BACKGROUND: Focal segmental glomerulosclerosis (FSGS) is a primary podocytopathy characterized by primary podocyte detection and high proteinuria. The search for biomarkers and factors associated with the progression of this disease is an important task nowdays.
OBJECTIVE: To assess the proteomic profile of urine in patients with FSGS and to isolate urinary biomarkers of podocytopathies.
METHODS: The study included 41 patients diagnosed with chronic glomerulonephritis, 27 men and 14 women. According to the morphological study, 28 patients were diagnosed with FSGS, 9 with steroid-sensitive nephrotic syndrome and 14 with steroid-resistant nephrotic syndrome. The comparison group included 13 patients with membranous nephropathy. The study of the urinary proteome was carried out by targeted liquid chromatography-mass spectrometry using multiple reaction monitoring with synthetic stable isotope labelled peptide standards.
RESULTS: The main differences in the protein profile of urine were found in the subgroups of steroid-sensitive (SS) and steroid-resistant (SR) FSGS. In the FSGS SR group, at the onset of the disease, there was a high concentration of proteins reflecting damage to the glomerular filter (apo-lipoprotein A-IV, orosomucoid, cadherin, hemopexin, vitronectin), as well as proteins associated with tubulo-interstitial inflammation and accumulation of extracellular matrix (retinol- and vitamin D-binding proteins, kininogen-1, lumican and neurophilin-2). Compared with the membranous nephropathy group, FSGS patients had significantly higher urinary concentrations of carnosinase, orosomucoid, cadherin-13, tenascin X, osteopontin, and zinc-alpha-2-glycoprotein.
CONCLUSIONS: Thus, in patients with SR FSGS, the proteomic profile of urine includes more proteins at elevated concentrations, which reflects severe damage to various parts of the nephron compared with patients with SS FSGS and membranous nephropathy.
Обоснование. Фокальный сегментарный гломерулосклероз (ФСГС) относится к первичным подоцитопатиям, которые характеризуются первичным повреждением подоцитов и высокой протеинурией. Поиск биомаркеров и факторов, участвующих в прогрессировании этого заболевания почек, является актуальной задачей в настоящее время. Цель. Оценить протеомный профиль мочи у больных с ФСГС и выделить мочевые биомаркеры подоцитопатий. Материалы и методы. В исследование включен 41 пациент с диагнозом хронического гломерулонефрита – 27 мужчин и 14 женщин. По данным морфологического исследования у 28 пациентов диагностирован ФСГС, у 9 – со стероид-чувствительным нефротическим синдромом и 14 – со стероид-резистентным (СР) нефротическим синдромом. В группу сравнения вошли 13 больных с мембранозной нефропатией. Исследование протеома мочи проводилось методом таргетной хромато-масс-спектрометрии в режиме мониторинга множественных реакций с использованием синтетических изотопно-меченых пептидных стандартов. Результаты. Наибольшие различия по белковому составу мочи выявлены в подгруппах стероид-чувствительного и СР ФСГС. В группе СР ФСГС в дебюте заболевания отмечалось высокое содержание белков, отражающих повреждение гломерулярного фильтра (аполипопротеин А-IV, орозомукоид, кадгерин, гемопексин, витронектин), а также белков, связанных с тубуло-интерстициальным воспалением и накоплением экстрацеллюлярного матрикса (ретинол- и витамин-D-связывающие белки, кининоген-1, люмикан и нейрофилин-2). По сравнению с группой мембранозной нефропатии у больных с ФСГС отмечена достоверно более высокая концентрация в моче карнозиназы, орозомукоида, кадгерина-13, тенасцина X, остеопонтина, цинк-α-2-гликопротеина. Заключение. Таким образом, у больных со СР ФСГС протеомный профиль мочи включает большее количество белков в повышенных концентрациях, что отражает тяжелое повреждение различных отделов нефрона по сравнению с больными со стероид-чувствительным ФСГС и мембранозной нефропатией.

