TMAO reductase, a biomarker for gut permeability defect induced inflammation, in mouse model of chronic kidney disease and dextran sulfate solution-induced mucositis.

BACKGROUND: The excretion of trimethylamine N-oxide (TMAO) (uremic toxin) into the intestine might be enhanced, due to the limited renal elimination in chronic kidney disease (CKD), possibly induced TMAO reductase (a TMAO-neutralizing enzyme) in gut bacteria. Detection of TMAO reductase in serum could be used as a biomarker of gut permeability defect. OBJECTIVE: To explore the correlation between serum TMAO reductase, gut leakage, and systemic inflammation in CKD. METHODS: Mouse models of gut leakage; including 5/6 nephrectomy-induced chronic kidney disease (CKD), a model without colitis, and 1.5% dextran sulfate solution (DSS), a colitis model, were performed. In parallel, serum samples from patients with chronic hemodialysis (n = 48) and the healthy control (n = 20) were analyzed. RESULTS: Gut-leakage (FITC-dextran, endotoxemia, and reduced intestinal tight junction protein) was detected in both CKD and DSS models. While TMAO reductase and TMAO were elevated in the serum of both mouse models and patients, TMAO reductase correlated with TMAO, gut- leakage, and serum IL-6 only in mice but not in patients. Notably, endotoxemia was used as a surrogate marker of gut leakage in patients. In patients, TMAO reductase and TMAO did not correlate with serum IL-6 and vascular complications using the ankle-brachial index and cardio-ankle vascular index. CONCLUSIONS: Serum TMAO reductase was elevated in CKD mice and patients with CKD. Serum TMAO reductase was correlated with TMAO and gut-leakage only in mice but not in patients. Further studies in patients are needed to determine the benefit of serum TMAO reductase in patients with CKD.

The beneficial effects of intradialytic parenteral nutrition in hemodialysis patients with protein energy wasting: a prospective randomized controlled trial.

In hemodialysis (HD) patients, protein-energy wasting (PEW) is highly prevalent and firstly treated with oral nutritional supplements (ONS). The extent to which intradialytic parenteral nutrition (IDPN) contributes to improve PEW status in HD patients intolerable to ONS remains unclear. Maintenance PEW HD patients being unable to tolerate ONS adverse effects, and having spontaneous energy and protein intake of ≥ 20 kcal/kg/day and ≥ 0.8 g/kg/day, respectively were randomly assigned 1:1 into IDPN and control groups. In IDPN group, most concentrated 3-in-1, fish-oil based parenteral nutrition was infused during HD for 3 months. The control group received intensive dietary counselling once weekly for 3 months. Both groups were then followed for additional 3 months after intervention. A total of 38 patients were randomized (mean age 67.6 years). After 3 months, serum albumin was significantly higher in the IDPN (n = 18) compared with control group (from 3.5 ± 0.3 to 3.8 ± 0.2 vs from 3.6 ± 0.3 to 3.5 ± 0.3 g/dL, respectively, p = 0.01). Spontaneous dietary intake (p = 0.04), body weight (p = 0.01), and malnutrition inflammation score (MIS, p = 0.01) were improved in the IDPN, but not in the control group. Muscle mass, strength, serum prealbumin, interleukin-6, high sensitivity-c reactive protein, and acylated ghrelin were not significantly different but leptin levels increased in the control group after 3 months (p = 0.03). At 6 months, serum albumin in the IDPN group was persistently higher than baseline (p = 0.04). Neither volume overload nor uncontrolled hyperglycemia was found throughout the study. In conclusion, a 3-month IDPN supplementation demonstrated a significant increase in serum albumin, body weight, spontaneous oral intake, and MIS; and appeared to be superior to continuing intensive dietary counselling among HD patients intolerable to ONS. The impacts of IDPN therapy on clinical outcomes may require larger scale with longer period of study.

Comparative efficacy between hemodialysis using super high-flux dialyzer with hemoperfusion and high-volume postdilution online hemodiafiltration in removing protein bound and middle molecule uremic toxins: A cross-over randomized controlled trial.

