Surgical Aortic Valve Replacement and Renal Dysfunction: From Acute Kidney Injury to Chronic Disease.

Background: Surgical aortic valve replacement (SAVR) is often complicated by acute kidney injury (AKI). Identifying patients at risk of AKI is important to start nephroprotective strategies or renal replacement therapy (RRT). This study investigated the incidence and risk factors of post-operative AKI in SAVR patients. Chronic kidney disease (CKD) developed in the post-cardiac-surgery follow-up period was also assessed. Methods: A total of 462 SAVR patients were retrospectively enrolled. The primary endpoint was the occurrence rate of AKI after surgery. Kidney recovery, during two planned outpatient clinic nephrological visits within 12 months after the surgery, was assessed. Results: A total of 76 patients experienced an AKI event. A Kaplan-Meier analysis revealed that subjects with CKD stage IV had a time to progression of 2.7 days, compared to patients with stages I-II, who were characterized by the slowest progression time, >11.2 days. A Cox regression indicated that CKD stages predicted a higher risk of AKI independently of other variables. During their ICU stay, 23 patients died, representing 5% of the population, most of them requiring RRT during their ICU stay. A severe CKD before the surgery was closely related to perioperative mortality. During the follow-up period, 21 patients with AKI worsened their CKD stage. Conclusions: AKI represents a common complication for SAVR patients in the early post-operative period, prolonging their ICU stay, with negative effects on survival, especially if RRT was required. Pre-operative CKD >3 stage is an independent risk factor for AKI in patients undergoing SAVR.

In Vitro Simulated Hemoperfusion on Seraph®-100 as a Promising Strategy to Counteract Sepsis.

Blood purification represents a treatment option for sepsis, improving inflammation and the hyper-activated immune system. This study investigates the binding efficacy of Seraph®-100 against 108 CFU/mL of Staphylococcus aureus (S. aureus), Pseudomonas aeruginosa (P. aeruginosa), and Escherichia coli (E. coli) during a simulated hemoperfusion treatment. The fluorescence-activated cell sorting (FACS) technique was used to evaluate the bacteria reduction, whereas kinetic analysis and cultures revealed bacterial detection and counting at established time points. At the end of the experiment, the filter was cut at three different levels, obtaining suspensions for cultures and scanning electron microscopy (SEM) analyses. The FACS technique revealed a 78.77% reduction of the total bacterial load at the end of the treatment, with maximum filter sequestration occurring in the first 30 min of the treatment. Non-linear regression analysis of kinetic experiments (T0-240 min) highlighted a lower growth rate of S. aureus than the other two Gram bacteria, demonstrating a greater affinity without influencing a reduction rate of 99% for all three bacteria. The analyses of the suspension aliquots of the filter sections confirmed these data, revealing 1 × 108 CFU/mL, equal to the initial bacterial charge. Furthermore, the filter head adsorbed approximately 50% of bacteria, whereas the remaining amount was equally distributed between the body and the tail, as corroborated by SEM analysis. In conclusion, Seraph®-100 adsorbed 108 CFU/mL of S. aureus, E. coli, and P. aeruginosa during an in vitro simulated hemoperfusion session.

Left Ventricular Mass Index Predicts Renal Function Decline in Patients with Chronic Kidney Disease.

