Urinary biomarkers predict advanced acute kidney injury after cardiovascular surgery.

BACKGROUND: Acute kidney injury (AKI) after cardiovascular surgery is a serious complication. Little is known about the ability of novel biomarkers in combination with clinical risk scores for prediction of advanced AKI. METHODS: In this prospectively conducted multicenter study, urine samples were collected from 149 adults at 0, 3, 6, 12 and 24 h after cardiovascular surgery. We measured urinary hemojuvelin (uHJV), kidney injury molecule-1 (uKIM-1), neutrophil gelatinase-associated lipocalin (uNGAL), α-glutathione S-transferase (uα-GST) and π-glutathione S-transferase (uπ-GST). The primary outcome was advanced AKI, under the definition of Kidney Disease: Improving Global Outcomes (KDIGO) stage 2, 3 and composite outcomes were KDIGO stage 2, 3 or 90-day mortality after hospital discharge. RESULTS: Patients with advanced AKI had significantly higher levels of uHJV and uKIM-1 at 3, 6 and 12 h after surgery. When normalized by urinary creatinine level, uKIM-1 in combination with uHJV at 3 h post-surgery had a high predictive ability for advanced AKI and composite outcome (AUC = 0.898 and 0.905, respectively). The combination of this biomarker panel (normalized uKIM-1, uHJV at 3 h post-operation) and Liano's score was superior in predicting advanced AKI (AUC = 0.931, category-free net reclassification improvement of 1.149, and p <  0.001). CONCLUSIONS: When added to Liano's score, normalized uHJV and uKIM-1 levels at 3 h after cardiovascular surgery enhanced the identification of patients at higher risk of progression to advanced AKI and composite outcomes.

Acute Kidney Injury Urine Biomarkers in Very Low-Birth-Weight Infants.

BACKGROUND AND OBJECTIVES: Serum creatinine (SCr)-based AKI definitions have important limitations, particularly in very low-birth-weight (VLBW) neonates. Urine biomarkers may improve our ability to detect kidney damage. We assessed the association between 14 different urine biomarkers and AKI in VLBW infants. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: We performed a prospective cohort study on 113 VLBW infants (weight ≤1200 g or <31 weeks' gestation) admitted to a regional neonatal intensive care unit at the University of Alabama at Birmingham between February 2012 and June 2013. SCr was measured on postnatal days 1, 2, 3, and 4 and was combined with clinically measured SCr to determine AKI according to Kidney Disease Improving Global Outcomes AKI definition (increase in SCr ≥0.3 mg/dl or ≥50% increase from previous lowest value). Urine was collected on the first 4 days (average number of urine collections, 3; range, 1-4). The maximum urine biomarkers and urine biomarker/creatinine levels were calculated for 12 urine biomarkers, and the minimum urine biomarker and biomarker/creatinine levels were assessed for two urine biomarkers. We compared these values between infants with and those without AKI. Ideal cutoffs, area under the receiver-operating characteristic curve , and area under the curve adjusted for gestational age were calculated. RESULTS: Cumulative incidence of AKI during the first 2 postnatal weeks was 28 of 113 (25%). Infants with AKI had higher maximum levels of urine cystatin C, neutrophil gelatinase-associated lipocalin, osteopontin, clusterin, and α glutathione S-transferase (2.0, 1.8, 1.7, 1.7, and 3.7 times higher, respectively) than infants without AKI. In addition, infants with AKI had lower minimum levels of epithelial growth factor and uromodulin than those without AKI (1.4 and 1.6 times lower, respectively). Most but not all participants had their maximum (or minimum) biomarker values preceding AKI. These associations remained after adjustment for gestational age. CONCLUSIONS: Urine biomarkers measured in the first 4 days of life are associated with AKI during the first postnatal weeks. Further evaluations are necessary to determine whether these biomarkers can predict important clinical outcomes. In addition, intervention studies that use biomarkers to stratify enrollment groups are needed before bedside evaluations can be incorporated into care.

