Long term clinical follow up of four patients with Wolfram syndrome and urodynamic abnormalities.

OBJECTIVES: Wolfram syndrome is characterised by insulin-dependent diabetes (IDDM), diabetes insipidus (DI), optic atrophy, sensorineural deafness and neurocognitive disorders. The DIDMOAD acronym has been recently modified to DIDMOAUD suggesting the rising awareness of the prevalence of urinary tract dysfunction (UD). End stage renal disease is the commonest cause of mortality in Wolfram syndrome. We present a case series with main objective of long term follow up in four children having Wolfram syndrome with evaluation of their urodynamic profile. METHODS: A prospective follow up of four genetically proven children with Wolfram syndrome presenting to a tertiary care pediatric diabetes clinic in Pune, India was conducted. Their clinical, and urodynamic parameters were reviewed. RESULTS: IDDM, in the first decade, was the initial presentation in all the four children (three male and one female). Three children had persistent polyuria and polydipsia despite having optimum glycemic control; hence were diagnosed to have DI and treated with desmopressin. All four patients entered spontaneous puberty. All patients had homozygous mutation in WFS1 gene; three with exon 8 and one with exon 6 novel mutations. These children with symptoms of lower urinary tract malfunction were further evaluated with urodynamic studies; two of them had hypocontractile detrusor and another had sphincter-detrusor dyssynergia. Patients with hypocontractile bladder were taught clean intermittent catheterization and the use of overnight drain. CONCLUSIONS: We report a novel homozygous deletion in exon 6 of WFS-1 gene. The importance of evaluation of lower urinary tract malfunction is highlighted by our case series. The final bladder outcome in our cases was a poorly contractile bladder in three patients.

New insights from the genetic work-up in early onset nephrotic syndrome: report from a registry in western India.

BACKGROUND: Eighty-five percent of infants with congenital nephrotic syndrome (CNS) and 66% with infantile NS (INS) are likely to have a monogenic etiology. There exists a significant genetic variability between different regions and ethnic groups. This study aimed to determine the genetic defects in children with CNS and INS by establishing a registry in western India. METHODS: In this cross-sectional study, pediatric nephrologists from 13 private and government institutions shared relevant clinical data and details of the genetic evaluation of children presenting with NS within the first year of life. RESULTS: The median age at presentation was 9 months (range 1-23, IQR 3-13 months), history of consanguinity between parents existed in 14 patients (34%), family history of similar illness in 6 (15%), and extra-renal manifestations in 17 (41%). Twenty-five (61%) were confirmed to have a monogenic etiology. NPHS1 gene was the most implicated (9/25) followed by PLCE1 (5/25). There were 12 variants of uncertain significance (VUS) involving 10 genes (10/25, 40%), and no definite genetic abnormality was found in 4 (25%). A re-analysis of these VUS attempted 2-3 years later facilitated reclassification of 7/12 (58%); increasing the diagnostic yield from 61 to 68.2%. CONCLUSIONS: Consistent with worldwide data, variants in NPHS1 gene were the most common cause of NS in infancy; however, PLCE1 was implicated more frequently in our cohort. NUP93 and COL4A3 were reported in early onset NS for the first time. Reclassification of VUS should be attempted, if feasible, since it may lead to a useful revision of diagnosis.

Delayed Hematological Remission Predicts Poor Renal Outcome in Children with Atypical Hemolytic Uremic Syndrome.

Background: Atypical hemolytic uremic syndrome (aHUS) is hemolytic uremic syndrome (HUS) without a coexisting disease or specific infection. Eculizumab is the standard of care for children with aHUS. However, since it is not yet available in India, plasma therapy remains the treatment of choice in these patients. We studied the clinical profile of children with aHUS and the determinants associated with low estimated glomerular filtration rate (eGFR) on follow-up. Materials and Methods: A retrospective chart review of children (1-18 years) with aHUS managed at a tertiary care center was done. Demographic details, clinical features, and investigations at presentation and on subsequent visits were noted. Details of treatment and duration of hospital stay were recorded. Results: Of 26 children, boys outnumbered girls (2:1). The mean age at presentation was 80 ± 37.6 months. All children were hypertensive during the early phase of illness. Anti-factor H antibodies were elevated in 84% (22/26). Plasma therapy was initiated for 25 patients, and in 17 children, additionally immunosuppression was given. The median duration to achieve hematological remission was 17 days. As compared to children with normal eGFR, those with CKD stage 2 or more had significant delay in initiation of plasma therapy (4 vs. 14 days) and also took a longer time to achieve hematological remission (15 vs. 28 days). The prevalence of hypertension and proteinuria at the last follow-up was 63% and 27%, respectively. Conclusion: Delayed initiation of plasma therapy and longer time to achieve hematological remission are associated with lower eGFR on follow-up. Long-term monitoring of hypertension and proteinuria is needed in these children.

Changes in bone biomarkers in response to different dosing regimens of cholecalciferol supplementation in children with chronic kidney disease.

