Urinary extracellular vesicles signature for diagnosis of kidney disease.

Congenital disorders characterized by the quantitative and qualitative reduction in the number of functional nephrons are the primary cause of chronic kidney disease (CKD) in children. We aimed to describe the alteration of urinary extracellular vesicles (uEVs) associated with decreased renal function during childhood. By nanoparticle tracking analysis and quantitative proteomics, we identified differentially expressed proteins in uEVs in bilateral renal hypoplasia, which is characterized by a congenitally reduced number of nephrons. This expression signature of uEVs reflected decreased renal function in CKD patients by congenital anomalies of the kidney and urinary tract or ciliopathy. As a proof-of-concept, we constructed a prototype ELISA system that enabled the isolation of uEVs and quantitation of expression of molecules representing the signature. The system identified decreased renal function even in its early stage. The uEVs signature could pave the way for non-invasive methods that can complement existing testing methods for diagnosing kidney diseases.

Degree of foot process effacement in patients with genetic focal segmental glomerulosclerosis: a single-center analysis and review of the literature.

Determining the cause of focal segmental glomerulosclerosis (FSGS) has crucial implications for evaluating the risk of posttransplant recurrence. The degree of foot process effacement (FPE) on electron micrographs (EM) of native kidney biopsies can reportedly differentiate primary FSGS from secondary FSGS. However, no systematic evaluation of FPE in genetic FSGS has been performed. In this study, percentage of FPE and foot process width (FPW) in native kidney biopsies were analyzed in eight genetic FSGS patients and nine primary FSGS patients. All genetic FSGS patients showed segmental FPE up to 38% and FPW below 2000 nm, while all primary FSGS patients showed diffuse FPE above 88% and FPW above 3000 nm. We reviewed the literature which described the degree of FPE in genetic FSGS patients and identified 38 patients with a description of the degree of FPE. The degree of FPE in patients with mutations in the genes encoding proteins associated with slit diaphragm and cytoskeletal proteins was varied, while almost all patients with mutations in other FSGS genes showed segmental FPE. In conclusion, the present study suggests that the degree of FPE in native kidney biopsies may be useful for differentiating some genetic FSGS patients from primary FSGS patients.

Association between Immunoglobulin M and Steroid Resistance in Children with Nephrotic Syndrome: A Retrospective Multicenter Study in Japan.

Background: The prognosis of steroid-resistant nephrotic syndrome (SRNS) in children is poorer than steroid-sensitive cases. Diagnosis of SRNS is made after observing the response to the initial 4-week corticosteroid therapy, which might be accompanied by side effects. However, predictive indicators at initial diagnosis remain unknown. We aimed to investigate whether selectivity index (SI) and other indicators at initial diagnosis-for example, serum IgM and total serum protein-albumin ratio (TA ratio, total serum protein level over albumin level)-can predict SRNS. Methods: A total of 80 children were enrolled from seven hospitals in Japan between January 2008 and December 2019 (mean age, 4.7 years; 65% male). Of the children enrolled, 13 (16%, M/F=5:8) had been diagnosed as steroid resistant after initial treatment with steroids. The association between serum IgM (tertile categories: low, 24-133; middle, 134-169; and high, 169.1-510 mg/dl), SI (<0.2 or ≥0.2), and TA ratio (tertile categories: low, 1.8-2.6; middle, 2.62-3.75; and high, 3.8-15.3) at initial diagnosis and steroid resistance was evaluated with logistic regression, adjusting for age and sex. Results: Low levels of serum IgM were significantly associated with steroid resistance (adjusted odds ratio, 6.94; 95% CI, 1.12 to 43.11). TA ratio and SI were not significantly associated with steroid resistance. Conclusions: Low levels of serum IgM at initial diagnosis might predict steroid resistance among Japanese children with idiopathic nephrotic syndrome.

Ensuring safe drug administration to pediatric patients with renal dysfunction: a multicenter study.

BACKGROUND: In pediatric patients, due to variations in baseline serum creatinine (Cr) reference values, renal dysfunctions sometimes go unnoticed. In addition, renally excreted drugs need dose adjustment while nephrotoxic drugs should be avoided altogether in patients with impaired renal function. However, most physicians are apparently unaware of these facts and may administer these drugs to vulnerable patients. METHODS: We administered a questionnaire to all physicians and pharmacists specializing in pediatric medical care at six Tokyo metropolitan government-run hospitals in Japan. RESULTS: 276 (59%) of 470 physicians and pharmacists participated. The rate of correct answers given by physicians who were asked to state the serum Cr reference range for 4-year-olds and 8-year-olds was 83 and 74%, respectively. On the other hand, the rate of correct answers given by pharmacists to the same question was only 27 and 24%, respectively. Only about 50% of physicians were aware that histamine H2-receptor antagonists and oseltamivir are renally excreted or that acyclovir and angiotensin II receptor blocker are nephrotoxic. However, most of the pharmacists recognized that histamine H2-receptor antagonists and oseltamivir are renally excreted drugs. CONCLUSIONS: For the majority of the investigated drugs, the awareness that we need to reduce dosages for patients with renal dysfunction was insufficient. To ensure safe drug administration, communication between physicians and pharmacists is paramount. There is an urgent need for the creation of a safe drug administration protocol for pediatric patients with renal dysfunction.

Nebulized hypertonic saline in infants hospitalized with moderately severe bronchiolitis due to RSV infection: A multicenter randomized controlled trial.

INTRODUCTION: The efficacy of nebulized hypertonic saline (HS) therapy for shortening hospital length of stay (LOS) or improving bronchiolitic symptoms remains controversial. Most studies enrolled small numbers of subjects and did not consider the role of respiratory syncytial virus (RSV), the most common cause of acute bronchiolitis. Our aim was to evaluate the efficacy and safety of nebulized HS therapy for acute bronchiolitis due to RSV in moderately ill hospitalized infants. MATERIALS AND METHODS: This was an open-label, multicenter, randomized controlled trial comparing a nebulized HS treatment group with a normal saline (NS) group. The subjects, 128 infants with bronchiolitis due to RSV, were admitted to five hospitals in Tokyo, Japan. Three-percent HS or NS was administered via bronchodilator four times daily post-admission. The primary outcome was LOS, defined as the time until the patients fulfilled the discharge criteria, namely, absence of fever, no need for supplemental oxygen, and adequate feeding. Survival analysis was conducted in accordance with the intention-to-treat principle. RESULTS: The baseline characteristics were similar between the two groups. There was no significant overall difference in LOS between the groups (4.81 ± 2.14 days in HS vs 4.61 ± 2.18 days in NS; P = 0.60). Survival analysis by log-rank test also showed no significance (P = 0.62). Multivariate adjustment did not significantly alter the results. The treatment was well-tolerated, with no adverse effects attributable to the use of HS. CONCLUSIONS: Nebulized HS therapy did not significantly reduce LOS among infants with bronchiolitis due to RSV.