Oxidative stress in pediatric nephrotic syndrome

Effect of octreotide on oxidative stress in the erythrocyte and kidney tissue in adriamycin-induced experimental nephrotic syndrome model

INTRODUCTION

Nephrotic syndrome (NS) is one of the reasons of end-stage kidney disease, and elucidating the pathogenesis and offer new treatment options is important. Oxidative stress might trigger pathogenesis systemically or isolated in the kidneys. Octreotide (OCT) has beneficial antioxidant effects. We aimed to investigate the source of oxidative stress and the effect of OCT on experimental NS model.

METHODS

Twenty-four non-uremic Wistar albino rats were divided into 3 groups. Control group, 2 mL saline intramuscular (im); NS group, adriamycin 5 mg/kg intravenous (iv); NS treatment group, adriamycin 5 mg/kg (iv) and OCT 200 mcg/kg (im) were administered at baseline (Day 0). At the end of 21 days, creatinine and protein levels were measured in 24-hour urine samples. Erythrocyte and renal catalase (CAT) and thiobarbituric acid reactive substance (TBARS) were measured. Renal histology was also evaluated.

RESULTS

There was no significant difference among the 3 groups in terms of CAT and TBARS in erythrocytes. Renal CAT level was lowest in NS group, and significantly lower than the control group. In treatment group, CAT level significantly increased compared with NS group. In terms of renal histology, tubular and interstitial evaluations were similar in all groups. Glomerular score was significantly higher in NS group compared with control group and it was significantly decreased in treatment group compared to NS group.

CONCLUSIONS

Oxidative stress in NS might be due to the decrease in antioxidant protection mechanism in kidney. Octreotide improves antioxidant levels and histology in renal tissue and might be a treatment option.

The Effect of Uncaria gambir Roxb. Extract on Superoxide Dismutase Activity in Proteinuric Wistar Rats Model

Nephrotic syndrome (NS) is a glomerular disease that is most often found in children with proteinuric as clinical manifestation. Gambier extract is a traditional medicine that has antioxidant effect. Its use to treat  proteinuric has never been done. Therefore, we conducted an analytical study on the effect of gambier on proteinuric and superoxide dismutase (SOD) activity in proteinuric Wistar rat’s model. This research is an experimental study with a posttest control group design. The aim is analyzing the effect of giving gambier extract in decreasing urinary protein creatinine ratio and increasing SOD activity. Male Wistar rats were given an injection of puromycin aminonucleoside 1.5mg/100g body weight (BW), subcutaneously for 5 consecutive days for being nephrosis. The experimental animals in this study were divided into four groups: K1, the control group, consist of group of rats that were injected with 0.15ml/100 g BW of aquabidest and not given gambier extract. While K2 group consist of rats induced by Puromycin and given 1 ml of aquabidest. K3 consist of groups of rats induced by Puromycin and then given gambier extract 26mg/200g BW. Group K4 consist of rats induced by Puromycin and then given 80mg/200g BW of gambier extract. The four groups were given treatment for 14 days, after which the rats were placed in a metabolic cage for 24 hours to collect urine samples and then knocked down with ketamine for intra-cardiac blood collection. The results of this study showed differences between the four groups of rats in terms of the mean urine protein/creatinine ratio (p=0.015) and SOD activity (p=0.036). Groups of rats that were given gambier extracts 80mg/200g BW had lower urine protein / creatinine ratio and higher SOD activity. Therapy of gambier 80 mg/200g BW is better in managing proteinuric compared to 26mg/200g.

Selected salivary parameters in children with idiopathic nephrotic syndrome: a preliminary study

Background

Disturbances in the levels of serum constituents occurring in chronic renal diseases can be reflected in the saliva composition. The aim of this study was to assess some selected salivary components in children suffering from idiopathic steroid-sensitive nephrotic syndrome (iNS).

