The citrus flavonoid, nobiletin inhibits neuronal inflammation by preventing the activation of NF-κB.

Nobiletin (5,6,7,8,3',4'-hexamethoxyflavone) is one of the flavonoids found in shikuwasa, a popular citrus fruit in Okinawa, Japan. It exerts various pharmacological effects, such as anti-tumor, antioxidant, and anti-inflammatory activities. We herein investigated whether nobiletin attenuated lipopolysaccharide (LPS)-induced inflammatory responses in the murine microglial cell line BV-2 and neuroinflammation in mice induced by an intracerebral injection of LPS. In BV-2 cells, nobiletin significantly inhibited the LPS-induced production of nitric oxide (NO) and prostaglandin E2 (PGE2) by preventing the mRNA expression of inducible NO synthase (iNOS) and cyclooxygenase-2 (COX-2), respectively. Nobiletin also inhibited the LPS-induced mRNA expression of CCL2, CXCL1, IL-6, and TNFα. Nobiletin markedly attenuated the transcriptional activity of the NF-κB p65 subunit without affecting the degradation of IκBα or the nuclear localization of the NF-κB p65 subunit. Nobiletin also inhibited the LPS-induced activation of JNK, but not ERK or p38, in BV-2 cells. Furthermore, the administration of nobiletin significantly suppressed the accumulation of microglia and induction of the mRNA expression of CCL2, CXCL1, IL-6, and TNFα in the murine brain induced by injecting LPS into the striatum. Collectively, these results suggest the potential of nobiletin as a candidate anti-inflammatory drug for the prevention of neuroinflammation.

CD4 + and CD8 + T-lymphocyte number as predictive marker of relapse after rituximab treatment in childhood-onset refractory nephrotic syndrome.

BACKGROUND: Rituximab is a promising option for refractory idiopathic nephrotic syndrome. However, no simple predictive markers for relapse after rituximab have been established. To determine such markers, we investigated the relationship between CD4 + and CD8 + cell counts and relapse after rituximab administration. METHODS: We retrospectively investigated patients with refractory nephrotic syndrome who received rituximab followed by immunosuppressive as maintenance therapy. Patients were divided into no relapse in 2 years after rituximab treatment or relapse group. After rituximab treatment, CD4 + /CD8 + cell counts were measured monthly, at prednisolone discontinuation, and at B-lymphocyte recovery. To predict relapse, these cell counts were analyzed using receiver operating characteristic (ROC). Additionally, relapse-free survival was reevaluated based on the result of ROC analysis for 2 years. RESULTS: Forty-eight patients (18 in the relapse group) were enrolled. At prednisolone discontinuation (52 days after rituximab treatment), the relapse-free group showed significantly lower cell counts than the relapse group (median CD4 + cell count: 686 vs. 942 cells/µL, p = 0.006; CD8 + : 613 vs. 812 cells/µL, p = 0.005). In the ROC analysis, CD4 + cell count > 938 cell/µL and CD8 + cell count > 660 cells/µL could predict relapse in 2 years (sensitivity, 56% and 83%; specificity, 87% and 70%). The patient group with both lower CD4 + and CD8 + cell counts showed significantly longer 50% relapse-free survival (1379 vs. 615 days, p < 0.001 and 1379 vs. 640 days, p < 0.001). CONCLUSIONS: Lower CD4 + and CD8 + cell counts in the early phase after rituximab administration may predict a lower risk of relapse.

Risks and renal outcomes of severe acute kidney injury in children with steroid-resistant nephrotic syndrome.