Background and Objectives: Several studies revealed a relation between abnormal cardiac remodeling and glomerular filtration rate (GFR) decline, but there are limited data regarding echocardiographic changes in chronic kidney disease (CKD). This study evaluated the abnormal cardiac structures characterizing patients with CKD, assessing the independent association between echocardiographic parameters and the risk of decline in renal function. Materials and Methods: In total, 160 patients with CKD were studied. All patients underwent an echocardiographic exam and 99mTc-DTPA renal scintigraphy to measure the GFR. After the baseline assessments, patients were followed prospectively for 12 months, or until the endpoint achievement, defined as a worsening in renal function (doubling of baseline serum creatinine, GFR decline ≥25%, the start of dialysis). Results: Patients with GFR values of 34.8 ± 15 mL/min, identifying stages III-IV of CKD, were associated with high levels of left ventricular mass index (LVMi) (101.9 ± 12.2 g/m2), which was related to proteinuria, systolic blood pressure, and pulmonary artery systolic pressure in a multiple regression model. During the observational period, 26% of patients reached the endpoint. Regression analysis revealed LVMi as a predictor of change in renal function after adjusting for kidney and cardiac risk factors. Multiple Cox regression indicated that an increase in LVMi was associated with a 12% increased risk of kidney disease progression (HR: 1.12; 95% CI: 1.04-1.16; p = 0.001). Conclusions: In patients with CKD, high LVMi represents an independent predictor of the progressive decline of the renal function, until the start of renal replacement therapy. Echocardiography can help identify patients at high risk for renal disease worsening in patients with CKD independently of clinical cardiac involvement.

Acute Kidney Injury and Sepsis after Cardiac Surgery: The Roles of Tissue Inhibitor Metalloproteinase-2, Insulin-like Growth Factor Binding Protein-7, and Mid-Regional Pro-Adrenomedullin.

BACKGROUND: Identifying a panel of markers detecting kidney injury before the glomerular filtration rate reduction is a challenge to improving the diagnosis and management of acute kidney injury (AKI) in septic patients. This study evaluated the roles of tissue inhibitor metal proteinase-2, insulin growth factor binding protein-7 (TIMP2*IGFBP7), and mid-regional pro-adrenomedullin (MR-proADM) in patients with AKI. PATIENTS AND METHODS: This study was prospectively conducted in an intensive care unit (ICU) enrolling 230 patients who underwent cardiac surgery. Biomarkers were evaluated before and after 4 h of the cardiac surgery. RESULTS: Whereas urine and creatinine alterations appeared at 23.2 (12.7-36.5) hours after cardiac surgery, urinary TIMP2*IGBP7 levels were higher at 4 h in AKI patients (1.1 ± 0.4 mg/L vs. 0.08 ± 0.02 mg/L; p < 0.001). Its concentration > 2 mg/L increases AKI risk within the following 24 h, clearly identifying the population at high risk of renal replacement therapy (RRT). In patients with sepsis, MR-proADM levels were 2.3 nmol/L (0.7-7.8 nmol/L), with the highest values observed in septic shock patients (5.6 nmol/L (3.2-18 nmol/L)) and a better diagnostic profile than procalcitonin and C-reactive protein to identify septic patients. MR-proADM values > 5.1 nmol/L and urine TIMP2*IGBP7 levels > 2 mg/L showed a significantly faster progression to RRT, with a mean follow-up time of 1.1 days. CONCLUSIONS: TIMP2*IGBP7 and MR-proADM precociously diagnose AKI in septic patients after cardiac surgery, giving prognostic information for RRT requirement.

The Switch from Ferric Gluconate to Ferric Carboxymaltose in Hemodialysis Patients Acts on Iron Metabolism, Erythropoietin, and Costs: A Retrospective Analysis.

Background and Objectives: Iron deficiency and anemia characterize patients on chronic hemodialysis (HD). Available intravenous iron agents, such as ferric gluconate (FG) and ferric carboxymaltose (FCM), vary in dosing regimens and safety profiles. The aim of the present study was to analyze the modification of the iron status, the correction of anemia, and the economic implications after the shift from FG to FCM therapy in chronic HD patients. We evaluated, during the study, the variations in iron metabolism, assessing ferritin and transferrin saturation, erythropoietin-stimulating agent (ESA) doses and the number of administrations, the effects on anemic status, and consequent costs. Materials and Methods: A retrospective study was performed with a follow-up period of 24 months, enrolling forty-two HD patients. The enrolment phase started in January 2015, when patients were treated with iv FG, and continued until December 2015, when FG was discontinued, and, after a wash-out period, the same patients were treated with FCM. Results: The iron switch reduced the administered dose of ESA by 1610.500 UI (31% of reduction; p < 0.001) during the entire study period and reduced the erythropoietin resistance index (ERI) (10.1 ± 0.4 vs. 14.8 ± 0.5; p < 0.0001). The FCM group had the highest percentage of patients who did not require ESA treatment during the study period. The FCM patients were characterized by higher levels of iron (p = 0.04), ferritin (p < 0.001), and TSAT levels (p < 0.001) compared to the FG patients. The annual cost during FG infusion was estimated at EUR 105,390.2, while one year of treatment with FCM had a total cost of EUR 84,180.7 (a difference of EUR 21,209.51 (20%), saving EUR 42.1 per patient/month (p < 0.0001). Conclusions: FCM was a more effective treatment option than FG, reducing ESA dose requirements, increasing Hb levels, and improving iron status. The reduced ESA doses and the decreased number of patients needing ESA were the main factors for reducing overall costs.

