Comparative analysis of hospitalizations among patients treated with hemodialysis and peritoneal dialysis in European pediatric nephrology centers: results from a prospective EPDWG/ESPN Dialysis Working Group study.

Background and hypothesis: Hospital admissions in pediatric dialysis patients need to be better studied, and most existing studies are retrospective and based on registry data. This study aimed to analyse and compare hospital admission rates, causes, length of stay (LOS), and outcomes in children treated with peritoneal dialysis (PD) and hemodialysis (HD). Methods: Data from 236 maintenance PD and 138 HD patients across 16 European dialysis centers were collected between 1 July 2017 and 30 June 2018. A total of 178 hospitalized patients (103 PD, 75 HD) were included for further analyses. Results: There were 465 hospitalization events (268 PD, 197 HD) with a rate of 0.39 admissions per 100 patient-days at risk (PDAR) and 2.4 hospital days per 100 PDAR. The admission rates were not significantly different between HD and PD patients. The most common causes of hospitalization were access-related infections (ARI) (17%), non-infectious complications of access (NIAC) (14%), and infections unrelated to access (12%). ARI was the leading cause in PD patients (24%), while NIAC was more common in HD patients (19%). PD patients had more ARIs, diagnostic procedures, and treatment adjustments (P < .05), while HD patients had more NIACs, infections unrelated to access, access placement procedures, and interventional/surgical procedures (P < .001). LOS was longer with acute admissions than non-acute admissions (P < .001). Overall LOS and LOS in the intensive care unit were similar between HD and PD patients. High serum uric acid and low albumin levels were significant predictors of longer LOS (P = .022 and P = .045, respectively). Young age, more significant height deficit, and older age at the start of dialysis were predictors of longer cumulative hospital days (P = .002, P = .001, and P = .031, respectively). Conclusion: Access-related complications are the main drivers of hospitalization in pediatric dialysis patients, and growth and nutrition parameters are significant predictors of more extended hospital stays.

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.

Characteristics and predictors of chronic kidney disease in children with myelomeningocele: a nationwide cohort study.

BACKGROUND: Myelomeningocele (MMC) is highly prevalent in developing countries, and MMC-related neurogenic bladder is an important cause of childhood chronic kidney disease (CKD). This nationwide study aimed to evaluate demographic and clinical features of pediatric patients with MMC in Turkey and risk factors associated with CKD stage 5. METHODS: Data from children aged 0-19 years old, living with MMC in 2022, were retrospectively collected from 27 pediatric nephrology centers. Patients > 1 year of age without pre-existing kidney abnormalities were divided into five groups according to eGFR; CKD stages 1-5. Patients on dialysis, kidney transplant recipients, and those with eGFR < 15 ml/min/1.73 m2 but not on kidney replacement therapy at time of study constituted the CKD stage 5 group. RESULTS: A total of 911 (57.8% female) patients were enrolled, most of whom were expectantly managed. Stages 1-4 CKD were found in 34.3%, 4.2%, 4.1%, and 2.4%, respectively. CKD stage 5 was observed in 5.3% of patients at median 13 years old (range 2-18 years). Current age, age at first abnormal DMSA scan, moderate-to-severe trabeculated bladder on US and/or VCUG, and VUR history were independent risk factors for development of CKD stage 5 (OR 0.752; 95%; CI 0.658-0.859; p < 0.001; OR 1.187; 95% CI 1.031-1.367; p = 0.017; OR 10.031; 95% CI 2.210-45.544; p = 0.003; OR 2.722; 95% CI 1.215-6.102; p = 0.015, respectively). Only eight CKD stage 5 patients underwent surgery related to a hostile bladder between 1 and 15 years old. CONCLUSION: MMC-related CKD is common in childhood in Turkey. A proactive approach to neurogenic bladder management and early protective surgery in selected cases where conservative treatment has failed should be implemented to prevent progressive kidney failure in the pediatric MMC population in our country.

Outcomes of Maintenance Peritoneal Dialysis in Children: A State Hospital Experience from Southeastern Turkey.

