Comprehensive evaluation of patients with primary hyperoxaluria type 1: A nationwide study.

BACKGROUND: Primary hyperoxaluria type 1 (PH1) is characterized by increased endogenous oxalate production and deposition as calcium oxalate crystals. The main manifestations are nephrocalcinosis/nephrolithiasis, causing impaired kidney function. We aimed to evaluate the clinical characteristics and overall outcomes of paediatric PH1 patients in Turkey. METHODS: This is a nationwide, multicentre, retrospective study evaluating all available paediatric PH1 patients from 15 different paediatric nephrology centres in Turkey. Detailed patient data was collected which included demographic, clinical and laboratory features. Patients were classified according to their age and characteristics at presentation: patients presenting in the first year of life with nephrocalcinosis/nephrolithiasis (infantile oxalosis, Group 1), cases with recurrent nephrolithiasis diagnosed during childhood (childhood-onset PH1, Group 2), and asymptomatic children diagnosed with family screening (Group 3). RESULTS: Forty-eight patients had a mutation consistent with PH1. The most common mutation was c.971_972delTG (25%). Infantile oxalosis patients had more advanced chronic kidney disease (CKD) or kidney failure necessitating dialysis (76.9% vs. 45.5%). These patients had much worse clinical course and mortality rates seemed to be higher (23.1% vs. 13.6%). Patients with fatal outcomes were the ones with significant comorbidities, especially with cardiovascular involvement. Patients in Group 3 were followed with better outcomes, with no kidney failure or mortality. CONCLUSION: PH1 is not an isolated kidney disease but a systemic disease. Family screening helps to preserve kidney function and prevent systemic complications. Despite all efforts made with traditional treatment methods including transplantation, our results show devastating outcomes or mortality.

Clinical and subclinical acute kidney injury in children with mild-to-moderate COVID-19.

BACKGROUND: Our aim was to identify acute kidney injury (AKI) and subacute kidney injury using both KDIGO criteria and urinary biomarkers in children with mild/moderate COVID-19. METHODS: This cross-sectional study included 71 children who were hospitalized with a diagnosis of COVID-19 from 3 centers in Istanbul and 75 healthy children. We used a combination of functional (serum creatinine) and damage (NGAL, KIM-1, and IL-18) markers for the definition of AKI and subclinical AKI. Clinical and laboratory features were evaluated as predictors of AKI and subclinical AKI. RESULTS: Patients had significantly higher levels of urinary biomarkers and urine albumin-creatinine ratio than healthy controls (p < 0.001). Twelve patients (16.9%) developed AKI based on KDIGO criteria, and 22 patients (31%) had subclinical AKI. AKI group had significantly higher values of neutrophil count on admission than both subclinical AKI and non-AKI groups (p < 0.05 for all). Neutrophil count was independently associated with the presence of AKI (p = 0.014). CONCLUSIONS: This study reveals that even children with a mild or moderate disease course are at risk for AKI. Association between neutrophil count and AKI may point out the role of inflammation in the development of AKI. IMPACT: The key message of our article is that not only children with severe disease but also children with mild or moderate disease have an increased risk for kidney injury due to COVID-19. Urinary biomarkers enable the diagnosis of a significant number of patients with subclinical AKI in patients without elevation in serum creatinine. Our findings reveal that patients with high neutrophil count may be more prone to develop AKI and should be followed up carefully. We conclude that even children with mild or moderate COVID-19 disease courses should be evaluated for AKI and subclinical AKI, which may improve patient outcomes.

Management of pediatric dialysis and kidney transplant patients after natural or man-made disasters.

Pediatric patients on kidney replacement therapy (KRT) are among the most vulnerable during large-scale disasters, either natural or man-made. Hemodialysis (HD) treatments may be impossible because of structural damage and/or shortage of medical supplies, clean water, electricity, and healthcare professionals. Lack of peritoneal dialysis (PD) solutions and increased risk of infectious/non-infectious complications may make PD therapy challenging. Non-availability of immunosuppressants and increased risk of infections may result in graft loss and deaths of kidney transplant recipients. Measures to mitigate these risks must be considered before, during, and after the disaster including training of staff and patients/caregivers to cope with medical and logistic problems. Soon after a disaster, if the possibility of performing HD or PD is uncertain, patients should be directed to other centers, or the duration and/or number of HD sessions or the PD prescription adapted. In kidney transplant recipients, switching among immunosuppressants should be considered in case of non-availability of the medications. Post-disaster interventions target treating neglected physical and mental problems and also improving social challenges. All problems experienced by pediatric KRT patients living in the affected area are applicable to displaced patients who may also face extra risks during their travel and also at their destination. The need for additional local, national, and international help and support of non-governmental organizations must be anticipated and sought in a timely manner.