BACKGROUND: Hemodialysis (HD) using super high-flux dialyzer (HD + SHF) comparably removed uremic toxins to high-volume postdilution online hemodiafiltration (olHDF). Integration of hemoperfusion (HP) to HD + SHF (HD + SHF + HP) might provide superior uremic toxin removing capability to high-volume postdilution olHDF. METHOD: The present study was conducted in thrice-a-week HD patients to compare the efficacy in removing indoxyl sulfate (IS), beta-2 microglobulin (ß2 M), and urea between high-volume postdilution ol-HDF and HD + SHF + HP, comprising HD + SHF as the main treatment plus HD + SHF + HP 1/week in the first 4 weeks and 1/2 weeks in the second 4 weeks. RESULTS: Ten prevalent HD patients with blood flow rate (BFR) above 400 ml/min were randomized into two sequences of 8-week treatment periods of HD + SHF + HP and later high-volume postdilution olHDF or vice versa. When compared with high-volume postdilution olHDF (convective volume of 26.02 ± 1.8 L/session), HD + SHF + HP provided comparable values of percentage reduction ratio of IS (52.0 ± 11.7 vs. 56.3 ± 7.5%, p = 0.14) and ß2 M (83.7 ± 4.9 vs. 84.0 ± 4.3%, p = 0.37) and slightly lower urea reduction ratio. Despite greater dialysate albumin loss (p = 0.008), there was no significant change in serum albumin level in HD + SHF + HP group. CONCLUSIONS: HD + SHF + HP could not provide superior efficacy in removing uremic toxins to high-volume postdilution olHDF. The use of low BFR of 200 ml/min during the first 2 h of HD + SHF + HP session, according to the instruction of manufacturer, might impair the efficacy of the HD + SHF part in removing uremic toxins.

Effect of Maintenance Intravenous Iron Treatment on Erythropoietin Dose in Chronic Hemodialysis Patients: A Multicenter Randomized Controlled Trial.

BACKGROUND: There is no consensus on intravenous (IV) iron supplement dose, schedule, and serum ferritin target in functional iron deficiency anemia to maintain optimum target levels of iron stores by several guidelines. OBJECTIVE: To examine the effect of IV iron supplementation to different targets of serum ferritin on erythropoietin dose and inflammatory markers in chronic hemodialysis (HD) patients with functional iron deficiency anemia. DESIGN: A multicenter, randomized, open-label study. SETTING: In a developing country, Thailand. PATIENTS: Chronic HD patients with functional iron deficiency anemia. MEASUREMENTS: Erythropoietin resistance index, high-sensitivity C-reactive protein, and fibroblast growth factor 23. METHODS: Two hundred adult chronic HD patients with transferrin saturation less than 30% and serum ferritin of 200 to 400 ng/mL were randomized 1:1 to maintain serum ferritin 200 to 400 ng/mL (low-serum ferritin group, N = 100) or 600 to 700 ng/mL (high-serum ferritin group, N = 100). During a 6-week titration period, participants randomized to the high-serum ferritin group initially received 600 mg IV iron (100 mg every week), while the participants in the low-serum ferritin group did not receive IV iron. During the 6-month follow-up period, the dose of IV iron was adjusted by protocol. RESULTS: The mean dose of IV iron was 108.3 ± 28.2 mg/month in the low-serum ferritin group and 192.3 ± 36.2 mg/month in the high-serum ferritin group. The mean serum ferritin was 367.0 ± 224.9 ng/mL in the low ferritin group and 619.6 ± 265.2 ng/mL in the high ferritin group. The erythropoietin resistance index was significantly decreased in the high-serum ferritin group compared to the low-serum ferritin group after receiving IV iron in the 6-week titration period (mean difference: -113.43 ± 189.14 vs 41.08 ± 207.38 unit/week/g/dL; P < .001) and 3-month follow-up period (mean differences: -88.88 ± 234.43 vs -10.48 ± 217.75 unit/week/g/dL; P = .02). LIMITATIONS: Short follow-up period. CONCLUSION: Maintaining a serum ferritin level of 600 to 700 ng/mL by IV iron administration of approximately 200 mg per month as a maintenance protocol can decrease erythropoietin dose requirements in chronic HD patients with functional iron deficiency anemia. TRIALS REGISTRATION: The study was registered with the Thai Clinical Trials Registry TCTR20180903003.