BACKGROUND: Risks and renal outcomes of severe acute kidney injury (AKI) in children with steroid-resistant nephrotic syndrome (SRNS), particularly those who require dialysis, have not been fully explored. METHODS: This retrospective cohort study enrolled children who had been diagnosed with idiopathic nephrotic syndrome at the National Center for Child Health and Development between March 2002 and December 2018. Children with steroid-sensitive nephrotic syndrome or SRNS-related gene mutations were excluded. RESULTS: Sixty-two children with SRNS (37 boys; median age, 3.6 years [interquartile range (IQR) 2.0-10.3]) were enrolled. Sixteen patients (25.8%) had severe AKI, including nine patients (14.5%) who received dialysis. The period from nephrotic syndrome (NS) onset to partial remission (median [IQR]) was not significantly influenced by dialysis status, but tended to be longer in the dialysis group (125 days [74-225] vs. 40 days [28-113]; p = 0.09); notably, no patient developed chronic kidney disease during the follow-up period. Infection and posterior reversible encephalopathy (PRES) were significantly associated with AKI. Patients with AKI tended to require dialysis in the presence of infection, undergo treatment with cyclosporine A, and have PRES. The period from onset of NS to AKI was significantly longer in the dialysis group (26 days [15.5-46.0] vs. 4 days [0.0-14.0]; p = 0.01). CONCLUSION: Dialysis was commonly required among children with SRNS who exhibited severe AKI. The period from onset of NS to partial remission tended to be longer in patients receiving dialysis, whereas renal prognosis was satisfactory during subsequent follow-up.

Glucocorticoid discontinuation in pediatric-onset systemic lupus erythematosus: a single-center experience.

BACKGROUND: Glucocorticoid discontinuation, a challenge in systemic lupus erythematosus (SLE), might be achievable with the advent of new therapeutic options. METHODS: This single-center study included 31 children with newly diagnosed pediatric SLE between 2002 and 2021, after the exclusion of patients who were followed for less than 1 year after treatment initiation and those lost to follow-up. Patient characteristics, clinical course including flares, treatment, glucocorticoid discontinuation, and outcomes were retrospectively analyzed. RESULTS: Glucocorticoids could be discontinued in 19 (61%) patients during a median observation period of 105.5 (range, 17-221) months. Of these, 5 (26%), 12 (63%), and 18 (95%) patients could discontinue glucocorticoids in 3, 5, and 10 years from treatment initiation, respectively. Additionally, 18 of the 19 patients did not experience flares after glucocorticoid discontinuation during a median duration of 37.2 (7.2-106.8) months. Three of the nineteen patients achieved drug-free remission. At last follow-up, all patients achieved low disease activity with or without glucocorticoids and 19, 8, and 1 patient were receiving mycophenolate mofetil (MMF), MMF plus tacrolimus, and MMF plus ciclosporin A, respectively. Flares were observed in 15 patients during the observation period. MMF as initial immunosuppressant (P = 0.01) and shorter interval between therapy initiation and achieving maintenance prednisolone dose of 0.1-0.15 mg/kg/day (P = 0.001) were associated with significantly reduced flare risk. Femoral head necrosis was observed in two patients. CONCLUSION: Despite the small sample size, these results support glucocorticoid discontinuation as a therapeutic target in pediatric SLE.

Mycobacterium avium complex peritonitis in a pediatric patient on peritoneal dialysis: A case report.

INTRODUCTION: Peritonitis due to Mycobacterium avium complex (MAC) is a rare but life-threatening complication in patients on peritoneal dialysis (PD). However, optimal therapeutic regimen, treatment duration, and appropriate timing of kidney transplantation (KT) after treatment are unknown. SYMPTOMS: We herein report a 4-year-old boy on PD due to end-stage kidney disease resulting from bilateral hypoplastic kidneys. He was admitted for peritonitis complaining fever, abdominal pain, and cloudy peritoneal effluent on PD after accidentally biting and opening the PD catheter while in the bath. Initial treatment with vancomycin and ceftazidime for 2 weeks was successful, although peritonitis recurred 37 days after discharge. DIAGNOSIS: Mycobacterial culture was positive 9 days after readmission, and MAC was grown in the PD culture on day 30. We diagnosed him with MAC peritonitis that occurred on PD. INTERVENTIONS: Clarithromycin, ethambutol, and rifampicin were initiated. The PD catheter was removed, and hemodialysis was initiated with a cuffed catheter inserted in the internal jugular vein. Follow-up observation for 8 months after the cessation of 1-year anti-mycobacterial therapy confirmed no recurrence of MAC infection, and the patient received living-donor KT from his father. OUTCOMES: His renal function was stable, with no recurrence of MAC peritonitis at 2 years after the KT. CONCLUSION: To the best of our knowledge, this is the first report of a patient who successfully underwent KT after receiving treatment for MAC peritonitis. One-year anti-mycobacterial therapy, PD catheter removal, 8-month observation after the cessation of therapy led the successful KT, although further investigation is warranted to confirm the efficacy of this approach.