Renal Function and Urinary Biomarkers in Cardiac Bypass Surgery: A Prospective Randomized Trial Comparing Three Surgical Techniques.

Background Cardiopulmonary bypass procedure is associated with an increased risk of renal impairment. To which extent structural damage causes functional decline is unknown. We evaluated perioperative kidney injury and function in patients treated with conventional extracorporeal circulation (CECC), minimized extracorporeal circulation (MECC), and off-pump coronary artery bypass grafting (OPCAB). Methods Blood and urine samples, collected at baseline and up to 72 hours after surgery from patients of the HEPCON trial (DRKS00007580, 120 patients randomized for heparin management and for surgical technique), were analyzed for differences in renal injury and function. Neutrophil gelatinase-associated lipocalin, α glutathione S-transferase, liver fatty acid-binding protein, and kidney injury molecule-1 were measured as urinary protein markers of renal tubular injury. Serum creatinine, blood urea levels, and estimated glomerular filtration rate were determined to monitor renal function. Results Markers of tubular injury differed significantly between surgical technique groups early after surgery, indicating the most detrimental effect in CECC. Hemolysis and hemodilution correlated with these early changes. A late rise did not show intergroup differences. Time courses of renal function parameters, as well as the development of acute kidney injury in 15 patients (13.5%), were irrespective of surgical technique. Heparin management did not influence renal parameters. Conclusion During coronary artery bypass grafting, CECC temporarily induces more tubular injury than MECC or OPCAB. However, late changes of renal function parameters occur irrespective of extracorporeal perfusion mode and even in off-pump surgery.

Differences in urinary proteins related to surgical margin status after radical prostatectomy.

Presented exploratory pilot study was aimed at evaluation of proteins present in urinary specimens collected from prostate cancer suffering subjects after radical prostatectomy, divided into two experimental cohorts: positive (n=15) and negative (n=15) surgical margins (PSM/NSM). The presence of PSM suggests inadequate cancer clearance and the possible need for additional treatment. Proper identification of these risk-patients is therefore of a paramount importance. Total protein profiles were firstly identified by using SDS-PAGE and compared by using partial least square discrimination analysis (PLS-DA), which revealed differences in molecular weights of 80-99 and 150-235 kDa between the experimental groups. For further identification of proteins, comparative proteomic technologies were employed. Two-dimensional gel electrophoresis with subsequent identification of protein spots by using MALDI-TOF mass fingerprinting revealed differential expression of proteins between NSM/PSM cohorts. Moreover, in PSM group, three uniquely identified proteins (cyclin-dependent kinase 6, galectin-3-binding protein and L-lactate dehydrogenase C chain) were found, which show tight connection with prostate cancer and presence of all of them was previously linked to certain aspects of prostate cancer. These proteins may be associated with the molecular mechanisms of prostate cancer development; hence, their identification may be helpful for the assessment of disease progression risk after radical prostatectomy, but also for possible early diagnosis.

Age-related differences in kidney injury biomarkers induced by cisplatin.

Acute kidney injury (AKI) occurs in a half of cisplatin (CDDP)-treated patients. Traditional biomarkers including blood urea nitrogen (BUN) and serum creatinine (SCr) are still used for detection of CDDP-induced AKI, but these biomarkers are not specific or sensitive. The aim of this study was to identify the specific and sensitive biomarkers against CDDP-induced renal injury between young (3-week-old) and old (20-week-old) rats. All animals were intraperitoneally injected once with CDDP (6 mg/kg). After 3 days, all animals were sacrificed and serum, urine, and kidney tissues were collected. Urinary and serum biomarkers as well as histological changes were measured. CDDP-induced proximal tubular damage was apparent from histopathological examination, being more severe in 3-week-old rats accompanied by increased number of TUNEL-positive apoptotic cells. This was associated with elevated urinary kidney injury molecule-1 (KIM-1), glutathione-S-transferase alpha (GST-α), vascular endothelial growth factor (VEGF), and tissue inhibitor of metalloproteinases-1 (TIMP-1). In contrast, the levels of neutrophil gelatinase-associated lipocalin (NGAL) and osteopontin were significantly increased in 20-week-old rats after CDDP treatment. These results indicate that the use of age-specific urinary biomarkers is necessary to diagnosis of CDDP-induced AKI. Especially, urinary KIM-1, GST-α, TIMP-1, and VEGF levels may help in the early diagnosis of young patients with CDDP-induced AKI.

