Zero-contrast PTRA and stenting for child with TRAS: A case report.

BACKGROUND: Kidney transplantation is often complicated by TRAS, and PTRA can effectively treat it. However, PTRA is not appropriate for patients with CKD because iodinated contrast agent may induce nephropathy. METHODS: This article reports about a 14-year-old boy with a history of kidney transplantation complicated by RAS. He initially underwent percutaneous balloon dilation to relieve the stenosis. One and half a year after dilation, he received zero-contrast PTRA and stenting under the guidance of external and IVUS with reference to previous PAG image. RESULTS: After successful stent implantation, the cross-sectional area of the renal artery lumen was significantly increased.The blood pressure and level of creatinine also decreased and kept stable during follow-up. CONCLUSION: This report suggests the feasibility of external ultrasound and IVUS guided, zero-contrast PTRA in patients with poor renal function or iodinated contrast allergy.

CUBN gene mutations may cause focal segmental glomerulosclerosis (FSGS) in children.

BACKGROUND: Imerslund-Gräsbeck Syndrome (IGS) is mainly caused by CUBN gene biallelic mutations. Proteinuria accompanies IGS specific symptoms in about half of the patients, isolated proteinuria is rarely reported. Here we present 3 patients with isolated proteinuria and focal segmental glomerulosclerosis (FSGS) caused by CUBN gene biallelic pathogenic variants. METHOD: Whole exome sequencing was performed on three children with isolated proteinuria. CUBN gene biallelic pathogenic variants were found and then verified by sanger sequencing. Their clinical, pathological and molecular genetic characteristics were analyzed and correlated accordingly. RESULTS: All three children presented with isolated proteinuria, no megaloblastic anemia. Their urine levels of ß2 microglobulin were normal or slightly higher. Renal biopsies showed focal segmental glomerulosclerosis with mild glomerular mesangial hypercellularity, partial effacement of foot processes and podocyte microvillation. Two of them were found to carry compound heterozygous mutations and one homozygous mutation of CUBN gene. Totally four CUBN gene biallelic pathogenic variants were identified, including c.9287 T > C (p.L3096P), c.122 + 1G > A, c.7906C > T (p.R2636*), c.10233G > A (p.W3411*). Except for intron splice-site mutation, all other variants are located in highly conserved sites of CUB domain for binding to albumin. CONCLUSION: The results demonstrate that CUBN gene mutations may cause isolated proteinuria pathologically presented as FSGS. Our cases extend the spectrum of renal manifestation and genotype of CUBN gene mutations.

FXR/TGR5 Dual Agonist Prevents Progression of Nephropathy in Diabetes and Obesity.

Bile acids are ligands for the nuclear hormone receptor farnesoid X receptor (FXR) and the G protein-coupled receptor TGR5. We have shown that FXR and TGR5 have renoprotective roles in diabetes- and obesity-related kidney disease. Here, we determined whether these effects are mediated through differential or synergistic signaling pathways. We administered the FXR/TGR5 dual agonist INT-767 to DBA/2J mice with streptozotocin-induced diabetes, db/db mice with type 2 diabetes, and C57BL/6J mice with high-fat diet-induced obesity. We also examined the individual effects of the selective FXR agonist obeticholic acid (OCA) and the TGR5 agonist INT-777 in diabetic mice. The FXR agonist OCA and the TGR5 agonist INT-777 modulated distinct renal signaling pathways involved in the pathogenesis and treatment of diabetic nephropathy. Treatment of diabetic DBA/2J and db/db mice with the dual FXR/TGR5 agonist INT-767 improved proteinuria and prevented podocyte injury, mesangial expansion, and tubulointerstitial fibrosis. INT-767 exerted coordinated effects on multiple pathways, including stimulation of a signaling cascade involving AMP-activated protein kinase, sirtuin 1, PGC-1α, sirtuin 3, estrogen-related receptor-α, and Nrf-1; inhibition of endoplasmic reticulum stress; and inhibition of enhanced renal fatty acid and cholesterol metabolism. Additionally, in mice with diet-induced obesity, INT-767 prevented mitochondrial dysfunction and oxidative stress determined by fluorescence lifetime imaging of NADH and kidney fibrosis determined by second harmonic imaging microscopy. These results identify the renal signaling pathways regulated by FXR and TGR5, which may be promising targets for the treatment of nephropathy in diabetes and obesity.

