Comparison of infants and children with urolithiasis: a large case series.

We evaluated the demographic features, etiologic risk factors, treatment strategies, and outcome of the infants and children with urolithiasis (UL). A retrospective multicenter study was conducted including 23 Pediatric Nephrology centers in Turkey. The medical records of 2513 children with UL were reviewed. One thousand, three hundred and four boys and 1209 girls (1.1:1) were reported. The mean age at diagnosis was 39.5 ± 35 months (0.4-231 months), and 1262 patients (50.2%) were in the first year of life (infants). Most of the cases with infantile UL were diagnosed incidentally. Microlithiasis (< 3 mm) was found in 794 patients (31.6%), and 64.5% of the patients with microlithiasis were infants. Stones were located in the pelvis-calyces in 63.2% (n: 1530) of the cases. The most common stone type was calcium oxalate (64.6%). Hypocitraturia was the most common metabolic risk factor (MRF) in children older than 12 months, but in infancy, hypercalciuria was more common. Fifty-five percent of the patients had received at least one medical treatment, mostly potassium citrate. At the end of a year's follow-up, most of the patients with microlithiasis (85%) showed spontaneous remission. The rate of spontaneous stone resolution in infants was higher than in children. Spontaneous remission rate was higher in cases with MRF ( - ) stones than in MRF ( +) stones. However, remission rate with medical treatment was higher in cases with MRF ( +) stones. This study represents the results of a large series of infants and children with UL and showed that there are several differences such as underlying metabolic and anatomic abnormalities, clinical course, and stone remission rates between infants and children with urinary stone disease.

A nationwide retrospective study in Turkish children with nephrocalcinosis.

BACKGROUND: Nephrocalcinosis (NC) is defined as calcium deposition in the kidney parenchyma and tubules. This study aims to determine the etiology, risk factors, and follow-up results of patients with NC in Turkey. METHODS: Patients diagnosed with NC in the pediatric nephrology Department Units of 19 centers from all geographical regions of Turkey over a 10-year period (2010-2019) were included in the study. The medical records from the centers were reviewed and demographic data, admission complaints, medical history, systemic and genetic disorders, risk factors for NC, treatment details, and presence of NC after one-year follow-up, were recorded retrospectively. RESULTS: The study sample included 195 patients (88 females, 107 males). The mean age at diagnosis was 39.44 ± 47.25 (0.5-208) months; 82/190 patients (43.2%) were diagnosed incidentally; 46/195 patients (23.6%) had an underlying disease; idiopathic hypercalciuria was detected in 75/195 (38.4%) patients. The most common systemic diseases were distal renal tubular acidosis in 11/46 patients (23.9%), primary hyperoxaluria in 9/46 patients (19.6%) and Bartter syndrome in 7/46 patients (15.3%). After one year of follow-up, NC resolved in 56/159 patients (35.2%) and they all did not have an underlying systemic disease. DISCUSSION: The most common presentation of NC was incidental. Distal renal tubular acidosis and primary hyperoxaluria were the main systemic diseases leading to NC, while hypercalciuria was the most common metabolic risk factor. Nephrocalcinosis was found to remain in most of the patients at a one-year follow-up. It may resolve particularly in patients with no underlying systemic disease.

Changes in Bacterial Resistance Patterns of Pediatric Urinary Tract Infections and Rationale for Empirical Antibiotic Therapy.