BACKGROUND: The effect of different dosing regimens of cholecalciferol supplementation on bone biomarkers has not been studied in children with chronic kidney disease (CKD). METHODS: This is a post hoc analysis of a multi-center randomized controlled trial which included children with CKD stages 2-4 with vitamin D deficiency (25-hydroxy vitamin D (25OHD) < 30 ng/ml) randomized 1:1:1 to receive an equivalent dose of oral cholecalciferol as daily, weekly or monthly treatment. Markers of bone formation (bone alkaline phosphatase (BAP), procollagen I N terminal peptide (PINP)), bone resorption (tartarate-resistant acid phosphatase 5b (TRAP), C terminal telopeptide (CTX)), and osteocyte markers (intact fibroblast growth factor 23 (iFGF23), sclerostin) and soluble klotho were measured at baseline and after 3 months of intensive replacement therapy. The change in biomarkers and ratio of markers of bone formation to resorption were compared between treatment arms. BAP and TRAP were expressed as age- and sex-specific z-scores. RESULTS: 25OHD levels increased with cholecalciferol supplementation, with 85% achieving normal levels. There was a significant increase in the BAP/TRAP ratio (p = 0.04), iFGF23 (p = 0.004), and klotho (p = 0.002) with cholecalciferol therapy, but this was comparable across all three therapy arms. The BAPz was significantly higher in the weekly arm (p = 0.01). The change in 25OHD (Δ25OHD) inversely correlated with ΔPTH (r = - 0.4, p < 0.001). CONCLUSIONS: Although cholecalciferol supplementation was associated with a significant increase in bone formation, the three dosing regimens of cholecalciferol supplementation have a comparable effect on the bone biomarker profile, suggesting that they can be used interchangeably to suit the patient's needs and optimize adherence to therapy. A higher resolution version of the Graphical abstract is available as Supplementary information.

Population pharmacokinetics and dose optimisation of colecalciferol in paediatric patients with chronic kidney disease.

AIMS: The prevalence of vitamin D deficiency is high in children with chronic kidney disease (CKD). However, current dosing recommendations are based on limited pharmacokinetic (PK) data. This study aimed to develop a population PK model of colecalciferol that can be used to optimise colecalciferol dosing in this population. METHODS: Data from 83 children with CKD were used to develop a population PK model using a nonlinear mixed effects modelling approach. Serum creatinine and type of kidney disease (glomerular vs. nonglomerular disease) were investigated as covariates, and optimal dosing was determined based on achieving and maintaining 25-hydroxyvitamin D (25(OH)D) concentration of 30-48 ng/mL. RESULTS: The time course of 25(OH)D concentrations was best described by a 1-compartment model with the addition of a basal concentration parameter to reflect endogenous 25(OH)D production from diet and sun exposure. Colecalciferol showed wide between-subject variability in its PK, with total body weight scaled allometrically the only covariate included in the model. Model-based simulations showed that current dosing recommendations for colecalciferol can be optimised using a weight-based dosing strategy. CONCLUSION: This is the first study to describe the population PK of colecalciferol in children with CKD. PK model informed dosing is expected to improve the attainment of target 25(OH)D concentrations, while minimising the risk of overdosing.

Determining the optimal cholecalciferol dosing regimen in children with CKD: a randomized controlled trial.

BACKGROUND: The optimal treatment regimen for correcting 25-hydroxyvitamin D (25OHD) deficiency in children with chronic kidney disease (CKD) is not known. We compared cholecalciferol dosing regimens for achieving and maintaining 25OHD concentrations ≥30 ng/mL in children with CKD stages 2-4. METHODS: An open-label, multicentre randomized controlled trial randomized children with 25OHD concentrations <30 ng/mL in 1:1:1 to oral cholecalciferol 3000 IU daily, 25 000 IU weekly or 100 000 IU monthly for 3 months (maximum three intensive courses). In those with 25OHD ≥30 ng/mL, 1000 IU cholecalciferol daily (maintenance course) was given for up to 9 months. Primary outcome was achieving 25OHD ≥30 ng/mL at the end of intensive phase treatment. RESULTS: Ninety children were randomized to daily (n = 30), weekly (n = 29) or monthly (n = 31) treatment groups. At the end of intensive phase, 70/90 (77.8%) achieved 25OHD ≥30 ng/mL; 25OHD concentrations were comparable between groups (median 44.3, 39.4 and 39.3 ng/mL for daily, weekly and monthly groups, respectively; P = 0.24) with no difference between groups for time to achieve 25OHD ≥30 ng/mL (P = 0.28). There was no change in calcium, phosphorus and parathyroid hormone, but fibroblast growth factor 23 (P = 0.002) and klotho (P = 0.001) concentrations significantly increased and were comparable in all treatment groups. Irrespective of dosing regimen, children with glomerular disease had 25OHD concentrations lower than non-glomerular disease (25.8 versus 41.8 ng/mL; P = 0.007). One child had a 25OHD concentration of 134 ng/mL, and 5.5% had hypercalcemia without symptoms of toxicity. CONCLUSION: Intensive treatment with oral cholecalciferol as daily, weekly or monthly regimens achieved similar 25OHD concentrations between treatment groups, without toxicity. Children with glomerular disease required higher doses of cholecalciferol compared with those with non-glomerular disease.

