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Background: The pathophysiological mechanisms crucial in the development of nephrotic syndrome (NS) in the pediatric population are still not fully understood. This study aimed to investigate the relationship between hypertension, oxidative stress, and inflammation in pediatric patients during the acute phase of the disease. Methods: The study included 33 children, aged 2 to 9 years, with nephrotic syndrome. Blood samples were collected during the acute phase and remission. Parameters of oxidative status were determined, including total oxidative status (TOS), advanced oxidation protein products (AOPP), prooxidant-antioxidant balance (PAB), sulfhydryl groups (-SH), paraoxonase 1 (PON1), and total antioxidant status (TAS) in serum, measured spectrophotometrically. Inflam - matory parameters such as pentraxin 3 (PTX3), leptin, program med cell death ligand 1 (PD-L1), and E-cadherin were determined using enzyme-linked immunosorbent assay (ELISA). Results: Patients with nephrotic syndrome and hypertension had significantly higher levels of advanced oxidation protein products and total antioxidant status (p=0.029 and p=0.003, respectively). During the acute phase of the disease, lower activity of sulfhydryl groups and paraoxonase 1 was observed compared to remission (p

Introduction. Congenital nephrotic syndrome (CNS) is a severe disease complicated by hemodynamic instability, infections, thrombosis, growth disorder and progressive renal failure leading to end-stage kidney disease within a few years. The mutations of NPHS1 encoding nephrin is the most common cause of the CNS. The aim of this paper was to present a patient with NPHS1 homozygous Ser350Pro missense mutation that unexpectedly caused a mild clinical course of CNS. Case outline. We present a female patient who was diagnosed with severe nephrotic syndrome at 2.5 months of age. While waiting for the result of the genetic analysis, she was treated unsuccessfully with corticosteroids and angiotensin converting inhibitor (ACEI) four weeks, and then under Cyclosporine A (CsA) and ACEI she achieved partial remission within three months. Initially, the milder clinical course was explained by the positive effect of CsA, but as partial remission persisted even after the discontinuation of this drug, it remains unclear what influenced the improvement of the clinical course of the disease. At the time of writing this paper, the patient was 10.9 years old with normal serum creatinine, normal blood pressure and non-nephrotic proteinuria. Conclusion. NPHS1 homozygous Ser350Pro missense mutation may be presented by a mild clinical course of CNS. Further studies are needed to clarify a more predictive CNS genotype/phenotype relationship.

Podocytopathies include a wide spectrum of primary or secondary glomerular diseases that are the consequence of the podocyte injuries. The damage of podocytes can occur due to congenital or acquired disorders of podocyte transcriptional regulators, altered components of the slit diaphragm complex, abnormal assembly, or function of the actin-based cytoskeleton, dysfunction of membranes or cytoplasmic proteins, and mitochondrial injury. Podocytes reactions to injurious stimulus include FP effacement, apoptosis, and loss of podocyte, developmental arrest associated by mild proliferative activity, and dedifferentiation with moderated proliferation. Based on histopathological findings, podocytopathy may be diagnosed such as minimal change nephropathy; focal segmental glomerulosclerosis, diffuse mesangial sclerosis, or collapsing glomerulopathy while in relation to their etiology can be categorized as idiopathic, genetic, and reactive. Podocytopathies may be diagnosed due to podocyte morphological changes, immunohistochemistry, circulating and urine biomarkers, and genetic analysis. The primary clinical focus in prevention should be to reduce the factors that can damage the podocytes and cause hyperperfusion/hypertrophy of the glomerulus. Nowadays, control of systemic and intra glomerular hypertension by pharmacological blockade of angiotensin II is a central in the prevention strategy, while regeneration of podocytes by stem cells is therapeutic strategy of the future.

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Pediatric renal stone disease is manifested as nephro/urolithiasis (UL) and/or nephrocalcinosis (NC). Compared to adults, UL in childhood is less common, and it is believed to be around 5% in industrialized countries, while the incidence of NC is even lower except for critically ill premature infants in whom it may reach 64%. The formation of UL and NC is caused by increased concentration of relevant solutes, and their aggregations and adherence to the renal tubules cell is facilitated by factors such as urine pH, inability of natural crystallization inhibitors, stasis of urine as well as renal tubule damage. UL is associated with significant morbidity because of pains, susceptibility to urinary tract obstruction and infections, and the necessity of surgical procedures. NC is usually asymptomatic but is frequently progressive, and more often than UL, leads to chronic renal failure. Although other imaging modalities can be used in the diagnosis of renal stone disease, ultrasound has the least risk and is most cost-effective. The majority cases of UL and NC in children are of metabolic origin and thus they are prone to recurrence and may cause chronic renal damage. Therefore, they deserve, even after their initial presentation a detailed metabolic evaluation. Genetic source of renal stone disease is suspected in the following conditions: early onset, familial prevalence, familial consanguinity, multiple or recurrent stones, and NC. For all UL/NC etiologies early identification and personalized treatment of the basic disorder is the most important.

Introduction. Recently, inactivation mutations of CYP24A1, the gene encoding vitamin D 24-hydroxylase, were identified in hypercalciuric nephrolithiasis and nephrocalcinosis. Here, we describe а long-term follow-up of a patient with hypercalciuric nephrolithiasis caused by CYP24A1 mutations. Case outline. A male Montenegro patient first presented with microhematuria at the age of five years. Hypercalciuria had been documented and for some time he had been treated by hydrochlorothiazide. After 12 years, the patient presented with macrohematuria and left-sided nephrolithiasis. He was found to have intermittent borderline hypercalcemia, suppressed parathyroid hormone, hypercalciuria, and increased plasma 25-hydroxy vitamin D [25(OH)D3]. The patient denied any vitamin D supplementation and all other causes of hypercalcemia were ruled out. Positive family history for nephrolithiasis (both parents and grandmother) and similar biochemical abnormalities detected in father and son pointed to an inherited disorder. A homozygous mutation in CYP24A1 (E143del) was found in the patient and his father, while mother is heterozygous. During the follow-up of two years, the patient underwent four extracorporeal shockwave lithotripsies, he was advised to increase water intake, and to avoid sunlight exposure. At the end of follow-up he was asymptomatic, and his renal ultrasound was normal, as well as his renal function, but hypercalciuria and low parathyroid hormone levels persisted. Conclusion. Hypervitaminosis D should be considered in children with idiopathic hypercalciuria, nephrolithiasis and nephrocalcinosis of unknown etiology. Recognition of CYP24A1 mutations in these patients may help to decrease the serious consequences by avoiding vitamin D supplements and excessive sun exposure. [Project of the Serbian Ministry of Education, Science and Technological Development, Grant no. 175079]