Methods

A case–control study was performed on iNS and healthy participants. In unstimulated mixed saliva, pH, buffer capacity, total protein, α-amylase, peroxidase, calcium, magnesium, inorganic phosphate, fluoride, urea, uric acid and salivary flow rate were measured. Oral condition was assessed using dmft, DMFT, API and GI indices, usage of fluoride specimens and frequency of tooth brushing. Statistical analysis was performed by Shapiro–Wilk, Brown-Forsythe, Student’s t, ANOVA, Tukey’s and Pearson’s chi-square tests, Pearson’s and Spearman’s correlations, logistic regression and receiver operating characteristic (ROC) curve analysis.

Results

The study involved 94 participants of both genders aged 4–17 (47 cases in relapse or remission phase of iNS and 47 controls) who were treated in the clinic of pediatric nephrology or outpatient dental clinic. Neither group differed in the number of caries-affected primary and permanent teeth, gingival condition or use of fluoride specimens. The iNS group presented lower levels of magnesium (0.41 ± 0.34 vs. 0.60 ± 0.38 mg/dL, P < 0.05) and fluoride (0.15 ± 0.10 vs. 0.21 ± 0.10 ppm, P < 0.01) and higher contents of urea (35.19 ± 15.55 vs. 25.21 ± 10.78 mg/dL, P < 0.01) and uric acid (2.90 ± 1.23 vs. 2.34 ± 1.04 mg/dL, P < 0.05) than the controls. In the iNS participants with relapse, a higher peroxidase activity and lower magnesium content than in the remission phase were found. ROC analysis showed a weak discriminatory power of these salivary constituents for the differentiation of participants with and without disease (accuracy from 66.0 to 67.0%, area under the ROC curve (AUC) from 0.638 to 0.682) and the relapse and remission phases (accuracy 70.2% and 68.1% and AUC 0.717 and 0.675, respectively).

Conclusions

Levels of urea, uric acid, magnesium and fluoride in saliva can be associated with the course of iNS. Salivary levels of peroxidase and magnesium can be related to the phase of the disease. However, the measurements of these parameters cannot be useful as a noninvasive tool in diagnosing iNS and the phase of the disease.

Increased ischemia-modified albumin levels in children with steroid-sensitive nephrotic syndrome

Objective:

Growing evidence shows that oxidative stress plays an important role in the development and progression of nephrotic syndrome (NS). In this study, we aimed to examine serum IMA levels as an indicator of oxidative stress in children with steroid-sensitive NS (SSNS) in remission and relapse.

Methods:

This cross-sectional study was carried out at the Pediatric Nephrology Unit of Sanliurfa Training and Research Hospital, Sanliurfa, Turkey, from April 2019 to December 2019. In this study Serum IMA and albumin levels were determined in 70 children with SSNS and 45 healthy controls. Among the children with SSNS, 50 were in remission and 20 were in relapse. Then, adjusted IMA levels were calculated from the IMA/albumin ratio.

Results:

IMA and adjusted IMA levels significantly increased and albumin significantly decreased in children with SSNS in relapse and remission compared with those of the healthy controls. Moreover, these alterations were more prominent in the relapse group than in the remission group. IMA was inversely correlated with albumin in children with SSNS (r= −0.881, p= <0.001).

Conclusions:

Our findings demonstrated that elevated IMA and adjusted IMA levels observed in patients with SSNS were associated with increased oxidative stress and could indirectly reflect the degree of oxidative damage in glomerular structures.

Curcumin, as a pleiotropic agent, improves doxorubicin-induced nephrotic syndrome in rats

ETHNOPHARMACOLOGICAL RELEVANCE

Curcumin, a phenolic compound extracted from the rhizome of turmeric (Curcuma longa L.), has been reported to have broad biological functions including potent antioxidant and renoprotective effects. It has been reported that Curcumin has a certain protective effect on the kidney. However, its mechanism of action needs further study.

AIM OF THE STUDY

The present research aims at investigating the therapeutic effects and its underlying mechanism of curcumin on NS.