The investigation of specific biochemical markers in monitoring kidney function of drug addicts.

INTRODUCTION: An increasingly important issue in the Polish population is drug abuse. It leads to extensive damage of parenchymal organs, including kidney. Establishing early markers of organ damage and their monitoring during rehabilitation therapy is therefore of pivotal importance. This study evaluated the utility of highly specific and selective markers (NGAL, IL-18, a and π-GST isoenzyme, and ß2-M). The influence of opioid drugs and other factors on kidney function (HIV and HCV infections, duration and the kind of drugs abused) was determined. MATERIALS AND METHODS: Urine collected from 83 subjects who abused drugs and 33 healthy volunteers was tested with ELISA using specific antibodies (IBL, Biotron, Bioporto-Diagnostics). HIV infection was confirmed with western-blotting and HCV with PCR. CD4 lymphocytes were quantified with flow cytometry. RFLP and PCR were used to determine the viral load of HIV and HCV (genotype). RESULTS: A significant increase of IL-18, NGAL and ß2M activity in heroin addicts compared to the control group was noted as well as the influence of HIV infection on NGAL and ß2M excretion. A statistically significant (p=0.04) correlation between the viral load and IL-18 concentration was noted while no significant influence of the duration and the kind of drugs abused, the route of intake or the age of addicts was seen. Only the NGAL concentration was sex dependent and significantly higher in women. DISCUSSION: This study showed the specific, clinical utility of IL-18, NGAL, and ß2M in the evaluation of renal function in drug addicts. Early detection of nephropathy with biochemical indicators might help prevent severe conditions that require hospitalization and intensive care.

Renal function and arterial blood pressure alterations after exposure to acetaminophen with a potential role of Nigella sativa oil in adult male rats.

Hepatic injury by acetaminophen (APAP) has been extensively studied, although the alterations of renal functions and arterial blood pressure (ABP) after APAP exposure are still uncertain, and the impact of Nigella sativa oil (NSO) in this case is poorly defined. Sixty adult male albino rats were involved in two sets of experiments. The first was exposed to a single high dose of APAP (2.5 g/kg) orally preceded by 4 ml NSO/kg orally, while the second received 750 mg APAP/kg/day orally for seven consecutive days and was pretreated with 2 ml NSO/kg/day. Proximal tubular injury was assessed by laboratory and histological studies, and arterial blood pressure was recorded in all animals. In both experiments, urinary α-glutathione S-transferase and neutral endopeptidase, and microproteinuria were dramatically increased early indicating glomerulus and proximal tubule dysfunction that was mediated by raising 8-isoprostanes. Concomitantly, urinary albumin, total protein, creatinine, urea, glomerular filtration rate, Na and K levels, plasma creatinine, and urea were all changed significantly after APAP administration. Currently, ABP increased significantly after APAP which was mostly mediated by renal impairment and increased both renin activity and aldosterone secretion. Pretreatment with NSO produced significant normalization of physiological parameters as well as suppression of structural changes. In conclusion, measurement of urinary biomarkers can be considered a powerful tool for early screening of renal injury and alteration of ABP after APAP treatment. Concomitant administration of NSO can counterbalance these detrimental effects.

Urine α-Glutathione S-transferase, systemic inflammation and arterial function in juvenile type 1 diabetes.