Introduction/Objective. Jeune syndrome (JS) is a rare hereditary ciliopathy characterized by asphyxiating thoracic dystrophy, shortened limbs and brachydactyly. Extraskeletal anomalies such as chronic renal failure (CRF), hepatic fibrosis, and retinitis pigmentosa may be a part of the JATD phenotype. The aim of this study is to present long-term follow-up of JS patients with early progressive kidney disease. Methods. This is a retrospective study of pediatric patients with JS and CRF who were treated at the University Children’s Hospital between January 1980 and December 2014. The patients’ data were retrospectively reviewed from the medical records. Results. There were thirteen patients from 11 families, five girls and eight boys mean aged 4.3 years at the time of diagnosis. All of the patients had characteristic skeletal findings, retinal degeneration and an early onset of CRF at age range from 1.5 to 7 years. Five patients had neonatal respiratory distress and congenital liver fibrosis was diagnosed in five patients. One patient died due to complications of CRF, while others survived during follow-up of mean 11 years. IFT140 mutations were found in four genetically tested patients. Conclusion. The average incidence rate of JS with renal phenotype in Serbia was about 0.2 per one million of child population. Long-term survival of JS patients depends on renal replacement therapy, while skeletal dysplasia, growth failure, respiratory and eyes problems have impact on the patients’ quality of life.

Introduction. Congenital nephrotic syndrome (CNF) is manifested at birth or within the first three months of life. The Finnish-type of CNF is caused by the mutation of the NPHS1 gene, which encodes nephrin in the podocyte slit diaphragm. It is a very severe disease, for which immunosuppressive therapy is not advised. Here we describe a patient with CNF who responded to CsA by partial remission. Case outline. A girl aged 2.5 months presented with severe non-syndromic steroid-resistant nephrotic syndrome. She needed aggressive support including daily albumin infusions and diuretics. Substitution of vitamin D, thyroxin, and anticoagulants were regularly administered. She was also treated with angiotensin converting enzyme inhibitor, without clear benefits regarding proteinuria. In addition, she received intravenous gamma-globulin replacement therapy and antibiotics during frequent infections. While waiting for the results of genetic analyses and faced with many problems related to daily albumin infusions, infections, and thromboembolic complications, cyclosporine A (CsA) was introduced as an alternative to early nephrectomy and consequent renal failure. The patient responded by partial remission and CsA treatment continued at home without the albumin infusions. After almost five years since the beginning of the treatment, the patient’s renal function remains unreduced. Conclusion. Our case demonstrates that CsA can induce partial remission in patients with genetic forms of steroid-resistant nephrotic syndrome without influencing the glomerular filtration rate. However, its long-term effect and safety should carefully be monitored. [Project of the Ministry of Education, Science and Technological Development of Republic of Serbia, Grant No. 175079]

Background: Unfavorable lipid profile presents one of most important risk factor for cardiovascular disease in renal pathology. Myeloperoxidase (MPO) as enzyme which oxidizes lipoproteins and paraoxonase1 (PON1) as anti-oxidative enzyme have been involved in pathogenesis of cardiovascular disease. In the present study we sought to assess oxidative stress status, lipoprotein subclasses distribution as well as functionality of high density lipoprotein (HDL) trough M PO/PON1 ratio in children with chronic kidney disease (CKD) and children after renal transplantation. Methods: PON1 activity and oxidative stress parameters were measured spectrophotometrically, while MPO concentration was determined using immunoassay. Separation of lipoprotein subclasses was performed by vertical gradient gel electrophoresis in 19 children with different stage of CKD and 19 post-transplantation patients (PT). Results: CKD patients had increased MPO/PON1 ratio and higher prevalence of smaller HDL subclasses when compared to PT subjects. Also, there was a significant positive correlation between MPO level and MPO/PON1 ratio with relative proportion of smaller HDL subclasses. Conclusions: Children with CKD have impaired HDL distribution that is improved after kidney transplantation. Since that measurement of HDL distribution and functionality are not routinely available, MPO/PON1 ratio may be useful marker that could provide necessary information.

Background: The aim of this study was to explore oxidative stress status, especially the enzyme myeloperoxidase in children with end-stage renal disease. Also, we investigated possible associations between the atherogenic index of plasma and these parameters. Methods: Lipid status parameters, oxidative stress status parameters, and myeloperoxidase concentration were measured in the sera of 20 children in the last stage of chronic renal disease (ESRD) and 35 healthy children of matching age and sex. The Atherogenic Index of Plasma (AIP) was calculated according to the appropriate equation. Results: We did not find any significant differences in myeloperoxidase concentrations between the investigated groups (p=0.394). Oxidative stress parameters were, however, significantly higher in the patient group (p

The hemolytic-uremic syndrome (HUS) is characterized by microangiopathic hemolytic anemia, thrombocytopenia, and acute kidney injury (AKI). The major cause of HUS in childhood (>90%) is infection with verocytotoxin (Shiga-like toxin - “Stx”)-producing bacteria, usually enterohemorrhagic Escherichia coli (VTEC/STEC). The infection may be transmitted by the consumption of undercooked meat, pasteurized dairy products, contaminated vegetables, fruits and water, or by contact with STEC diarrhea. After an incubation period of three to eight days, patients commonly develop bloody diarrhea followed in 5-22% by HUS that may be complicated by central nervous system, pancreatic, skeletal, and myocardial involvement. HUS is one of the main causes of AKI in children in Europe. The management of HUS includes the usual treatment of children with AKI. Transfusion with packed red blood cells is needed in case of a severe anemia, while platelet transfusions are limited to the need for a surgical procedure or in active bleeding. Currently, there is no consensus on the use of antibiotic therapy. Treatment with plasma and/or plasma exchange has not been proven beneficial in STEC-HUS. Eculizumab has been used for the treatment of STEC-HUS, but the value of this treatment remains to be determined. The mortality of HUS is reported to be 3-5%. About 12% of patients will progress to end-stage renal failure within four years and about 25% will have long-term complications, including hypertension, proteinuria, renal insufficiency, and insulin-dependent diabetes mellitus. Transplantation can be performed without increased risk for the recurrence of the disease.