MATERIALS AND METHODS

The conditionally immortalized mouse podocyte cell line was utilized to evaluate the podocyte-protective effect of curcumin and its effects on NF-κB pathway and Nrf2/ARE pathway in podocyte in vitro. Furthermore, the DOX-induced NS rats were utilized to investigate the therapeutic effects and its underlying mechanism of curcumin against NS in vivo.

RESULTS

The consequences of this study revealed that curcumin activated Nrf2, inhibited NF-κB pathway and up-regulated podocin in DOX-induced podocyte. Further research results showed that curcumin can considerably alleviate proteinuria and improve hypoalbuminemia in NS rats, and lower blood lipid levels to alleviate hyperlipidemia in NS rats, indicating that curcumin has significant therapeutic effects on rat NS. Further observation by electron microscopy and detection showed that curcumin can improve renal function and podocyte injury, which may be related to the repairment of mRNA expression and podocin protein. Interestingly, the results of the blood rheology test showed that curcumin can effectively reduce whole blood viscosity (WBV) and plasma viscosity (PV), and reduce hematocrit (Hct). In addition, the oxidative stress state of kidney in NS rats was considerably reversed by curcumin, which may be achieved by activating Nrf2 and increasing the expression of antioxidant enzymes HO-1, NQO-1. We also found that NF-κB pathway is activated in the kidney of NS rats, and curcumin can inhibit the activation of NF-κB by down-regulating the expression of NF-κB p65, reducing the level of p-IκBα and up-regulating the expression of IκBα.

CONCLUSION

These findings suggest that curcumin, as a multifunctional agent, exerts a protective effect on DOX-induced nephrotic syndrome in rats, which provides a pharmacological basis for the further development of curcumin and also provides a basis for the advantages of multi-targeted drugs in the processing of NS.

NOX-mediated impairment of PDGF-induced DNA synthesis in peripheral blood lymphocytes of children with idiopathic nephrotic syndrome

BackgroundCellular oxidative stress, inflammatory responses, and immunogenic events are involved in pathogenesis of idiopathic nephrotic syndrome (INS); however, the exact mechanism remains unknown. We examined NADPH oxidase (NOX) activity and platelet-derived growth factor (PDGF)-induced DNA synthesis in peripheral blood lymphocytes (PBL) of patients with INS.MethodsPBL from 15 patients with INS and 15 age- and gender-matched controls were isolated, and enzyme activities of NOX, catalase, and superoxide dismutase (SOD) were measured along with the assay of malondialdehyde levels and bromo-deoxyuridine incorporation. Protein expression of NOX-1 was measured using western blot analysis.ResultsPatients with INS had significantly (P<0.01) higher NOX activity and increased protein expression of NOX-1 in PBL as compared with controls. Catalase and SOD activities were markedly lower with lipid peroxide levels significantly (P<0.01) increased in patients with INS. Ex vivo DNA synthesis in PDGF-stimulated PBL was significantly (P<0.01) reduced in patients with INS; however, diphenyliodonium, an inhibitor of NOX, markedly corrected impairment in growth factor-induced BrdU incorporation.ConclusionsThese results show that NOX activation might have a role in regulation of lymphocytic activity in patients with INS through the impairment of PDGF mitogenic function and might contribute toward pathogenesis of nephrotic syndrome.

Plasma levels of oxidative stress in children with steroid-sensitive nephrotic syndrome and their predictive value for relapse frequency

BACKGROUND

Oxidative stress has been reported to play an important role in children with primary nephrotic syndrome (PNS). However, the results of previous studies are controversial.

METHODS

Forty children with steroid-sensitive nephrotic syndrome (SSNS) and 20 age- and sex-matched healthy controls were enrolled. Patients were followed-up for 12-18 months and divided into three subgroups: frequent relapse (n = 10), non-frequent relapse (n = 12), and non-relapse (n = 18). The plasma levels of advanced oxidation protein products (AOPP), malondialdehyde (MDA), and superoxide dismutase (SOD) were tested in controls and patient group at first presentation and after 4 weeks of steroid treatment.