Risk factors for post-nephrectomy hypotension in pediatric patients.

BACKGROUND: Although hypotension is a life-threatening complication of nephrectomy in children, risk factors for its development remain unknown. We evaluated the incidence, clinical course, and associated risk factors of pediatric post-nephrectomy hypotension in an observational study. METHODS: This retrospective observational study included the clinical data of children who underwent nephrectomy in our center between 2002 and 2020. Patients undergoing nephrectomy at kidney transplantation and those who developed hypotension before nephrectomy were excluded. RESULTS: The study included 55 nephrectomies in 51 patients, including 42 unilateral, 4 two-stage bilateral, and 5 simultaneous bilateral nephrectomies. The diagnoses were isolated Wilms tumor, neuroblastoma, congenital nephrotic syndrome, Denys-Drash syndrome, WAGR (Wilms tumor, aniridia, genitourinary malformations, and mental retardation) syndrome, and autosomal recessive polycystic kidney disease in 24, 10, 9, 6, 1, and 1 patient, respectively. Post-nephrectomy hypotension developed in 11 (20%) patients. Two patients (3.6%) had persistent hypotension; both had their kidneys resected, and one patient (1.8%) died. Male sex, kidney disease, resection of both kidneys, low estimated glomerular filtration rate, increased left ventricular posterior wall thickness in diastole, hypertension before nephrectomy, antihypertensive use, hyperreninemia, and hyperaldosteronism were significantly associated with post-nephrectomy hypotension. Multivariate logistic regression analysis revealed that hypertension before nephrectomy was the only significant risk factor for post-nephrectomy hypotension (P = 0.04). CONCLUSIONS: Hypertension before nephrectomy is a significant risk factor for pediatric post-nephrectomy hypotension. Life-threatening hypotension, which might occur after bilateral nephrectomy in infants, should be considered, especially in children with higher risks.

Valganciclovir prophylaxis for cytomegalovirus infection in pediatric kidney transplant recipients: a single-center experience.

BACKGROUND: There are two approaches for treating cytomegalovirus (CMV) infection occurring after kidney transplantation (KTx). One is preemptive therapy in which treatment is started after confirming positive CMV antigenemia using periodic antigenemia assay. The other approach is prophylactic therapy in which oral valganciclovir (VGCV) is started within 10 days after KTx and continued for 200 days. The Transplantation Society guidelines recommend prophylactic therapy for high-risk (donor's CMV-IgG antibody positive and recipient's negative) pediatric recipients. However, the adequate dose and side effects of VGCV are not clear in children, and there is no sufficient information about prophylaxis for Japanese pediatric recipients. METHODS: A single-center retrospective analysis was conducted on case series of high-risk pediatric patients who underwent KTx and received oral VGCV prophylaxis at the Department of Pediatric Nephrology, Tokyo Women's Medical University, between August 2018 and March 2019. Data were collected using medical records. RESULTS: The dose of administration was 450 mg in all the study patients (n = 5). Reduction or discontinuation was required in four of five patients due to adverse events, which included neutropenia in one patient, anemia in two patients, and neutropenia and digestive symptoms in one patient. Late-onset CMV disease occurred in all patients. No seroconversion was observed during prophylaxis. CONCLUSIONS: Our preliminary study suggests that the dosage endorsed by The Transplantation Society may be an overdose for Japanese pediatric recipients. Further studies are required to examine the safety and efficacy of VGCV prophylaxis in Japanese pediatric recipients.