SGLT2 Protein Expression Is Increased in Human Diabetic Nephropathy: SGLT2 PROTEIN INHIBITION DECREASES RENAL LIPID ACCUMULATION, INFLAMMATION, AND THE DEVELOPMENT OF NEPHROPATHY IN DIABETIC MICE.

There is very limited human renal sodium gradient-dependent glucose transporter protein (SGLT2) mRNA and protein expression data reported in the literature. The first aim of this study was to determine SGLT2 mRNA and protein levels in human and animal models of diabetic nephropathy. We have found that the expression of SGLT2 mRNA and protein is increased in renal biopsies from human subjects with diabetic nephropathy. This is in contrast to db-db mice that had no changes in renal SGLT2 protein expression. Furthermore, the effect of SGLT2 inhibition on renal lipid content and inflammation is not known. The second aim of this study was to determine the potential mechanisms of beneficial effects of SGLT2 inhibition in the progression of diabetic renal disease. We treated db/db mice with a selective SGLT2 inhibitor JNJ 39933673. We found that SGLT2 inhibition caused marked decreases in systolic blood pressure, kidney weight/body weight ratio, urinary albumin, and urinary thiobarbituric acid-reacting substances. SGLT2 inhibition prevented renal lipid accumulation via inhibition of carbohydrate-responsive element-binding protein-ß, pyruvate kinase L, SCD-1, and DGAT1, key transcriptional factors and enzymes that mediate fatty acid and triglyceride synthesis. SGLT2 inhibition also prevented inflammation via inhibition of CD68 macrophage accumulation and expression of p65, TLR4, MCP-1, and osteopontin. These effects were associated with reduced mesangial expansion, accumulation of the extracellular matrix proteins fibronectin and type IV collagen, and loss of podocyte markers WT1 and synaptopodin, as determined by immunofluorescence microscopy. In summary, our study showed that SGLT2 inhibition modulates renal lipid metabolism and inflammation and prevents the development of nephropathy in db/db mice.

G Protein-Coupled Bile Acid Receptor TGR5 Activation Inhibits Kidney Disease in Obesity and Diabetes.

Obesity and diabetes mellitus are the leading causes of renal disease. In this study, we determined the regulation and role of the G protein-coupled bile acid receptor TGR5, previously shown to be regulated by high glucose and/or fatty acids, in obesity-related glomerulopathy (ORG) and diabetic nephropathy (DN). Treatment of diabetic db/db mice with the selective TGR5 agonist INT-777 decreased proteinuria, podocyte injury, mesangial expansion, fibrosis, and CD68 macrophage infiltration in the kidney. INT-777 also induced renal expression of master regulators of mitochondrial biogenesis, inhibitors of oxidative stress, and inducers of fatty acid ß-oxidation, including sirtuin 1 (SIRT1), sirtuin 3 (SIRT3), and Nrf-1. Increased activity of SIRT3 was evidenced by normalization of the increased acetylation of mitochondrial superoxide dismutase 2 (SOD2) and isocitrate dehydrogenase 2 (IDH2) observed in untreated db/db mice. Accordingly, INT-777 decreased mitochondrial H2O2 generation and increased the activity of SOD2, which associated with decreased urinary levels of H2O2 and thiobarbituric acid reactive substances. Furthermore, INT-777 decreased renal lipid accumulation. INT-777 also prevented kidney disease in mice with diet-induced obesity. In human podocytes cultured with high glucose, INT-777 induced mitochondrial biogenesis, decreased oxidative stress, and increased fatty acid ß-oxidation. Compared with normal kidney biopsy specimens, kidney specimens from patients with established ORG or DN expressed significantly less TGR5 mRNA, and levels inversely correlated with disease progression. Our results indicate that TGR5 activation induces mitochondrial biogenesis and prevents renal oxidative stress and lipid accumulation, establishing a role for TGR5 in inhibiting kidney disease in obesity and diabetes.

Simultaneous mutations of LAMB2 and NPHP1genes in a Chinese girl with isolated congenital nephrotic syndrome: a case report.