CONTEXTE: Il n'existe aucun consensus sur la dose et la posologie du supplément de fer administré par voie intraveineuse (IV) dans le traitement de l'anémie ferriprive fonctionnelle, ni sur la cible de ferritine sérique permettant de maintenir les réserves ferriques optimales définies par les différentes recommandations. OBJECTIF: Examiner l'effet d'un supplément de fer IV, à différentes cibles de ferritine sérique, sur la dose d'érythropoïétine et les marqueurs inflammatoires de patients sous hémodialyse chronique atteints d'une anémie ferriprive fonctionnelle. TYPE D'ÉTUDE: Essai multicentrique ouvert à répartition aléatoire. CADRE: L'étude s'est tenue en Thaïlande, un pays en développement. SUJETS: Des patients sous hémodialyse chronique atteints d'anémie ferriprive fonctionnelle. MESURES: L'indice de résistance à l'érythropoïétine, la protéine C réactive très sensible et le facteur de croissance des fibroblastes 23. MÉTHODOLOGIE: Deux cents adultes sous HD chronique présentant une saturation en transferrine inférieure à 30 % et un taux de ferritine sérique entre 200 et 400 ng/mL ont été répartis en deux groupes (ratio 1:1). On visait le maintien d'un taux de ferritine sérique entre 200 et 400 ng/mL dans le premier groupe (faible taux de ferritine sérique; n=100) et entre 600 et 700 ng/mL dans le deuxième groupe (taux élevé de ferritine sérique; n=100). Au cours d'une période d'ajustement de six semaines, les sujets du groupe à taux élevé de ferritine sérique ont initialement reçu une dose de 600 mg de fer par IV (100 mg par semaine) alors que les sujets de l'autre groupe n'en ont pas reçu. La dose de fer IV a été ajustée selon le protocole au cours des six mois de suivi. RÉSULTATS: La dose moyenne de fer administrée par IV était de 108,3 ±28,2 mg/mois pour les sujets du groupe à faible taux de ferritine sérique et de 192,3 ±36,2 mg/mois pour les sujets du groupe à taux élevé de ferritine sérique. En ce qui concerne les taux de ferritine sérique, ceux-ci s'établissaient respectivement à 367,0 ±224,9 ng/mL et à 619,6 ±265,2 ng/mL. Les sujets du groupe à taux élevé de ferritine sérique présentaient un indice de résistance à l'érythropoïétine significativement réduit par rapport à ceux du groupe à faible taux après avoir reçu un supplément de fer IV durant la période d'ajustement de six semaines (différence moyenne: -113,43 ±189,14 contre 41,08 ±207,38 unités/semaine/g/dL; p<0,001) et après trois mois de suivi (différence moyenne: -88,88 ±234,43 contre -10,48 ±217,75 unités/semaine/g/dL; p=0,02). LIMITES: Courte période de suivi. CONCLUSION: Le maintien d'un taux de ferritine sérique entre 600 et 700 ng/mL par l'administration IV d'une supplémentation en fer, à raison d'environ 200 mg par mois (protocole de maintien), peut contribuer à réduire la posologie d'érythropoïétine chez les patients hémodialysés et atteints d'anémie ferriprive fonctionnelle. ENREGISTREMENT DE L'ESSAI: L'essai a été enregistré selon le registre des essais cliniques thaïlandais TCTR20180903003.

Clinical and subclinical acute kidney injury in multidrug-resistant septic patients treated with colistimethate sodium: Incidence and clinical outcomes.

AIM: Colistimethate sodium (CMS) has been postulated as the principal cause of high incidence of clinical acute kidney injury (AKI) in multidrug-resistance (MDR) septic patients with normal baseline serum creatinine (sCr) who were treated with CMS. This prospective observational study was conducted to examine the incidence and clinical outcomes of clinical and subclinical AKI in MDR septic patients receiving CMS. METHODS: Forty-two MDR septic patients with normal sCr who required CMS were included. Clinical AKI was diagnosed by increased sCr levels according to the KDIGO2012 criteria while subclinical AKI was identified by elevated levels of urinary neutrophil gelatinase-associated lipocalin (uNGAL > 150 ng/mL) or urinary liver-type fatty-acid-binding protein (uL-FABP > 10.5 ng/mL). RESULTS: Clinical AKI was noted in 47.6% of patients on day 5 and 38.1% on day 7 after initiating CMS. By using uL-FABP, subclinical AKI was observed in 45.2% and 54.8% on day 5 and 7, respectively. At baseline prior to CMS treatment, subclinical AKI was already present in 90%. The baseline uL-FABP was superior to the baseline uNGAL in early prediction of clinical AKI on day 5. The subclinical AKI patients had comparable worse outcomes as clinical AKI patients. CONCLUSION: The incidence of subclinical AKI in MDR septic patients before CMS treatment was extremely high. The baseline uL-FABP provided the best predictive capacity of clinical AKI. The causes of clinical AKI might include the persistence of sepsis process, subclinical AKI and CMS nephrotoxicity. Proper management of subclinical AKI patients before CMS initiation should be concerned to prevent further renal damage and improve patient and renal outcomes.