Introduction. The causes of acute tubulointerstitial nephritis can be grouped into four broad categories: medications, infections, immunologic diseases, or idiopathic processes. Here we report a 17-year-old female who developed acute kidney injury (AKI) due to granulomatous interstitial nephritis (GIN) associated with influenza A: H1N1 infection. Case Outline. The illness presented after two weeks of respiratory tract infection, skin rash and hypermenorrhea. On admission the patient was febrile, with bilateral pedal edema, macular skin rash, and auscultatory finding that suggested pneumonia. Laboratory investigations showed normocytic anemia, azotemia, hematuria and proteinuria. Renal ultrasound was normal. Antinuclear antibodies, antineutrophil cytoplasmic antibodies, lupus anticoagulant, antiphospholipid antibodies were negative with normal complement. Urine cultures including analysis for Mycobacterium tuberculosis were negative. The diagnosis of influenza A: H1N1 infection was made by positive serology. A kidney biopsy showed interstitial nephritis with peritubular granulomas. Glomeruli were normal. Staining for immunoglobulins A, M, G, and E was negative. The girl was treated with oseltamivir phosphate (Tamiflu; Genentech, Inc., South San Francisco, CA, USA) for five days, as well as with tapered prednisone after a starting dose of 2 mg/kg. The treatment resulted in a complete remission during two years of follow-up. Conclusion. We present a severe but reversible case of GIN and AKI associated with influenza A: H1N1 infection. Although a causal effect cannot be confirmed, this case suggests that influenza A: H1N1 should be considered in the differential diagnosis of GIN manifested with AKI in children. [Projekat Ministarstva nauke Republike Srbije, br. 175079]

A normal development of lower urinary tract function control evolves from involuntary bladder empting (incontinence) during infancy to daytime urinary continence, and finally a successful day and night continence that is generally achieved by the 5th to 7th year of age. This gradual process primarily depends on the progressive maturation of the neural control of the lower urinary tract, but it is also influenced by behavioral training that evolves through social support. Functional voiding disorders (bladder dysfunction) are common problems during childhood. They are present in 5-15 % of general pediatric population, and in one-fifth of school-age children or in over one-third of patients of the pediatric urologist or nephrologist. More than half of children with bladder dysfunction have vesicoureteral reflux, and more than two-thirds have recurrent urinary tract infections. There is also a frequent association of bladder dysfunction with constipation and encopresis (dysfunctional elimination syndrome). Bladder dysfunction may cause a permanent damage to the upper urinary tract and kidneys. In addition, urinary incontinence, as the most common manifestation of bladder dysfunction can be the cause of major stress in schoolage children and have a negative effect on the child’s feeling of self-esteem. Thus, a timely detection and treatment of this group of disorders in children is highly significant.

Introduction: Childhood obesity is related to cardiovascular diseases and diabetes mellitus type 2 in later life. Resistin, an adipokine primarily secreted by monocytes and tissue macrophages in humans, is considered to be associated with these conditions. The Aim: To examine the correlations between resistin concentration and anthropometric parameters, lipid status, inflammatory markers and parameters of insulin resistance in obese children and adolescents. Material and Methods: The study included 66 patients (40 boys, 26 girls), which underwent anthropometric measuring and laboratory testing (glucose level, total cholesterol, high-density lipoprotein cholesterol (HDL-cholesterol), low-density lipoprotein cholesterol (LDL-cholesterol), triglycerides, uric acid, high-sensitivity C-reactive protein (hsCRP) and glycosylated hemoglobin (HbA1c). Insulin resistance was estimated with HOMA-IR (homeostasis model assessment of insulin resistance). Results: We determined that 63.3% of our patients had dyslipidemia, while hsCRP and uric acid levels suggested an ongoing inflammation. We established that there was a correlation between resistin concentration and waist to hip ratio (WHR) (r=0.294, p

Despite recent advances in the management of children with chronic renal disease (CRD), growth retardation remains its most visible comorbid condition. Growth retardation has adverse impact on morbidity and mortality rates, quality of life and education, and in adult patients on job family life, and independent leaving accomodation. Pathophysiology of impaired growth in CRD is complex and still not fully understood. The following complications are: anorexia, malnutrition, inflammation, decreased residual renal function, dialysis frequency and adequacy, renal anemia, metabolic acidosis, fluid/electrolyte imbalance, renal osteodistrophy, growth hormone (GH) and insulin-like growth factor -1 (IGF-1) resistance. Malnutrition is most frequent and most important factor contributing to the degree of growth retardation in infancy. The degree of renal dysfunction is the major determinant of variability in growth from third year of age until puberty onset, while in puberty hypergonadotropic hypogonadism has negative effect. The main factors that influence growth after renal transplantation are the age of the recipient and glucocorticoid drugs dosage with negative effect and allograft function with positive effect. In order to improve growth in children with CRD it is necessary to include: diet with optimal caloric intake, correction of fluid/ electrolyte imbalance, correction of acidosis, renal osteodistrophy and anemia. If growth velocity is insufficient to normalize growth, it is necessary to start recombinant human GH (rhGH) therapy at 0.05 mg/kg per day (0.35 mg/kg per week or 28 IU/m2 per week) administered by subcutaneous injection.