This study aimed to evaluate the clinical features, laboratory features, and outcomes of pediatric patients on peritoneal dialysis (PD) and compare the factors affecting mortality. The demographic, clinical, and laboratory data of 50 patients on maintenance PD followed up for more than 3 months were retrospectively analyzed for non-survivors and survivors to evaluate all factors affecting mortality. The patients (26 boys and 24 girls) had a mean age of 85.4 ± 58.7 months (range: 1-194 months) at the initiation of PD. The mean duration of dialysis at follow-up was 27.8 ± 21.7 months (range: 3-115 months). The rate of peritonitis was one episode per 27.27 patient months. PD was discontinued because of transplantation in eight patients, death in eight patients, and shifting to hemodialysis in three patients. In the Kaplan-Meier analysis, the 1-year patient survival rate at 1 year, 2 years, and 5 years was 81.8%, 51.7%, and 12.3%, respectively. Non-survivors were significantly younger at the start of kidney replacement therapy, had a final younger age at dialysis, and had lower albumin levels than survivors. We excluded four patients with a follow-up period of <6 months. Cox regression analysis revealed a low albumin status (P = 0.014, hazard ratio: 0.230) and a high level of ferritin (P = 0.002, hazard ratio: 1.002) to be risk factors for mortality. This study showed a high mortality rate. Hypoalbuminemia, a younger age at the start of kidney replacement therapy, and a younger final age at dialysis had a significant association with mortality.

Clinical usefulness of anti-nuclear antibody in childhood: real-world experience at a tertiary care center : Usefulness of ANA in pediatric autoimmune diseases.

We evaluated the reasons for requesting anti-nuclear antibody (ANA) analysis in clinical practice at a tertiary center and the performance of ANA in pediatric autoimmune diseases. Patients under 18 years of age who underwent ANA testing for various symptoms between 2013 and 2017 were included. We retrieved data from medical records, including demographic and clinical characteristics, diagnoses, ANA results, titers, and staining patterns. The performance assessment tools were calculated according to the ANA titer for autoimmune diseases. Risk factors for autoimmune diseases in ANA-positive patients were evaluated using logistic regression analysis. Changes in ANA titer and seroconversion were evaluated using repeated ANA analyses. A total of 3812 patients underwent ANA. Medical records of 3320 patients were obtained. The rate of ANA positivity was 27.4%. ANA was requested most frequently because of musculoskeletal findings in 1355 patients (40.8%). Juvenile idiopathic arthritis (n = 174, 20.2%) was the most common diagnosis in ANA-positive patients, followed by systemic lupus erythematosus (n = 52, 6%). For autoimmune diseases, a titer of ≥ 1:100, a sensitivity of 40.1%, and a specificity of 77.1% were observed. At a titer ≥ 1:1000, the sensitivity and specificity were 24.1% and 89%, respectively. Homogeneous staining was an additional risk factor for autoimmune diseases in ANA-positive patients by multivariate logistic regression analysis (OR [95% CI]: 4.562 [3.076-6.766], p < 0.001).    Conclusion: Our results revealed that the performance of the ANA test in diagnosing autoimmune diseases in pediatric clinical practice was poor. Therefore, clinical findings should be carefully evaluated before ANA testing is performed. What is Known: • ANA can be detected in systemic autoimmune rheumatic diseases. • The diagnostic role of ANA is controversial, especially in childhood. What is New: • One in four patients who requested the ANA test had an autoimmune disease. • Less than half of patients with an autoimmune disease had ANA positivity.

The effects of hospital and dialysis unit characteristics on hospitalizations for access-related complications among children on maintenance dialysis: a European, multicenter, observational, cross-sectional study.

BACKGROUND: Previous studies investigating hospitalizations in dialysis patients have focused primarily on patient-centered factors. We analyzed the impact of hospital and dialysis unit characteristics on pediatric dialysis patients' hospitalizations for access-related complications (ARCs). METHODS: This cross-sectional study involved 102 hemodialysis (HD) and 163 peritoneal dialysis (PD) patients. Data between July 2017 and July 2018 were analyzed. RESULTS: Children's hospitals (CHs) had more pediatric nephrologists and longer PD experience (years) than general hospitals (GHs) (p = 0.026 and p = 0.023, respectively). A total of 53% of automated PD (APD) and 6% of continuous ambulatory PD (CAPD) patients were in CHs (p < 0.001). Ninety-three percent of APD and 69% of CAPD patients were treated in pediatric-specific PD units (p = 0.001). CHs had a higher prevalence in providing hemodiafiltration (HDF) than GHs (83% vs. 30%). Ninety-seven percent of HDF vs. 66% for conventional HD (cHD) patients, and 94% of patients with arteriovenous fistula (AVF) vs. 70% of those with central venous catheters (CVC), were dialyzed in pediatric-specific HD units (p = 0.001 and p = 0.016, respectively). Eighty patients (51 PD and 29 HD) had 135 (84 PD, 51 HD) hospitalizations. CAPD was an independent risk factor for hospitalizations for infectious ARCs (I-ARCs) (p = 0.009), and a health center's PD experience negatively correlated with CAPD patient hospitalizations for I-ARCs (p = 0.041). cHD and dialyzing in combined HD units significantly increased hospitalization risk for non-infectious (NI-)ARCs (p = 0.044 and p = 0.017, respectively). CONCLUSIONS: CHs and pediatric-specific dialysis units have higher prevalence of APD and HDF use. Hospitalizations for I-ARCs in CAPD are lower in centers with longer PD experience, and pediatric HD units are associated with fewer hospitalizations due to NI-ARCs. A higher resolution version of the Graphical abstract is available as Supplementary information.