The role of intraoperative parameters on predicting laparoscopic abdominal surgery associated acute kidney injury.

BACKGROUND: Laparoscopic abdominal surgery has been widely used to reduce the length of hospital stay and complications from open abdominal surgery. During the operation, the creation of pneumoperitoneum is used for better visualization of the operating field. However, the effect of pneumoperitoneum on kidney function is unknown. We aimed to identify risk factors and predictors associated with AKI development following laparoscopic abdominal surgery. METHODS: A single-center prospective cohort study of laparoscopic abdominal surgery patients between June 2012 and December 2013. Acute kidney injury (AKI) was identified by Kidney Disease Improving Global Outcome (KDIGO) criteria. Urinary neutrophil gelatinase associated lipocalin (uNGAL) was measured on the first 3 days after surgery as a surrogate marker of AKI. RESULTS: Of the 64 patients, 23 (35%) developed postoperative AKI. The mean age, initial blood pressure, and initial glomerular filtration rate were not different between AKI and non-AKI groups. Inflation time and exposure index were significantly higher in the AKI group compared to non-AKI group (192.0 vs 151.1 min, p = 0.045, and 2325.9 vs 1866.1 mmHg-minutes, p = 0.035). Operation time, mean intra-abdominal pressure, duration of intraoperative hypotension, amount of blood loss and intravenous fluid were not different between groups. In multivariable analysis adjusted for age, diabetes, baseline estimated glomerular filtration rate, and type of operation (urological surgery), exposure index was significantly associated with postoperative AKI, with odds ratio (95% CI) 1.47 (1.05-2.04), p = 0.024. By combining the intraoperative parameters with clinical model the area under the receiver operating characteristic curve was 0.71 (95% CI 0.58-0.84). CONCLUSIONS: AKI was a common condition in laparoscopic abdominal surgery. Exposure index has been proposed as a novel predictor of laparoscopic abdominal surgery associated AKI.

Early versus standard initiation of renal replacement therapy in furosemide stress test non-responsive acute kidney injury patients (the FST trial).

BACKGROUND: The timing of initiation of renal replacement therapy (RRT) in severe acute kidney injury (AKI) remains controversial, with early initiation resulting in unnecessary therapy for some patients while expectant therapy may delay RRT for other patients. The furosemide stress test (FST) has been shown to predict the need for RRT and therefore could be used to exclude low-risk patients from enrollment in trials of RRT timing. We conducted this multicenter pilot study to determine whether FST could be used to screen patients at high risk for RRT and to determine the feasibility of incorporating FST into a trial of early initiation of RRT. METHODS: FST was performed using intravenous furosemide (1 mg/kg in furosemide-naive patients or 1.5 mg/kg in previous furosemide users). FST-nonresponsive patients (urine output less than 200 mL in 2 h) were then randomized to early (initiation within 6 h) or standard (initiation by urgent indication) RRT. RESULTS: FST was completed in all patients (100%). Only 6/44 (13.6%) FST-responsive patients ultimately received RRT while 47/60 (78.3%) nonresponders randomized to standard RRT either received RRT or died (P <  0.001). Among 118 FST-nonresponsive patients, 98.3% in the early RRT arm and 75% in the standard RRT arm received RRT. The adherence to the protocol was 94.8% and 100% in the early and standard RRT group, respectively. We observed no differences in 28-day mortality (62.1 versus 58.3%, P = 0.68), 7-day fluid balance, or RRT dependence at day 28. However, hypophosphatemia occurred more frequently in the early RRT arm (P = 0.002). CONCLUSION: The furosemide stress test appears to be feasible and effective in identifying patients for randomization to different RRT initiation times. Our findings should guide implementation of large-scale randomized controlled trials for the timing of RRT initiation. TRIAL REGISTRATION: clinicaltrials.gov, NCT02730117 . Registered 6 April 2016.

The effect of early renal replacement therapy guided by plasma neutrophil gelatinase associated lipocalin on outcome of acute kidney injury: A feasibility study.