Acute kidney injury (AKI) is a clinical condition considered to be the consequence of a sudden decrease (>25%) or discontinuation of renal function. The term AKI is used instead of the previous term acute renal failure, because it has been demonstrated that even minor renal lesions may cause far-reaching consequences on human health. Contemporary classifications of AKI (RIFLE and AKIN) are based on the change of serum creatinine and urinary output. In the developed countries, AKI is most often caused by renal ischemia, nephrotoxins and sepsis, rather than a (primary) diffuse renal disease, such as glomerulonephritis, interstitial nephritis, renovascular disorder and thrombotic microangiopathy. The main risk factors for hospital AKI are mechanical ventilation, use of vasoactive drugs, stem cell transplantation and diuretic-resistant hypervolemia. Prerenal and parenchymal AKI (previously known as acute tubular necrosis) jointly account for 2/3 of all AKI causes. Diuresis and serum creatinine concentration are not early diagnostic markers of AKI. Potential early biomarkers of AKI are neutrophil gelatinase-associated lipocalin (NGAL), cystatin C, kidney injury molecule-1 (KIM-1), interleukins 6, 8 and 18, and liver-type fatty acid-binding protein (L-FABP). Early detection of kidney impairment, before the increase of serum creatinine, is important for timely initiated therapy and recovery. The goal of AKI treatment is to normalize the fluid and electrolyte status, as well as the correction of acidosis and blood pressure. Since a severe fluid overload resistant to diuretics and inotropic agents is associated with a poor outcome, the initiation of dialysis should not be delayed. The mortality rate of AKI is highest in critically ill children with multiple organ failure and hemodynamically unstable patients.

Renal hypertension is one of the earliest and the most prevalent complications of pediatric chronic kidney disease (CKD). Among renal patients, hypertension is frequently underdiagnosed and undertreated. For casual blood pressure measurement, the best method is auscultatory, while for ambulatory blood pressure measurement, oscillometric method is the most commonly used. Both casual and ambulatory blood pressure measurement provide more powerful means of diagnosing hypertension. Masked hypertension is a condition in which casual blood pressure is normal but ambulatory blood pressure is elevated. The risk of cardiovascular morbidity and mortality is higher with masked hypertension as compared to the controls. Children and adolescents with CKD are at high risk of cardiovascular disease that has been established as the leading cause of death in patients with end stage renal disease. Left ventricular hypertrophy remains the most thoroughly documented form of end-organ damage caused by hypertension in children and adolescents with CKD. Based on clear evidence on the correlation between blood pressure and cardiovascular morbidity, mortality, and renal function, renal hypertension must be aggressively treated. Target blood pressure for patients with renal hypertension should be at low normal values:

Introduction. Post-transplant lymphoproliferative disorder (PTLD) is a heterogeneous group of diseases, characterized by abnormal lymphoid proliferation following transplantation. It is a disease of the immunosuppressed state, and its occurrence is mostly associated with the use of T-cell depleting agents, and also intensification of immunosuppressive regimens. In the majority of cases, PTLD is a consequence of Epstein-Barr virus (EBV) infection and is a B-cell hyperplasia with CD-20 positive lymphocytes. The 2008 World Health Organization classification for lymphoid malignancies divides PTLD into four major categories: early lesions, polymorphic PTLD, monomorphic PTLD and Hodgkin PTLD. The treatment and prognosis depend on histology. The cornerstone of PTLD therapy includes reduction/withdrawal of immunosuppression, monoclonal anti CD-20 antibody (rituximab) and chemotherapy. Outline of Cases. We reported here our experiences with three patients, two girls aged 7.5 and 15 and a 16-year old boy. They had different organ involvement: brain, combined spleen-liver and intestines, respectively. Even though EBV was a trigger of lymphoid proliferation as it was confirmed by histopathology or in cerebrospinal fluid, qualitative EBV-PCR was positive only in one patient at disease presentation. Reduction of immunosuppression therapy was applied in treatment of all three patients, while two of them received rituximab and ganciclovir. They had an excellent outcome besides many difficulties in diagnosis and management of disease. Conclusion. Qualitative EBV-PCR is not useful marker in pediatric transplant recipients. Our suggestion is that patients with the risk factors like T-cell depleting agents, immunosuppressant protocol or increasing immunosuppressive therapy and EBV miss-match with donor must be more accurately monitored with quantitative EBV PCR. [Projekat Ministarstva nauke Republike Srbije, br. 175085]

Introduction. Frasier syndrome (FS) is a genetic form of glomerulopathy, which results from mutations in the Wilms’ tumour suppressor gene (WT1). Proteinuria in FS has been traditionally considered unresponsive to any medication and FS inevitably progresses to end stage renal failure. Case Outline. We present a patient with FS who had atypical clinical manifestation and unusual beneficial antiproteinuric response to renin-angiotensin system (RAS) inhibitors given in combination with indomethacin. After 13 years of follow-up, the patient is now 17-year old with normal renal functions and no proteinuria. Conclusion. RAS inhibitors combined with indomethacin showed beneficial effect in our patient. Thus, this combination might be the initial treatment of patients with FS. If this treatment strategy was not satisfied for at least 3 months, then CsA would be considered to be administered taking account of the nephrotoxicity and the increased risk of malignancy. Further prospective study is required to clarify this issue. [Projekat Ministarstva nauke Republike Srbije, br. OI175079]

Introduction. Urinary tract infection is common in childhood. Depending on the localization of the infection, severity of its clinical presentation and possible acute and long-term complications, it may be described as either acute cystitis or acute pyelonephritis. Objective. The aim of this study was to assess the resistance patterns of uropathogens during the last 5 years in newborns and young children with acute pyelonephritis. Methods. Uropathogens resistance to commonly usable anti-microbial agents (ampicillin, a combination of sulphamethoxasole and trimethoprim, cephalexin, ceftriaxone, cefotaxime, ceftazidime, gentamycin, amikacin, ciprofloxacin, imipenem and nalidixic acid) was retrospectively studied in newborns and young children treated during early (2005-2007) and late (2008-2009) study periods. Anti-bacterial susceptibility testing of the urine isolates was performed by the standard disc diffusion method. Results. 117 newborns and 294 children aged 9.3±0.7 months were treated during early (n=136) or late (n=275) study period due to the first episode of acute pyelonephritis. Escherichia coli was the most common bacterial pathogen (85.5%). Compared to children older than one month, newborns had higher degree of antibacterial resistance to 2nd and 3rd generation cephalosporins, aminoglycosides, and nalidixic acid during early, and to ceftazidime, aminoglycosides and nalidixic acid during late study period. Also, multidrug resistance was more common in newborns during the early study period. Conclusion. Newborns had higher rate of antibacterial resistance than young children. The progressive increase of anti-microbial resistance in children with acute pyelonephritis is of great concern.