BACKGROUND: The causative agent spectrum and resistance patterns of urinary tract infections in children are affected by many factors. AIMS: To demonstrate antibiotic resistance in urinary tract infections and changing ratio in antibiotic resistance by years. STUDY DESIGN: Retrospective cross-sectional study. METHODS: We analysed antibiotic resistance patterns of isolated Gram (-) bacteria during the years 2011-2014 (study period 2) in children with urinary tract infections. We compared these findings with data collected in the same centre in 2001-2003 (study period 1). RESULTS: Four hundred and sixty-five uncomplicated community-acquired Gram (-) urinary tract infections were analysed from 2001-2003 and 400 from 2011-2014. Sixty-one percent of patients were female (1.5 girls : 1 boy). The mean age of children included in the study was 3 years and 9 months. Escherichia coli was the predominant bacteria isolated during both periods of the study (60% in study period 1 and 73% in study period 2). Bacteria other than E. coli demonstrated a higher level of resistance to all of the antimicrobials except trimethoprim-sulfamethoxazole than E. coli bacteria during the years 2011-2014. In our study, we found increasing resistance trends of urinary pathogens for cefixime (from 1% to 15%, p<0.05), amikacin (from 0% to 4%, p<0.05) and ciprofloxacin (from 0% to 3%, p<0.05) between the two periods. Urinary pathogens showed a decreasing trend for nitrofurantoin (from 17% to 7%, p=0.0001). No significant trends were detected for ampicillin (from 69% to 71%), amoxicillin-clavulanate (from 44% to 43%), cefazolin (from 39% to 32%), trimethoprim-sulfamethoxazole (from 32% to 31%), cefuroxime (from 21% to 18%) and ceftriaxone (from 10% to 14%) between the two periods (p>0.05). CONCLUSION: In childhood urinary tract infections, antibiotic resistance should be evaluated periodically and empiric antimicrobial therapy should be decided according to antibiotic sensitivity results.

Is microalbuminuria a risk factor for hypertension in children with solitary kidney?

BACKGROUND: The correlations between ambulatory blood pressure measurements (ABPM) and serum cystatin C (Cys C), serum creatinine (Cr), microalbumin (MA), and ß2-microglobulin (ß2-MG) levels in 24 h (24-h) urine were analyzed in children with solitary kidney (SK) and compared to healthy children. METHODS: Fifty children with normal functioning SK and 25 controls were studied. The ABPM, serum Cys C, serum Cr, MA, and ß2-MG levels in 24-h urine were measured in all children. Clinical symptoms and signs, laboratory results, urinary ultrasonography, voiding cystourethrography, and Dimercaptosuccinic acid (DMSA) scintigraphy results were recorded in the SK group. Four patients with Wilms' tumor and two with renal scarring were excluded from the study. RESULTS: The mean ages of the SK group and controls were 9.6 ± 3.6 and 9.3 ± 3.3 years, respectively. The serum Cys C and Cr levels, 24-h urinary ß2-MG and MA levels were similar in both groups (p > 0.05). However, 24-h urinary MA excretion was higher in patients living with SK more than 5 years (p = 0.01). Standard deviation scores of ABPM parameters showed no significant correlation with serum Cr, serum Cys C, MA, and ß2-MG in 24-h urine of both groups. CONCLUSIONS: Children with SK have increased 24-h urinary MA excretion in the long term, and need prolonged follow-up to detect early deterioration of renal function and to prevent end-organ damage later in life.

Urinary stone disease in the first year of life: is it dangerous?

PURPOSE: We have evaluated the clinical, radiological and metabolic features of infantile urolithiasis (UL). MATERIALS AND METHODS: We have reviewed the medical records of 93 children who were diagnosed as having UL before 1 year of age. We recorded patient demographics, the age at diagnosis, presenting symptoms, family history, the localizations and dimensions of stones, urinary metabolic examinations, as well as physical, laboratory, and radiologic findings. Our secondary objective was to compare some features of this group with those of older children with UL followed-up in the same clinic which were previously reported. RESULTS: We evaluated 93 children referred to our pediatric nephrology clinics. A family history of UL was 56.2 % in the study group. Resolution of stones was observed in 30.1 % of the cases. Urinary tract infections (UTIs) were detected in 65.9 % of females and 46.2 % of males. At least one urinary metabolic abnormality was found in 79.5 % of all the children. Most commonly seen metabolic abnormality was hypercalciuria. In all patients stones were located in kidneys except one infant who had an ureteral stone together with a kidney stone. Fifteen (16.1 %) children had an accompanying systemic disorder. CONCLUSIONS: Among pediatric urinary stone diseases infantile UL can be regarded as a separate clinical entity. Coexistence of systemic disorders and anatomic anomalies at high frequencies may indicate a role of distinct pathogenetic mechanisms. In addition, high rates of UTIs and metabolic abnormalities in this age group justify screening for these parameters during follow-up of these children.