To assess the renal elasticity values using (SWE) and correlate the values with steroid sensitivity to distinguish between steroid-resistant nephrotic syndrome (SRNS) and steroid-sensitive nephrotic syndrome (SSNS) in children.
In this IRB-approved cross-sectional study, 83 children (4-14 years) diagnosed with nephrotic syndrome were included from July 2021 to December 2022. SWE measurements were done for each kidney\'s upper pole, interpolar region, and lower pole. Mean as well as median SWE were calculated. Correlation of the renal stiffness values was done with different laboratory findings (blood urea, serum creatinine, 24 h urine protein, serum albumin, and serum cholesterol), the grayscale findings (cortical echogenicity, and corticomedullary differentiation), and the final diagnosis of SRNS and SSNS. The statistical tests were done at a significance level of α = 0.05.
The median (IQR) overall SWE of kidneys was higher in SRNS group 12.64 (8.4-19.68) kPa than SSNS group 9.87 (8.20-12.56) kPa. The difference was significant (p = 0.004). At a cut-off of ≥ 10.694 kPa (AUROC- 0.641), the overall SWE predicted SRNS group with a sensitivity of 70% and a specificity of 63%. A significant correlation (p < 0.05) was found between the SWE and 24-h urine protein, cortical echogenicity, and corticomedullary differentiation in SSNS, while only between SWE and corticomedullary differentiation in SRNS.
The mean SWE was higher in children with SRNS. While SWE has potential to differentiate SSNS from SRNS, a different study design where SWE is performed at presentation is needed for confirmation.

UNASSIGNED: Pediatric nephrotic syndrome (NS) requires routine proteinuria monitoring, which is costly and affects patients\' quality of life. The gold-standard 24-h urine protein (UP) measurement is challenging in children, and first-morning urine collection requires specific conditions, making it difficult in outpatient settings. Studies have reported comparability of second or random morning urine sample to the first-morning specimen. This study aimed to compare outcomes of random morning proteinuria measurements to 24-h UP and the roles of the urinary protein creatinine ratio (UPCR) and dipstick tests in pediatric NS, based on International Pediatric Nephrology Association (IPNA) 2022 Guidelines.
UNASSIGNED: Twenty-four-hour and morning urine samples were collected from 92 pediatric NS patients. These were subjected to automated analyses for 24-h UP, UPCR, and semi-automated dipstick analysis. A blinded doctor performed manual dipstick analysis.
UNASSIGNED: UPCR had a stronger correlation with 24-h UP than with automated and manual urine dipstick tests. UPCR had the highest sensitivity and specificity for predicting no remission/relapse and high sensitivity but low specificity for complete remission. The optimal UPCR cutoff for remission was 0.44 mg/mg and for no remission/relapse was 2.08 mg/mg. Automated and manual dipstick tests demonstrated limited sensitivity but high specificity and similar AUC values for remission/relapse.
UNASSIGNED: UPCR was sensitive and specific for diagnosing no remission/relapse and sensitive but not specific for detecting remission. Manual and automated urine dipstick tests were comparable for remission and no remission/relapse detection. This study supports the IPNA 2022 Guidelines, as 2 mg/mg was the optimal UPCR cutoff for no remission/relapse, while for remission the optimal cutoff was 0.4 mg/mg.

Patients with acute graft-versus-host disease (GVHD) have an increased risk for infectious complications after allogeneic hematopoietic cell transplantation (HCT), but the risk according to response to therapy has not been well studied. We performed a retrospective analysis of the infectious complications for 1 year following allogeneic HCT at the University of Minnesota including 1143 pediatric and adult patients with and without aGVHD. The patients with aGVHD were classified into treatment response groups based on response to corticosteroids as first-line therapy: steroid-sensitive (SS; n = 114), steroid-resistant (SR; n = 103), and steroid-dependent (SD; n = 168) aGVHD. We observed that the cumulative incidence and density of infections in patients with SS aGVHD parallel the values in patients without GVHD. Infection density (ie, number of infections occurring per 100 days at risk) was greater in the patients with aGVHD compared with patients in both early and later post-transplantation periods. In GVHD patients, among the infections developed from the onset of aGVHD through 80 days of treatment, and until 1 year following transplantation, SS and SD patients had fewer bacterial and viral infections than SR patients. The overlap of nonrelapse mortality between SS and SD GVHD patients is a function of SD GVHD being responsive to steroid therapy, even if continued therapy is required. In summary, although valid goals may include reducing unneeded antibacterial antibiotic therapy and preserving microbiome diversity, these data suggest that anti-infective therapy is justified by the density of infections observed during active GVHD treatment.