BACKGROUND: Despite marked improvement in therapy and monitoring of patients with insulin-dependent (type 1) diabetes, diabetic nephropathy remains a serious complication, with subsequent end-stage renal disease in about 20% of cases. OBJECTIVE: To investigate in young patients with type 1 diabetes whether urine α-Glutathione S-transferase to creatinine ratio (α-GST:crea) relates to markers of systemic inflammation and subclinical vasculopathy. DESIGN: Children and adolescents (median age and diabetes duration 14 and 6 years, respectively) with type 1 diabetes screened in a previous study for proximal tubular (urine α-GST:crea ratio) and renal (plasma creatinine, cystatin C glomerular filtration rate (GFR), and timed urine albumin excretion rate (AER)) function were, within the same timeframe, also investigated for vascular (blood pressure, carotid artery intima-media thickness (IMT) and compliance (CAC), brachial artery flow-mediated dilatation (FMD) and plasma cyclic guanosine monophosphate (cGMP) and inflammatory (C-reactive protein (CRP), and tumor necrosis factor-alpha (TNF-α)) profiles. Exposure to environmental tobacco smoke (ETS) was assessed through questionnaire (n=67 respondents). RESULTS: None of the patients (n=69) had overt renal insufficiency. AER correlated with age (p=0.01, r=0.3), diabetes duration (p=0.02, r=0.3), FMD (p=0.04, r=-0.3, n=52), CAC (p=0.03, r=-0.3, n=62) and cGMP (p=0.01, r=-0.3, n=59). α-GST:crea was lower (p=0.03) in patients than in controls. α-GST:crea appeared to be particularly lower in older patients (p=0.004, r=-0.34 vs age), in those with worse diabetic control (p=0.03, r=-0.26 vs HbA1c), and in those with lower carotid artery elasticity (p=0.017, r=0.3 vs CAC). Although ETS had no direct significant impact on α-GST:crea, α-GST:crea correlated with FMD only in patients with ETS (r=0.5, p=0.009, n=13). α-GST:crea showed positive association with TNF-α (p=0.01, r=0.3). CONCLUSION: In children and adolescents with type 1 diabetes, lower levels of urine excretion of α-GST:crea appear to be associated with decreasing elasticity and endothelial vasomotor function of peripheral arteries, especially in patients with ETS. In contrast, higher levels of α-GST:crea are more common in patients with elevated markers of systemic inflammation. Large scale prospective studies are needed to clarify the meaning and mechanisms of this association.

Protective effect of apocynin, a NADPH-oxidase inhibitor, against contrast-induced nephropathy in the diabetic rats: a comparison with n-acetylcysteine.

The aim of this study was to investigate the effects of apocynin, a NADPH (nicotinamide adenine dinucleotide phosphate)-oxidase inhibitor, in diabetic rats with nephropathy induced by contrast medium (CIN). Diabetes was induced in male Wistar rats by a single dose of streptozotocin (60 mg/kg i.v.). Animals were then divided into the following groups: 1) control group (diabetic rats treated i.v. with saline solution); 2) iomeprol group (iomeprol at 10 ml/kg was injected i.v. 30 min after saline administration); 3) apocynin group (identical to the iomeprol group, except for pre-treatment with apocynin 5mg/kg i.v., 30 min before iomeprol injection) and 4) N-acetylcysteine group (NAC) (same as iomeprol group, except for the treatment with NAC 20 mg/kg i.v. 30 min before iomeprol injection). CIN in animals were assessed 24h after administration of iomeprol. Apocynin significantly attenuates the impaired glomerular function, concentration of Na(+), K(+), alpha glutathione S-transferase levels in urine and neutrophil gelatinase-associated lipocalin levels in plasma caused by iomeprol. In kidney, immunohistochemical analysis of some inflammatory mediators, such as nitrotyrosine, poly-ADP-ribosyl polymerase, tumor necrosis factor-α, interleukin-1ß as well as apoptosis (evaluated as terminal deoxynucleotidyltransferase-mediated UTP end labeling assay) revealed positive staining in tissue obtained from iomeprol group. These parameters were markedly reduced in animals treated with apocynin. Similarly, these parameters were also markedly modified by NAC pre-treatment. Here, we have shown that apocynin attenuates the degree of iomeprol-induced nephropathy in diabetic rats.