Morphologic Analysis of Urinary Podocytes in Focal Segmental Glomerulosclerosis.

Background: The development of glomerulosclerosis in FSGS is associated with a reduction in podocyte number in the glomerular capillary tufts. Although it has been reported that the number of urinary podocytes in FSGS exceeds that of minimal-change nephrotic syndrome, the nature of events that promote podocyte detachment in FSGS remains elusive. Methods: In this study, we provide detailed, morphologic analysis of the urinary podocytes found in FSGS by examining the size of the urinary podocytes from patients with FSGS, minimal-change nephrotic syndrome, and GN. In addition, in urinary podocytes from patients with FSGS and minimal-change nephrotic syndrome, we analyzed podocyte hypertrophy and mitotic catastrophe using immunostaining of p21 and phospho-ribosomal protein S6. Results: The size of the urinary podocytes was strikingly larger in samples obtained from patients with FSGS compared with those with minimal-change nephrotic syndrome and GN (P=0.008). Urinary podocytes from patients with FSGS had a higher frequency of positive immunostaining for p21 (P<0.001) and phospho-ribosomal protein S6 (P=0.02) than those from patients with minimal-change nephrotic syndrome. Characteristic features of mitotic catastrophe were more commonly observed in FSGS than in minimal-change nephrotic syndrome urinary samples (P=0.001). Conclusions: We posit that the significant increase in the size of urinary podocytes in FSGS, compared with those in minimal-change nephrotic syndrome, may be explained by hypertrophy and mitotic catastrophe.

Prophylactic rituximab administration in children with complicated nephrotic syndrome.

BACKGROUND: Rituximab is effective for maintaining remission in patients with complicated nephrotic syndrome, although a history of steroid-resistant nephrotic syndrome (SRNS) is a risk factor for early relapse. We investigated the efficacy of prophylactic rituximab treatment for maintaining remission after B cell recovery. METHODS: Patients with complicated steroid-dependent or frequently relapsing nephrotic syndrome with history of SRNS who received a single dose of rituximab (375 mg/m2) and continued immunosuppressive agents were enrolled in this retrospective study. Patients were divided into two groups: a prophylaxis group, which received additional rituximab treatment at B cell recovery and a non-prophylaxis group. The relapse-free period from the last rituximab infusion (the second treatment in prophylaxis group and the first treatment in non-prophylaxis group) was compared between two groups using the Kaplan-Meier method, and risk factors for early relapse were calculated using multivariate analysis by Cox proportional hazards model. RESULTS: Sixteen patients in the prophylaxis group and 45 in the non-prophylaxis group were enrolled. Fifty-percent relapse-free survival after the last rituximab treatment was 667 days in the former and 335 days in the latter (p = 0.001). Multivariate analysis showed that additional rituximab treatment was the only significant negative factor for early relapse, with a hazard ratio of 0.40 (p = 0.02). Fifty-percent relapse-free survival after B cell recovery was much longer in the prophylaxis group (954 vs. 205.5 days, p = 0.003). CONCLUSIONS: Additional rituximab treatment at B cell recovery can maintain prolonged remission even after B cell recovery in patients with complicated nephrotic syndrome with history of SRNS.

A girl with MIRAGE syndrome who developed steroid-resistant nephrotic syndrome: a case report.

