Evaluation of screening with urine dipsticks and renal ultrasonography for 3-year-olds in Chiba City over 30 years.

BACKGROUND: Urinary screening for 3-year-olds cannot adequately detect congenital anomalies of the kidney and urinary tract (CAKUT). METHODS: Urinary screening for 3-year-olds was investigated over 30 years. Dipsticks for proteinuria, hematuria, glycosuria, leukocyturia, and nitrite at first screening, and dipsticks, urinary sediments, and renal ultrasonography at second screening were performed. Screening results were evaluated. RESULTS: The positive rates of proteinuria, hematuria, leukocyturia, and nitrite relative to 218,831 children at the first screening were 1.0%, 4.6%, 2.3%, and 0.88%, respectively. Thirty-seven glomerular disease, 122 CAKUT, and 5 urological disease cases were found. We detected 6 stage 3-4 chronic kidney disease (CKD) and 3 end-stage kidney disease cases, including 3 CAKUT, comprising 2 bilateral renal hypoplasia and 1 vesicoureteral reflux (VUR), and 6 glomerular diseases, comprising 4 focal segmental glomerulosclerosis and 2 Alport syndrome. The positive rates relative to 218,831 children and CKD detection rates for each tentative diagnosis of mild hematuria, severe hematuria, proteinuria and hematuria, proteinuria, and suspected urinary tract infection were 1.4% and 0.67%, 0.11% and 3.7%, 0.01% and 28.6%, 0.02% and 45.0%, and 0.08% and 9.7%, respectively. Among 14 VUR cases with significant bacteriuria, 13 were found by leukocyturia, 12 had grade ≥ IV VUR, and 10 had severe renal scars. CONCLUSIONS: Nine stage 3-5 CKD cases comprising 3 CAKUT and 6 glomerular disease were found by urinary screening of 3-year-olds among 218,831 children. The combination of urine dipsticks including leukocyturia at the first screening and ultrasonography at the second screening appeared useful.

A review of clinical characteristics and genetic backgrounds in Alport syndrome.

Alport syndrome (AS) is a progressive hereditary renal disease that is characterized by sensorineural hearing loss and ocular abnormalities. It is divided into three modes of inheritance, namely, X-linked Alport syndrome (XLAS), autosomal recessive AS (ARAS), and autosomal dominant AS (ADAS). XLAS is caused by pathogenic variants in COL4A5, while ADAS and ARAS are caused by those in COL4A3/COL4A4. Diagnosis is conventionally made pathologically, but recent advances in comprehensive genetic analysis have enabled genetic testing to be performed for the diagnosis of AS as first-line diagnosis. Because of these advances, substantial information about the genetics of AS has been obtained and the genetic background of this disease has been revealed, including genotype-phenotype correlations and mechanisms of onset in some male XLAS cases that lead to milder phenotypes of late-onset end-stage renal disease (ESRD). There is currently no radical therapy for AS and treatment is only performed to delay progression to ESRD using nephron-protective drugs. Angiotensin-converting enzyme inhibitors can remarkably delay the development of ESRD. Recently, some new drugs for this disease have entered clinical trials or been developed in laboratories. In this article, we review the diagnostic strategy, genotype-phenotype correlation, mechanisms of onset of milder phenotypes, and treatment of AS, among others.

Clinical significance of IgM and C1q deposition in the mesangium in pediatric idiopathic nephrotic syndrome.