BACKGROUND: LAMB2 mutations cause Pierson syndrome (OMIM 609049), an autosomal recessive genetic disease typically characterized by congenital nephrotic syndrome (CNS) and early onset renal failure, as well as bilateral microcoria. NPHP1 mutations cause familial juvenile nephronophthisis type 1 (NPHP1, OMIM 256100), another autosomal recessive renal disease that usually occurs years after birth. Both Pierson syndrome and nephronophthisis cause end-stage renal disease and rare kidney diseases in children. We report an extremely rare case of concurrent mutations of LAMB2 and NPHP1 in a Chinese girl with isolated CNS and the association of the phenotype with novel non-truncating mutations of LAMB2. CASE PRESENTATION: A-34-day-old girl presented with CNS but no eye abnormalities, and mild hyperechogenicity of kidneys. A novel c.1176_1178delTCT mutation caused deletion of a glycine in exon 9 of LAMB2, and another mutation c.4923 + 2 T > G led to a splicing error. In addition, compound heterozygous mutations of NPHP1 were identified in this child using next generation sequencing, and confirmed by Sanger sequencing. CONCLUSION: Mutations of the LAMB2 and NPHP1 are present in infants with isolated CNS. Next generation sequencing enabled high-throughput screening for mutant genes promptly, with clinically significant outcomes. In addition, our results expand the phenotype spectrum of LAMB2 mutations as the only renal manifestation.

Liver X receptors preserve renal glomerular integrity under normoglycaemia and in diabetes in mice.

AIMS/HYPOTHESIS: Liver X receptors (LXRs) α and ß are nuclear hormone receptors that are widely expressed in the kidney. They promote cholesterol efflux from cells and inhibit inflammatory responses by regulating gene transcription. Here, we hypothesised (1) that LXR deficiency would promote renal decline in a mouse model of diabetes by accelerating intraglomerular cholesterol accumulation and, conversely, (2) that LXR agonism would attenuate renal decline in diabetes. METHODS: Diabetes was induced with streptozotocin (STZ) and maintained for 14 weeks in Lxrα/ß (+/+) (Lxrα, also known as Nr1h3; Lxrß, also known as Nr1h2) and Lxrα/ß (-/-) mice. In addition, STZ-injected DBA/2J mice were treated with vehicle or the LXR agonist N,N-dimethyl-hydroxycholenamide (DMHCA) (80 mg/kg daily) for 10 weeks. To determine the role of cholesterol in diabetic nephropathy (DN), mice were placed on a Western diet after hyperglycaemia developed. RESULTS: Even in the absence of diabetes, Lxrα/ß (-/-) mice exhibited a tenfold increase in the albumin:creatinine ratio and a 40-fold increase in glomerular lipid accumulation compared with Lxrα/ß (+/+) mice. When challenged with diabetes, Lxrα/ß (-/-) mice showed accelerated mesangial matrix expansion and glomerular lipid accumulation, with upregulation of inflammatory and oxidative stress markers. In the DN-sensitive STZ DBA/2J mouse model, DMHCA treatment significantly decreased albumin and nephrin excretion (by 50% each), glomerular lipids and plasma triacylglycerol (by 70%) and cholesterol (by 48%); it also decreased kidney inflammatory and oxidative stress markers compared with vehicle-treated mice. CONCLUSIONS/INTERPRETATION: These data support the idea that LXR plays an important role in the normal and diabetic kidney, while showing that LXR, through its inhibitory effect on inflammation and cholesterol accumulation in glomeruli, could also be a novel therapeutic target for DN.

Early onset stage III diabetic nephropathy in a child with Prader-Willi syndrome treated with dulaglutide: a case report.

Background: Prader-Willi syndrome (PWS) is a multisystem genetic disorder caused by chromosomal imprinting gene defects, with approximately 70% of cases resulting from paternal deletion of the chromosomal region 15. The main clinical features include severe infantile hypotonia, early-onset childhood obesity, hyperphagia, and underdeveloped external genitalia. As individuals with PWS age, they may exhibit irritability, social dysfunction, impaired gonadal development, and metabolic syndrome. Previous literature places the prevalence of type 2 diabetes mellitus (T2DM) in PWS at approximately 7-24%. Oxytocin is a neuropeptide secreted by the paraventricular (PVN) and supraoptic (SON) nuclei of the hypothalamus and regulates energy metabolism, which is involved in PWS. Due to age limitations, very few patients progress to diabetic nephropathy during childhood, and reports of typical diabetic nephropathy in PWS during childhood are extremely rare. Dulaglutide is a glucagon-like peptide-1 (GLP-1) receptor agonist which can be used in the treatment of T2DM. Case Description: This article reports a case of a child with PWS complicated by stage III diabetic nephropathy, providing a retrospective analysis of the diagnosis and treatment process, as well as a review of domestic and international literature, to enhance understanding of this condition. And this article provides a treatment idea for PWS patients with diabetic nephropathy. Conclusions: It is very important to enhance understanding of PWS. And we offer new diagnostic and possible therapeutic approaches for pediatric patients with diabetic nephropathy.