BACKGROUND: Recently, urinary exosomal miRNAs are gaining increasing attention as their expression profiles are often associated with specific diseases and they exhibit great potential as noninvasive biomarkers for the diagnosis of various diseases. The present study was aimed to evaluate the expression status of selected miRNAs (miR-1, miR-215-5p, miR-335-5p and let-7a-5p) in urine samples from children with NS [steroid sensitive (SSNS)] and [steroid resistant (SRNS)] along with healthy control group.
METHODS: MicroRNA isolation was carried out in urine samples collected from SSNS (100 nos), SRNS (100 nos), and healthy controls (50 nos) using MiRNeasy Mini Kit, followed by cDNA conversion for all the four selected miRNAs using Taqman advanced miRNA cDNA synthesis kit and their expression was quantified by Taqman Advanced miRNA assay kits using Real Time PCR Machine and Rotogen-Q in SSNS and SRNS patients and healthy control subjects.
RESULTS: Quantification of all the four miRNAs (miR-1, mir-215, miR-335, let-7a) were found to be upregulated in both SSNS and SRNS as compared to control group. Further, the comparison of microRNAs within the case groups revealed significant downregulation of three microRNAs-miR-1, miR-215, miR- 335 and upregulation of let-7a in SRNS group as compared to SSNS. The t-test performed for all the four miRNAs was found to be statistically significant.
CONCLUSIONS: The aberrant expression of all the four microRNAs in both SSNS and SRNS as compared to healthy subjects may serve as novel biomarkers to distinguish between NS and healthy controls. The differential expression of microRNA let-7a is useful to discriminate SSNS and SRNS.

Congenital nephrotic syndrome (CNS) is a rare autosomal recessive disorder that occurs in the first 0 to 3 months of life. The course of CNS is progressive, often leading to end-stage renal disease within 2 to 3 years. Most patients with CNS are resistant to glucocorticoids and immunosuppressive drugs. We report a girl aged 1 month and 20 days who was admitted to hospital with a history of abdominal distension and palpebral edema. She was diagnosed with CNS and administered a glucocorticoid (methylprednisolone) for 2 years. Targeted high-throughput next-generation sequencing showed mutations in the NPHS1 gene. She had a favorable outcome after 2 years of treatment. She has remained in complete remission for the last 6 months. From a clinical point of view, the outcome of CNS may be associated with end-stage renal disease or even death. Appropriate pharmacotherapy is beneficial to maintain a normal function and integrity of the glomerular barrier. An aggressive treatment plan is required to save the life of patients with CNS, even if a heterozygous mutation is detected by genetic analysis.

Complete remission of idiopathic nephrotic syndrome (INS) in response to corticosteroids has been widely adopted as an indicator of satisfactory long-term outcomes in pediatric patients. The approach was based on the results of studies conducted in the 1960s and 1970s. The studies found that corticosteroid-responsive minimal change disease (MCD) was the most frequent diagnosis in INS patients. In more recent years, studies have reported increased frequency of focal segmental glomerulosclerosis (FSGS) and primary corticosteroid resistance without a corresponding increase of FSGS. It became unclear whether withholding kidney biopsy before treatment with corticosteroids is still the best management practice. We performed a retrospective chart review at the UPMC Children\'s Hospital of Pittsburgh and identified patients who were referred for evaluation of edema or proteinuria between 2002 and 2014. We identified 114 pediatric patients with INS who were treated initially with a corticosteroid (prednisone or prednisolone) 2 mg/kg (max 60 mg)/day for 4-6 weeks followed by 2 mg/kg (max 60 mg) every other day for 4-6 weeks and had not received a corticosteroid-sparing agent before completing at least 8 weeks of the initial therapy. Corticosteroid resistance in pediatric INS patients was independently associated with the black race, older age at presentation (>8 years), and female sex. The majority of blacks who were resistant to corticosteroids had a tissue diagnosis of MCD. Among the whites who were steroid-resistant, MCD and FSGS were diagnosed in similar proportions of cases. Thus, the tissue diagnosis in could not predict the response to corticosteroids. Nineteen percent of whites with FSGS were steroid-sensitive and none of the blacks with FSGS responded to corticosteroids. These data suggest that the histologic diagnosis of FSGS could not rule out response to corticosteroids, at least, in the white patient population. In summary, our data demonstrate that at this time, the therapeutic response to corticosteroids continues to be a valid approach for the initial evaluation and therapy of children diagnosed with INS at our center. Future studies should evaluate the mechanisms of changing characteristics of pediatric INS. The specific role of patient demographics, ethnicity, as well as genetic and environmental factors could be evaluated by a prospective, multicenter study.