RESULTS

Patients had higher AOPP and MDA levels but lower SOD compared with controls. AOPP levels were significantly higher in the frequent relapse subgroup compared with the non-frequent relapse and non-relapse subgroups, respectively. No significant differences were found in the plasma levels of MDA and SOD among the three subgroups. AOPP >87.55 μmol/l before steroid treatment and AOPP >78.5 μmol/l after 4-week steroid treatment were positively correlated with the relapse frequency in patients with SSNS.

CONCLUSIONS

Children with SSNS have oxidative stress. The plasma levels of AOPP before and after 4-week steroid treatment may predict whether patients with SSNS will relapse frequently.

Salvianolic acid A as a multifunctional agent ameliorates doxorubicin-induced nephropathy in rats

Nephrotic syndrome (NS) is still a therapeutic challenge. To date there is no ideal treatment. Evidence suggest that multidrug therapy has more effect than monotherapy in amelioration of renal injury. Salvianolic acid A (SAA) is the major active component of Salviae Miltiorrhizae Bunge. Previous studies have demonstrated that SAA is a multi-target agent and has various pharmacological activities. The pleiotropic properties of SAA predict its potential in the treatment of NS. The study investigated the effect of SAA on doxorubicin-induced nephropathy. The kidney function related-biochemical changes, hemorheological parameters and oxidative stress status were determined, and histological examination using light and transmission electron microcopies and western blot analysis were also performed. Results revealed that treatment with SAA alleviated histological damages, relieved proteinuria, hypoalbuminemia and hyperlipidemia, reduced oxidative stress, as well as improving hemorheology. Furthermore, SAA restored podocin expression, down-regulated the expression of NF-κB p65 and p-IκBα while up-regulating IκBα protein expression. Overall, as a multifunctional agent, SAA has a favorable renoprotection in doxorubicin-induced nephropathy. The anti-inflammation, antioxidant, amelioration of podocyte injury, improvement of hemorheology and hypolipidemic properties may constituent an important part of its therapeutic effects. All these indicate that SAA is likely to be a promising agent for NS.

Are oxidized low-density lipoprotein and C-reactive protein markers of atherosclerosis in nephrotic children?

BACKGROUND

Lipid disorders are known to be linked to disturbance in oxidative reactions and play an important role in the progression and complications of idiopathic nephrotic syndrome (INS).

AIMS

The aim of this study was to assess oxidized low-density lipoprotein (oxLDL), high-sensitive C-reactive protein (hs-CRP) serum concentrations and other parameters of lipid metabolism in children with INS during relapse and remission of proteinuria.

METHODS

The examination was performed on 23 children and adolescents diagnosed with INS. Reference group consisted of 22 participants. The study was carried out twice: in the relapse of INS (A) and in remission of proteinuria during glucocorticoid treatment (B).

RESULTS

OxLDL was higher in INS patients, in both examinations when compared with reference participants. hs-CRP showed no differences between nephrotic and healthy children. We found higher concentration of oxLDL in children, who where frequent relapsers. Cholesterol, triglycerides/high density lipoprotein cholesterol and platelets were higher in INS patients (both A and B) in comparison with healthy children.

CONCLUSIONS

We observed presence of pro-atherogenic lipid profile in INS. Elevation of oxLDL may reflect increased oxidative stress and higher risk of atherosclerosis in INS, therefore it seems to be relevant to find patients of risk of atherosclerosis to consider lipid lowering treatment with antioxidants.

Serum levels of malondialdehyde, vitamin C and E in idiopathic nephrotic syndrome: a meta-analysis