Paraoxonase 1 polymorphisms in patients with primary glomerulonephritis: a single-center study in Turkey.

INTRODUCTION: Human paraoxonase 1 (PON1) is an enzyme related with high-density lipoprotein cholesterol. The link between genetic polymorphisms of PON1 and hyperlipidemia and increased lipid oxidation may explain these complications in the course of glomerular diseases. In this study, we aimed to investigate PON1 192 and PON1 55 polymorphisms in patients with primary glomerulonephritis and healthy individuals. MATERIALS AND METHODS: Eighty-six patients with biopsy-proven primary glomerulonephritis and 50 healthy controls were included in the study. Clinical characteristics, lipid profile, paraoxonase activity, and PON1 genotypes (PON1 192 and PON1 55) of all of the participants were studied. RESULTS: Histopathological diagnoses of the patients were membranoproliferative glomerulonephritis (53.5%), focal segmental glomerulosclerosis (33.7%), and membranous nephropathy (12.8%). The patients had lower PON1 activity levels than the healthy controls. No differences were observed in PON1 192 genotypes between the two groups. However, the controls were more likely to carry PON1 55 LM genotype (odds ratio, 4.10; 95% confidence interval, 1.96 to 8.61; P < .001) and M allele (odds ratio, 3.0; 95% confidence interval, 1.45 to 6.19; P = .003) compared to the patients with primary glomerulonephritis. There was a marked elevation in the frequency of PON1 55 LL genotype in the patients compared to the controls (odds ratio, 0.33; 95% confidence interval, 0.16 to 0.68; P = .003). CONCLUSIONS: This preliminary study shows that the LL genotype might be a risk factor for the development of primary glomerulonephritis and the M allele might be a protective factor against its progression.

Clinical spectrum of antenatally detected urinary tract abnormalities with respect to hydronephrosis at postnatal ultrasound scan.

AIM: The purpose of this study was to compare the outcome of infants having antenatally detected urinary tract abnormalities (AUTAs) with respect to the presence of hydronephrosis in postnatal ultrasonography (US) examination. PATIENTS AND METHODS: Between January 1999 and October 2009, 256 infants diagnosed with AUTAs were prospectively followed. Infants were divided into two groups according to the presence of hydronephrosis in postnatal US examination: Group 1, infants with hydronephrosis; Group 2, infants without hydronephrosis (including renal cyst, agenesis, ectopic kidney). The events of interest were the presence and diagnoses of uropathy, AUTA resolution, urinary tract infection (UTI), development of renal parenchymal defects (RPDs)--focal or global scarring, dysplasia--, acute kidney injury (AKI) and chronic kidney disease (CKD), and the need for surgery and dialysis treatment. RESULTS: The most commonly detected underlying abnormalities were ureteropelvic junction obstruction (44.8 %), vesicoureteral reflux (VUR) (30.0 %) and megaureter (9.5 %) in patients with postnatal hydronephrosis. On the other hand, multicystic dysplastic kidney (43.5 %), renal agenesis (19.4 %) and VUR (19.4 %) were mostly encountered abnormalities in patients without postnatal hydronephrosis. RPDs were significantly more common among patients with postnatal hydronephrosis compared to those without hydronephrosis (37 vs. 21 %, P = 0.02). The incidence of UTI and VUR was higher in infants with postnatal hydronephrosis than in infants without hydronephrosis. There was no statistically significant difference in terms of the development of AKI and CKD and the need for surgery and dialysis treatment between patients with hydronephrosis and those without hydronephrosis. CONCLUSION: Infants with AUTAs should be investigated postnatally. The findings from this study will help to identify the natural history and outcome of infants with AUTAs according to the postnatal US parameters.

Quadricuspid aortic valve diagnosed by transthoracic echocardiography in childhood.

Quadricuspid aortic valve is a rare congenital malformation of the heart leading to significant aortic regurgitation or stenosis. Its diagnosis by transthoracic echocardiography is difficult. Most of the cases are diagnosed during surgery or autopsy. Associated abnormalities of the coronary arteries should also be searched, since surgical injury may have devastating results. We herein present an eight-year-old girl found to have a quadricuspid aortic valve during evaluation of chronic renal disease and systemic hypertension.