Peritoneal dialysis for term neonates in a neonatal intensive care unit.

BACKGROUND: This study aimed to evaluate the indications, complications, and outcomes of peritoneal dialysis (PD) in term neonates from a state hospital. METHODS: The demographic, clinical, and laboratory data of 67 newborn term infants who underwent PD within the first 4 weeks of life between June 2014 and June 2019 were retrospectively analyzed. RESULTS: Twenty-five patients (37.3%) were male, 42 (63.7%) were female. The mean gestational age was 38.3 ± 0.8 (range: 37-40) weeks and mean birthweight 3,100 ± 504.9 g (range: 1,800-5,000 g). The mean age of patients at the start of dialysis was 7.97 ± 8.34 days (range:1-44 days) and the mean duration for dialysis was 3 ± 5.42 days (range 1-40 days). The majority of patients who underwent PD had inborn error of metabolism (59.7%). The most common complication was dialysate leakage. Thirty-three neonates (49.2%) died during PD process because of underlying disease, 17 patients (25.4%) were referred to other centers, and 17 patients (25.4%) were discharged. There were seven acute kidney injury patients associated with hypernatremic dehydration. There were statistically significant differences between non-survivors and survivors in terms of dialysis duration, birthweight, weight at admission, requirements for mechanical ventilation, and inotrop agent, and also the renal angina index. CONCLUSIONS: In our region, hypernatremic dehydration is still a one of the major cause for acute kidney injury (AKI) in newborns. In state hospitals, pediatric specialists must be present in neonatal intensive care units in order not to refer unstable patients to other centers and to provide high-quality patient care.

Sociodemographic features and outcomes of peritonitis episodes in children on peritoneal dialysis.

INTRODUCTION: Peritoneal dialysis (PD) is one of the most preferred kidney replacement therapies in children. However, it has an important complication such as peritonitis. This study was planned to investigate the causes and frequency of peritonitis in children with PD. METHODS: The demographic features, peritonitis episodes, and microbiological characteristics of PD patients followed up for 5 years. RESULTS: Overall, 50 pediatric PD patients who met the study criteria in a 5-year period were included in the study. Consanguineous marriage was 64% and 44% of the mothers was illiterate. A total of 19 patients had no peritonitis episode, and a total of 54 peritonitis episode were experienced. The overall peritonitis rate was one episode per 24.4 patient-months. Culture negativity rate was 44%. CONCLUSION: Even though factors such as the education level of the parents, the number of people or rooms in the house, dialysis modality were thought to influence peritonitis episodes, they could not be shown statistically.

Erythropoietin Resistance Index and the Affecting Factors in Children with Peritoneal Dialysis.

BACKGROUND: Erythropoiesis-stimulating agents (ESAs) are used to treat anemia in CKD. Erythropoietin resistance index (ERI) is a useful tool used to evaluate the response to ESAs. In this study, we aimed to evaluate the causes of high ERI in children undergoing peritoneal dialysis (PD). METHOD: Patients who had been on PD for at least 1 year were included in this retrospective study. Demographic characteristics, residual kidney function (RKF), adequacy of dialysis, peritoneal glucose exposure, the number and reason for hospitalization, and medications were recorded. Anemia and laboratory parameters that may affect anemia were noted by taking the average of laboratory values in the last follow-up year (time-averaged). The weekly ESA dose was proportioned to the annual average hemoglobin value and body weight to calculate the ERI in terms of U/kg/week/g/dL. RESULTS: A total of 100 patients were included in the study. The mean ESA dose and ERI value were 119.8 ± 66.22 U/kg/week and 13.01 ± 7.52 U/kg/week/g/dL, respectively. It was determined that the patients <5 years of age have very high ERI value, and these patients need 2 times more ESA than those >10 years of age. Absence of RKF, large number of hospitalization, and ACEI use were also found to affect the ERI value negatively. CONCLUSION: We demonstrate that the most important factor affecting ERI value is young age. We also reveal that absence of RKF, large number of hospitalization, and ACEI use are also important variables affecting the ERI value.