A splice site mutation in the TSEN2 causes a new syndrome with craniofacial and central nervous system malformations, and atypical hemolytic uremic syndrome.

Recessive mutations in the genes encoding the four subunits of the tRNA splicing endonuclease complex (TSEN54, TSEN34, TSEN15, and TSEN2) cause various forms of pontocerebellar hypoplasia, a disorder characterized by hypoplasia of the cerebellum and the pons, microcephaly, dysmorphisms, and other variable clinical features. Here, we report an intronic recessive founder variant in the gene TSEN2 that results in abnormal splicing of the mRNA of this gene, in six individuals from four consanguineous families affected with microcephaly, multiple craniofacial malformations, radiological abnormalities of the central nervous system, and cognitive retardation of variable severity. Remarkably, unlike patients with previously described mutations in the components of the TSEN complex, all the individuals that we report developed atypical hemolytic uremic syndrome (aHUS) with thrombotic microangiopathy, microangiopathic hemolytic anemia, thrombocytopenia, proteinuria, severe hypertension, and end-stage kidney disease (ESKD) early in life. Bulk RNA sequencing of peripheral blood cells of four affected individuals revealed abnormal tRNA transcripts, indicating an alteration of the tRNA biogenesis. Morpholino-mediated skipping of exon 10 of tsen2 in zebrafish produced phenotypes similar to human patients. Thus, we have identified a novel syndrome accompanied by aHUS suggesting the existence of a link between tRNA biology and vascular endothelium homeostasis, which we propose to name with the acronym TRACK syndrome (TSEN2 Related Atypical hemolytic uremic syndrome, Craniofacial malformations, Kidney failure).

Increased risk for kidney sequelae surrogates in survivors of Wilms tumor.

BACKGROUND: There is evidence of increased risk of hypertension, albuminuria, and development of chronic kidney disease (CKD) in long-term follow-up of survivors of Wilms tumor (WT). However, most studies were conducted in heterogeneous groups, including patients with solitary kidney. In addition, little is known about tubular dysfunction. This study aimed to investigate kidney sequelae, including CKD development, hypertension, and glomerular and tubular damage in WT survivors. METHODS: This cross-sectional, single-center study included 61 patients treated for WT. Surrogates for kidney sequelae were defined as presence of at least one of the following: decrease in GFR for CKD, hypertension detected by ambulatory blood pressure monitoring, albuminuria (albumin-to-creatinine ratio [ACR] > 30 mg/g), or increase in at least one tubular biomarker (beta-2-microglobulin, neutrophil gelatinase-associated lipocalin, kidney injury marker-1, and liver fatty acid-binding protein) in 24-h urine. RESULTS: Median age of patients was 11.7 years, with median follow-up of 8.8 years. Thirty-eight patients (62%) had at least one surrogate for kidney sequelae. Twenty-four patients (39%) had CKD, 14 patients (23%) had albuminuria, 12 patients (21%) had hypertension, and 11 patients (18%) had tubular damage. Urine ACR was significantly higher in patients with advanced tumor stage and patients with nephrotoxic therapy than their counterparts (p < 0.05), but neither eGFR nor tubular biomarkers showed any association with tumor- or treatment-related factors. CONCLUSIONS: A considerable number of patients with WT have kidney sequelae, especially early-stage CKD with a high prevalence. Albuminuria emerges as a marker associated with tumor stages and nephrotoxic treatment. A higher resolution version of the Graphical abstract is available as Supplementary information.

Refining genotype-phenotype correlations in 304 patients with autosomal recessive polycystic kidney disease and PKHD1 gene variants.