Urinary levels of interleukin-6 and interleukin-8 in patients with vesicoureteral reflux and renal parenchymal scar.

The objective of this study was to assess the urine levels of interleukin-6 (IL-6) and interleukin-8 (IL-8) as noninvasive markers of vesicoureteral reflux (VUR) and renal parenchymal scarring (RPS) in children in the absence of a recent urinary tract infection (UTI) episode. Urine concentrations of IL-6 and IL-8 in 114 children aged 1 month to 16 years were evaluated. The children were divided into four groups: group 1, 26 children with VUR and RPS; group 2, 27 children with VUR without RPS; group 3, 34 children with RPS without VUR, group 4, 27 children without VUR and RPS, as the control group. After the first assessment, the children were divided into four larger groups for comparison purposes: group A (groups 1+2), 53 children with VUR; group B (groups 3+4), 61 children without VUR; group C (groups 1+3), 60 children with RPS; group D (groups 2+4), 54 children without RPS. Urinary IL-6 and IL-8 concentrations were determined. To avoid dilution effects and to the standardize samples, urinary levels of IL-6 and IL-8 were expressed as the ratio of cytokine to urinary creatinine (pg/mg). The median urine IL-6/creatinine was significantly higher in patients with VUR than in those without VUR (5.72 vs. 3.73). In patients with VUR, there was a significant but rather weak correlation between IL-6/creatinine concentrations and there flux grade (p<0.05, R=0.305). The median urine IL-8/creatinine was significantly higher in patients with RPS than in those without RPS (43.12 vs. 16.36). In patients with RPS, there was a significant but rather weak correlation between IL-8/creatinine concentrations and the renal scar grade (p<0.05, R=0.251). The results of this study provide preliminary evidence that children with VUR have a high urine IL-6 concentration, whereas children with RPS have a high urine IL-8 concentration.

Hereditary spherocytosis with immunoglobulin A nephropathy.

Hereditary spherocytosis is a familial hemolytic anemia. Immunoglobulin A (IgA) nephropathy associated with hereditary spherocytosis has not been reported in children. Here, we report a case of a 17-year-old boy with IgA nephropathy and hereditary spherocytosis. The patient was diagnosed with hereditary spherocytosis at the age of 12 years and splenectomy was done at the age of 15 years. Later, the patient presented with macroscopic hematuria and proteinuria. Kidney biopsy of the boy was consistent with IgA nephropathy. Treatment with angiotensin-converting enzyme inhibitor was started. The patient became free of proteinuria after the 6th month of therapy.

Clinical and metabolic features of urolithiasis and microlithiasis in children.

We evaluated the clinical, radiological and metabolic features of 162 children with urolithiasis or microlithiasis who had been referred to our pediatric nephrology clinics between 1998 and 2008 with suspected urolithiasis. The medical histories of these children (78 girls, 84 boys), who ranged in age from 2 months to 16 years (mean age 5.59 +/- 0.35 years), were reviewed retrospectively for clinical and metabolic features of urinary tract calculi. Urinary tract infections (UTI) were present in 45.9% of the cases. The most common presenting symptoms were flank pain or restlessness (25.3%) and hematuria (21.6%), followed by UTI (16%), whereas 23.5% of the cases were detected incidentally during evaluation for other medical conditions. Other symptoms at presentation included dysuria, passing stones, penile edema, enuresis, vomiting and anorexia. Urine analysis revealed metabolic abnormalities in 87% of the cases, including hypercalciuria (33.8%), hypocitraturia (33.1%), hyperoxaluria (26.5%), hyperuricosuria (25.4%), hypocitraturia + hypercalciuria (21.1%), hyperphosphaturia (20.8%) and cystinuria (5.7%). Almost 50% of the patients had a positive family history for urolithiasis. The most frequently involved site was in the kidneys (86%). Ureters and bladder were involved in 12 and 2% of the cases, respectively. A family history of urolithiasis, presenting symptoms and underlying metabolic abnormalities were similar for microlithiasis and the patients with larger stones. However, in our study population, microlithiasis was mainly a disease of young infants, with a greater chance for remission and often not associated with structural changes. The presenting symptoms of urolithiasis show a wide spectrum, so that a high index of suspicion is important for early detection. A metabolic abnormality can be identified in 87% of cases of urolithiasis. Detection of microlithiasis may explain a number of symptoms, thus reducing invasive diagnostic procedures and allowing early recognition of metabolic abnormalities. These results draw attention to the importance of screening for UTIs in patients with urolithiasis.