Nephrotoxicity of hexachloro-1:3-butadiene in the male Hanover Wistar rat; correlation of minimal histopathological changes with biomarkers of renal injury.

Hexachloro-1:3-butadiene (HCBD) causes damage specifically to the renal proximal tubule in rats. In the present study, injury to the nephron of male Hanover Wistar rats was characterized at 24 h following dosing with HCBD in the range 5-90 mg kg⁻¹ to determine the most sensitive biomarkers of damage, that is, the biomarkers demonstrating significant changes at the lowest dose of HCBD, using a range of measurements in serum and urine, renal histopathology, and renal and hepatic gene expression. Histologically, kidney degeneration was noted at doses as low as 10 mg kg⁻¹ HCBD. Significant changes in the hepatic and renal gene expression categories of xenobiotic metabolism and oxidative stress were observed at 5 mg kg⁻¹ HCBD, and in the kidney alone, evidence of inflammation at 90 mg kg⁻¹ HCBD. Increases in the urinary excretion of α-glutathione S-transferase (α-GST) and kidney injury molecule-1 (KIM-1) were seen at 10 mg kg⁻¹ HCBD, and increases in urinary excretion of albumin and total protein were evident at 15 mg kg⁻¹ HCBD. The most sensitive, noninvasive biomarkers of HCBD-induced renal toxicity in Hanover Wistar rats were urinary α-GST and KIM-1. Urinary albumin measurement is also recommended as, although it is not the most sensitive biomarker, together with α-GST, albumin showed the largest relative increase of all the biomarkers investigated, and the protein is easily measured.

Urinary biomarkers for monitoring disease progression in the Han:SPRD-cy rat model of autosomal-dominant polycystic kidney disease.

The Han:SRPD-cy rat is a well-recognized model of human autosomal-dominant polycystic kidney disease. The disease is characterized by the development of progressive renal cysts, leading to declining renal function. Disease progression typically is monitored by measurement of plasma urea concentration. Although plasma urea may be an adequate measure of overall renal function, urinary biomarkers capable of accurately monitoring disease progression may be equally useful. The goal of this study was to assess several urinary biomarkers as potential markers of disease progression in male and female Han:SPRD-cy rats. These biomarkers were compared with changes in plasma urea concentration and morphometric changes as the disease progressed. Urinary activity of N-acetyl-ß-D-glucosaminidase and concentration of α-glutathione S-transferase were measured as markers of proximal tubular dysfunction, glutathione S-transferase Yb1 as a distal tubular marker, and collagen IV as a biomarker for glomerular lesions. Urinary albumin was used as biomarker of glomerular or proximal tubular lesions. Albuminuria increased in male rats as the disease progressed, correlating with increasing plasma urea and morphologic changes. Urine concentrations of α-glutathione S-transferase decreased significantly in the male heterozygotic compared with wildtype rats in the later stages of the disease. Urinary concentrations of glutathione S-transferase Yb1 and collagen IV and activity of N-acetyl-ß-D-glucosaminidase did not change during disease progression. Measurement of urinary albumin and concentrations of α-glutathione S-transferase may be useful for monitoring disease progression in the male Han:SPRD-cy rat model in future experiments.

Potentially detrimental effects of N-acetylcysteine on renal function in knee arthroplasty.