Introduction. The choice of empiric therapy of acute pyelonephritis (APN) in children should be based on the knowledge of Escherichia coli (E. coli) as the most common uropathogen and its antibiotic sensitivities considering that nowadays ESBL-producing [ESBL (+)] E. coli is on the rise worldwide. Objective. To examine in vivo susceptibility of ESBL (+) E. coli to ceftriaxone (CTX), and to evaluate the options for empiric therapy for APN in children. Methods. Retrospective study of CTX empiric therapy of APN in children treated at the University Children΄s Hospital in Belgrade from January 2005 to December 2009. ESBL phenotypic confirmatory test with ceftazidime, CTX and cefotaxime was performed for all urine isolates by disc diffusion method on Mueller-Hinton agar plates. In vivo sensitivity of CTX documented by clinical response to empiric CTX therapy was compared between two groups of children: group I with ESBL (+) E. coli and group II with ESBL (-) E. coli APN. Results. Group I with ESBL (+) APN consisted of 94 patients and group II of 120 patients with ESBL (-) APN, respectively. All patients received CTX as empiric therapy at a mean dose of 66.9 mg during 7.2±2.6 days of therapy. Clinical effect of CTX was similar in patients with ESBL (+) compared to those with ESBL (-) APN. Conclusions. In vitro resistance of ESBL E. coli to CTX determined by standard methods is not sufficiently predictive for its in vivo sensitivity. Therefore CTX may be used as empiric therapy for acute pyelonephritis in children.

Introduction. Pseudo-Bartter syndrome encompasses a heterogenous group of disorders similar to Bartter syndrome. We are presenting an infant with pseudo-Bartter syndrome caused by congenital chloride diarrhoea. Case Outline. A male newborn born in the 37th gestational week (GW) to young healthy and non-consanguineous parents. In the 35th GW a polyhydramnios with bowel dilatation was verified by ultrasonography. After birth he manifested several episodes of hyponatremic dehydration with hypochloraemia, hypokalaemia and metabolic alkalosis, so as Bartter syndrome was suspected treatment with indomethacin, spironolactone and additional intake of NaCl was initiated. However, this therapy gave no results, so that at age six months he was rehospitalized under the features of persistent watery diarrhoea, vomiting, dehydration and acute renal failure (serum creatinine 123 μmol/L). The laboratory results showed hyponatraemia (123 mmol/L), hypokalaemia (3.1 mmol/L), severe hypochloraemia (43 mmol/L), alcalosis (blood pH 7.64, bicarbonate 50.6 mmol/L), high plasma renin (20.6 ng/ml) and aldosterone (232.9 ng/ml), but a low urinary chloride concentration (2.1 mmol/L). Based on these findings, as well as the stool chloride concentration of 110 mmol/L, the patient was diagnosed congenital chloride diarrhoea. In further course, the patient was treated by intensive fluid, sodium and potassium supplementation which resulted in the normalization of serum electrolytes, renal function, as well as his mental and physical development during 10 months of follow-up. Conclusion. Persistent watery diarrhoea with a high concentration of chloride in stool is the key finding in the differentiation of congenital chloride diarrhoea from Bartter syndrome. The treatment of congenital chloride diarrhoea consists primarily of adequate water and electrolytes replacement.

Introduction. Infantile nephropathic cystinosis (INC) is a metabolic disorder due to impaired carrier-mediated transport of cystine out of cellular lysosomes. Objective. To examine the prevalence and clinical characteristics of INC in paediatric patients with end- stage renal disease (ESRD) in Serbia and give a recent statement of the disease. Methods. ESRD database of the Centre for Paediatric Renal Replacement Therapy (RRT) in Serbia was used to identify all patients with INC who started RRT before age of 19 years during the period January 1980 - December 2008; their records concerning clinical characteristics, therapy and outcome were evaluated. Results. Only three of 298 paediatric patients with ESRD had INC. The first signs of the illness were recognised during infancy. Fancony syndrome was diagnosed in the second year, but the diagnosis of cystinosis was delayed at mean 6 years. ESRD occurred in the first decade of life. All patients under- went cadaver kidney transplantation. At the end of the study period all patients were alive. A 31-year-old female patient was on maintenance chemodialysis due to graft failure after functioning for 11 years. She was growth retarded, single, unemployed, with severe signs of renal dystrophy. Two male patients (14.3 and 14.7 years old) had normal graft function, normal education, and good quality of life, although they were also severe growth retarded. Conclusion. The prevalence of infantile nephropathic cystinosis is low in Serbia. The diagnosis of cystinosis was delayed in all patients, although they exhibited the typical course of the disease.

Introduction. Henoch-Schönlein purpura (HSP) is the most common vasculitis of childhood. It is characterized by symptoms including nonthrombocytopenic purpura, abdominal pain, haematuria/proteinuria, and arthralgia/arthritis. The pleiomorphism of clinical signs in HSP could be confused with other conditions or other vasculitis forms. Objective. Evaluation of HSP clinical presentation, the onset and severity of renal manifestation in affected children and their outcome. Methods. A retrospective study of 49 patients diagnosed with HSP was conducted from September 1999 to September 2009. Children with severe renal manifestations (nephrotic range proteinuria, with or without nephrotic or nephritic syndrome) have undergone kidney biopsy. Results. Twenty-five patients developed renal manifestations after onset of the disease. In our study child’s older age was a risk factor for association with HSP nephritis. Six of the patients required kidney biopsy. They were successfully treated with various immunosuppressive protocols, as well as three of nine patients with nephrotic range proteinuria. Two patients developed most severe form of HSP nephritis, nephrotic-nephritic syndrome with histology grade IIIb/IVb. During the study period (average follow-up 6 years), all patients had a normal global renal function with mild proteinuria in only two cases. The prognosis of renal involvement was better than reports from other patient series. Conclusion. Long-term morbidity of HSP is predominantly attributed to renal involvement. During the study period, no patient had renal insufficiency or end stage renal disease after various combinations of immunosuppressive treatment. It is recommended that patients with HSP nephritis are followed for longer periods of time with a regular measurement of renal function and proteinuria.