It is well documented that oxidative stress is involved in the pathogenesis of idiopathic nephrotic syndrome (INS). Malondialdehyde (MDA) is a measurement of lipid oxidation; vitamin C and E are important components of antioxidants. However, the association between MDA, vitamin C or E levels and INS remains elusive. A meta-analysis was performed to investigate the alteration of serum levels of MDA, vitamin C and E in INS compared with controls. Eight studies were included in our meta-analysis according to predefined criteria. Active INS patients demonstrated significantly higher level of serum MDA (SMD: 2.13, 95% CI: 1.511 to 2.749, p < 10(-4)), markedly lower levels of serum vitamin C (SMD: -1.449, 95% CI: -2.616 to -0.281, p = 0.015) and E (SMD: -1.45, 95% CI: -2.544 to -0.356, p = 0.009) compared with those in controls. Active steroid-sensitive nephrotic syndrome (SSNS) patients showed comparable levels of serum vitamin C and E to those in controls. INS subjects in the remission stage demonstrated significantly higher level of serum MDA (SMD: 1.028, 95% CI: 0.438 to 1.617, p < 10(-4)), markedly lower level of serum vitamin C (SMD: -2.235, 95% CI: -3.048 to -1.421, p < 10(4)) and similar level of serum vitamin E compared with those in controls. No significant publication bias was observed. In conclusion, the disorder of MDA and vitamin C persists in the remission stage of INS. It seems that the serum levels of vitamin C and E is associated with the responsiveness of INS to steroids. However, more studies should be performed in the future.

Subclinical cardiovascular disease and its association with risk factors in children with steroid-resistant nephrotic syndrome

BACKGROUND

The aim of this study was to evaluate the presence of subclinical cardiovascular disease (CVD) and its relation to risk factors in pediatric patients with steroid-resistant nephrotic syndrome (NS).

METHODS

Thirty-seven patients with normal renal function were compared with 22 healthy controls regarding the presence of subclinical CVD. Measurements included aortic pulse wave velocity (PWV), carotid intima media thickness (IMT), and left ventricular mass (LVM). Patients were additionally assessed for blood pressure (BP) pattern and the presence of hypertension by 24-h ambulatory blood pressure monitoring.

RESULTS

Compared with the controls, patients had significantly higher mean aortic PWV-standard deviation scores (SDS), mean carotid IMT-SDS, and LVM index (p < 0.001 for all). Increased aortic PWV was noted in 5 % of patients, increased carotid IMT in 22 %, and increased LVM index in 19 %. Five patients (14 %) were hypertensive, and mean BP indexes, SDS, and BP loads during nighttime were significantly higher than those during daytime (p < 0.001 for all). Multivariate analysis revealed a significant relationship between PWV-SDS and ferritin (R(2) = 0.269, p = 0.006) and between carotid IMT-SDS and proteinuria (R(2) = 0.141, p = 0.022). The LVM index was independently associated only with higher body mass index SDS (R(2) = 0.317, p < 0.001). In addition, six patients (16 %) had multiple abnormal subclinical CVD markers, and increased subclinical CVD risk was independently associated only with higher low-density lipoprotein cholesterol (R(2) = 0.292, p = 0.044).

CONCLUSIONS

Based on these results, steroid-resistant NS children generally are at high risk of cardiovascular complications, but the increased risk is likely to be multifactorial.

Evaluation of paraoxonase activity in children with nephrotic syndrome

Background

It has been proposed that reactive oxygen species (ROS) is involved in the pathogenesis of various diseases. Paraoxonase, a high-density lipoprotein associated enzyme, prevents low-density lipoproteins from oxidation.

Objectives

The aim of the present study was to investigate the serum activities of paraoxonase-1 (PON-1), and aryleterase (ARE) as well as total antioxidant capacity (TAC) in children with nephrotic syndrome in acute and remission phase.

Patients and Methods

The study consisted of 20 patients in acute and remission phases and 23 healthy controls. PON-1 and ARE activities were determined spectrophotometrically using paraoxone and phenyacetate as substrate, respectively. TAC was measured using ferric reducing ability of plasma (FRAP).

Results

The levels of PON, ARE, and TAC were significantly lower in acute phase of nephrotic syndrome compared with the remission phase. The levels of PON, ARE and TAC increased in remission phase.

Conclusions

Our results revealed that the determination of paraoxonase activity might be a biomarker for responses to nephrotic syndrome treatment, which needs to be fully clarified.