Autosomal recessive polycystic kidney disease (ARPKD) is a severe disease of early childhood that is clinically characterized by fibrocystic changes of the kidneys and the liver. The main cause of ARPKD are variants in the PKHD1 gene encoding the large transmembrane protein fibrocystin. The mechanisms underlying the observed clinical heterogeneity in ARPKD remain incompletely understood, partly due to the fact that genotype-phenotype correlations have been limited to the association of biallelic null variants in PKHD1 with the most severe phenotypes. In this observational study we analyzed a deep clinical dataset of 304 patients with ARPKD from two independent cohorts and identified novel genotype-phenotype correlations during childhood and adolescence. Biallelic null variants frequently show severe courses. Additionally, our data suggest that the affected region in PKHD1 is important in determining the phenotype. Patients with two missense variants affecting amino acids 709-1837 of fibrocystin or a missense variant in this region and a null variant less frequently developed chronic kidney failure, and patients with missense variants affecting amino acids 1838-2624 showed better hepatic outcome. Variants affecting amino acids 2625-4074 of fibrocystin were associated with poorer hepatic outcome. Thus, our data expand the understanding of genotype-phenotype correlations in pediatric ARPKD patients and can lay the foundation for more precise and personalized counselling and treatment approaches.

Natural history of patients with infantile nephrolithiasis: what are the predictors of surgical intervention?

BACKGROUND: We evaluated the risk factors for the requirement of surgical intervention in infants with nephrolithiasis. METHODS: The medical records of 122 (156 kidney units (KU)) infants were reviewed. The clinical features, stone characteristics, changes in stone status, and treatment protocols were noted. The stone status of the KU was categorized into 3 groups according to the change in size between the first and last ultrasound: resolution, unchanged, and growth. RESULTS: The median age was 8 months (r: 2-12). The median length of follow-up was 16 months (r: 10-36). Resolution was detected in 94 KUs (60%). Stone growth was detected in 39 KUs (25%), and stone size was unchanged in 23 KUs (15%). Surgical intervention was required in 26 patients (17%). A history of intensive care unit (ICU) follow-up and a stone size > 5 mm at time of diagnosis were defined as independent risk factors for stone growth (p = 0.005, < 0.001, respectively). The surgical intervention rate was higher in stones > 5 mm and stones with pelvic localization (p = 0.018, 0.021, respectively). Stone resolution was higher in patients with stone size ≤ 5 mm (p = 0.018). CONCLUSION: A stone size > 5 mm at the time of diagnosis and a history of ICU follow-up are independent risk factors for stone growth. Pelvic localization of stones and stones > 5 mm are associated with an increased risk of surgical intervention.

Evaluation of non-infectious complications of peritoneal dialysis in children: a multicenter study.

BACKGROUND: Peritoneal dialysis (PD) is the most common kidney replacement therapy in children. Complications associated with PD affect treatment success and sustainability. The aim of this study was to investigate the frequency of PD-related non-infectious complications and the predisposing factors. METHODS: Retrospective data from 11 centers in Turkey between 1998 and 2018 was collected. Non-infectious complications of peritoneal dialysis (NICPD), except metabolic ones, in pediatric patients with regular follow-up of at least 3 months were evaluated. RESULTS: A total of 275 patients were included. The median age at onset of PD and median duration of PD were 9.1 (IQR, 2.5-13.2) and 7.6 (IQR, 2.8-11.9) years, respectively. A total of 159 (57.8%) patients encountered 302 NICPD within the observation period of 862 patient-years. The most common NIPCD was catheter dysfunction (n = 71, 23.5%). At least one catheter revision was performed in 77 patients (28.0%). Longer PD duration and presence of swan neck tunnel were associated with the development of NICPD (OR 1.191; 95% CI 1.079-1.315, p = 0.001 and OR 1.580; 95% CI 0.660-0.883, p = 0.048, respectively). Peritoneal dialysis was discontinued in 145 patients; 46 of whom (16.7%) switched to hemodialysis. The frequency of patients who were transferred to hemodialysis due to NICPD was 15.2%. CONCLUSIONS: Peritoneal dialysis-related non-infectious complications may lead to discontinuation of therapy. Presence of swan neck tunnel and long duration of PD increased the rate of NICPD. Careful monitoring of patients is necessary to ensure that PD treatment can be maintained safely.

