Background: Impaired endothelial function is a precursor of the atherosclerotic process leading to cardiovascular adverse events. This study evaluated endothelial dysfunction using endothelial markers in children with steroid-resistant NS (SRNS) and frequently relapsing or steroid-dependent NS (FRNS/SDNS). Methods: This was a cross-sectional study with short-term follow up. Thirty-five patients with nephrotic syndrome (NS), aged 1–18 years, including 19 with frequent relapses or steroid-dependent NS (FRNS/SDNS) and 16 with steroid resistant NS (SRNS), and 19 age- and gender-matched controls, were enrolled for the study. Soluble thrombomodulin (sTM), plasminogen activator inhibitor 1 (PAI-1), and von Willebrand factor (vWF) levels were measured in patients with FRNS/SDNS in relapse and after 6 months of steroid-induced remission, at diagnosis in SRNS, and in controls. Results: Levels of vWF, PAI-1, and sTM were significantly higher than controls in patients with active NS (FRNS/SDNS in relapse or SRNS; P < 0.0001). Patients with FRNS/SDNS had significantly elevated vWF levels, compared to controls, even after 6 months of corticosteroid therapy. Levels of vWF were significantly higher for patients with recently diagnosed SRNS than relapse of FRNS/SDNS (P < 0.0001). Conclusion: Children with FRNS/SDNS and SRNS have significant endothelial dysfunction in all stages of disease in varying severity. It is unclear whether persistently elevated biomarkers of endothelial dysfunction contribute to future atherosclerotic events in patients with NS.

Objective: This study was planned to study serum cystatin C (CysC) levels in sick neonates admitted in neonatal intensive care unit (NICU) with predisposing risk factor(s) for development of acute kidney injury (AKI). We evaluated serum levels of CysC and creatinine in sick neonates. Methods: Ninety-four sick neonates with prematurity, sepsis, respiratory distress, and/or perinatal asphyxia requiring NICU admission were enrolled. Serum levels of creatinine and CysC were measured on day 3 of life. Results: Serum levels of both cystatin C and creatinine were significantly elevated in neonates who developed AKI versus those who did not (CysC: 2.18 ± 0.59 vs. 1.91 ± 0.47 mg/dl, P = 0.04; creatinine: 1.68 ± 0.75 vs. 0.89 ± 0.40, P < 0.001). Levels of CysC were elevated in sick neonates with risk factors of developing AKI. Conclusions: Serum levels of CysC are elevated in sick neonates at risk of AKI. CysC is a useful indicator of risk of AKI in ill neonates.

Background: Nephropathic infantile cystinosis, the most common cause of renal Fanconi syndrome, presents in early infancy with impaired growth, polyuria and polydipsia, and progresses to end stage renal disease during the first decade. Diagnosis is based on corneal examination for cystine crystals, leukocyte cystine content and genetic testing of the CTNS gene. Information on clinical features and genotype of Indian children with cystinosis is limited. Methods: We describe clinical features, renal outcomes and genetic variants in the CTNS gene in Indian children with cystinosis. Results: We included 19 patients with cystinosis from 17 families predominantly presenting with poor growth (95%), polyuria (84%) and refractory rickets (74%). Cystine crystals were present in 84%. Fanconi syndrome was common; two had nephrocalcinosis and 9 presented with eGFR <60 ml/ min/ 1.73 m². Genetic analysis, performed in 11 families, (12 patients) showed 8 variants. Five were reported, pathogenic variants, one was likely pathogenic and two were rare or novel variants of unknown significance. Conclusion: The p.Thr7PhefsTer7 variant, common to five unrelated patients, might be a population hotspot. Eight (42%) patients have been initiated on therapy with cysteamine. Studies with prolonged follow-up are necessary to define renal and extrarenal outcomes and the effect of cysteamine in Indian children.

Familial Mediterranean fever (FMF) is a rare autosomal recessive autoinflammatory disorder, characterized by recurrent episodes of transient fever and polyserositis. Nonamyloid renal involvement has been reported rarely in patients with FMF, such as immunoglobulin A (IgA)nephropathy, in childhood. We report a 7-year-old girl, who was first seen at 1.5 years of age with nephrotic range proteinuria and edema. Based on renal histological demonstration of mesangial proliferation and mesangial IgA deposits, a diagnosis of IgA nephropathy was made. Following recurrent episodes of fever, abdominal pain, and bone pain, a diagnosis of periodic fever was suspected. A known homozygous mutation (p. P369S) was detected in exon 3 of MEPV, the gene encoding pyrin, indicating the diagnosis of FMF. Hence, FMF and IgA nephropathy might coexist. Kidney biopsy is indicated in patients with FMF and early onset of proteinuria to rule out renal involvement with amyloidosis or glomerulonephritis to enable decisions on management.

We report a newborn baby girl with a rare cause of hyperammonemia, in which a session of continuous renal replacement therapy (CRRT) was performed successfully despite the child's small size. The baby was born at 34 weeks' gestation with a birth weight of 2.2 kg and was referred on day 4 of life with lethargy, bradycardia, hypothermia, hypoglycemia, and metabolic acidosis associated with hyperammonemia. Following the insertion of the GamCath line, CRRT was performed using continuous venovenous hemodialysis modality, Ultraflux AV Paed dialyzer (Fresenius Medical Care), and multiFiltrate pediatric kit. Over 19 h of therapy, serum ammonia level reduced from >700 μmol/L to 103 μmol/L. Next-generation sequencing revealed a homozygous pathogenic variation in SLC25A20 (NM_000387; exon2; c.109C>T; p.R37X), leading to a diagnosis of carnitine-acylcarnitine translocase deficiency. The child succumbed during a subsequent hospital stay. This case instructively informs on the feasibility and efficacy of CRRT in the management of neonatal hyperammonemia.

We hereby describe a case of nephropathic cystinosis who presented as growth failure, polydipsia, and renal Fanconi syndrome. The diagnosis was based on demonstration of elevated leukocyte cystine content and mutations in CTNS. Management with oral cysteamine and cysteamine eyedrops along with adequate nutrition and appropriate supplements, was associated with improvement in growth and development.

Nephrocalcinosis in children can arise due to a variety of metabolic conditions and appropriate diagnosis can lead to specific management and has implications in prognosis. Familial hypomagnesemia with hypercalciuria and nephrocalcinosis (FHHNC) is a rare disease with varied manifestations which is caused by mutations in CLDN16 and CLDN19, and has a high rate of progression to kidney failure in the second to third decades of life. Early diagnosis aids in retardation of the progression to kidney failure. We present two unrelated patients presenting with nephrocalcinosis and deranged renal function, who had a novel pathogenic variation (c.685C > T; p.Q229X), leading to the diagnosis of FHHNC. Genetic testing is crucial in patients presenting with nephrocalcinosis for diagnosis and prognostication.

Bartter syndrome is a rare inherited tubulopathy characterized by hypokalemic metabolic alkalosis, polyuria, growth retardation, and often, medullary nephrocalcinosis. Many disorders present with similar clinical and metabolic features and pose diagnostic dilemma. We describe a young infant girl with growth retardation, hypokalemic metabolic alkalosis, and medullary nephrocalcinosis but without polyuria or urinary chloride wasting. Clinical exome sequencing revealed compound heterozygous variations in SLC26A3 (c.1514+5G > A and c.168del), the gene implicated in congenital chloride diarrhea. This case highlights the utility of genetic testing for definitive diagnosis and specific management in cases where Bartter syndrome is suspected.