The co-existence of membranoproliferative glomerulonephritis type 1 and coeliac disease: a case report.

Coeliac disease is an autoimmune enteropathy characterised by chronic inflammation of the small intestinal mucosa and the presence of typical autoantibodies. Coeliac disease may be a risk factor for renal disease. Immunoglobulin A (IgA) nephropathy is reported in the majority of these cases. Only one adult patient had been reported with membranoproliferative glomerulonephritis (MPGN) and coeliac disease. Here, we report a case in a 12-year-old girl with coeliac disease who presented with severe anaemia and later developed nephrotic syndrome. Renal biopsy of the patient was consistent with MPGN type 1, which has not been previously reported in children with coeliac disease. A gluten-free diet was started. After 6 months of this diet, her nephrotic syndrome resolved completely. This case is presented to draw attention to the rare association of coeliac disease and MPGN type 1.

The protective effect of oxytocin on renal ischemia/reperfusion injury in rats.

AIM: Oxytocin was previously shown to have anti-inflammatory effects in different inflammation models. The major objective of the present study was to evaluate the protective role of oxytocin (OT) in protecting the kidney against ischemia/reperfusion (I/R) injury. MATERIALS AND METHODS: Male Wistar albino rats (250-300 g) were unilaterally nephrectomized, and subjected to 45 min of renal pedicle occlusion followed by 6 h of reperfusion. OT (1 mg/kg, ip) or vehicle was administered 15 min prior to ischemia and was repeated immediately before the reperfusion period. At the end of the reperfusion period, rats were decapitated and kidney samples were taken for histological examination or determination of malondialdehyde (MDA), an end product of lipid peroxidation; glutathione (GSH), a key antioxidant; and myeloperoxidase (MPO) activity, an index of tissue neutrophil infiltration. Creatinine and urea concentrations in blood were measured for the evaluation of renal function, while TNF-alpha and lactate dehydrogenase (LDH) levels were determined to evaluate generalized tissue damage. Formation of reactive oxygen species in renal tissue samples was monitored by chemiluminescence technique using luminol and lucigenin probes. RESULTS: The results revealed that I/R injury increased (p<0.01-0.001) serum urea, creatinine, TNF-alpha and LDH levels, as well as MDA, MPO and reactive oxygen radical levels in the renal tissue, while decreasing renal GSH content. However, alterations in these biochemical and histopathological indices due to I/R injury were attenuated by OT treatment (p<0.05-0.001). CONCLUSIONS: Since OT administration improved renal function and microscopic damage, along with the alleviation of oxidant tissue responses, it appears that oxytocin protects renal tissue against I/R-induced oxidative damage.

Oxytocin alleviates oxidative renal injury in pyelonephritic rats via a neutrophil-dependent mechanism.