A homozygous HOXA11 variation as a potential novel cause of autosomal recessive congenital anomalies of the kidney and urinary tract.

Congenital anomalies of the kidney and urinary tract (CAKUT) is the leading cause of end-stage kidney disease in children. Until now, more than 50 monogenic causes for CAKUT have been described, all of which only explain 10% to 20% of all patients with CAKUT, suggesting the presence of additional genes that cause CAKUT when mutated. Herein, we report two siblings of a consanguineous family with CAKUT, both of which rapidly progressed to chronic kidney disease in early childhood. Whole-exome sequencing followed by homozygosity mapping identified a homozygous variation in HOXA11. We therefore showed for the first time an association between a homozygous HOXA11 variation with CAKUT in humans, expanding the genetic spectrum of the disease.

Disasters, children and the kidneys.

Following disasters, children are physically, psychologically and socially more vulnerable than adults; consequently, their morbidity and mortality are higher. The risks are especially high for orphans and unaccompanied children who are separated from their families, making them frequently victims of human trafficking, slavery, drug addiction, crime or sexual exploitation. Education of children and families about disaster-related risks and providing special protection in disaster preparedness plans may mitigate these threats. Kidney disease patients, both paediatric and adult, are extra vulnerable during disasters, because their treatment is dependent on technology and functioning infrastructure. Acute kidney injury, chronic kidney disease patients not on dialysis and dialysis and transplant patients are faced with extensive problems. Overall, similar treatment principles apply both for adults and paediatric kidney patients, but management of children is more problematic, because of substantial medical and logistic difficulties. To minimize drawbacks, it is vital to be prepared for renal disasters. Preparedness plans should address not only medical professionals, but also patients and their families. If problems cannot be coped with locally, calling for national and/or international help is mandatory. This paper describes the spectrum of disaster-related problems in children and the specific features in treating acute and chronic kidney disease in disasters.

Factors influencing blood pressure and microalbuminuria in children with type 1 diabetes mellitus: salt or sugar?

BACKGROUND: The aim of the study is to identify the effect of salt intake and diabetes itself on blood pressure (BP) profile and microalbuminuria in children with type one diabetes mellitus (T1DM). Our hypothesis is that higher amount of salt consumption and/or hyperglycemia may impair blood pressure pattern in children with T1DM. METHODS: This cross-sectional study included 84 children and adolescents with T1DM (62% females, age 13.9 ± 3.2 years, disease duration 7.3 ± 3.1 years, 43% poorly controlled diabetes) and 54 aged- and sex-matched healthy children with an adequately collected 24-h urine samples. Urine sodium, creatinine, and microalbumin were measured and salt intake was assessed on the basis of sodium excretion in 24-h urine. Blood pressure profile of the children with T1DM was evaluated with 24-h ambulatory blood pressure monitoring. RESULTS: Compared to the children with well-controlled diabetes, children with poorly controlled diabetes had significantly higher standard deviation scores (SDS) of nighttime systolic BP (0.22 ± 1.28 vs - 0.87 ± 0.76, p = 0.003) and lower dipping in diastole (13.4 ± 5.9 vs 18.4 ± 8.1, p = 0.046). Among T1DM group, children with the highest quartile of salt intake had higher nighttime systolic and diastolic BP-SDS (0.53 ± 1.25 vs - 0.55 ± 0.73, p = 0.002 and 0.89 ± 1.19 vs 0.25 ± 0.63, p = 0.038, respectively) and lower dipping in systole compared to their counterparts (7.7 ± 5.0 vs 11.5 ± 6.1, p = 0.040). High averaged HbA1c was independently associated with higher both daytime and nighttime systolic BP-SDS (p = 0.010, p < 0.001) and nighttime diastolic BP-SDS (p = 0.001), and lower diastolic dipping (p = 0.001). High salt intake was independently associated with higher nighttime systolic BP-SDS (p = 0.002) and lower systolic dipping (p = 0.019). A 24-h MAP-SDS was the only independent risk factor for microalbuminuria (p = 0.035). CONCLUSION: Beside poor diabetic control, high salt consumption appears to be an important modifiable risk factor for impaired BP pattern, which contributes to the development of diabetic kidney disease in children with T1DM.