Ischaemia/reperfusion induces systemic inflammation and oxidative stress and thereby remote organ injury in the kidney. In a double-blind, placebo-controlled clinical trial of 30 patients undergoing knee arthroplasty with tourniquet, this study evaluated the effect of N-acetylcysteine (NAC) infusion on renal function by measuring urine alpha-1-microglobulin, N-acetyl-beta-D-glucosaminidase (NAG), glutathione-S-transferase-alpha and -phi and serum creatinine and cystatin C concentrations up to 24 h post-operatively. Compared to the baseline, urine alpha-1-microglobulin/creatinine increased in both groups and was higher in the NAC group than in the placebo group at tourniquet deflation and at 3 h thereafter. Urine NAG/creatinine increased at deflation and at 3 h thereafter in the NAC group and the ratio was higher than in the placebo group. The two sensitive indicators of proximal tubular damage and function used in the present study suggest that use of NAC in clinical setting of ischaemia/reperfusion injury may increase the risk of remote kidney injury.

Preclinical evaluation of novel urinary biomarkers of cadmium nephrotoxicity.

As a result of the widespread use of Cd in industry and its extensive dissemination in the environment, there has been considerable interest in the identification of early biomarkers of Cd-induced kidney injury. Kim-1 is a transmembrane glycoprotein that is not detectable in normal kidney, but is up-regulated and shed into the urine following ischemic or nephrotoxic injury. Recent studies utilizing a sub-chronic model of Cd exposure in the rat have shown that Kim-1 is an early urinary marker of Cd-induced kidney injury. Kim-1 was detected in the urine 4-5 weeks before the onset of proteinuria and 1-3 weeks before the appearance of urinary metallothionein and Clara cell protein 16, which are standard markers of Cd nephrotoxicity. In the present study, we have compared the time course for the appearance of Kim-1 in the urine with the time course for the appearance of alpha glutathione-S-transferase (alpha-GST), N-acetyl-beta-D-glucose amidase (NAG) and Cd, each of which have been used or proposed as urinary markers of Cd nephrotoxicity. Adult male Sprague-Dawley rats were given daily subcutaneous injections of 0.6 mg (5.36 micromoles)/kg Cd, 5 days per week for up to 12 weeks. One day each week, 24 h urine samples were collected and analyzed for protein, creatinine and the various markers. The results showed that significant levels of Kim-1 appeared in the urine as early as 6 weeks into the treatment protocol and then continued to rise for the remainder of the 12 week treatment period. By contrast, significant levels of alpha-GST and NAG did not appear in the urine until 8 and 12 weeks, respectively, while proteinuria was not evident until 10 weeks. The urinary excretion of Cd was below the level of detection until week 4 and then showed a slow, linear increase over the next 6 weeks before increasing markedly between weeks 10 and 12. These results provide additional evidence that Kim-1 is a sensitive biomarker of the early stages of Cd-induced proximal tubule injury.

Importance of urinary measurement of glutathione S-transferase in renal dysfunction patients after on- and off-pump coronary artery bypass surgery.

BACKGROUND: Acute renal failure (ARF) occurring after on-pump and off-pump cardiac surgery was assessed by urinary alpha glutathione S-transferase measurement (alpha-GST) in patients who already had renal dysfunction. METHODS: Fifty-one patients with plasma creatinine levels ranging between 1.5 and 2.0 mg/dL were included in the study. On-pump coronary artery bypass was performed in 25 of them, and off-pump surgery in the other 25 patients. Urinary alpha-GST levels, plasma creatinine levels, creatinine clearance and fractional excretion of sodium were measured. RESULTS: Urinary alpha-GST levels were found to be significantly increased at 24 hours postoperatively. A weak correlation was detected between alpha-GST levels and plasma creatinine, creatinine clearance and fractional excretion of sodium. Preoperative and postoperative 24 hour levels showed a positive predictive value for the occurrence of acute renal failure. CONCLUSIONS: Tubular damage produced by cardiopulmonary bypass is not the only factor associated with postoperative ARF. Because factors independent of pump usage can adversely affect renal function, excluding pump usage alone is not sufficient to prevent postoperative ARF in patients who have preoperative renal dysfunction.