Mutations in the NUP93, NUP107 and NUP160 genes cause steroid-resistant nephrotic syndrome in Chinese children.

BACKGROUND: The variants of nucleoporins are extremely rare in hereditary steroid-resistant nephrotic syndrome (SRNS). Most of the patients carrying such variants progress to end stage kidney disease (ESKD) in their childhood. More clinical and genetic data from these patients are needed to characterize their genotype-phenotype relationships and elucidate the role of nucleoporins in SRNS. METHODS: Four patients of SRNS carrying biallelic variants in the NUP93, NUP107 and NUP160 genes were presented. The clinical and molecular genetic characteristics of these patients were summarized, and relevant literature was reviewed. RESULTS: All four patients in this study were female and initially presented with SRNS. The median age at the onset of the disease was 5.08 years, ranging from 1 to 10.5 years. Among the four patients, three progressed to ESKD at a median age of 7 years, ranging from 1.5 to 10.5 years, while one patient reached stage 3 chronic kidney disease (CKD3). Kidney biopsies revealed focal segmental glomerulosclerosis in three patients. Biallelic variants were detected in NUP93 in one patient, NUP107 in two patients, as well as NUP160 in one patient respectively. Among these variants, five yielded single amino acid substitutions, one led to nonsense mutation causing premature termination of NUP107 translation, one caused a single nucleotide deletion resulting in frameshift and truncation of NUP107. Furthermore, one splicing donor mutation was observed in NUP160. None of these variants had been reported previously. CONCLUSION: This report indicates that biallelic variants in NUP93, NUP107 and NUP160 can cause severe early-onset SRNS, which rapidly progresses to ESKD. Moreover, these findings expand the spectrum of phenotypes and genotypes and highlight the importance of next-generation sequencing in elucidating the molecular basis of SRNS and allowing rational treatment for affected individuals.

Steroid-resistant nephrotic syndrome associated with certain SGPL1 variants in a family: Case report and literature review.

Objectives: Steroid-resistant nephrotic syndrome (SRNS) is a clinical syndrome characterized by the lack of response to standard steroid therapy, usually progressing to end-stage renal disease. We reported two cases of female identical twins with SRNS caused by SGPL1 variants in one family, reviewed the relevant literature, and summarized their clinical phenotypes, pathological types, and genotypic characteristics. Methods: Two cases of nephrotic syndrome caused by SGPL1 variants were admitted to Tongji Hospital, affiliated with Tongji Medical College of Huazhong University of Science and Technology. Their clinical data were retrospectively collected, and the peripheral blood genomic DNA was captured and sequenced by whole exome sequencing. Related literature published in PubMed, CNKI, and Wan fang databases was reviewed. Results: We described two Chinese identical twin girls with isolated SRNS due to compound heterozygous variants in the SGPL1 (intron4 c.261 + 1G > A and intron12 c.1298 + 6T > C). The patients were followed up for 60.0 months and 53.0 months, respectively, having no extra-renal manifestations. They all died due to renal failure. A total of 31 children with SGPL1 variants causing nephrotic syndrome (including the reported two cases) were identified through a literature review. Conclusions: These two female identical twins were the first reported cases of isolated SRNS caused by SGPL1 variants. Almost all homozygous and compound heterozygous variants of SGPL1 had extra-renal manifestations, but compound heterozygous variants in the intron of SGPL1 may have no obvious extra-renal manifestations. Additionally, a negative genetic testing result does not completely rule out genetic SRNS because the Human Gene Mutation Database or ClinVar is constantly being updated.

Clinical, histological and molecular characteristics of Alport syndrome in Chinese children.