Serum albumin level accurately reflects antioxidant potentials in idiopathic nephrotic syndrome

BACKGROUND

Recent observation revealed that serum albumin plays an important role in the host defense mechanism as it is one of the important antioxidants. This study was conducted to investigate whether hypoalbuminemia contributes to a decreased biological antioxidant potentials (BAP) in idiopathic nephrotic syndrome (INS).

METHODS

Fifty three heparinised blood samples were obtained from 8 patients with INS (median 13.5 years). Eighteen samples from 6 patients with Henoch-Schönlein purpura (HSP median 7 years) were served as control. Intravenous human albumin preparation was also applied for comparison. Measurement of BAP in blood and human albumin preparation was determined by a newly developed devise called FRAS4(®). Comparison among groups and relationships between BAP and albumin concentrations or c-reactive protein (CRP) were studied by Kruskal-Wallis test and Spearman rank correlation test, respectively.

RESULTS

Serum levels of BAP was significantly lower in patients with nephrotic relapse than those in patients with nephrotic remission or HSP. BAP correlated well with serum albumin levels. Positive relationship was also found between concentration of albumin in human preparation and BAP. Weakly positive CRP sera disclosed both hypoalbuminemia and low BAP.

CONCLUSION

Our results suggest that decreased antioxidant potentials caused by hypoalbuminemia in INS may contribute to an aberrant immunity.

Antioxidant status of children with idiopathic nephrotic syndrome

The production of free radicals can cause renal injury and play an important role in the pathogenesis of idiopathic nephrotic syndrome. Markers of reactive oxygen species (ROS) were evaluated in 48 patients with active nephrotic syndrome (ANS) and 30 age- and gender-matched healthy children. Plasma malondialdehyde (MDA), protein carbonyl, nitrite, copper, zinc, selenium, ascorbic acid, and superoxide dismutase (SOD) levels were estimated in patients with ANS and controls. Measurements were repeated in 39 cases after achievement of remission, and in 10 other children who were in remission of >6 months' duration. Plasma MDA and nitrite levels were significantly higher and selenium was lower in ANS patients compared with controls. Plasma protein carbonyl, copper ascorbic acid, zinc, and superoxide dismutase levels were comparable in ANS patients and controls. Plasma copper level was significantly higher in active cases than in the remission and long-term remission groups. Selenium value showed a rise and then normalized in long-term remission. Among different sub-groups of ANS, no significant differences were found in the levels of various parameters, except plasma selenium, which was significantly lower in first-attack nephrotic syndrome (FANS) in comparison to infrequently relapsing nephrotic syndrome (IRNS) and frequently relapsing nephrotic syndrome (FRNS) patients. Thus, we observed evidence of oxidative stress and impaired antioxidant defense during acute nephrotic syndrome. Antioxidant status recovered completely only during long-term remission.

Diagnostic and Therapeutic Significance of the Oxidative Stress Parameters in Children

Pharmacotherapy of pediatric diseases represents a major challenge considering that the majority of medicines in everyday practice have not been pediatrically evaluated. The efficacy of therapy depends to a large extent on the knowledge of pathophysiological processes in the children organism at different ages. Therefore, research in that direction is of the utmost importance. An imbalance in the production of free oxygen/nitrogen species and parameters of antioxidative protection is a significant factor in many diseases (e.g. heart failure, pulmonary hypertension, asthma, neonatal sepsis, cancer etc.) in children of different age groups. Reactive oxygen/nitrogen species serve as cell signaling molecules for normal biologic processes. An increase in their generation can cause damages which can disrupt normal physiological cellular processes and eventually cause cell death. This review outlines the previous assessments of oxidative stress parameters in children of different ages for some diseases. Also, the potential diagnostic and therapeutic possibilities for the oxydative stress parameters in children have been considered.