Tolvaptan resistance is related with a short-term poor prognosis in patients with lung cancer and syndrome of inappropriate anti-diuresis.

Purpose: Tolvaptan (TVP), a vasopressin receptor antagonist, represents a therapeutic option in the syndrome of inappropriate anti-diuresis (SIAD). The aim of this study was to evaluate the effect of TVP to treat and solve hyponatremia in oncologic patients. Methods: 15 oncologic patients who developed SIAD have been enrolled. Patients receiving TVP belonged to group A, whereas group B was characterized by hyponatremic patients treated with hypertonic saline solutions and fluid restriction. Results: In group A, the correction of serum sodium was achieved after 3.7±2.8 days. In group B, the target levels were obtained more slowly, after 5.2±3.1 days (p: 0.01) than in group A. The hospital stay and incidence of re-hospitalization were higher in group B than in group A. In this latter, 37% of patients had hyponatremic relapses, notwithstanding the progressive increase of doses from 7.5 to 60 mg per day of TVP, revealing a complete lack of response to TVP. In these patients, a growth of tumor mass or new metastatic lesions has been revealed. Conclusion: TVP improved hyponatremia more efficiently and stably than hypertonic solutions and fluid restrictions. Positive consequences have been obtained about the rate of chemotherapeutical cycles concluded, hospital stay, rate of relapse of hyponatremia, and re-hospitalization. Our study also suggested potential prognostic information that could be deduced from TVP patients, in whom sudden and progressive hyponatremia occurred, despite TVP dosage increase. A re-staging of these patients to rule out tumor mass growth or new metastatic lesions is suggested.

Free Light Chains, High Mobility Group Box 1, and Mortality in Hemodialysis Patients.

Background: Uremic toxins are associated with immune dysfunction and inflammation. The inadequate removal by hemodialysis (HD) of serum free light chains (FLCs) determines their accumulation. This study evaluated FLCs in HD patients, analyzing their relations with other biomarkers, such as serum high mobility group box 1 (HMGB1). Methods: FLC and HMGB1 were evaluated in a cohort of 119 HD patients. κFLC and λFLC were summated to give a combined (c) FLC concentration. Patients were followed prospectively until the end of the observation period of four years, or until the endpoint: the patient's death. Results: cFLC values in HD patients were 244.4 (197.9−273.5) mg/L. We detected a significant reduction in CD8+ cells and a decreased CD4+/CD8+ ratio. HMGB1 levels were 94.5 (55−302) pg/mL. After multivariate analysis, cFLCs correlated with ß2-microglobulin and the CD4+/CD8+ ratio. Subjects with cFLC values above 263 mg/L and with sHMGB1 values < 80 pg/mL experienced a significantly faster evolution to the endpoint (mean follow-up time to progression of 27.5 and 28.5 months, respectively; p < 0.001). After an adjusted multivariate Cox analysis, cFLCs were associated with 11% increased risk of death, whereas low sHMGB1 increased this risk by 5%. Conclusions: cFLCs and HMGB1 reflect the inflammation and immune dysfunction in HD patients representing two strong and independent risk markers of mortality.