BACKGROUND: Alport syndrome is caused by COL4A3, COL4A4, or COL4A5 gene mutations. The present study aims to compare the clinicopathological features, gene mutations, and outcome of Chinese children with different forms of Alport syndrome. METHODS: One hundred twenty-eight children from 126 families diagnosed with Alport syndrome through pathological and genetic examination between 2003 and 2021 were included in this single-center retrospective study. The laboratory and clinicopathological features of the patients with different inheritance patterns were analyzed. The patients were followed-up for disease progression and phenotype-genotype correlation. RESULTS: Of the 126 Alport syndrome families, X-linked forms accounted for 77.0%, autosomal recessive for 11.9%, autosomal dominant for 7.1%, and digenic for 4.0%. Among the patients, 59.4% were males and 40.6% were females. Altogether, 114 different mutations were identified in 101 patients from 99 families by whole-exome sequencing, of which 68 have not been previously reported. The most prevalent type of mutation was glycine substitution, which was identified in 52.1%, 36.7%, and 60% of the patients with X-linked Alport syndrome, autosomal recessive and autosomal dominant Alport syndrome, respectively. At the end of a median follow up of 3.3 (1.8-6.3) years, Kaplan-Meier curves showed kidney survival was significantly lower in autosomal recessive compared to X-linked Alport syndrome (P = 0.004). Pediatric patients with Alport syndrome seldom presented extrarenal involvement. CONCLUSIONS: X-linked Alport syndrome is the most frequent form found in this cohort. Progression was more rapid in autosmal recessive than in X-linked Alport syndrome.

Case Report: The Application of Dupilumab in Atopic Dermatitis Children Complicated With Nephrotic Syndrome.

Nephrotic syndrome (NS) tends to be more common in patients with history of allergies. Atopic dermatitis (AD) is one of the most common allergic diseases in children. Dupilumab, a dual IL-4 and IL-13 inhibitor, has been widely used to treat AD patients. However, the efficacy and safety of Dupilumab in NS is unclear. We reported two AD patients with NS comorbidities treated with Dupilumab. The outcomes showed the good control of NS and less systemic steroids and/or immunosuppressive agents use during the Dupilumab treatment period, accompanied by significant relief of AD symptoms. We suggest prospective pilot studies and randomized controlled trials could be carried out to validate the efficacy and safety of Dupilumab in the treatment of NS patients.

A novel variant site of Alstrom syndrome in a Chinese child: a case report.

Background: Alstrom syndrome (ALMS) is an ultra-rare multisystem genetic disorder caused by autosomal recessive inheritance of the ALMS1 gene. It manifests as multisystem dysfunction, displaying unique clinical signs and symptoms and various severity, which may lead to delayed prognosis or misdiagnosis in medical practice. Although almost 300 pathogenic variants have been reported, there are some variant sites that have not been recognized yet. Case Description: We report a case of a 14-year-old boy with manifestations, including binocular vision loss, acanthosis nigricans, type 2 diabetes, insulin resistance, elevated transaminase, hepatic fibrosis, and proteinuria. Compound heterozygous variants in the ALMS1 gene have been discovered by whole exon sequencing. One of his variant sites was C. 8158C>T, which was from his father. And the other variant site was C. 3575C>A, which was from his mother. To the great of our knowledge, this site has not been reported before. Both of the variants make the synthesis of the peptide chain terminated in advance and an incomplete polypeptide chain is formed. Conclusions: The clinical presentations of ALMS are complicated and varied. Although early diagnosis can be made according to typical clinical symptoms, whole exon sequencing is necessary for the diagnosis of ALMS, as indicated by our study.

Clinical and Renal Histology Findings and Different Responses to Induction Treatment Affecting the Long-Term Renal Outcomes of Children With ANCA-Associated Vasculitis: a Single-Center Cohort Analysis.

Introduction: Antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) is relatively rare in children. This article aimed to analyze clinical and renal histology findings and different responses to induction treatment associated with the long-term renal outcomes in children with AAV in a single center. Methods: All pediatric patients with AAV admitted to Tongji Hospital from January 2002 to January 2021 were included in the study. The demographic, clinical, pathological, laboratory, and treatment data and outcomes were collected and analyzed to identify predictors associated with response to induction treatment and progression to end-stage renal disease (ESRD). Results: In total, 48 children with AAV were included in this cohort; 81.25% of them were women, and 91.7% were microscopic polyangiitis (MPA). Kidney involvement was found in 45 patients (93.75%). The most common histopathological subtype was crescentic form in this cohort according to Berden's classification. In total, 34 patients (70.8%) showed eGFR <60 ml/min/1.73 m2 at the time of diagnosis. Complete and partial remission was achieved in 8 patients (16.7%) and 19 patients (39.6%), respectively, following 6-month induction treatment. Half of the patients eventually progressed to ESRD at a mean time of (13.04 ± 15.83) months after diagnosis. The independent predictors of nonremission following induction treatment and progression to ESRD were baseline eGFR <60 ml/min/1.73 m2 and hypertension at diagnosis. Renal survival significantly decreased over time in patients with renal sclerotic subtypes or those with nonremission following induction treatment by Kaplan-Meier curve estimation. Conclusions: Our study demonstrates that women, MPA, and crescentic subtypes are predominant in pediatric AAV in China. Initial renal failure (eGFR <60 ml/min/1.73 m2), hypertension, sclerotic pathological subtype, and nonremission following induction treatment are predictive of long-term renal outcomes.