PURPOSE: The optimal time and the parameter utilized for decision to initiate renal replacement therapy (RRT) in acute kidney injury (AKI) are still controversial. Recently, high levels of plasma NGAL (pNGAL) has been strongly correlated with poor AKI outcome. This is a feasibility study conducted to test whether early RRT initiation guided by pNGAL could improve AKI outcome. MATERIAL AND METHODS: The study comprised of triage trial and interventional trial running subsequently. As a guide for triage to RRT, we measured pNGAL at the enrollment time. Forty patients with pNGAL≥400ng/mL (high pNGAL group) were randomized to 'early' or 'standard' group. Patients with pNGAL<400ng/mL (n=20) were defined as low pNGAL group. RESULTS: The triggering pNGAL selected AKI patients with more severity of illness and worse clinical outcome. However, in high pNGAL group, early RRT did not result in different 28-day mortality from the standard group. The median numbers of day free from mechanical ventilation were significantly higher in the early RRT group. CONCLUSIONS: Our finding suggested that it was feasible to use pNGAL to triage severe AKI patients. However, early initiation of RRT in this high risk group did not affect the 28-day mortality.

Neutrophil Gelatinase Associated Lipocalin (NGAL) in Leptospirosis Acute Kidney Injury: A Multicenter Study in Thailand.

AKI is one of the most serious complications of leptospirosis, an important zoonosis in the tropics. Recently, NGAL, one of the novel AKI biomarkers, is extensively studied in various specific settings such as sepsis, cardiac surgery, and radiocontrast nephropathy. In this multicenter study, we aimed to study the role of NGAL as an early marker and an outcome predictor of leptospirosis associated AKI. Patients who presented with clinical suspiciousness of leptospirosis were prospectively enrolled in 9 centers from August 2012 to November 2014. The first day of enrollment was the first day of clinical suspicious leptospirosis. Blood and urine samples were serially collected on the first three days and day 7 after enrollment. We used three standard techniques (microscopic agglutination test, direct culture, and PCR technique) to confirm the diagnosis of leptospirosis. KDIGO criteria were used for AKI diagnosis. Recovery was defined as alive and not requiring dialysis during hospitalization or maintaining maximum KDIGO stage at hospital discharge. Of the 221 recruited cases, 113 cases were leptospirosis confirmed cases. Thirty seven percent developed AKI. Median uNGAL and pNGAL levels in those developing AKI were significantly higher than in patients not developing AKI [253.8 (631.4) vs 24.1 (49.6) ng/ml, p < 0.001] and [1,030 (802.5) vs 192.0 (209.0) ng/ml, p < 0.001], respectively. uNGAL and pNGAL levels associated with AKI had AUC-ROC of 0.91, and 0.92, respectively. Both of urine NGAL and pNGAL level between AKI-recovery group and AKI-non recovery were comparable. From this multicenter study, uNGAL and pNGAL provided the promising result to be a marker for leptospirosis associated AKI. However, both of them did not show the potential role to be the predictor of renal recovery in this specific setting.

Urine neutrophil gelatinase-associated lipocalin: a diagnostic and prognostic marker for acute kidney injury (AKI) in hospitalized cirrhotic patients with AKI-prone conditions.

BACKGROUND: Acute kidney injury (AKI) is known to increase mortality in hospitalized cirrhotic patients; therefore early identification is utmost significance. There are only a few studies evaluating the cut-off level of urine neutrophil gelatinase-associated lipocalin (uNGAL) for diagnosing AKI and its prognostic value in cirrhotic patients. We aimed to determine the accuracy of uNGAL as a biomarker for early identification of AKI and to determine the cut-off level of uNGAL for diagnosing AKI in hospitalized cirrhotic patients; and (2) to explore the association of 30-day liver-related mortality with uNGAL level. METHODS AND MATERIAL: We prospectively enrolled cirrhotic patients admitted at the King Chulalongkorn Memorial Hospital during May 1, 2011 to Dec 31, 2013. UNGAL levels were measured within 24 h after admission. Clinical and laboratory data were obtained. Patients were followed up to 30 days. RESULTS: Of 137 cirrhotic hospitalized patients, 121 cirrhotic patients (88.3 %) with AKI-prone conditions were included with mean age of 57.3 ± 14.7 years. Thirty-five patients (29 %) developed AKI within 72 h of admission. The causes of AKI were prerenal azotemia (68.6 %), acute tubular necrosis (25.7 %), hepatorenal syndrome (5.7 %), respectively. The mean uNGAL level was significantly higher in the patients who developed AKI compared with those who did not (290.6 ± 356.3 vs. 54.4 ± 73.7 ng/mL; P = 0.0001). The AUC of uNGAL for diagnosing AKI was 0.83 (95 % [CI]: 0.76-0.91) with the optimal cut-off level of 56 ng/mL, providing 77.1 % sensitivity and 73.3 % specificity. Fourteen percent of subjects died during the 30-day follow-up period. The mean uNGAL levels were significantly higher in the mortality group. The AUC of uNGAL in predicting mortality was 0.75 (95 % [CI]: 0.66-0.85), with a best cut-off level of 72 ng/mL providing 70.6 % sensitivity and 69.2 % specificity. However, in multivariate logistic regression analysis, uNGAL is not an independent factor for 30-day liver-related mortality prediction. CONCLUSIONS: uNGAL is a valid marker for the early detection of AKI in hospitalized cirrhotic patients with AKI-prone conditions; however, its level could not independently predict 30-day liver-related mortality.