Immune System Dysfunction and Inflammation in Hemodialysis Patients: Two Sides of the Same Coin.

Biocompatibility in hemodialysis (HD) has considerably improved in recent decades, but remains an open issue to be solved, appearing essential to reduce systemic inflammation and enhance patients' clinical outcomes. Clotting prevention, reduction in complement and leukocyte activation, and improvement of antioxidant effect represent the main goals. This review aims to analyze the different pathways involved in HD patients, leading to immune system dysfunction and inflammation. In particular, we mostly review the evidence about thrombogenicity, which probably represents the most important characteristic of bio-incompatibility. Platelet activation is one of the first steps occurring in HD patients, determining several events causing chronic sub-clinical inflammation and immune dysfunction involvement. Moreover, oxidative stress processes, resulting from a loss of balance between pro-oxidant factors and antioxidant mechanisms, have been described, highlighting the link with inflammation. We updated both innate and acquired immune system dysfunctions and their close link with uremic toxins occurring in HD patients, with several consequences leading to increased mortality. The elucidation of the role of immune dysfunction and inflammation in HD patients would enhance not only the understanding of disease physiopathology, but also has the potential to provide new insights into the development of therapeutic strategies.

Updates on hemodialysis techniques with a common denominator: The personalization of the dialytic therapy.

Hemodialysis (HD) is a life-saving therapy for patients with end-stage renal disease. In dialyzed patients, the prevalence of multi-morbidity is rising driven by various factors, such as the population aging, the incomplete correction of uremia, and the side effects of the dialysis therapy itself. Each dialyzed patient has their own specific clinical and biochemical problems. It is therefore unthinkable that the same dialysis procedure can be able to meet the needs of every patient on chronic dialysis. We have very sophisticated dialysis machines and different dialysis techniques and procedures beyond conventional HD, such as hemodiafiltration (HDF) with pre- and post-dilution, acetate-free biofiltration (AFB), hemofiltration (HF), and expanded HD. Each of these techniques has its own specific characteristics. To solve some intradialytic clinical issues, such as arterial hypotension and arrhythmias, we have biofeedback systems with automatic regulation of the blood volume, body temperature, arterial pressure, as well as potassium profiling techniques in the dialysis bath. New technical innovations, such as citrate-containing dialysate or heparin-coated membranes, could reduce the risk of bleeding. To better address to patient needs, the strengths and weaknesses of each of these systems must be well-known, in order to have a personalized dialysis prescription for each patient.

Acute and chronic kidney disease after pediatric liver transplantation: An underestimated problem.

Acute and chronic kidney injuries represent critical issues after liver transplantation (LTx), but whereas renal dysfunction in adult transplant patients is well documented, little is known about its prevalence in childhood. It is a challenge to accurately evaluate renal function in patients with liver disease, due to several confounding factors. Creatinine-based equations estimating glomerular filtration rate, validated in nephropathic patients without hepatic issues, are frequently inaccurate in end-stage liver disease, underestimating the real impact of renal disease. Moreover, whereas renal issues observed within 1 year from LTx were often related to acute injuries, kidney damage observed after 5-7 years from LTx, is due to chronic, irreversible mechanisms. Most immunosuppression protocols are based on calcineurin inhibitors (CNIs) and corticosteroids, but mycophenolate mofetil or sirolimus could play significant roles, also in children. Early diagnosis and personalized treatment represent the bases of kidney disease management, in order to minimize its close relation with increased mortality. This review analyzed acute and chronic kidney damage after pediatric LTx, also discussing the impact of pre-existent renal disease. The main immunosuppressant strategies have been reviewed, highlighting their impact on kidney function. Different methods assessing renal function were reported, with the potential application of new renal biomarkers.

Ferric carboxymaltose versus ferric gluconate in hemodialysis patients: Reduction of erythropoietin dose in 4 years of follow-up.