BACKGROUND: MIRAGE syndrome is a recently discovered rare genetic disease characterized by myelodysplasia (M), infection (I), growth restriction (R), adrenal hypoplasia (A), genital phenotypes (G), and enteropathy (E), caused by a gain-of-function mutation in the SAMD9 gene. We encountered a girl with molecularly-confirmed MIRAGE syndrome who developed steroid-resistant nephrotic syndrome. CASE PRESENTATION: She was born at 33 weeks gestational age with a birth weight of 1064 g. She showed growth failure, mild developmental delays, intractable enteropathy and recurrent pneumonia. She was diagnosed as MIRAGE syndrome by whole exome sequencing and a novel SAMD9 variant (c.4615 T > A, p.Leu1539Ile) was identified at age four. Biopsied skin fibroblast cells showed changes in the endosome system that are characteristic of MIRAGE syndrome, supporting the genetic diagnosis. Proteinuria was noted at age one, following nephrotic syndrome at age five. A renal biopsy showed focal segmental glomerulosclerosis (FSGS) with immune deposits. Steroid treatment was ineffective. Because we speculated that her nephrosis was a result of genetic FSGS, we decided not to introduce immunosuppressive agents and instead started enalapril to reduce proteinuria. Although her proteinuria persisted, her renal function was normal at age eight. CONCLUSIONS: This is the first detailed report of a MIRAGE syndrome patient with nephrotic syndrome. Because patients with MIRAGE syndrome have structural abnormalities in the endosomal system, we speculate that dysfunction of endocytosis in podocytes might be a possible mechanism for proteinuria.

Oral intake of α­glucosyl­hesperidin ameliorates selenite­induced cataract formation.

Hesperetin is a natural flavonoid with robust antioxidant properties. Our previous study reported that hesperetin can prevent cataract formation. However, an important consideration regarding hesperetin consumption is the limited bioavailability due to its poor solubility. The present study investigated the anti­cataract effects of α­glucosyl hesperidin in vivo and in vitro using a selenite­induced cataract model. SD rats (age, 13 days) were orally administered PBS (0.2 ml) or α­glucosyl hesperidin (200 mg/kg) on days 0, 1 and 2. Sodium selenite was subcutaneously administered to the rats 4 h after the first oral administration on day 0. Antioxidant levels in the lens and blood were measured on day 6. In vitro, human lens epithelial cells were treated with sodium selenite (10 µM) and/or hesperetin (50 or 100 mM) for 24 h and analyzed for apoptosis markers using sub­G1 population and Annexin V­FITC/propidium iodide staining and DNA ladder formation. α­glucosyl hesperidin treatment significantly reduced the severity of selenite­induced cataract. The level of antioxidants was significantly reduced in the selenite­treated rats compared with in the controls; however, they were normalized with α­glucosyl hesperidin treatment. In vitro, hesperetin could significantly reduce the number of cells undergoing apoptosis induced by sodium selenite in human lens epithelial cell lines. Overall, oral consumption of α­glucosyl hesperidin could delay the onset of selenite­induced cataract, at least in part by modulating the selenite­induced cell death in lens epithelial cells.

Association between the clinical presentation of congenital anomalies of the kidney and urinary tract (CAKUT) and gene mutations: an analysis of 66 patients at a single institution.

BACKGROUND: The association between the clinical presentation of congenital anomalies of the kidney and urinary tract (CAKUT) and gene mutations has yet to be fully explored. METHODS: In this retrospective cohort study, we examined patients with CAKUT who underwent gene analysis. The analysis was performed in patients with bilateral renal lesions, extrarenal complications, or a family history of renal disease. The data from the diagnosis, gene mutations, and other complications were analyzed. RESULTS: In total, 66 patients with CAKUT were included. Of these, gene mutations were detected in 14 patients. Bilateral renal lesions were significantly related to the identification of gene mutations (p = 0.02), and no gene mutations were observed in patients with lower urinary tract obstruction (six patients). There was no significant difference in the rate of gene mutations between those with or without extrarenal complications (p = 0.76). The HNF1ß gene mutation was identified in most of the patients with hypodysplastic kidney with multicystic dysplastic kidney (six of seven patients). There was no significant difference in the presence or absence of gene mutations with respect to the renal survival rate (log-rank test p = 0.53). The renal prognosis varied, but the differences were not statistically significant for any of the gene mutations. CONCLUSIONS: CAKUT with bilateral renal lesions were significantly related to gene mutations. We recommend that CAKUT-related gene analysis be considered in cases of bilateral renal lesions. No gene mutations were observed in patients with lower urinary tract obstruction. The renal prognosis varied for each gene mutation.