Enhanced vascular endothelial growth factor and inflammatory cytokine removal with online hemodiafiltration over high-flux hemodialysis in sepsis-related acute kidney injury patients.

Hypercytokinemia plays a central role in pathogenesis and is related to the high mortality in sepsis-related acute kidney injury (AKI). Besides the established cytokines, vascular endothelial growth factor (VEGF) is demonstrated as an important factor in enhancing vascular leakage in sepsis. This prospective randomized trial was conducted to compare the efficacy of cytokine removal between online hemodiafiltration (HDF), which combines convective and diffusive solute removal, and high-flux hemodialysis (HD). Twenty-eight sepsis-related AKI patients were included and randomized into online HDF and high-flux HD. The percentages of the reduction ratio in plasma cytokines were measured as primary outcomes. Other clinical parameters were determined as secondary outcomes. When compared with high-flux HD, online HDF provided significantly greater percentages of the reduction ratio in plasma cytokine levels, including VEGF (P < 0.001), IL-6 (P = 0.001), IL-8 (P = 0.021), IL-10 (P = 0.011), and tumor necrosis factor-α (P = 0.029). There were no significant differences in intradialytic blood pressures. Online HDF revealed better renal recovery and shorter length of hospitalization than high-flux HD. In conclusion, online HDF in sepsis-related AKI could provide significantly better removal of VEGF and other cytokines and these were associated with better renal outcome than high-flux HD. Thus, online HDF would offer a potential role in hypercytokinemic state in sepsis-related AKI.

Potential role of neutrophil gelatinase-associated lipocalin in identifying critically ill patients with acute kidney injury stage 2-3 who subsequently require renal replacement therapy.

Delayed initiation of renal replacement therapy (RRT) in critically ill acute kidney injury (AKI) patients results in high mortality while too early RRT causes unnecessary risks of the treatment. Current traditional indications cannot clearly identify the appropriate time for initiating RRT. This prospective cohort study was conducted to determine the accuracy of using plasma neutrophil gelatinase-associated lipocalin (pNGAL) and urine NGAL (uNGAL) in early identifying of the AKI patients who subsequently required RRT. Forty-seven critically ill patients with AKI stage 2-3 who did not reach the traditional indications for RRT were enrolled in this study. The pNGAL, uNGAL, and other parameters were determined in each patient. The primary end point was RRT initiation according to the traditional indications within 3 days. The mean age of the patients was 63.0 ± 18.1 years. pNGAL could predict subsequent RRT requirements with area under ROC 0.813 (P < 0.001, 95%CI 0.66-0.90). The cut-off point of 960 ng/mL provided sensitivity and specificity of 72.2 and 89.6%, respectively, and positive and negative predictive values of 81.25% and 83.8%, respectively. The uNGAL provided slightly lower significance of statistical parameters. The combination of pNGAL level of 960 ng/mL and APACHE II score of 20 improved statistical values. In conclusion, pNGAL is an excellent early biomarker for RRT initiation in critically ill patients with AKI stage 2-3. The pNGAL value of 960 ng/mL, alone or in combination with APACHE II score might be used as the early new indicator for early initiation of RRT in AKI stage 2-3 and this might improve patient survival.

A miniaturized immunoassay platform to measure neutrophil gelatinase-associated lipocalin (NGAL) for diagnosis of acute kidney injury.