Introduction Familial hypomagnesaemia with hypercalciuria and nephrocalcinosis (FHHNC) is a rare autosomal recessive disease characterized by excessive renal magnesium and calcium wasting, bilateral nehrocalcinosis and progressive renal failure. This is the first report of FHHNC of four patients in Serbia. Outline of Cases The first three patients were siblings from the same family. The index case, a 9-yearold girl, presented with severe growth retardation, polyuria and polydipsia, while her brothers, 11 and 7 years old, were disclosed during family member screening. The father had a urolithiasis when aged 18 years, while intermittent microhaematuria and bilateral microlithiasis persisted later on. The fourth patient, a 16-year-old boy with sporadic FHHNC was discovered to have increased proteinuria at routine examination of urine before registration for secondary school. He was well grown up, normotensive, but had moderate renal failure (CKD 3 stage), mild hypomagnesaemia and severe hypercalciuria and nephrocalcinosis. Beside typical clinical and biochemical data, the diagnosis of FHHNC was confirmed by mutation analysis of the CLDN16 gene; in all four affected individuals a homozygous CLDN16 mutation (Leu151Phe) was found. Treatment with magnesium supplementation resulted in the normalization of serum magnesium levels only in one patient (patient 4), but hypercalciuria persisted and renal failure progressed in all patients. Conclusion FHHNC is a rare cause of chronic renal failure. The first four patients with FHHNC in Serbia have been here described. The diagnosis of FHNNC based on the findings of nephrocalcinosis with hypomagnesiaemia and hypercalciuria, was confirmed by homozygous paracellin1-mutation exhibiting a Leu151Phe. .

Introduction. Growth retardation is a hallmark of chronic illnesses such as chronic kidney disease in children, and it is associated with increased morbidity and mortality. The growth hormone (GH) resistance observed in uraemia can be overcome by supraphysiological doses of exogenous GH. Objective. We would like to present our first results of recombinant human growth hormone (rhGH) treatment, mainly in children on haemodialysis. Methods. Sixteen children, aged 4.5-17.1 years (mean age 11.25±3.57) with height below -2.0 standard deviation score (SDS) for age or height velocity below -2.0 SDS for age, were selected to receive rhGH therapy at our Nephrology and Haemodialysis Department. Most of them were on haemodialysis (14 children) with mean spent time 2.88±2.68 years (0-9 years) before the initiation of rhGH therapy. One half of patients were prepubertal (8 children) and the second half were in early puberty (testicular volume between 4 and 8 ml for boys and breast development B2 or B3 in girls). All patients received 28-30IU/m² rhGH per week by daily subcutaneous injection. The year before rhGH therapy served as a control period. Results. During the first year of treatment, mean height velocity in haemodialysis patients increased from 2.25 cm/year to 6.59 cm/year (p

Introduction. Balkan endemic nephropathy (BEN) is a familial chronic progressive tubulointerstitial disease of unknown aetiology that occurs with high prevalence in endemic rural environments of Serbia, Bosnia and Herzegovina, Croatia, Bulgaria and Romania. It has been documented only in adults. Objective. The aim of this study was to examine clinical markers of BEN in children and adolescent offspring of BEN patients. Methods. Prospective clinical trial involved two groups of children and adolescents: I consisted of 30 offspring of BEN patients and II of 29 offspring of non-BEN dialysis patients, both of them living in the same South Morava region of Serbia. All of them were healthy at the time of the investigation, not receiving any drugs. The study included personal and family history, physical examination, comprehensive laboratory analyses and renal ultrasound. Blood pressure (BP) was determined by using casual BP and 24 h ABPM in subjects older than 5 years. Urinary proteins were investigated by analysing microalbumin, alfa 1 microglobulin, beta 2 microglobulin and SDS-PAGE electrophoresis. GFR was measured by estimated creatinine clearance and by serum Cystatin C concentrations. Results. There were no statistically significant differences in age, gender, history of urinary tract infections or functional voiding disorders between these two groups. All of the studied subjects had normal BP and GFR. Renal ultrasound was abnormal only in BEN offspring (6.66%) as well as increased urine concentrations of microalbumin (3.3%), alpha 1 microglobulin (10%) and beta 2 microglobulin (13.3%) while low molecular protein (

Obesity, especially upper body fat distribution, has become an increasingly important medical problem in children and adolescents. Outcomes related to childhood obesity include, as in adult population, hypertension, type 2 diabetes mellitus, dyslipidemia, left ventricular hypertrophy, obstructive sleep apnea, orthopedic and socio-psychological problems. Obese children are at approximately 3-fold higher risk for hypertension from non-obese ones. Obesity-hypertension appears to be characterized by a preponderance of isolated systolic hypertension, increased heart rate and blood pressure variability, increased levels of plasma catecholamine and aldosterone, and salt-sensitivity. Lifestyle changes of weight loss, healthier diet and regular physical exercise are effective in obesity-hypertension control, though pharmacological treatment is frequently necessary. Screening for dyslipidemia and impaired glucose tolerance should be performed in paediatric patients with obese hypertension on regular basis, at least once annually or semiannually to discover metabolic syndrome and to prevent its increased cardiovascular risk. Of course, prevention of obesity is the primary goal. .

Background/Aim. Ureteropelvic junction obstruction and vesicoureteral reflux are the most frequent entities identified on the basis of antenatal hydronephrosis. The aim of this study was to determine the incidence and pattern of abnormal renal scintigraphy findings in postnatal investigation of children with antenatal hydronephrosis. Methods. Twenty four infants (19 boys and five girls) presented with antenatal hydronephrosis and mild to moderate hydronephrosis on ultrasound in newborn period were referred for renal scintigraphy. Ten patients with vesicoureteral reflux documented on micturating cystoureterography underwent 99mTc-DMSA renal scintigraphy and 14 patients were subjected to 99mTc-DTPA scintigraphy. Results. Anteroposterior pelvic diameter on ultrasound ranged from 11 to 24 mm. Renal DMSA scans identified congenital scars in two boys with bilateral reflux of grade V and unilateral reflux of grade III. Relative kidney uptake (RKU) less than 40% was found in three, and poor kidney function (RKU less than 10%) in two patients. Significant obstruction was shown on DTPA diuretic renal scintigraphy in 6/14 patients. Some slowing in dranaige (T1/2 greater than 10 minutes) with no reduction in differential renal function was identified in three patients. Differential renal function less than 10% was obtained in one case. Conclusion. A high percent of abnormal renal scintigraphy findings was obtained. Renal scintigraphy was useful in determination of underlying cause of antenatally detected hydronephrosis.