BACKGROUND: In biopsy-proven idiopathic nephrotic syndrome (INS), immunoglobulin M (IgM) and C1q are occasionally deposited in the mesangium. In pediatric nephrology, the significance of mesangial IgM or C1q deposits is controversial, based on previous reports. The aim of this study was to explore the clinical significance of mesangial IgM and/or C1q deposits in pediatric INS patients, especially the initial responses to steroids and final outcomes. METHODS: We reviewed the clinical courses of 70 children with steroid-dependent or steroid-resistant INS who underwent a renal biopsy at our hospital from 1998 to 2010. There were 30 mesangial IgM immunofluorescence (IF)-positive (IgM+) children. The IgM+ group was compared with the IgM IF-negative (IgM-) group. In addition, we reviewed the clinical characteristics of 8 mesangial C1q IF-positive (C1q+) children. RESULTS: Of the 30 IgM+ children, 10 (33.3%) were steroid-dependent (IgM- group: 18/40, 45%) and 14 (46.7%) were steroid-resistant (IgM- group: 11/40, 27.5%; p<0.05). Although a high frequency of steroid-resistant INS was observed in the IgM+ group, the efficacy of cyclosporine (CyA) therapy was relatively good (all 14 steroid-resistant children obtained complete or partial remission). Moreover, all 8 C1q+ children obtained complete remission after CyA therapy, although they had a high frequency of steroid resistance (7/8, 87.5%), and 1 child was steroid-dependent. CONCLUSIONS: Our results indicate that, regardless of the histological pattern (minimal change disease, focal segmental glomerulosclerosis or diffuse mesangial hypercellularity), children with IgM+ and/or C1q+ INS have good responses to CyA. IgM+ and/or C1q+ may be markers of the initial disease severity of INS.

Primary membranoproliferative glomerulonephritis on the decline: decreased rate from the 1970s to the 2000s in Japan.

BACKGROUND: A prolonged change in the rate of primary membranoproliferative glomerulonephritis (MPGN) was identified using a Japanese database of renal biopsies. METHODS: We retrospectively investigated 6,369 renal biopsies that were performed between 1976 and 2009. Primary MPGN patients were selected, and the clinical and pathological findings were examined. We also statistically analyzed the changing rate of the onset of primary MPGN according to each decade. RESULTS: Seventy-nine cases with primary MPGN (1.2 % of total biopsies) were diagnosed. The age of the patients ranged from 6-79 years (average 34.6 years). There were 24 children and 55 adults, including 37 male and 42 female patients. Thirty-six cases of primary MPGN (45.6 %) showed nephrotic syndrome-8 childhood and 28 adult cases. In the pathological classification of 44 samples using electron microscopy, 29 cases were MPGN type I, 1 case was MPGN type II, and 14 cases were MPGN type III. The secular change of the rate of primary MPGN onset showed a statistically significant reduction from the 1970s to the 2000s. The rate of primary MPGN onset in the child population also significantly decreased, but not in the adult population. Among the clinical parameters, disease severity and prognosis remained unchanged. Regarding treatment in recent years, steroid pulse therapy became more available but the administration of warfarin and anti-platelet drugs significantly decreased. CONCLUSION: We concluded that the rate of total primary MPGN and that of pediatric patients with primary MPGN decreased.

A case report of mediastinal seminoma arising after renal transplantation.

Recipients of organ transplantation on immunosuppressive medications are at increased risk for developing de novo malignancies, including skin cancer, Kaposi's sarcoma, in situ carcinomas of the uterine cervix, anogenital cancers, renal cell carcinoma, and post-transplant lymphoproliferative disorders (PTLD). However, there are few case reports of germ cell tumors after organ transplantation. There are some case reports of testicular seminoma, but not mediastinal seminoma. This case report is the first description of a mediastinal seminoma that developed de novo 28 months after renal transplantation and that was initially diagnosed as PTLD. To improve outcomes of organ transplant recipients, it is important to report rare cases of malignancies arising while on immunosuppressive medications. When we detect mediastinal tumor arising after organ transplantation while on immunosuppressive therapy, diseases other than PTLD should be considered in the differential diagnosis.

Cyclic stretch induces proliferation and TGF-beta1-mediated apoptosis via p38 and ERK in ureteric bud cells.

