus who had postsurgical lesions>5 cm2 without ischemia or infection were recruited consecutively and treated with DWC-saturated dressings. These dressings were renewed once daily and were compared with a group of patients that had been previously treated with diluted povidone iodine (group B,n = 15) using a quasi-experimental study design. Both sets of patients also received standard systemic antibiotic therapy, as per the practice in this center, and local surgical debridement. Patients had weekly assessments until wounds had re-epithelialized completely. Patients in group A had statistically significant shorter healing time and duration of antibiotic therapy and a higher healing rate at 6 months compared with those in group B (p < .01). Recurrence of infection, requirement for debridement procedures, and requirement for minor amputations were significantly less frequent during follow-up in group A patients (p < .05) when compared with those in group B. These preliminary data suggest that DWC used as a wound dressing together with other local and systemic therapies may have a role in reducing healing time as well as complications in patients with diabetes who have postsurgical lesions of the diabetic foot. These data propose the need for a robust controlled study of DWC-saturated dressings to explore its full potential.

Antiplatelet agents in hemodialysis

Patients affected by cardiovascular disease (CVD) are treated with antiplatelet agents (AA) and/or anticoagulant drugs, which are fundamental in the management of stroke, coronary atherosclerotic disease, peripheral vascular disease and atrial fibrillation. CVD is the most important cause of death in chronic renal failure (CRF). Death rates from myocardial infarction (MI) and from all other cardiac causes exceed those for the general population. Incidence of MI in CRF is triple that in the general population. Moreover, mortality is seven- to eight-fold higher in patients requiring chronic hemodialysis compared to the general population, and approximately 40% of deaths in this population are attributable to coronary artery disease (CAD). For these reasons, AA are widely used in patients affected by CRF. Current data do not support a protective effect of antiplatelet administration in hemodialytic patients as primary prevention of cardiovascular mortality. Different results have been obtained concerning secondary prevention of CVD. The Cooperative Cardiovascular Project demonstrated that dialysis patients treated with aspirin following MI had a 43% lower mortality. Another study reported that the use of aspirin and beta-blockers following MI was associated with lower mortality in CRF patients. However, aspirin plus clopidogrel seems to increase the hemorrhagic risk without a significant reduction in cardiovascular mortality and there are insufficient data to support the use of new AA drugs in hemodialytic patients. In conclusion, since CRF patients are one of the groups at highest risk for atherosclerotic events, it could be reasonable to use aspirin in HD patients. However, the bleeding risk in HD patients needs to be strongly evaluated, especially before starting dual AA treatment.

Pure red cell aplasia induced by epoetin zeta

Pure red cell aplasia (PRCA) may develop in patients with chronic kidney disease receiving erythropoiesis-stimulating agents (ESA). We report on a 72-year-old patient who developed hypo-proliferative anaemia unresponsive to ESA following the administration of epoetin zeta subcutaneously for 7 months. On the basis of severe isolated hypoplasia of the erythroid line in the bone marrow and high-titre neutralizing anti-erythropoietin antibodies (Ab), a diagnosis of Ab-mediated PRCA was made. Epoetin zeta was discontinued and the patient was given steroids. This was associated with anaemia recovery. To our knowledge this is the first PRCA case related to epoetin zeta.

A Metastatic Squamous Cell Carcinoma in a Diabetic Foot Case Report

A 72-year-old male was referred to our hospital for a plantar ulceration that had occurred many years earlier. The lesion, with exuberant granulation and large areas of necrosis and fibrin, had long been treated by plastic surgeons with no positive evolution. At admission in our hospital no ischemia was detected, and foot radiograph was negative for bone involvement. The patient underwent a foot magnetic resonance imaging, which showed high vascularization in the plantar region and early capture of the contrast medium. We then performed multiple biopsies of the ulceration that revealed a moderately differentiated squamous cell carcinoma. The total body computed tomography exam raised a systemic involvement. A lymph node biopsy and immunohistochemistry assay on the pleural cytological sample proved the presence of a primary squamous cell carcinoma of the foot with systemic dissemination. Although rare, squamous cell carcinoma could be associated with chronic nonhealing ulcers; therefore, when a lesion does not heal, despite adequate standard treatment, its etiopathogenesis should be challenged.

A2A receptors and methamphetamine toxicity: a role of adenosine as an endogenous neurotoxin

Adenosine A2A are a class of purinergic receptors largely expressed in dopamine (DA)-rich areas of the central nervous system. In particular, they are abundant within basal ganglia, where they modulate the activity of various neurotransmitters, including DA. Despite the lack of knowledge on their fine physiological mechanisms, it is worth to mention that A2A antagonists prevent neuronal death and dyskinesia in Parkinsonism. Moreover the neuroprotective effects observed after blockade of adenosine A2A receptors in several models of neurotoxicity suggests a toxic effect for endogenous adenosine In the light of these evidences, in the present study, by using in vitro models of DA neurons, we investigated: (i) whether A2A antagonists protect DA containing neurons against methamphetamine (METH); (ii) whether activation of A2A receptors produce neurodegeneration. This was done either using A2A agonist receptor NECA or the endogenous compound adenosine; (iii) whether specific cell mechanisms are involved in these phenomena. We found that A2A antagonists protect DA cells against METH neurotoxicity. Moreover, we found that NECA and adenosine both produced a toxic effects. In the light of the key role of autophagy in modulating the survival of DA neurons we found that A2A antagonists increase, while A2A agonists decrease, autophagy. These results suggest that neuroprotection induced by A2A antagonists may be mediated by enhancement of autophagy. As expected we found that pre-treatment with a non-adenosine related inducer of autophagy produced the same protective effects obtained with A2A antagonists. Our data indicate for the first time, that A2A antagonists are protective in DA neurons against METH. Such an effect appear to be mediated by the enhancement of autophagy. On the other hand we found that activation of A2A receptor produces neurotoxicity. Interestingly these effects was reproduced by administering endogenous adenosine. This suggests that adenosine may produce neurodegeneration by inhibiting the autophagy pathway.