Do children with solitary or hypofunctioning kidney have the same prevalence for masked hypertension?

BACKGROUND: Having a low nephron number is a well-known risk factor for hypertension. There is an inverse relationship between the filtration surface area and systemic hypertension. A significant percentage of masked hypertension can be detected in children with nephron loss by ambulatory blood pressure monitoring (ABPM). METHODS: We prospectively investigated ABPM results of children having reduced kidney mass with normal office blood pressures (BPs) and kidney function. Forty-three children with congenital solitary kidney (group 1), 11 children with acquired solitary kidney (group 2), and 76 children with hypofunctioning kidney (group 3) were compared with age, gender, and BMI-matched healthy control group (group 4). The dietary salt intake of 76 patients was evaluated as salt equivalent (g/day). The primary endpoint was change from baseline in mean 24-h ABPM variables and the proportion of patients with masked hypertension when assessed by ABPM. RESULTS: The masked hypertension ratio of all patients was 12.3% when assessed with ABPM. Night hypertension was significantly higher in all patient groups than in the control group (p = 0.01). Diastolic BP loads of groups 1 and 3 were higher than in controls (p = 0.024). Systolic BP loads were higher only in group 1 than in the control group (p = 0.003). The dietary salt equivalent of patients in group 1 correlated positively with 24-h SBP and mean arterial pressure (MAP) values. Patients with excessive dietary salt intake in group 1 had a significantly higher diastolic BP load than those without excessive salt intake in group 1 (p = 0.002). CONCLUSIONS: Masked hypertension can be seen in children with a solitary kidney or when one of the kidneys is hypofunctioning. Systolic BP loads are higher in children with congenital solitary kidney, and salt intake correlates with systolic BP profiles especially in those. Our results suggest that being born with a congenital solitary kidney increases predisposition to hypertension and salt sensitivity.

Predictors of poor kidney outcome in children with C3 glomerulopathy.

BACKGROUND: C3 glomerulopathy (C3G) is characterized by heterogeneous clinical presentation, outcome, and predominant C3 accumulation in glomeruli without significant IgG. There is scarce outcome data regarding childhood C3G. We describe clinical and pathological features, treatment and outcomes, and risk factors for progression to chronic kidney disease stage 5 (CKD5) in the largest pediatric series with biopsy-proven C3G. METHODS: Sixty pediatric patients with C3G from 21 referral centers in Turkey were included in this retrospective study. Patients were categorized according to CKD stage at last visit as CKD5 or non-CKD5. Demographic data, clinicopathologic findings, treatment, and outcome data were compared and possible risk factors for CKD5 progression determined using Cox proportional hazards model. RESULTS: Mean age at diagnosis was 10.6 ± 3.0 years and follow-up time 48.3 ± 36.3 months. Almost half the patients had gross hematuria and hypertension at diagnosis. Nephritic-nephrotic syndrome was the commonest presenting feature (41.6%) and 1/5 of patients presented with nephrotic syndrome. Membranoproliferative glomerulonephritis was the leading injury pattern, while 40 patients had only C3 staining. Patients with DDD had significantly lower baseline serum albumin compared with C3GN. Eighteen patients received eculizumab. Clinical remission was achieved in 68.3%. At last follow-up, 10 patients (16.6%) developed CKD5: they had lower baseline eGFR and albumin and higher frequency of nephrotic syndrome and dialysis requirement than non-CKD5 patients. Lower serum albumin and eGFR at diagnosis were independent predictors for CKD5 development. CONCLUSIONS: Children with C3G who have impaired kidney function and hypoalbuminemia at diagnosis should be carefully monitored for risk of progression to CKD5. Graphical abstract.

Additional VCUG-related parameters for predicting the success of endoscopic injection in children with primary vesicoureteral reflux.