The optimal therapeutic regimen for children at onset of idiopathic nephrotic syndrome (INS) is still under debate. A better knowledge of the disease\'s course is necessary to design more appropriate and/or personalized treatment protocols.
We report the 5-year outcome of patients included from December 2007 to May 2010 in the prospective multicentric and multiethnic population-based NEPHROVIR study. Patients were treated at onset according to the French steroid protocol (3990 mg/m2, 18 weeks). Data were collected at 5 years or last follow-up.
Out of the 188 children with nephrotic syndrome (121 boys, 67 girls; median age 4.1 years), 174 (93%) were steroid-sensitive. Six percent of steroid-sensitive patients required intravenous steroid pulses to get into remission. Relapse-free rate for steroid-sensitive patients was 21% (36/174) at last follow-up (median 72 months). A first relapse occurred in138 steroid sensitive patients (79%) with a median time of 8.3 months (IQ 3.4-11.3). Out of the 138 relapsers, 43 were frequent relapsers. Age at onset below 4 years was the only predictive factor of relapse, while gender, ethnicity, and delay to first remission were not. At 96 months of follow-up, 83% of frequent relapsers were still under steroids and/or immunosuppressive drugs.
The treatment of the first flare deserves major improvements in order to reduce the prevalence of relapsers and the subsequent long-lasting exposure to steroids and immunosuppression.

OBJECTIVE: To explore the expression of P-glycoprotein (P-gp) in the peripheral blood nucleated cells (PBNCs) of children with nephrotic syndrome in relation to their clinical response to glucocorticoid treatment.
METHODS: Thirty-six children with nephrotic syndrome (20 cases of steroid-responsive and 16 cases of steroid-resistant) were examined. All the participants were subjected to complete history taking, thorough clinical examination, laboratory investigations (24-h urinary protein, serum albumin, complete blood count with differential white blood cell count, serum cholesterol, serum urea, serum creatinine) and functional assay of P-gp using FACS Calibur flowcytometry. P-gp assay was done in both groups during remission.
RESULTS: P-gp activity was significantly higher in steroid-resistant than steroid-sensitive cases.
CONCLUSIONS: P-gp can be used as a predictor of outcome, as a part of laboratory evaluation of the cases before starting steroid therapy, so as to determine whether to use alternative line of therapy or use one of the P-gp inhibitors with steroid therapy.

Idiopathic nephrotic syndrome is the most common glomerular disease in childhood, affecting 1 to 3 per 100,000 children under the age of 16. It most commonly occurs in ages between 2 and 10. Its cause is unknown and its histology corresponds to minimal change disease in 90% of cases, or focal segmental glomerulosclerosis. 80 to 90% of cases respond to steroids (steroid-sensitive nephrotic syndrome) with good prognosis and long-term preservation of renal function over time. 70% of patients with SSNS have one or more relapses in their evolution, and of these, 50% behave as frequent relapsing or steroid-dependent, a group that concentrate the risk of steroid toxicity. Patients with steroid-resistant nephrotic syndrome have a poor prognosis and 50% of them evolve to end-stage renal disease. The goal of therapy is to induce and maintain remission of the disease, reducing the risk secondary to proteinuria while minimizing the adverse effects of treatments, especially with prolonged use of corticosteroids. This paper is the result of the collaborative effort of the Nephrology Branch of the Chilean Society of Pediatrics with aims at helping pediatricians and pediatric nephrologists to treat pediatric SNI. In this first part, recommendations of steroid-sensitive nephrotic syndrome are discussed.