Diagnosis of Wilson's disease: a comprehensive review

Wilson's disease is an autosomal recessive disorder of copper metabolism. The culprit gene is ATP7B. The worldwide prevalence is about 1 in 30,000, which may vary by population. Higher prevalence rates were reported using more sensitive screening techniques and pilot population screening. Typical presentations include neuropsychiatric and hepatic dysfunction, whereas atypical presentations are protean. Diagnosis relies on a high clinical suspicion, typical neurological symptoms, presence of Kayser-Fleischer rings, and reduced serum ceruloplasmin concentration. The conventional value of < 0.20 g/l is not a universal diagnostic value. Age of the subjects and analytical variations should be considered when interpreting these levels. Patients with inconclusive findings require further investigations such as 24 h urinary free-copper excretion, penicillamine challenge test, liver copper measurement, and detection of gene mutations. Direct molecular diagnosis remains the most decisive tool. Other tests such as non-ceruloplasmin-bound copper are unreliable. Potential pitfalls and limitations of these diagnostic markers are critically reviewed in this paper. The mainstays of therapy are trientine, penicillamine, and/or zinc. Liver transplantation is lifesaving for those with advanced disease. Ceruloplasmin oxidase activity and serum free-copper concentration should be monitored in patients on long-term de-coppering therapy to prevent iatrogenic copper deficiency.

Anti-oxidant status in relation to lipoproteins, leptin and pro-inflammatory cytokines in children with steroid-sensitive nephrotic syndrome

BACKGROUND

Reactive oxygen species and cytokines are reported to play a role in the proteinuria of nephrotic syndrome. The aim of this study was to investigate indirect evidence of oxidant activity together with leptin, lipoproteins and pro-inflammatory cytokines in children with steroid-sensitive nephrotic syndrome.

METHODS

A total of 40 children with steroid-sensitive nephrotic syndrome (20 with newly onset or relapse comprised group I and 20 in remission while receiving steroids comprised group II) and 20 sex and age matched healthy control children were included. The following indirect parameters of oxidant activity were determined: serum malondialdehyde, erythrocyte superoxide dismutase, catalase and whole-blood-reduced glutathione. Serum leptin, lipids and lipoproteins were also determined.

RESULTS

Similar glutathione, increased malondialdehyde levels and decreased superoxide dismutase and catalase activity were observed in group I patients compared with controls. There was no significant difference in these variables between group I and group II (P >0.05). Tumour necrosis factor-alpha and interleukin-6 concentrations were similar in patients and controls. Concentrations of interleukin-1beta and interleukin-8 were higher in the active phase of nephrotics compared with controls (P <0.05). Significant positive correlations were found between malondialdehyde and interleukin-1beta, interleukin-6, leptin and lipoprotein (a) (P <0.05). There were significant negative correlations between anti-oxidants and leptin, lipoprotein (a) and several cytokines (P <0.05).

CONCLUSIONS

Changes in the concentrations of malondialdehyde, superoxide dismutase, catalase and glutathione are compatible with increased amounts of oxidation in steroid-sensitive nephrotic syndrome. Leptin and pro-inflammatory cytokines may be related to excessive protein permeability in nephrotic syndrome.

Increased protein glycation in non-diabetic pediatric nephrotic syndrome: possible role of lipid peroxidation

BACKGROUND

Malondialdehyde (MDA), ascorbic acid and reduced glutathione (GSH) have been reported to play a possible role in glycation of proteins. This study was performed to evaluate this correlation in nephrotic syndrome patients by comparing the levels of fructosamine with MDA, ascorbic acid and GSH.

METHODS

Fifteen children with nephrotic syndrome during relapse and 10 age- and sex-matched healthy controls were enrolled for this study. Whole blood GSH, plasma MDA, total ascorbic acid and fasting glucose were analyzed in both the groups. Partial correlation analysis was performed to predict the independent association of MDA, ascorbic acid and GSH on fructosamine.

RESULTS

Plasma MDA and fructosamine levels were found to be increased in nephrotic syndrome patients when compared with controls. Plasma ascorbic acid and whole blood GSH were decreased in nephrotic group vs. healthy controls. Partial correlation analysis showed a significant positive correlation between fructosamine and MDA.

CONCLUSIONS

Present data point to a possible involvement of MDA in the glycation of protein in non-diabetic nephrotic syndrome patients, and provide support for the potential use of an antioxidant therapy in these patients.