We previously reported that p38 mitogen-activated protein kinase (p38) and phosphorylated ERK are upregulated in cyst epithelium of human renal dysplasia and obstructive uropathy in fetal lambs (Omori S, Fukuzawa R, Hida M, Awazu M. Kidney Int 61: 899-906, 2002; Omori S, Kitagawa H, Koike J, Fujita H, Hida M, Pringle KC, Awazu M. Kidney Int 73: 1031-1037, 2008). Dysplastic epithelium is characterized by proliferation, apoptosis, and upregulation of Pax2 and transforming growth factor (TGF)-beta1. In the present study, we investigated whether cyclic mechanical stretching of ureteric bud cells, a mimic of the hydrodynamic derangement after fetal urinary tract obstruction, reproduces events seen in vivo. Cyclic stretch activated p38 and ERK and upregulated Pax2 expression in a time-dependent manner in ureteric bud cells. Stretch-stimulated Pax2 expression was suppressed by a p38 inhibitor, SB203580, or a MEK inhibitor, PD98059. 5-Deoxyuridine incorporation was increased by stretch at 24 h, which was also abolished by SB203580 or PD98059. On the other hand, apoptosis was not induced at 24 h by stretch but was significantly increased at 48 h. TGF-beta1 secretion was increased by stretch at 24 h, which was inhibited by SB203580 or PD98059. Inhibition of p38 or ERK as well as anti-TGF-beta antibody abolished the stretch-induced apoptosis. Finally, exogenous TGF-beta1 induced apoptosis of ureteric bud cells, which was inhibited by SB203580 and PD98059. In conclusion, cyclic stretch induces Pax2 upregulation, proliferation, and TGF-beta1-mediated apoptosis, features characteristic of dysplastic epithelium, via p38 and ERK in ureteric bud cells.

WT1 intron 9 splice acceptor site mutation in a 46,XY male with focal segmental glomerulosclerosis.

The Wilms' tumor suppressor gene (WT1) plays crucial roles in urogenital and gonadal development. Germline mutations of WT1 have been reported in patients with Denys-Drash syndrome (DDS) and Frasier syndrome (FS). Based on clinical overlaps reported to date, it has been suggested that these two syndromes should be considered as part of a spectrum of diseases caused by WT1 gene mutations, rather than as separate diseases. We report a new mutation in an intron 9 splice acceptor site (IVS -1G-->) in a Japanese 46,XY male patient with focal segmental glomerulosclerosis (FSGS) and bilateral cryptorchism. The clinical phenotype of this patient resembled FS without male pseudohermaphroditism. Interestingly, although the patient's right kidney was diagnosed with FSGS, his left kidney showed severe hypoplasia. There are no previous case reports of FSGS and renal hypoplasia in the same individual with a WT1 mutation. The findings for this case further suggest that the renal phenotype has various manifestations and is not always decided by the type of WT1 mutation. The possibility that the position of the WT1 mutation may influence the course of the nephropathy should be evaluated in a larger patient cohort.

A case of Moebius syndrome presenting with congenital bilateral vocal cord paralysis.

We describe a female infant with bilateral facial paralysis and abducens palsy. To the best of our knowledge, this is the first report of Moebius syndrome presenting with congenital bilateral vocal cord paralysis (CBVCP). Although CBVCP can be part of a recognizable syndrome, i.e. Down syndrome, 22q deletion syndrome, Robinow's syndrome and cerebro-oculo-facio-skeletal syndrome, no reports of Moebius syndrome with CBVCP were found in the literature. CBVCP is often associated with central nervous system abnormalities. However, our patient had no detectable brain abnormalities. The etiology of Moebius syndrome remains unknown. It is interesting that the clinical manifestations of Moebius syndrome can include CBVCP. However, the pathophysiology of CBVCP is unknown and further investigations into the etiology of Moebius syndrome are required.

Interstitial 1q43-q43 deletion with left ventricular noncompaction myocardium.

We describe a newborn infant with del(1)(q) syndrome, presenting with rare congenital cardiomyopathy and left ventricular noncompaction myocardium (LVNC), as well as typical clinical features such as facial dysmorphism and psychomotor retardation. Although conventional chromosome banding at 850 bands per haploid set indicated a karyotype of 46,XX,add(1)(q42.3), FISH analysis confirmed that the deleted portion was limited to within q43, and q44 was preserved. Therefore, the chromosome constitution is 46,XX,del(1)(q43q43), which has not previously been reported in the literature. Screening for the mutations in the candidate genes for LVNC, i.e. G4.5, CSX, Dystrobrevin, FKBP12, and Desmin, produced negative results. Interestingly, the deleted portion includes the locus for the cardiac ryanodine receptor type 2 gene (RyR2), that selectively binds to the FKBP12 homolog, FKBP12.6. The relationship between this rare myocardial abnormality and deletion of q43 is currently unknown and awaits further accumulation of cases with the same chromosomal aberration.

Role of integrin-linked kinase in epithelial-mesenchymal transition in crescent formation of experimental glomerulonephritis.