Long-Term Clinical and Immunological Impact of Severe COVID-19 on a Living Kidney Transplant Recipient - A Case Report.

The long-term impact of COVID-19 on transplant recipients remains unknown. We describe the case of a 30-year-old male kidney transplant recipient from Wuhan, China that was treated for severe COVID-19 in February 2020. He suffered an acute lung and renal injury and required systemic treatment including adjustment of his immunosuppressant regime. He was followed up to 1-year after discharge. No chronic lung fibrosis or deterioration of his pulmonary function was observed. Despite COVID-19 mediated damage to his renal tubular cells, no transplant rejection occurred. His immunological profile demonstrated both cellular anti-SARS-CoV-2 reactivity and specific humoral immunity, indicating that it is beneficial for the transplanted patients to be immunized with SARS-CoV-2 virus vaccine. This case will help guide clinical decision making for immunocompromised individuals that become infected with SARS-CoV-2.

CCL2 regulation of MST1-mTOR-STAT1 signaling axis controls BCR signaling and B-cell differentiation.

Chemokines are important regulators of the immune system, inducing specific cellular responses by binding to receptors on immune cells. In SLE patients, decreased expression of CCL2 on mesenchymal stem cells (MSC) prevents inhibition of B-cell proliferation, causing the characteristic autoimmune phenotype. Nevertheless, the intrinsic role of CCL2 on B-cell autoimmunity is unknown. In this study using Ccl2 KO mice, we found that CCL2 deficiency enhanced BCR signaling by upregulating the phosphorylation of the MST1-mTORC1-STAT1 axis, which led to reduced marginal zone (MZ) B cells and increased germinal center (GC) B cells. The abnormal differentiation of MZ and GC B cells were rescued by in vivo inhibition of mTORC1. Additionally, the inhibition of MST1-mTORC1-STAT1 with specific inhibitors in vitro also rescued the BCR signaling upon antigenic stimulation. The deficiency of CCL2 also enhanced the early activation of B cells including B-cell spreading, clustering and signalosome recruitment by upregulating the DOCK8-WASP-actin axis. Our study has revealed the intrinsic role and underlying molecular mechanism of CCL2 in BCR signaling, B-cell differentiation, and humoral response.

Possible PKHD1 Hot-spot Mutations Related to Early Kidney Function Failure or Hepatofibrosis in Chinese Children with ARPKD: A Retrospective Single Center Cohort Study and Literature Review.

PKHD1 mutations are generally considered to cause autosomal recessive polycystic kidney disease (ARPKD). ARPKD is a rare disorder and one of the most severe conditions leading to end-stage renal disease in childhood. With the biallelic deletion mutation, patients have difficulty in surviving the perinatal period, resulting in perinatal or neonatal death. This study retrospectively analyzed patient characteristics, imaging characteristics, laboratory examinations and family surveys from 7 Chinese children with different PKHD1 gene mutations diagnosed by high-throughput sequencing from January 2014 to February 2018. Of the 7 children, there were 3 males and 4 females. Eight missense mutations, two frameshift mutations, two deletion mutations, and two intronic slicing mutations were identified. Six of the mutations have not previously been identified. In the literature search, we identified a total of 29 Chinese children with PKHD1 mutations. The missense mutation c.2507T>C in exon 24 was found in one patient in our study, and five patients with liver fibrosis but normal renal function were reported in the literature. The missense mutation c.5935G>A in exon 37 was found in two patients in our study and three cases in the literature. Four patients had renal failure at an age as young as 1 year of those five patients with the missense mutation c.5935G>A in exon 37. It was concluded that: (1) Kidney length more than 2-3 SDs above the mean and early-onset hypertension might be associated with PKHD1-associated ARPKD; (2) The more enlarged the kidney size is, the lower the renal function is likely to be; (3) c.5935G>A may be a hot spot that leads to early renal failure in Chinese children with PKHD1 mutations; (4) c.2507T>C may be a hot-spot mutation associated with hepatic lesions in Chinese children with PKHD1.