BACKGROUND: Ferric carboxymaltose (FCM) is a parenteral, dextran-free iron formulation designed to overcome the limitations of existing iron preparations. The main aim of this study was to retrospectively examine results obtained from a long period of FCM therapy in hemodialysis patients who have been previously treated with ferric gluconate (FX). Markers of iron metabolism, erythropoietin (EPO) doses, and effects on anemic status have been analysed. METHODS: The study was performed with a follow up period of 4 years, when patients were treated before with FX and then switched to FCM. A total of 25 patients were included in the study. RESULTS: FCM increased transferrin saturation (TSAT) levels by 11.9% (P < 0.001) with respect to FX. Events of TSAT less than 20% were reduced during FCM. The monthly dose of EPO was reduced in the FCM period (-6,404.1 international unit [IU]; 95% confidence interval, -10,643.5 IU; -2,164.6 IU; P = 0.003), as well as the erythropoietin resistance index (P = 0.004). During the period with FCM, ferritin levels were higher than during FX (P < 0.001), while transferrin was reduced (P = 0.001). CONCLUSION: During FCM treatment, minor doses of EPO were administered if compared to those delivered during FX therapy. Stable and on target levels of hemoglobin were maintained with better control of anemia through high levels of ferritin and TSAT.

Erythropoietin and the truths of science.

In recent years, the use of recombinant human erythropoietin (rHuEpo) has exploded all over the world, and thanks to this, the anemia of patients with chronic renal failure has practically been resolved with its administration. Administration of rHuEpo certainly plays a role in regenerative medicine in vitro and in vivo, because it intervenes in angiogenesis, the persistent natural regenerative activity of humans. Unfortunately, in recent randomized studies, the beneficial effects of rHuEpo have been accompanied by an unanticipated increase in mortality. Its effects are negative in presence of cancer development, but positive in other conditions, as it can protect heart tissue, brain and kidney. Now that its adverse effects have caused the US Food and Drug Administration to issue a black-box warning, it may be time to review what we know about the history and physiology of this plasma factor that appears to be more than just an erythrocyte production factor. Directions for future research hold promise, but only after we have fully understood the physiology of this potent growth factor.

Genomic damage in endothelial progenitor cells from uremic patients in hemodialysis.

INTRODUCTION: End stage renal disease (ESRD) is associated with a high incidence of cardiovascular disease and cancer. Patients undergoing hemodialysis show a reduced number and an impaired function of endothelial progenitor cells (EPCs), which in physiological conditions contribute to repair the vascular damage. In patients with ESRD, massive oxidative genome damage has been demonstrated but the role of HD in causing it is still a controversial issue. The aim of our study was to analyze the effects of a single HD session on the number of cells marked with CD34 (including sub-type cells known to be EPCs); we then evaluated the genomic damage in these cells using COMET assay. PATIENTS AND METHODS: We quantified CD34(+) cells in blood samples in 30 patients in hemodiafiltration treatment for 3.5 to 4 hours 3 times/week and in 30 healthy volunteers. In HD patients, blood samples were drawn at different time intervals: start of dialysis (T(0)), at the end of the treatment (T(end)) and 24 hours afterwards in the interdialytic day (T(inter)). Staining and analysis was performed using the ISHAGE (International Society of Hematotherapy and Graft Engineering) guidelines. EPCs count was conducted using a multiparameter flow cytometric lyse no-wash method. Genomic damage was evaluated by Comet assay. RESULTS: The number of CD34(+) cells in the HD patients at the beginning of the dialysis session (T(0)) was significantly lower than in healthy controls. HD patients showed a significant increase in CD34 number at the end of the session (T(end)) with respect to T(0). In the interdialytic period (T(int)), the number of CD34(+) cells was significantly reduced with respect to T(end). COMET assay performed on CD34(+) cells showed a higher basal level of genomic damage in HD patients than in controls; it increased in a statistically significant manner after the hemodialysis session, while in the interdialytic period it came back to T(0) level. CONCLUSIONS: Uremic status is characterized by lower levels of circulating EPCs, which increase after a single session of HD together with genomic damage to the CD34(+) cells.