BACKGROUND: Glomerular parietal epithelial-mesenchymal transition (EMT) is a key event in crescent formation of glomerulonephritis (GN). Integrin-linked kinase (ILK) is an integrin cytoplasmic-binding protein that has been implicated in the regulation of cell adhesion, extracellular matrix organization and EMT. Transforming growth factor-beta (TGF-beta) is involved in the induction and progression of EMT in several tissues. METHODS: To investigate whether ILK is involved in the crescent formation in GN, we studied the expression of ILK protein and activity in crescentic GN induced in Wistar Kyoto (WKY) rats. In addition, we investigated whether transforming growth factor-beta1 (TGF-beta1) could induce glomerular EMT and ILK by using cultured parietal epithelial cell (PEC). RESULTS: The expression of ILK was strongly induced in cellular crescents at day 7 and followed by a decrease in fibrocellular crescents at day 28. ILK-expressing cells in cellular crescents were double-positive for protein gene product 9.5 (PEC marker), alpha-smooth muscle actin (alpha-SMA, myofibroblasts marker) and TGF-beta1, indicating a possible contribution of ILK and TGF-beta1 to EMT in crescent formation in GN. Consistent with the finding of histological ILK expression in crescents, western blot and kinase activity assay showed an increase in both ILK protein and activity, peaking at day 7 of GN (3.7- and 3.5-fold of control, respectively). The expression of ILK increased to 3.1-fold of control when EMT was induced in cultured PEC by TGF-beta1. CONCLUSION: The present results provide the first evidence that expression and activity of ILK are increased in cellular crescents of experimental GN. Enhanced expression and activity of ILK, possibly by TGF-beta1, is associated with the induction of EMT by PEC and thereby, may participate in the formation of cellular crescents in GN.

Murine metanephric mesenchyme possesses characteristics of vascular endothelial cells in vitro.

BACKGROUND/AIMS: Although the renal microvasculature, including the glomerular capillaries, is generally considered to develop from the metanephric mesenchyme, this has not been unequivocally demonstrated. Using a murine metanephric mesenchymal cell line (MS7), we tested whether the metanephric mesenchyme expresses phenotypic characteristics of endothelial cells and differentiates into vascular endothelial cells in vitro. METHODS: MS7 cells were examined for the mRNA expression of endothelial markers by reverse transcription (RT)-PCR. Moreover, we attempted to induce the appearance of new endothelial markers by stimulation with growth factors and exposure to hypoxia. RESULTS: Before induction, MS7 cells expressed mRNA of fetal liver kinase 1 (Flk1), fms-like tyrosine kinase (Flt1), tyrosine kinase with Ig and EGF homology domains 2 (Tie2), CD31, and podocalyxin. However, they did not express mRNA for vascular endothelial-cadherin (VE-cadherin) or von Willebrand factor (vWF), which are markers specific for endothelial cells and mature endothelial cells. In the immunocytochemical analysis, MS7 absorbed DiI-acetylated LDL virtually, but the results of staining with anti-VE-cadherin, vWF, or CD31 antibodies were negative. MS7 cells that were cultured for 14 days after reaching confluence began to express VE-cadherin and vWF mRNA. In addition, immunofluorescence showed abundant granules stained with anti-vWF antibody in the cytoplasm. Stimulation with vascular endothelial growth factor (VEGF), or basic fibroblast growth factor (bFGF), or exposure to a hypoxic condition did not influence their characteristic changes. CONCLUSION: Our results suggest that metanephric mesenchymal (MS7) cells possess some characteristics of endothelial cells, and they are potent to differentiate into mature vascular endothelium in vitro.

Nevo syndrome with an NSD1 deletion: a variant of Sotos syndrome?

A 17-month-old girl with clinical manifestations of Nevo syndrome and NSD1 (nuclear receptor binding SET domain protein 1) deletion is described. Nevo syndrome is a rare overgrowth syndrome showing considerable phenotypic overlap with Sotos syndrome-another, more frequent overgrowth syndrome caused by NSD1 mutations or deletions. About a half of Japanese Sotos syndrome patients carry a 2.2-Mb common deletion encompassing NSD1 and present with frequent brain, cardiovascular, or urinary tract anomalies. The girl we described had the common deletion and showed patent ductus arteriosus, atrial septal defect, vesicoureteral reflux, and bilateral hydronephrosis. It was thus concluded that the clinical manifestations, including the Nevo syndrome phenotype, were caused by the microdeletion.