In this study, we describe the development and evaluation of a slide-based immunoassay platform for the detection of neutrophil gelatinase associated-lipocalin (NGAL) in plasma and urine samples. The capture NGAL antibody was immobilized onto a microscope slide before an analysis of NGAL based on a sandwich immunoassay was further carried out. This assay system exhibited linearity between 50 to 1000 ng/ml of NGAL. The coefficients of variability (CVs) indicated good reproducibility and repeatability of the system. The levels of plasma NGAL measured by the slide-based system were highly correlated with those of ELISA, while this system over-predicted urine NGAL.

Effects of different levels of endotoxin contamination on inflammatory cytokine production by peripheral blood mononuclear cells after high-flux hemodialysis.

BACKGROUND: In Thailand, dialysate endotoxin contamination levels vary from less than 0.001 to 2.0 EU/ml. This difference has prompted an investigation on the production of proinflammatory cytokines and counter-inflammatory mediators of peripheral blood mononuclear cells (PBMCs) after high-flux dialysis. METHODS: Patients from four hemodialysis (HD) centers who met the inclusion/exclusion criteria were enrolled into the study. PBMCs were isolated by Ficoll density gradient centrifugation and cultured. Supernatants were tested for interleukin 6 (IL-6), IL-1ß and IL-1 receptor antagonist (IL-1Ra) concentration by ELISA. RESULTS: HD centers 1, 2, 3 and 4 had mean dialysate endotoxin contamination levels of 0.001, 0.026, 0.558 and 1.960 EU/ml, respectively. HD center 4 had the highest levels of IL-6 (1,052.3 ± 240.7 pg/10(6) PBMCs), IL-1ß (1,297.1 ± 334.6 pg/10(6) PBMCs) and IL-1Ra (2,713.4 ± 1,255.3 pg/10(6) PBMCs). There were no significant differences in cytokine production between HD centers 1 and 2. CONCLUSION: Our study showed that ultrapure dialysate can minimize the risk of stimulating inflammatory cells. Ultrapure dialysate may prevent or delay endotoxin exposure-related complications.

Tissue engineering of an implantable bioartificial hemofilter.

The first step in the tissue engineering of an implantable bioartificial kidney is the development of an implant that produces ultrafiltrate to replace glomerular function. A fabricated device containing synthetic hollow hemofiltration fibers was placed around the femoral vascular pedicle in rats, which initiated new tissue formation with a mature and durable neocapillary bed. The transudate fluid produced by this newly formed capillary bed accumulated through the hollow fibers into a subcutaneous port to allow evaluation of the fluid. In its first phase, this study evaluated various hollow fibers and tissue induction processes by the measurement of fluid volume, urea nitrogen, and total protein continuously for 6 weeks. New tissues formed within the implants surrounding the fibers, and the vascular density, vessel sizes, and percent cross-sectional vascular area were assessed by means of histomorphometric analysis after 6 weeks. The volume of fluid formation correlated with both vascular density and fiber membrane surface area. The implant fluid-to-serum ratios demonstrated a permselective filtrate. In a second phase, platelet-derived growth factor and vascular endothelial growth factor versus carrier alone were infused directly into the implants for the first 4 weeks in vivo through osmotic pumps and followed up to 9 weeks. Cumulative implant fluid volumes were significantly greater in the growth factor-treated group than in control animals and were associated with greater numbers of small-caliber blood vessels. These results provide the initial proof of concept in developing a tissue-engineered hemofilter prototype on a small scale in a rodent model.

Oxidative stress from rapid versus slow intravenous iron replacement in haemodialysis patients.

METHODS AND RESULTS: Oxidative stress was examined in 19 erythropoietin-treated haemodialysis patients who were receiving 100 mg of iron sucrose every 2 weeks by two intravenous methods, rapid injection and slow infusion. There were no significant differences in incidence of iron oversaturation state between the two methods. Regarding oxidative stress markers, the values of plasma and red blood cell thiobarbituric acid reactive substances (TBARS) expressed in terms of malonyldialdehyde (MDA) equivalents following the two methods did not increase, and the values of area under the curve (AUC) of both markers were not different between both regimens. Also, there were no significant differences in the values of plasma and AUC of anti-oxidant markers including total anti-oxidant status, reduced thiols, and vitamin E among both periods treated with two intravenous iron methods. CONCLUSION: As such, both intravenous iron methods could be safely used without enhancing oxidative stress in haemodialysis patients. The rapid injection method would be the preferred method of intravenous iron administration because it is more convenient while still retaining the safety profile.