A quantitative grading system of vesicoureteral reflux by contrastenhanced voiding urosonography.

AIMS: Contrast-enhanced voiding urosonography (ceVUS) is a well-established imaging modality for the diagnosis of vesicoureteral reflux (VUR). However, discrepancies of grading diagnosis of VUR exist due to the qualitative grading criteria currently used in clinics. This study aimed to evaluate numerical markers for a quantitative VUR grading system. MATERIAL AND METHODS: CeVUS images of grade II-VVUR were analysed. A quantitative indicator, i.e. sectional area ratio (SAR), on the imaging section with maximum cross-section area and the presence of kidney hilum was calculated to distinguish different grades of VUR. The diagnostic performance of SAR was evaluated using receiver operating characteristic curve (ROC) analysis, and the maximum Youden Index was used to determine the optimal cut-off values. RESULTS: A total of 63 patients with 126 PelviUreteral Units were enrolled. The SAR value increased significantly along with the increase of VUR grade. SAR had an excellent diagnostic performance in grading VUR. For differentiating VUR of grade II vs III, III vs IV and IV vs V, the area under the ROC curve values of SAR were 0.967, 0.943 and 0.865, respectively, while the optimal SAR cut-off values were 14.3%, 34.9% and 51.0%, respectively. The quantitative grading system based on the optimal SAR cut-off values showed excellent consistency with the qualitative grading system of VUR currently used in clinic. CONCLUSIONS: The numerical indicator SAR calculated from ceVUS may be used to establish a quantitative VUR grading system with excellent diagnostic performance and can potentially serve as a reliable tool for the evaluation and follow-up of VUR.

Relationship between Vesicoureteral Reflux and Glomerular Filtration Rate in Children.

Vesicoureteral reflux (VUR) is one of the most common urinary tract anomalies in children and causes renal damage and studies focusing on the effect of VUR on renal function are rare. We recruited 35 primary VUR patients with recurrent urinary tract infection (UTI) and 10 non-VUR patients with recurrent UTI. Contrast-enhanced voiding urosonography (ceVUS) was performed for VUR grading, and renal dynamic imaging was used for evaluating glomerular filtration rate (GFR, mL/min). Standardized GFR (sGFR), namely GFR/BSA (mL·min-1·m-2), was calculated based on the body surface area (BSA). Total sGFR (tsGFR, mL·min-1·m-2) was obtained from the sum of sGFR on the left and right sides of all the children. The risk of renal regurgitation was equal in the unilateral reflux group. The sGFR of children with grade IV (45.74±18.05 mL·min-1·m-2) and grade V (49.67±23.63 mL·min-1·m-2) reflux was significantly lower than that in children with grade III (77.69 ±22.21 mL·min-1·m-2). The renal function compensation of contralateral non-reflux kidney increased in unilateral reflux group, which was higher than that in the control group and level II, IV and V of reflux group respectively. In VUR group of the same grade, sGFR decreased with the age at diagnosis. In unilateral grade V reflux group, the tsGFR was lower than that in the unilateral grade III reflux group (133.51±48.21 vs. 186.87±53.49 mL·min-1·m-2). The patients with VUR of unilateral grade II were significantly older than those with VUR of unilateral grades III and IV. This study indicates that severe VUR is significantly associated with decreased renal function. Therefore, VUR should be diagnosed early and managed individually.

Are They Just Two Children COVID-19 Cases Confused With Flu?

COVID-19, an emerging infectious disease, has quickly spread all over the world. All human populations are susceptible to this disease. Here we present two pediatric COVID-19 cases, both of whom exhibited negative SARS-CoV-2 nucleic acid tests upon nasopharyngeal swab and were initially diagnosed with influenza A infection. COVID-19 was later confirmed in both patients by serum antibodies of SARS-CoV-2 and nucleic acid test on stool samples. Because children are susceptible to many respiratory pathogens, especially influenza, we concluded that children can be coinfected with multiple pathogens, and more attention should be paid to the exploration of SARS-CoV-2 during the pandemic of COVID-19. This report shows the possibility of misdiagnosis or missed diagnosis of children with COVID-19. We suggest that highly suspected pediatric COVID-19 cases with negative nucleic acid tests on nasopharyngeal swabs should be further checked by performing a nucleic acid test on stool samples and testing serum for antibodies against SARS-CoV-2.