Vascular Access Choice, Complications, and Outcomes in Children on Maintenance Hemodialysis: Findings From the International Pediatric Hemodialysis Network (IPHN) Registry.

RATIONALE & OBJECTIVE: Arteriovenous fistulas (AVFs) have been recommended as the preferred vascular access for pediatric patients on maintenance hemodialysis (HD), but data comparing AVFs with other access types are scant. We studied vascular access choice, placement, complications, and outcomes in children. STUDY DESIGN: Prospective observational cohort study. SETTING & PARTICIPANTS: 552 children and adolescents from 27 countries on maintenance HD followed up prospectively by the International Pediatric HD Network (IPHN) Registry between 2012 and 2017. PREDICTOR: Type of vascular access: AVF, central venous catheter (CVC), or arteriovenous graft. OUTCOME: Infectious and noninfectious vascular access complication rates, dialysis performance, biochemical and hematologic parameters, and clinical outcomes. ANALYTICAL APPROACH: Univariate and multivariable linear mixed models, generalized linear mixed models, and proportional hazards models; cumulative incidence functions. RESULTS: During 314 cumulative patient-years, 628 CVCs, 225 AVFs, and 17 arteriovenous grafts were placed. One-third of the children with an AVF required a temporary CVC until fistula maturation. Vascular access choice was associated with age and expectations for early transplantation. There was a 3-fold higher living related transplantation rate and lower median time to transplantation of 14 (IQR, 6-23) versus 20 (IQR, 14-36) months with CVCs compared with AVFs. Higher blood flow rates and Kt/Vurea were achieved with AVFs than with CVCs. Infectious complications were reported only with CVCs (1.3/1,000 catheter-days) and required vascular access replacement in 47%. CVC dysfunction rates were 2.5/1,000 catheter-days compared to 1.2/1,000 fistula-days. CVCs required 82% more revisions and almost 3-fold more vascular access replacements to a different site than AVFs (P<0.001). LIMITATIONS: Clinical rather than population-based data. CONCLUSIONS: CVCs are the predominant vascular access choice in children receiving HD within the IPHN. Age-related anatomical limitations and expected early living related transplantation were associated with CVC use. CVCs were associated with poorer dialysis efficacy, higher complication rates, and more frequent need for vascular access replacement. Such findings call for a re-evaluation of pediatric CVC use and practices.

Risk Factors for Early Dialysis Dependency in Autosomal Recessive Polycystic Kidney Disease.

OBJECTIVE: To identify prenatal, perinatal, and postnatal risk factors for dialysis within the first year of life in children with autosomal recessive polycystic kidney disease (ARPKD) as a basis for parental counseling after prenatal and perinatal diagnosis. STUDY DESIGN: A dataset comprising 385 patients from the ARegPKD international registry study was analyzed for potential risk markers for dialysis during the first year of life. RESULTS: Thirty-six out of 385 children (9.4%) commenced dialysis in the first year of life. According to multivariable Cox regression analysis, the presence of oligohydramnios or anhydramnios, prenatal kidney enlargement, a low Apgar score, and the need for postnatal breathing support were independently associated with an increased hazard ratio for requiring dialysis within the first year of life. The increased risk associated with Apgar score and perinatal assisted breathing was time-dependent and vanished after 5 and 8 months of life, respectively. The predicted probabilities for early dialysis varied from 1.5% (95% CI, 0.5%-4.1%) for patients with ARPKD with no prenatal sonographic abnormalities to 32.3% (95% CI, 22.2%-44.5%) in cases of documented oligohydramnios or anhydramnios, renal cysts, and enlarged kidneys. CONCLUSIONS: This study, which identified risk factors associated with onset of dialysis in ARPKD in the first year of life, may be helpful in prenatal parental counseling in cases of suspected ARPKD.

Leptin and ghrelin in chronic kidney disease: their associations with protein-energy wasting.