INTRODUCTION Renal scarring is the most common cause of arterial hypertension in children. High blood pressure (BP) and microalbuminuria contribute to the progression of chronic renal disease. OBJECTIVE The aims of the study were: to assess BP in children with renal scarring by continuous ambulatory blood pressure measurement (ABPM) in comparison to the casual method (CBP), and to determine the correlation between ambulatory blood pressure (ABP) and/or casual blood pressure (CBP) values and proteinuria in children with renal scarring. METHOD This forward-looking study comprised thirty-five children (26 girls and 9 boys), aged between 3-13 years, 10.4±3.9, X+SD. Blood pressure was measured using the casual method (CBP) with a mercury manometer; BP was measured three times and the average was taken as a referent value. ABPM was performed using the oscillometric method with the Space Labs device, model 90207. RESULTS 45.71% of patients were classified as hypertensive by ABPM, while only 22.6% of CBP measurements were above the 95th percentile (p

After a 15-year break, pediatric renal transplantation restarted again at the University Children's Hospital of Belgrade. Owing to this, best relationship between the number of new patients with terminal renal failure and those with functioning graft has been recently achieved, and mortality of children with terminal renal failure has been decreased to zero. The aim of this paper was to show the recent results achieved in pediatric renal transplantation at the University Children's Hospital in Belgrade. During the period from June 2001 till June 2003,10 patients, 6 boys and 4 girls, aged 5 to 15 years (9.5± 3.8) underwent transplantation of kidney harvested from a live matched donor. Out of these, two patients underwent pre-emptive transplantation. Urine from the graft started immediately after anastomosis was performed, while serum creatinine normalized after 15 to 120 hours. Daclizumab was the most commonly used as immunosuppressive induction agent, but the maintenance immunosuppressive therapy consisted of Imuran or Mycophenolate Mofetil (MMF), Neoral or Tacrolimus (FK 506) and prednisone. At the end of follow up, after 18.7±8.4 months, nine patients had normal, and one patient slightly decreased renal graft function. Growth after transplantation and nutritional status were improved in all patients, and all of them achieved complete psychosocial rehabilitation. These results showed that the University Children's Hospital in Belgrade fulfilled all necessary conditions to become a specialized Center for Pediatric Renal Transplantation.

The management of idiopathic nephrotic syndrome (INS) in children includes immunosuppressive and symptomatic treatment. The response to corticosteroid therapy is the best prognostic marker of the disease. The majority of children with INS (about 85%) are steroid-sensitive as they normalize proteinuria within 4 weeks of daily, oral prednisone administration. The most of steroid-sensitive patients (94%) has minimal change of nephrotic syndrome, while the majority (80.5%-94.4%) of those who are steroid-resistant has focal segmental glomerulosderosis or mesangioproliferative glomerulonephritis. Initial therapy of INS consists of 60 mg/m2/day prednisone daily for 4 weeks followed by 40 mg/m2 on alternate days for 4 weeks, thereafter decreasing alternate day therapy every month by 25% over the next 4 months. Thus, the overall duration of the initial cortico-steroids course is 6 months that may be significantly protective against the future development of frequent relapses. Approximately 30% of patients experience only one attack and are cured after the first course of therapy; 10-20% have only 3 or 4 steroid-responsive episodes before permanent cure; the remaining 40-50% of patients are frequent relapsers, or steroid-dependent. Standard relapse therapy consists of 60 mg/m2/ day prednisone until urine is protein free for at least 3 days, followed by 40 mg/m2 on alternate days for 4 weeks. The treatment of frequent-relapses and steroid-dependent INS includes several different regimens: maintenance (6 months) alternate steroid therapy just above steroid threshold (0.1-0.5 mg/kg/ 48h), levamisole, alkylating agents (cyclophosphamide or chlorambucil) or cyclosporine. The worse prognosis is expected in steroid-resistant patients who are the most difficult to treat. Renal biopsy should be performed in them. At present, there is no consensus on therapeutic regimen for steroid-resistant patients. The following immunosuppressive drugs have been used with varying success: cyclosporine, intravenous methyl prednisone pulses alone or combined with or followed by alkylating agents, plasma-exchange, and angiotensin-converting enzyme (ACE) inhibitors. Symptomatic treatment includes: 1) dietary regimen with normal protein intake and salt restriction, 2) calcium and vitamin D are prescribed with steroids, 3) diuretics should be used in case of severe edema, 4) infusion of albumin in case of severe hypovolemia, 5) treatment of hypertension, 6) anticoagulant therapy, and 7) prophylactic antibiotics in high-risk patients.

Voiding dysfunction in children was analyzed in 91 patients in a period from January 1st to October 1st 1998. Most of the patients had functional voiding disorder (92.31%), and only 7.69% manifested monosymptomatic night enuresis. The number of girls was bigger in the group of patients with voiding dysfunction while the boys were predominant in the group with mono-symptomatic nocturnal enuresis. More than a half of children with functional voiding disorder had repeated urinal infections (58.23%), incontinence (93.49%), need for urgent voiding (68.13%), and vesicoureteral reflux (47.61%). The most common type of voiding dysfunction was urge syndrome/urge incontinence. The incidence of dysfunctional voiding disorder was more often in children with scaring changes of kidney which were diagnosed by static scintigraphy.

Arterial hypertension in pediatric patients with neurofibromatosis type 1 (NF 1) is usually due to renal artery stenosis (RAS) mainly involving the proximal part of the vessel. The treatment modalities are highly individualized. In severe and/or bilateral RAS, antihypertensive drugs are either ineffective or have the potential risk for acute renal failure, while percutaneous transluminal angioplasty (PTA) has limited success due to the ostial localization of RAS and the tough fibrotic tissue involved that is refractory to dilatation Renal autotransplantation has potential advantages when medical control and PTA/or bypass techniques failed. Here we report 5 year-old girl with NF 1 and hyponatremic hypertensive syndrome due to severe bilateral disease, occluded proximal part of the right artery and ostial stenosis (80%) of the left one. Only left kidney was identified on 99 in Tc DTP A, but the right one was visualized on the renal ultrasonography and in the late phase of arterial renography due to well developed collateral circulation. Multiple antihyper-tensive drugs (nifedipine, labetolol and minoxidil) in maximal doses and PTA failed to normalize BP while short term therapy with ACEIwith NF1 and hyponatremic hypertensive syndrome due to severe bilateral renovascular disease; occluded proximal part of the right renal artery and ostial stenosis (80%) of the left one. Only left kidney was identified on 99m Tc DTPA, but the right one was visualized on the renal ultrasonography and in the late phase of arterial renography due to well developed collateral circulation. Multiple antyphypertensive drugs (nifedipine, labetolol and minoxidil) in maximal doses and PTA failed to normalize BP while. short term therapy with ACEI, captopril induced transient acute renal failure. Autotransplantation of right kidney saved its function and improved BP control. Our current case Autotransplantation of right kidney saved its function and improved BP control. Our current case is illustrative for a difficult management of renovascular hypertension in children with NF1. This is the first and up to now the only case of autotransplantation performed in Yugoslavia.