Association of urinary 90 kDa angiotensin- converting enzyme with family history of hypertension and endothelial function in normotensive individuals

We described angiotensin-I-converting enzyme (ACE) isoforms with molecular masses of 190, 90, and 65 kDa in the urine of normotensive offspring of hypertensive subjects. Since they did not appear in equal amounts, we suggested that 90 kDa ACE might be a marker for hypertension. We evaluated the endothelial response in normotensive offspring with or without family history of hypertension and its association with the 90 kDa ACE in urine. Thirty-five normotensive subjects with a known family history of hypertension and 20 subjects without a family history of hypertension, matched for age, sex, body weight, and blood pressure, were included in the study. Endothelial function was assessed by ultrasound and a sample of urine was collected for determination of ACE isoforms. In the presence of a family history of hypertension and detection of 90 kDa ACE, we noted a maximal flow mediated dilation of 12.1 ± 5.0 vs 16.1 ± 6.0 percent in those without a previous history of hypertension and lacking urinary 90 kDa ACE (P < 0.05). In subjects with a family history of hypertension and presenting 90 kDa ACE, there were lower levels of HDL-cholesterol (P < 0.05) and higher levels of triglycerides (P < 0.05). Subjects with 90 kDa ACE irrespective of hypertensive history presented a trend for higher levels of triglycerides and HDL-cholesterol (P = 0.06) compared to subjects without 90 kDa ACE. Our data suggest that the 90 kDa ACE may be a marker for hypertension which may be related to the development of early atherosclerotic changes.

Tubular function in diabetic children assessed by Tamm-Horsfall protein and glutathione S-transferase.

In a previous study, we found urinary excretion of Tamm-Horsfall protein (THP) to be persistently decreased in 25% of patients during the first year after diagnosis of diabetes mellitus. We thus wanted to study another marker for distal tubular function, pi glutathione S-transferase (pi-GST) and compare this and THP with proximal tubular function evaluated with alpha-GST and alpha-1-microglobulin (HC) in patients with longer duration of diabetes. One hundred and eighty-four diabetic and 16 control children were studied with timed overnight urine collections. Median age was 14 years, and median age at diagnosis was 8 years. The urinary excretion of alpha- and pi-GST was significant lower in diabetic than control children. There were no differences in the excretion of HC and THP. Diabetic children with decreased alpha-GST had higher albumin excretion, HbA 1c levels, and longer diabetes duration but decreased THP excretion and cystatin-C clearance compared with those with normal excretion. In contrast, a decreased pi-GST or THP excretion was not associated with such differences. Diabetic children with increased HC excretion had increased HbA 1c levels. Diabetic children, before the stage of microalbuminuria, may have signs of both proximal and distal tubular dysfunction, which is related to diabetes duration and poor metabolic control. Alpha-GST and pi-GST seem to be more sensitive than other parameters studied.

[Urinary N-acetyl-beta-D-glucosaminidase and its isoenzymes in smoking and non-smoking workers at copper foundry occupational co-exposed to arsenic cadmium and lead]. / Aktywnosc N-acetylo-beta-D-glukozaminidazy i jej izoform w moczu palacych i niepalacych pracowników huty narazonych zawodowo na arsen, kadm i olów.