BACKGROUND: Urinary tract infection (UTI) may cause inflammation of the renal parenchyma and may lead to impairment in renal function and scar formation. Oxidant injury and reactive oxygen species (ROS) have been found responsible in the pathogenesis of UTI. The neurohypophyseal hormone oxytocin (OT) facilitates wound healing and is involved in the modulation of immune and inflammatory processes. We investigated the possible therapeutic effects of OT against Escherichia coli induced pyelonephritis in rats both in the acute and chronic setting. METHODS: Twenty-four Wistar rats were injected 0.1 ml solution containing E. coli ATCC 25922 10(10) colony forming units/ml into left renal medullae. Six rats were designed as sham group and were given 0.1 ml 0.9% NaCl. Pyelonephritic rats were treated with either saline or OT immediately after surgery and at daily intervals. Half of the pyelonephritic rats were decapitated at the 24th hour of E. coli infection, and the rest were followed for 7 days. Renal function tests (urea, creatinine), systemic inflammation markers [lactate dehydrogenase (LDH) and tumor necrosis factor alpha (TNF-alpha)] and renal tissue malondialdehyde (MDA) as an end product of lipid peroxidation, glutathione (GSH) as an antioxidant parameter and myeloperoxidase (MPO) as an indirect index of neutrophil infiltration were studied. RESULTS: Blood urea, creatinine, and TNF-alpha levels were increased, renal tissue MDA and MPO levels were elevated and GSH levels were decreased in both of the pyelonephritic (acute and chronic) rats. All of these parameters and elevation of LDH at the late phase were all reversed to normal levels by OT treatment. CONCLUSION: OT alleviates oxidant renal injury in pyelonephritic rats by its anti-oxidant actions and by preventing free radical damaging cascades that involves excessive infiltration of neutrophils.

Comparison of direct radionuclide cystography and voiding cystourethrography in detecting vesicoureteral reflux.

BACKGROUND: Fluoroscopic voiding cystourethrography (VCUG) is a widely used imaging test for the diagnosis of vesicoureteral reflux (VUR). However, high gonadal radiation and intermittent imaging are the main disadvantages of VCUG. Direct radionuclide cystography (DRC) has been advocated for the detection of VUR with increased sensitivity and low radiation doses, however, having the disadvantage of providing less anatomical details for urethral evaluation. In this study, DRC has been compared with standard fluoroscopic VCUG for detection of VUR. METHODS: A total of 41 children (82 kidney ureter units, KUU) aged 1 month-126 months (median, 15 months) were studied sequentially using DRC and VCUG. The indications of VUR studied were urinary tract infection in 29 children, VUR follow up in eight children and antenatal dilatation history in four children. RESULTS: A total of 18 refluxing ureters were detected by DRC, 22 refluxing ureters by VCUG and 14 refluxing ureters by both methods. The two methods were concordant for the detection and exclusion of VUR in 85% of KUU. VUR was missed by VCUG in four KUU (three severe, one mild) whereas VUR was missed by DRC in eight KUU (four grade I, four grade III). CONCLUSIONS: There was a good correlation between DRC and VCUG in the evaluation of VUR. DRC provides continuous monitoring and low gonadal radiation exposure. DRC can be used in the diagnosis of VUR as an alternative to VCUG in selected cases.

Urinary tract infection and hyperbilirubinemia.

The aim of this study was to evaluate the incidence of urinary tract infection (UTI) in newborns with asymptomatic, unexplained indirect hyperbilirubinemia in the first two weeks of life. Jaundiced infants, otherwise clinically well, less than two weeks of ages, with a total bilirubin level above 15 mg/dl were eligible for the study. A bilirubin work-up including glucose-6-phosphate dehydrogenase (G-6 PD) level, as well as urinalysis and a urine culture were performed in all patients. Patients with UTI, defined as more than 10,000 colony-forming units per milliliter of a single pathogen obtained by bladder catheterization, were evaluated for sepsis. Renal function tests and renal ultrasound were performed in cases with UTI. During follow-up, voiding cystourethrogram (VCUG) and dimercaptosuccinic acid scintigraphy (DMSA) were performed as well. A total of 102 patients were enrolled. The bilirubin work-up of patients did not demonstrate any significant underlying disorder. None of the infants had a high direct bilirubin level. UTI was diagnosed in eight (8%) cases [Enterobacter aerogenes (3/8:38%), Enterococcus faecalis (2/8:25%), Klebsiella pneumoniae (2/8:25%) and Escherichia coli (1/8:12%)]. Of those eight patients, only four (50%) had pyuria. Bacteriuria was present in seven (88%) patients. The sepsis screen was negative in all but one case with a high C-reactive protein (CRP) level. None of the patients had a positive blood culture. Renal function tests were within normal levels in all patients. Renal ultrasound showed urinary tract abnormalities in three (38%) patients (hydronephrosis, n=1 and pelviectasis, n=2). VCUG was performed in all patients during the study period and one had unilateral grade 3-4 reflux, while only one patient had a diverticulum of the bladder. DMSA was performed in seven patients and none had renal scars. It is of importance that UTI can occur in asymptomatic, jaundiced infants even in the first week of life. Although it is well known that UTI is a common cause of prolonged jaundice, urine culture should be considered in the bilirubin work-up of infants older than three days of age with an unknown etiology.