Aquaretic inhibits renal cancer proliferation: Role of vasopressin receptor-2 (V2-R).

Vasopressin (AVP) is a hormone with antidiuretic properties that is also involved in cellular proliferation of breast, pulmonary, and pancreatic neoplasias, attributable to the interaction with specific receptors, among which is the V2-R. Using a culture model of CAKI-2 and A498 cancer cells, our study aimed to verify if renal carcinoma cells also express V2-R and whether receptor activation modulates their proliferation. Immunofluorescence and RT-PCR showed that both CAKI-2 and A498 cells effectively synthesize and express the V2-R. Administration of the vasopressin analogue DDAVP induced an evident growth in both CAKI-2 and A498 cell lines. However, this proliferative effect was completely avoided by the preventive addition of the V2-R antagonist SR121463B (satavaptan). Our study shows for the first time that renal cancer may effectively synthesize and express the V2-R. Furthermore, AVP exerts in vitro a proliferative effect by acting on this receptor, as the selective V2-R blockage is able to completely prevent the cellular growth. A validation of these findings with in vivo models is required to ascertain if the eventual presence of V2-R could influence the aggressiveness of human renal neoplasias. From this point of view, a new, interesting therapeutical application of V2-R antagonists in the treatment of renal cancer could also be proposed, similar to that successfully described in the treatment of autosomal polycystic kidney disease (ADPKD).

Down with the erythropoietin. Long live the erythropoietin!

In recent years the use of erythropoietin has exploded, and the anaemia of patients with chronic renal failure has been practically resolved with the administration of rHuEpo (recombinant human, Erythropoietin). However, as a result of an intense commercial campaign, strong therapies with this growth hormone, prescribed to achieve surprising sporting performances, got athletes to run the risk of thrombosis and vascular accidents because of red blood cells increase. Erythropoietin represents a significant subject of research. In fact, besides the ability of stimulating erythrocyte production, it has many pleiotropic effects. Several studies allow the assertion that EPO, in different concentrations, has protective effects mainly on central nervous system and cardiovascular system through various mechanisms, among which a key role seems to be held by the ability to stimulate angiogenesis. The consequent problem is that anaemia therapy with rHuEpo in patients with cancer may accelerate the progression of neoplastic disease by promoting tumour angiogenesis and, thus, metastasization. The study of angiogenic process in tumours led to the synthesis of drugs that, blocking VEGF, exert an anti-angiogenic action, contrasting cancer spread. However, benefits are relatively modest. Is erythropoietin perhaps the further angiogenic hormone to block in tumour pathology? Therefore, Epo plays a role in Regenerative Medicine since it intervenes in a persistent natural regenerative activity of humans: angiogenesis. The understanding of the regeneration mechanisms of complex structures in the adult salamander has opened original lines of research. Regenerative Medicine tries to develop therapeutic pathways through the stimulation of natural regenerative processes in humans.

Regenerative medicine: does Erythropoietin have a role?

Regenerative Medicine, a recent new medical domain, aims to develop new therapies through the stimulation of natural regenerative processes also in human beings. In this field, Erythropoietin (EPO) represents a significant subject of research. Several studies allow the assertion that EPO, in different concentrations, has protective effects mainly on the central nervous system, cardiovascular system and renal tissue. This action is carried out through one of few regenerative activities of human beings: angiogenesis. This mechanism, which involves endothelial stem cells and VEGF (Vascular Endothelial Growth Factor), has been experimentally demonstrated with Recombinant human erythropoietin (rHuEPO) and Darbepoetin, a long-acting EPO derivate. Furthermore, the demonstration of a cardiac production of EPO in Fugu rubripes and in Zebrafish has led cardiologists to "discover" Erythropoietin, postulating a hypothetical role in treatment of cardiovascular disease for this hormone. This is some of the experimental evidence which demonstrates that EPO can be in reason considered an important element of research of Regenerative Medicine and put in the network of drugs able to regenerate tissues and organs.