BACKGROUND: This study aimed to evaluate plasma concentrations of leptin and total ghrelin in children with chronic kidney disease (CKD) and assess their roles in protein-energy wasting (PEW). METHODS: This study consisted of three different CKD populations [CKD group (20 patients with non-dialysis CKD), dialysis group (39 patients on dialysis), and kidney transplant (KTx) group (35 KTx recipients)] and control group (18 healthy children). Plasma leptin and total ghrelin levels were measured. Multi-frequency bioimpedance analysis was used for the assessment of fat and lean mass. PEW was defined using criteria including body mass, muscle mass, growth, serum albumin level, and protein intake. RESULTS: While plasma leptin levels did not differ among the study groups, total ghrelin levels were significantly higher in the dialysis group (P < 0.001). Seven dialysis patients (18%) and one CKD patient (5%) but none of the KTx recipients met the criteria of PEW. Dialysis patients with PEW had lower plasma leptin levels compared to their counterparts (P = 0.018); however, total ghrelin levels did not differ between the two groups (P = 0.10). Low leptin level in dialysis patients was independently associated with lower fat mass index (P < 0.001) and lower height-specific SD scores of BMI (P = 0.019). CONCLUSIONS: PEW is prevalent in dialysis patients. Low levels of leptin seem to be associated with PEW. Our result suggests that low leptin levels may be a consequence rather than a cause of PEW. Longitudinal studies are required to investigate this complex relationship between leptin and PEW in pediatric dialysis patients.

Outbreak of Shiga toxin-producing Escherichia-coli-associated hemolytic uremic syndrome in Istanbul in 2015: outcome and experience with eculizumab.

BACKGROUND: This study aims to identify epidemiological and clinical characteristics of patients and report our experience with eculizumab treatment during an outbreak of hemolytic uremic syndrome (HUS) caused by Shiga toxin-producing Escherichia coli (STEC) in Istanbul in 2015. METHODS: Thirty-two children (21 females, median age 3.25 years) were included in this study. Demographic, clinical and laboratory data, and treatment details were retrospectively collected. Renal outcomes were assessed at last follow-up visit. To assess the effect of eculizumab on prognosis of STEC-HUS, subgroup analysis was performed on patients who required dialysis. RESULTS: A high number of cases occurred within a certain region of Istanbul. Stool samples were cultured from 21 patients (65%), and enteroaggregative E. coli (EAEC; n = 7) and enterohemorrhagic E. coli (EHEC; n = 3) strains were detected. Rates of dialysis treatment, neurological manifestations, and death were 59%, 25%, and 3%, respectively. Mean follow-up duration was 8.6 ± 2.6 months (range 3-12 months). None of the patients (n = 25) was on dialysis at the final visit. The complete renal recovery rate was 54%. Nine patients were treated with eculizumab. At final follow-up visit, no differences in estimated glomerular filtration rate, proteinuria level, or hypertension incidence were observed between patients treated with eculizumab and those not treated with eculizumab. CONCLUSIONS: An outbreak of EAEC occurred in a specific region of Istanbul. Livestock markets were suspected as the source. Evidence for beneficial effects of eculizumab on renal outcome was not clear in this cohort.

Time-averaged hemoglobin values, not hemoglobin cycling, have an impact on outcomes in pediatric dialysis patients.

BACKGROUND: During erythropoietin-stimulating agent (ESA) treatment, hemoglobin (Hb) levels usually fluctuate; this phenomenon is known as "Hb cycling (HC)." In this study, we aimed to evaluate the predictors of HC and its impact on left ventricular hypertrophy (LVH) as a patient-important outcome parameter in pediatric dialysis patients. METHODS: Records of patients followed up in nine pediatric nephrology centers between 2008 and 2013 were reviewed. More than 1 g/dL decrease or increase in Hb level was considered as HC. Patients were divided into two groups according to 12-month Hb trajectory as rare cycling (RC) (≤ 3) and frequent cycling (FC) (> 3 fluctuation) as well as three groups based on T-A-Hb levels: < 10, 10-11, and > 11 g/dL. RESULTS: Two hundred forty-five dialysis (160 peritoneal dialysis (PD) and 85 hemodialysis (HD)) patients aged 12.3 ± 5.1 (range 0.5-21) years were enrolled in this study. Fifty-two percent of the patients had RC, 45% had FC, and only 3% had no cycling. There were no differences between HC groups with respect to age, dialysis modality, having anemia, hospitalization rate, residual urine volume, and mortality. Although left ventricular mass index (LVMI) tended to be higher in RC than FC group (65 ± 37 vs 52 ± 23 g/m2.7, p = 0.056), prevalence of LVH was not different between the groups (p = 0.920). In regression analysis, FC was not a risk factor for LVH, but low T-A Hb level (< 10 g/dL) was a significant risk for LVH (OR = 0.414, 95% CI 0.177-0.966, p = 0.04). The target Hb levels were more often achieved in PD patients, and the number of deaths was significantly lower in non-anemic patients (Hb level > 11 g/dL). CONCLUSION: Hb cycling is common among dialysis patients. Severity of anemia rather than its cycling has more significant impact on the prevalence of LVH and on inflammatory state.