INTRODUCTION AND OBJECTIVE: Prediction of vesicoureteral reflux (VUR) prognosis and decision for treatment are usually made according to the reflux grading classification. But the management of VUR is still controversial since there are difficulties in distinguishing reflux grade due to inter- and intra-observer variations. Previous studies have demonstrated that the distal ureteral diameter ratio (UDR) on voiding cystourethrography (VCUG) may be more predictive for clinical prognosis than reflux grade. We aimed to predict the success of endoscopic injection in primary VUR by creating new models that include other additional parameters (timing of reflux, delayed post-voiding contrast drainage of the upper urinary tract) as well as UDR. STUDY DESIGN: A total of 200 patients aged 2-15 years with primary VUR undergoing endoscopic injection were retrospectively evaluated. Demographic and clinical data for a total of 248 renal units were recorded. Besides reflux grade and laterality, distal ureteral diameter, UDR, timing of reflux [early filling, late filling or voiding] and presence of contrast delay in upper tract drainage were also assessed on VCUG. According to the complete resolution of VUR on the control VCUG at the postoperative 3rd month, the renal units were divided into two main groups: successful (n = 171, 68.9%) and unresolved (n = 77, 31.1%) RESULTS: The failure rate of endoscopic injection was found to be 4.068 times greater with early filling reflux on VCUG, 3.076 times greater with UDR>0.24, 2.745 times greater with delayed contrast drainage of the upper urinary tract, 2.666 times greater with the presence of scar in DMSA, 2.493 times greater with bladder-bowel dysfunction and 2.341 times greater with febrile urinary tract infection. We also observed that a model in which all VCUG-related parameters were combined provided a better estimation of endoscopic injection outcomes compared to only the reflux grade (AUC: 0.903 vs. 0.604, respectively). DISCUSSION: Distal ureteral dilatation is considered to be a more decisive factor for clinical outcomes of primary VUR rather than upper urinary tract dilatation since ureterovesical junction anatomy plays a more important role in primary VUR pathophysiology. Studies investigating new prediction models on this topic have recently become more popular. However, a consensus has not yet been achieved. CONCLUSION: We consider that UDR level, the timing of reflux and delayed upper tract drainage on VCUG may be more predictive parameters of endoscopic injection success compared with reflux grade, and could facilitate selecting the best candidates for surgery.

Treatment and long-term outcome in primary nephrogenic diabetes insipidus.

BACKGROUND: Primary nephrogenic diabetes insipidus (NDI) is a rare disorder and little is known about treatment practices and long-term outcome. METHODS: Paediatric and adult nephrologists contacted through European professional organizations entered data in an online form. RESULTS: Data were collected on 315 patients (22 countries, male 84%, adults 35%). Mutation testing had been performed in 270 (86%); pathogenic variants were identified in 258 (96%). The median (range) age at diagnosis was 0.6 (0.0-60) years and at last follow-up 14.0 (0.1-70) years. In adults, height was normal with a mean (standard deviation) score of -0.39 (±1.0), yet there was increased prevalence of obesity (body mass index >30 kg/m2; 41% versus 16% European average; P < 0.001). There was also increased prevalence of chronic kidney disease (CKD) Stage ≥2 in children (32%) and adults (48%). Evidence of flow uropathy was present in 38%. A higher proportion of children than adults (85% versus 54%; P < 0.001) received medications to reduce urine output. Patients ≥25 years were less likely to have a university degree than the European average (21% versus 35%; P = 0.003) but full-time employment was similar. Mental health problems, predominantly attention-deficit hyperactivity disorder (16%), were reported in 36% of patients. CONCLUSION: This large NDI cohort shows an overall favourable outcome with normal adult height and only mild to moderate CKD in most. Yet, while full-time employment was similar to the European average, educational achievement was lower, and more than half had urological and/or mental health problems.

Evaluation of the children with C3 glomerulopathy.