Prevalence and subtypes of hypertension in normal-weight and obese Indian adolescents: a cross-sectional study.

This cross-sectional study examined the prevalence, stages, subtypes of hypertension, and the associated risk factors in adolescent school children in Western India. We screened 2,644 adolescents, from 10 different private and government schools in urban and rural areas for hypertension, as defined by the 2017 Clinical Practice Guidelines. The association of stages and subtypes with age, gender, body mass index, type of school, and place of residence was analysed. 197 children (7.5%) had hypertension; 170 (6.4%) had stage I, 27 (1%) had stage II and 76 (2.9%) had elevated blood pressure (EBP). The risk of EBP was higher in children > 15 years of age (p = 0.006). Compared with normal-weight children, obese, and overweight children had a higher risk of hypertension [odds ratio (OR) 9 (5.84, 13.88) and 3.77 (2.59, 5.48) respectively], whereas underweight children had a lower risk [OR 0.39 (0.16, 0.98)]. Normal-weight hypertension was seen in 5.2% and was higher in children from government schools (9.4%). Systolic-diastolic hypertension (SDH) was the most common subtype, seen in 136 (5.1%). SDH was more common in girls, in rural children, and in those with stage II hypertension. Isolated diastolic hypertension, seen in 51 (1.9%), was more common in boys, in urban children, and in those with EBP.

Novel Mutations in the DGKE Gene in Two Indian Patients with Early-onset Atypical Haemolytic Uraemic Syndrome.

Atypical haemolytic uremic syndrome (aHUS) is a clinically and genetically heterogeneous condition caused by a complex interplay between genomic susceptibility factors and environmental influences. Pathogenic variants in the DGKE gene are recently identified in cases with infantile-onset autosomal recessive aHUS. The presence of low serum C3 levels, however, has rarely been described in cases of DGKE-associated aHUS. Molecular genetic testing was performed by a commercial next-generation sequencing (NGS) panel as well and by an in-house developed targeted NGS for DGKE gene. Copy number variations (CNVs) were computed from NGS data by calculating a normalised copy number ratio of aligned number of reads at targeted genomic regions against multiple reference regions of the same sample and multiple controls. We report here two such novel clinically relevant variants (c.727_730delTTGT and c.251_259delGCGCCTTC) in the DGKE gene, in two families of infantile aHUS with low serum C3 levels.

Congenital Nephrotic Syndrome in India in the Current Era: A Multicenter Case Series.

BACKGROUND: There is a paucity of information on epidemiology, diagnosis, and treatment outcomes of congenital nephrotic syndrome (CNS) in developing countries. METHODS: Retrospective (2012-2017) review of case records undertaken across 12 Indian pediatric nephrology centers. RESULTS: Sixty-five children (58% male, median birth weight 2.4 kg [interquartile range (IQR) 2.1-2.86]) were identified with CNS. Nearly half (45%) were preterm with previous history of fetal loss/sibling death in 22% and history of consanguinity in a third. No infective etiology was confirmed. Genetic reports available for 15 (23%) children identified causal mutations in 10 (8 in NPHS1 [1 novel variant], 1 in WT 1 [novel variant], and 1 in PLCE-1 gene). In addition, 1 child was clinically diagnosed as Galloway Mowat syndrome. Next-generation sequencing showed 80% yield and Sanger sequencing 20%. Albumin infusion and angiotensin-converting enzyme inhibitors were used initially in around two-third of cohort, while only 12% of children received indomethacin. Totally, 22 (34%) children were lost to follow-up after initial visit, and among the rest median follow-up was 69 days (IQR 20-180) with 18 (42%) deaths. Eight children showed partial response (including 2 with NPHS1 compound mutation), 1 complete response, and all of them were alive at last follow-up in contrast to 53% mortality among nonresponders, p = 0.004. CONCLUSION: This largest reported series on CNS from India revealed suboptimal management with poor outcome as well as low number of CNS being subjected to genetic evaluation.

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.

Measurement of Intra-abdominal Pressure in Critically-ill Children.

INTRODUCTION: It is being increasingly recognized that intra-abdominal hypertension is an important cause of organ dysfunction. This pilot study was done to determine the feasibility of measuring intra-abdominal pressures (IAP) in critically-ill children using simple inexpensive equipment available in the PICU. MATERIALS AND METHODS: This was a prospective study done in the paediatric intensive care unit (PICU) of a tertiary care general hospital. Thirty-two consecutive patients admitted to the PICU, staying for more than 24 h and requiring a urinary catheter were studied. IAP was measured by the intravesical method, using a disposable manometer, twice a day for seven days or till discharge/death, Risk factors associated with IAH were recorded. RESULTS: The majority of the patients had an IAP less than 5 mm Hg. Three patients had grade 1 intra-abdominal hypertension (IAP>12 mm Hg). CONCLUSION: It is feasible to measure IAP in paediatric patients without the use of sophisticated equipment.