Malnutrition in the elderly patient on dialysis.

Approximately one-third of all dialysis patients have mild to moderate malnutrition, while 6-8% have severe malnutrition, which is associated with increased morbidity and mortality rates and numerous pre-existing factors directly correlated with, or existing prior to, replacement hemodialysis. However, moderate to severe malnutrition (present in 10-30% of dialysis patients) is a prevalent cause of death among the elderly. Many of these patients have a particularly unstable cardiovascular and metabolic status that, independent of any underlying uremia and/or dialysis, impacts negatively on both their quality of life and clinical status. Moreover, their condition is often further exacerbated by dialysis itself, with its acute (e.g., hypotension and sensorial alterations) and chronic complications, including an exacerbation of malnutrition and systemic vascular disease. Malnutrition can occur secondary not only to erroneous dietary choices or uremia, but it may also depend on the patient's level of tolerance to dialysis and on the dialysis modality. Despite the improvements made to dialysis techniques, the nutritional condition of elderly patients on dialysis for chronic renal failure remains a cause for concern. In this patient category, it is therefore mandatory to ensure the daily supervision of nutritional status and early control when the first signs of malnutrition appear.

Neutrophil gelatinase-associated lipocalin (NGAL) and progression of chronic kidney disease.

BACKGROUND AND OBJECTIVES: Chronic kidney disease (CKD) has recently assumed epidemic proportion, becoming a troubling emerging cause of morbidity, especially if it progresses to terminal stage (ESRD). The authors aimed to evaluate whether neutrophil gelatinase-associated lipocalin (NGAL), a novel specific biomarker of acute kidney injury, could predict the progression of CKD. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: Serum and urinary NGAL levels, together with a series of putative progression factors, were evaluated in a cohort of 96 patients (mean age: 57 +/- 16 years) affected by nonterminal CKD (eGFR > or =15 ml/min/1.73 m(2)) of various etiology. Progression of CKD, assessed as doubling of baseline serum creatinine and/or onset of ESRD, was evaluated during follow-up. RESULTS: At baseline, both serum and urinary NGAL were inversely, independently, and closely related to eGFR. After a median follow-up of 18.5 mo (range 1.01 to 20), 31 patients (32%) reached the composite endpoint. At baseline, these patients were significantly older and showed increased serum creatinine, calcium-phosphate product, C-reactive protein, fibrinogen, daily proteinuria, and NGAL levels, whereas eGFR values were significantly lower. Univariate followed by multivariate Cox proportional hazard regression analysis showed that urinary NGAL and sNGAL predicted CKD progression independently of other potential confounders, including eGFR and age. CONCLUSION: In patients with CKD, NGAL closely reflects the entity of renal impairment and represents a strong and independent risk marker for progression of CKD.

Arrhythmias and hemodialysis: role of potassium and new diagnostic tools.

Cardiovascular diseases represent the main causes of death in patients affected by renal failure, and arrhythmias are frequently observed in patients undergoing hemodialysis. Dialytic treatment per se can be considered as an arrhythmogenic stimulus; moreover, uraemic patients are characterized by a "pro-arrhythmic substrate" because of the high prevalence of ischaemic heart disease, left ventricular hypertrophy and autonomic neuropathy. One of the most important pathogenetic element involved in the onset of intra-dialytic arrhythmias is the alteration in electrolytes concentration, particularly calcium and potassium. It may be very useful to monitor the patient's cardiac activity during the whole hemodilaytic session. Nevertheless, the application of an extended intradialytic electrocardiographic monitoring is not simple because of several technical and structural impairments. We tried to overcome these difficulties using Whealthy, a wearable system consisting in a t-shirt composed of conductors and piezoresistive materials, integrated to form fibers and threads connected to tissutal sensors, electrodes, and connectors. ECG and pneumographic impedance signals are acquired by the electrodes in the tissue, and the data are registered by a small computer and transmitted via GPRS or Bluetooth.