The kidneys are the critical organs in the case of a long-term occupational or environmental exposure to heavy metals and tobacco smoke. In diagnostics of renal damage useful are the methods which determine the activity of renal enzymes, quantify in urine (e.g. beta-glucuronidase, N-acetyl-beta-D-glucosaminidase). N-acetyl-beta-D-glucosaminidase (NAG) is one of the most often determined factors of tubular damage, since its activity increases in early stages of renal injury, ahead of appearance of excretory dysfunction. The aim of this research was to assess the influence of occupational exposure of copper-foundry workers to heavy metals (arsenic, cadmium, lead) on total activity of N-acetyl-beta-D-glucosaminidase and its molecular forms in urine. The investigated group was made up of 95 founders (smokers n = 51, non-smokers n = 44) and 43 people in control group (smokers n = 16, non-smokers n = 27). The concentrations of arsenic (As) and cadmium (Cd) were determined in urine, whilst the level of lead (Pb) was determined in whole blood. The activities of NAG and its isoforms were determined in urine. Smoking and non-smoking founders' urine demonstrated 14 times higher concentrations of arsenic levels in comparison with smoking and nonsmoking control group. Cadmium concentrations were 3.5 times higher in urine of smoking founders in comparison with smoking control group and about 3 times higher in case of nonsmoking founders in comparison with non-smoking control group. 7 times increase of lead concentration was observed in the whole blood within the smoking founders group in comparison with the smoking control group. In the blood of non-smoking founders was demonstrated about 10 times increase of lead concentration in comparison with the non-smoking control group. About 3-times increase of total NAG's activity was observed in urine of smoking founders and 4-times increase of non-smoking founders in comparison with smoking and non-smoking control group. The highest activity of NAG-B was observed in urine of smoking founders (11.35 +/- 7.85 U/g creatinine), then non-smoking founders (9.7 +/- 8.75 U/ g creatinine). It was confirmed, that the activity of N-acetyl-beta-D-glucosaminidase is a good factor in the assessment of occupational exposure to heavy metals like arsenic, cadmium and lead.

Renal tubular dysfunction in schizophrenic patients treated with antipsychotic drugs.

Several factors have been considered in relation to the free radical formation in schizophrenia, such as the disease itself, drug treatment and smoking. Several chemicals and drugs may cause damage to the renal tubules by different subcellular mechanisms including oxidative stress, and the aim of our study was the investigation of tubular dysfunction in schizophrenic patients. The urinary excretion of beta-N-acetylhexosaminidase (Hex) and its isoenzymes Hex A and Hex B, alpha1-microglobulin, albumin, total proteins and fractionated porphyrins were determined in 45 schizophrenic patients treated with first- and second-generation antipsychotics. In 7 patients, an increase in proteinuria of tubular origin was found, and in one as a result of mixed glomerular/tubular origin. The group of patients had a significantly higher level of excretion than the control group (n = 54) of total Hex (p < 0.001), Hex A (p < 0.05), Hex B (p < 0.001) and the relative proportion of this isoenzyme (p < 0.001). In some cases with normal levels of total Hex and urinary alpha1-microglobulin, the proportion of Hex B was already increased. Significant correlations were found for total Hex and its isoenzymes with alpha1-microglobulin (p < 0.001). Also, the porphyrins had significant correlations with total Hex (p < 0.001), Hex A (p < 0.05), Hex B (p < 0.005) and alpha1-microglobulin (p < 0.001). In the group of patients studied, it was possible to reveal early tubular cell damage (affected structural integrity) with increased excretion of Hex B, possibly mediated by free radicals, previous to the decrease in tubular reabsorption of proteins with low molecular mass filtered by the glomerulus (affected functional integrity).

Leukodepletion improves renal function in patients with renal dysfunction undergoing on-pump coronary bypass surgery: a prospective randomized study.

BACKGROUND: We aimed to show the impact of leukodepletion on renal function in patients undergoing on-pump coronary revascularization. PATIENTS AND METHODS: Fifty patients awaiting elective on-pump coronary revascularization with normal preoperative cardiac functions and with plasma creatinine levels ranging between 1.5 and 2.0 mg/dL were prospectively randomized into two groups: on-pump CABG with (group A: n = 25) and without leukodepletion (group B, n = 25). Renal glomerular and tubular injury were assessed by urinary alpha glutathione s-transferase (GST), plasma creatinine, and blood urea nitrogen (BUN) levels. RESULTS: The patients consisted of 14 females and 36 males with a mean age of 57.6 +/- 5.3 years. In the leukodepletion group, the mean levels of creatinine, BUN and urinary GST were found to be decreased on the first, third and fifth postoperative days compared with the control group. There was no mortality. Three patients in the control group needed postoperative dialysis. CONCLUSION: Patients with renal dysfunction undergoing on-pump CABG surgery seem to benefit from leukodepletion as a measure to prevent tubular damage and renal impairment compared with a control group.