C3 glomerulopathy (C3G) is a clinical spectrum that presents with a variety of symptoms, ranging from a mild disease with asymptomatic microhematuria and/or proteinuria to severe disease with nephritic or nephrotic syndrome and renal impairment. Herein, we aim to document the clinical and laboratory findings, response to immunosuppressive and supportive treatment and prognosis of the children with C3G. We retrospectively reviewed the medical records of patients diagnosed with membranoproliferative glomerulonephritis (MPGN). Kidney biopsy materials were reexamined for the diagnosis of C3G. The inclusion criteria for C3G are the dominant C3 staining with or without scanty immunoglobulins (Ig) deposition on immuno- fluorescence (IF) and MPGN patterns on light microscope. Twelve of 69 patients with MPGN were included in the study based on the definition criteria of C3G. Ten of them had only C3 staining and the rest of the patients had both C3 staining and a small amount of IgG/M staining on IF microscopy. One patient was on remission with only ACEI. The rest of the patients used immunosuppressive treatment and two of them needed eculizumab therapy. One of them did not respond to the treatment of eculizumab and progressed to end-stage renal failure. C3G is a disease characterized by a heterogeneous clinical presentation and outcome. Because of this broad spectrum of disease, treatment may vary widely. We think that complement-targeting therapy with eculizumab should be an alternative option for refractory cases, especially in the early stage of disease, if they did not respond to immunosuppressive treatment.

Calcified renal artery aneurism in the right kidney causing hypertension.

The renal artery aneurysm (RAA) is defined as a renal artery segment that is twofold dilated than normally. It is very rare in children and often asymptomatic. However, it can cause severe hypertension (HTN) and kidney failure. Herein, we report a 14-year-old boy who with RAA which was presented with back pain. His medical history was remarkable for essential HTN that was refractory to antihypertensive medications. Plain abdominal radiography revealed calcification at the right flank area. On computed tomography images, calcification surrounding the right renal artery was detected. Selective renal angiography showed totally occluded right renal artery segment. Calcified RAA was detected on the operation and removed. Two months after, blood pressure was under control, but there was no functioning right kidney on DMSA. We think that clinicians should keep in mind RAA in the differential diagnosis of treatment-resistant HTN and use other radiologic methods even if Doppler is normal.

Patient Outcomes of Henoch-Schönlein Purpura Nephritis According to the New Semiquantitative Classification.

Background: A new semiquantitative classification (SQC) for pediatric Henoch-Schönlein nephritis (HSN) was defined recently. The outcomes of pediatric HSN patients are reevaluated according to the new classification. Methods: Primary kidney biopsies from 80 HSN patients were scored using the new SQC. The International Study of Kidney Disease in Children (ISKDC) and SQC classifications were compared in terms of the patient outcomes. Outcomes were defined as: Outcome A (n = 44) patients with no sign of renal disease, Outcome B (n = 32) patients with minor urinary abnormalities, and Outcome C (n = 4) patients with active renal disease. Results: The patients with outcome C had significantly higher biopsy scores and chronicity indices than patients in group A. There was no significant difference in areas under the curve between total biopsy SQC scores and ISKDC findings. Conclusions: Our results suggest that the modified SQC is not more sensitive than ISKDC classification for predicting the outcome in HSN cases.

Treatment and long-term outcome in primary distal renal tubular acidosis.

BACKGROUND: Primary distal renal tubular acidosis (dRTA) is a rare disorder, and we aimed to gather data on treatment and long-term outcome. METHODS: We contacted paediatric and adult nephrologists through European professional organizations. Responding clinicians entered demographic, biochemical, genetic and clinical data in an online form. RESULTS: Adequate data were collected on 340 patients (29 countries, female 52%). Mutation testing had been performed on 206 patients (61%); pathogenic mutations were identified in 170 patients (83%). The median (range) presentation age was 0.5 (0-54) years and age at last follow-up was 11.0 (0-70.0) years. Adult height was slightly below average with a mean (SD score) of -0.57 (±1.16). There was an increased prevalence of chronic kidney disease (CKD) Stage ≥2 in children (35%) and adults (82%). Nephrocalcinosis was reported in 88%. Nephrolithiasis was more common with SLC4A1 mutations (42% versus 21%). Thirty-six percent had hearing loss, particularly in ATP6V1B1 (88%). The median (interquartile range) prescribed dose of alkali (mEq/kg/day) was 1.9 (1.2-3.3). Adequate metabolic control (normal plasma bicarbonate and normocalciuria) was achieved in 158 patients (51%), more commonly in countries with higher gross domestic product (67% versus 23%), and was associated with higher height and estimated glomerular filtration rate. CONCLUSION: Long-term follow-up from this large dRTA cohort shows an overall favourable outcome with normal adult height for most and no patient with CKD Stage 5. However, 82% of adult patients have CKD Stages 2-4. Importance of adequate metabolic control was highlighted by better growth and renal function but was achieved in only half of patients.