Silicate calculi, a rare cause of kidney stones in children.

BACKGROUND: Urinary silicate calculi in humans are extremely rare. Reported cases of silicate calculi are mostly documented in adults and are commonly related to an excessive intake of magnesium trisilicate in food or drugs. Published studies on the presence of silicate calculi in children are scarce. CASES: Three cases of silicate kidney stones without prior silicate intake are reported. Two patients underwent surgical treatment, and the third patient was treated using conservative methods. Urinalysis revealed no underlying metabolic abnormalities. Analyses revealed that silicate was the major component of the stones. CONCLUSION: Siliceous deposits in urinary stones may be more common than anticipated, and the underlying pathophysiology remains to be clarified.

Effect of the timing of dialysis initiation on left ventricular hypertrophy and inflammation in pediatric patients.

BACKGROUND: The optimal time for dialysis initiation in adults and children with chronic kidney disease remains unclear. The aim of this study was to evaluate the impact of dialysis timing on different outcome parameters, in particular left ventricular (LV) morphology and inflammation, in pediatric patients receiving peritoneal dialysis and hemodialysis. METHODS: The medical records of pediatric dialysis patients who were followed-up in nine pediatric nephrology centers in Turkey between 2008 and 2013 were retrospectively reviewed. In addition to demographic data, we retrieved anthropometric measurements, data on dialysis treatment modalities, routine biochemical parameters, complete blood count, serum ferritin, parathormone, C-reactive protein (CRP), and albumin levels, as well as echocardiographic data and hospitalization records. The patients were divided into two groups based on their estimated glomerular filtration rate (eGFR) levels at dialysis initiation, namely, an early-start group, characterized by an eGFR of >10 ml/min/1.73 m2, and a late-start group, with an eGFR of < 7 ml/min/1.73 m2. The collected data were compared between these groups. RESULTS: A total of 245 pediatric dialysis patients (mean age ± standard deviation 12.3 ± 5.1 years, range 0.5-21 years) were enrolled in this study. Echocardiographic data were available for 137 patients, and the mean LV mass index (LVMI) was 58 ± 31 (range 21-215) g/m2.7. The LVMI was 75 ± 30 g/m2.7(n = 81) and 34 ± 6 g/m2.7(n = 56) in patients with or without LV hypertrophy (LVH) (p < 0.001). Early-start (eGFR >10 ml/min/1.73 m2) versus late-start dialysis (eGFR < 7 ml/min/1.73 m2) groups did not significantly differ in LVMI and LVH status (p > 0.05) nor in number of hospitalizations. Serum albumin levels were significantly higher in the early-dialysis group compared with the late-dialysis group (3.3 ± 0.7 vs. 3.1 ± 0.7 g/dl, respectively; p < 0.05). The early-start group had relatively higher time-averaged albumin levels (3.2 ± 0.5 vs. 3.1 ± 0.5 g/dl; p = > 0.05) and relatively lower CRP levels (3.64 ± 2.00 vs. 4.37 ± 3.28 mg/L, p > 0.05) than the late-start group, but these differences did not reach statistical significance. CONCLUSION: Although early dialysis initiation did not have a significant effect on important clinical outcome parameters, including LVH, inflammatory state, and hospitalization, in our pediatric dialysis patients, this area of study deserves further attention.