INTRODUCTION Numerous epidemiological studies have shown that blood pressure (BP) is positively related to cardiovascular morbidity and mortality. Although the relationship between BP and the incidence of morbid events is consistent and highly significant, it is difficult to predict the absolute risk. Several studies have shown that the organ damage associated with hypertension correlate to a greater degree with 24h average BP than with clinic BP and the most of them evaluated left ventricular hypertrophy in these patients. OBJECTIVE To evaluate the correlation between left ventricular mass index (LVMi) and BP, BP variability, pulse pressure (PP) BP load and hyperbaric index (HBI). DESIGN AND METHODS Ambulatory blood pressure monitoring (ABPM) was performed in 30 children with renal disease aged 12.7 ± 5.5 years. Ten of them had normal renal function, 3 had renal transplant and 17 of them had end-stage renal disease and were on chronic haemodialysis. All of the patients were submitted to an echocardiographic evaluation and LVMi was calculated according to Penn convention. Ambulatory blood pressure monitoring was performed during the 24h period and average values of systolic and diastolic BP were evaluated. As an index of variability of BP values we used standard deviation (SD) of mean. Evaluation of average BP values has some disadvantages - it does not take into account the peaks of blood pressure and the values are lower if the circadian rhythm of BP is preserved - for this reason BP load and HBI were evaluated as well. BP load represented the percentage of BPs exceeding the upper limits of normal and HBI the integrated area under the ambulatory BP curve. For the upper limits of normal we used 95th percentile from the multicenter study of German authors. RESULTS There was no correlation between LVMi and evaluated parameters. CONCLUSIONS The response of myocardium to chronic increase of the afterload is highly individual, and probably the role of genetics in this is very important. Echocardiogarphy (LVMi) could not be used with certainty for the evaluation of ventricular mass.

The aim of this study was to analyse the demographic variables of chronic non-terminal (CRF) and terminal (TRF) renal failure patients (pts) younger than 19 years treated in Serbia in June 2001. The prevalence of CRF pts was registered as 4,7 per million total population (pmtp) or 14,1 per million child population (pmcp) while corresponding values for TRF pts were 4,5 pmtp or 13,5 pmcp. The incidence of TRF pts during the period Jan.2000-Jan.2002 was 4,35 pmcp. Boys dominated only among CRF pts (34:14); 60,4% beeing between the ages of 6 and 19 yrs while at the time of diagnosis of HBI, 33,3 % of boys were yanger than 2 yrs.The causes of CRF were: reflux nephropathy 58,3%, congenital kidney disease 16,7%, familial/hereditary 14,6% glomerulonephritis 6,2% and Willms tu 4,1%. Reflux nephropathy was also the most common underlying disease of TRF accounted for 36,9% of total cases while glomerulonephritis was responsible for 23,9 %. Reflux nephropathy was associated with neural tube defect in 53,3% and with congenital lower urinary tract obstruction in 66,7%. The most of CRF (81,25%) and TRF pts (95,6%) were from Serbia, the others were from Monte Negro and Republic Srpska. The most of CRF (65%) and TRF (80%) pts were treated in University Children’s Hospital in Belgrade. Of CRF pts 46% had serum sreatinine 100-200 μmol/l, in 11% of pts it was 400-600 μmol/l and 2% of pts were in pre-terminal CRF. One third of CRF pts had proteinuria 150-500 mg/l, and second third had proteinuria greater of 1000 mg/l. Anemia was present in 54% of CRf pts, and arterial hypertension in 56%. Hemodialysis was dominant treatment modality for TRF pts and only 23,9% had functioning transplant. Conclusion: This is the first national study of demographic characteristics of pediatric CRF in Serbia. Since its prevalence is considerably lower than that in Western and North European countries the true prevalence is some what higher. The increasing incidence of pediatric TRF from 2,85 pmcp to 4,35 pmcp reflect better diagnosis and treatment of these patients in the recent years.

The diagnosis of hypertension in patients on chronic haemodialysis is not easy because the blood pressure changes as a consequence of therapy (haemodialysis) and attenuated circadian rhythm of blood pressure is often present. The estimation of representative blood pressure levels is difficult because it is not known whether blood pressures measured before starting or after completion of haemodialysis are predictive for the average interdialytic blood pressure. Our group of patients consisted of 18 children with endstage renal failure, aged 13.5 ± 3.2 years, treated with chronic haemodialysis from 0.1 to 110 (mean 25.8, median 19) months. Ambulatory blood pressure monitoring was performed during 44h interdialytic period. Blood pressure was also measured with sphygmomanometer before starting and after completion of heamodialysis. The average blood pressure values for the last ten haemodialyses were evaluated as well. Multiregression analysis showed significant correlation between interdialytic blood pressure (systolic and diastolic) and blood pressures measured before haemodialysis (r = 0.74; ρ < 0.001, r = 0.78; ρ < 0.001, respectively) and after haemodialysis (r = 0.76; ρ < 0.01, r = 0.6; ρ < 0.05, respectively). Statistically high correlation between these blood pressures was also confirmed for the average blood pressure values for the last 10 haemodialyses (r = 0.78; ρ < 0.001, r = 0.75; ρ < 0.001 and r = 0.78; ρ < 0.001, r = 0.86; ρ < 0.001, respectively). Our findings show that blood pressures measured before starting or after completion of haemodialysis give good information about interdialytic blood pressure in children on chronic haemodialysis.