Paraoxonase 1 192 and 55 polymorphisms in nephrotic children.

Human paraoxonase 1 (PON1) is a serum enzyme related to high-density lipoprotein which has a major role in preventing oxidative modification of low-density lipoprotein. Due to its amino acid substitution PON1 has two genetic polymorphisms. These polymorphisms are characterized by the location of glutamine (A genotype) and arginine (B genotype) at position 192, and leucine (L genotype) and methionine (M genotype) at position 55. Hyperlipidemia and increased lipid oxidation in nephrotic syndrome may lead to glomerulosclerosis and progression of the glomerular disease. In this study we aimed to investigate PON1 192 and PON1 55 polymorphisms in children with focal segmental glomerulosclerosis (FSGS) and control subjects. The study included 25 children with biopsy-proven FSGS and 30 healthy controls. We demonstrated a statistically significant difference between FSGS patients and control subjects with respect to the distribution of the PON1 polymorphism. The AA genotype was less frequent and the AB+BB genotype was more frequent in FSGS patients than in controls (48 versus 73% for AA genotype and 52 versus 27% for AB+BB genotype, p<0.05). Distributions of PON1 55 genotypes of FSGS and control subjects were also statistically different (76 versus 43% for LL genotype and 24 versus 57% for LM+MM genotype, p<0.05) (case-control study, dominant model, Fisher's exact test). The distributions of both genotypes in subgroups of FSGS (stable renal function versus declining renal function) were not statistically different. We conclude in this preliminary study that presence of B allele and/or L allele may be risk factors for the development of FSGS in children.

Membranous nephropathy in Schimke immuno-osseous dysplasia.

Schimke immuno-osseous dysplasia is a rare autosomal recessive multi-system disorder, with clinical features of growth retardation, spondylo-epiphyseal dysplasia, nephrotic syndrome and immunodeficiency beginning in childhood. Here, we report a new case, in a 10-year-old boy with characteristic symptoms of Schimke immuno-osseous dysplasia. The patient presented with short stature and, later, developed nephrotic syndrome and peritonitis. In addition, he had perinuclear anti-neutrophilic cytoplasmic antibody (p-ANCA)-positive arthritis. Renal pathology of the patients with this disease usually show focal segmental glomerulonephritis, whereas our patient had membranous nephropathy, which has not previously been reported.

Hypercalciuria and recurrent urinary tract infections: incidence and symptoms in children over 5 years of age.

Hypercalciuria is an important and common risk factor in the formation of renal stones. In this study we evaluated the incidence and the clinical presentation of hypercalciuria in 75 children over 5 years of age with the diagnosis of recurrent urinary tract infection (UTI). We measured random urinary calcium/creatinine value (three times), 24-h urinary calcium excretion, serum calcium, phosphorus, electrolytes, blood gas, blood urea nitrogen and creatinine levels. Hypercalciuria was found in 32 patients (43%). The mean urinary calcium/creatinine ratio for hypercalciuric patients was 0.50+/-0.21 mg/mg (min: 0.24, max: 2.60). The mean urinary calcium/creatinine ratio for the rest of the study population--those without hypercalciuria--was 0.10+/-0.04 mg/mg (min: 0.01, max: 0.18). Presenting symptoms of the hypercalciuric patients and normocalciuric patients were similar. History of familial urolithiasis was positive in 19 patients (59%). Predisposing urinary tract abnormalities in recurrent UTI was shown in 12 of the hypercalciuric patients (12/32, 37.5%) and 8 of the normocalciuric patients (8/43, 19%) without a statistically significant difference between. We conclude that hypercalciuria is not a rare finding among recurrent UTI cases in Turkish children. Hypercalciuria does not modify the clinical presentation of UTI, and we suggest the investigation of urinary calcium excretion in children with recurrent UTI.