In situ expression of connective tissue growth factor in human crescentic glomerulonephritis.

Connective tissue growth factor (CTGF) has recently been recognized as an important profibrotic factor and is up-regulated in various renal diseases with fibrosis. The present study describes the sequential localization of CTGF mRNA and its association with transforming growth factor (TGF)-beta1 in human crescentic glomerulonephritis (CRGN). Furthermore, we examined the phenotype of CTGF-expressing cells using serial section analysis. Kidney biopsy specimens from 18 CRGN patients were examined using in situ hybridization and immunohistochemistry. CTGF mRNA was expressed in the podocytes and parietal epithelial cells (PECs) in unaffected glomeruli. In addition, it was strongly expressed in the cellular and fibrocellular crescents, particularly in pseudotubule structures. Serial sections revealed that the majority of CTGF mRNA-positive cells in the crescents co-expressed the epithelial marker cytokeratin, but not a marker for macrophages. Moreover, TGF-beta1, its receptor TGF-beta receptor-I, and extracellular matrix molecules (collagen type I and fibronectin) were co-localized with CTGF mRNA-positive crescents. Our results suggest that CTGF is involved in extracellular matrix production in PECs and that it is one of the mediators promoting the scarring process in glomerular crescents.

Connective tissue growth factor participates in scar formation of crescentic glomerulonephritis.

Glomerular crescents are a major determinant of progression in various renal diseases. Some types of growth factors are known to be involved in the evolution of crescents and the subsequent scar formation. Although glomerular parietal epithelial cells (PECs) are the major component of cellular crescents, the influence of growth factors on PECs is unknown. We performed immunohistochemical studies and in situ hybridization to examine alterations in connective tissue growth factor (CTGF) expression and to identify CTGF-synthesizing cells in crescents in the crescentic glomerulonephritis model of Wistar Kyoto rats. In addition, we examined the roles of fibroblast growth factor (FGF)-2, platelet-derived growth factor (PDGF)-BB, transforming growth factor (TGF)-beta, and CTGF in cell proliferation and matrix synthesis in an established rat PEC cell line (PEC line). In an acute phase of rat crescentic glomerulonephritis, a major component of the crescents were macrophages, which did not express CTGF mRNA. However, in the advanced phase, crescents strongly expressed CTGF mRNA and the epithelial marker pan-cadherin but did not express the macrophage marker ED1, suggesting that PECs synthesized the CTGF. In the PEC line, FGF-2 predominantly promoted [(3)H]thymidine incorporation compared with PDGF-BB. Both TGF-beta and PDGF-BB strongly stimulated extracellular matrix synthesis in association with up-regulation of endogenous CTGF, but TGF-beta showed a predominant role. FGF-2 had a minor effect on it. In addition, blockade of endogenous CTGF using an antisense oligodeoxynucleotide significantly attenuated both TGF-beta- and PDGF-BB-induced extracellular matrix synthesis. These results suggest that several growth factors promote cell proliferation and matrix production in PECs. CTGF-mediated matrix production via the TGF-beta or PDGF-BB pathway in PECs may, in part, play a role in the progression of scar formation in crescents.

Variable expression of podocyte-related markers in the glomeruloid bodies in Wilms tumor.

Several podocyte-related markers are organized to express in glomerular differentiation. However, whether expression of them is virtually synchronized and a reliable indicator of the state of differentiation is unknown. The present study investigated, by immunohistochemistry, the divergent expression of several podocyte markers in the improperly differentiated glomeruloid bodies from four cases of Wilms tumors. The glomeruloid bodies were classified into immature (IGB) or mature forms (MGB) based on morphology and epithelial features. Podocytes in IGB expressed WT1, synaptopodin, podocalyxin, and nephrin, and their expression was stronger in MGB. In contrast, Pax2 was strong in IGB and diminished in MGB. p27 was first expressed in MGB. The expression pattern in each molecule mimics normal glomerulogenesis. Podocytes in MGB showed persistent expression of bcl-2 and cytokeratin with synaptopodin, podocalyxin, and nephrin by serial section, a finding unusual for normal glomerulogenesis. Moreover, parietal cells in MGB also occasionally expressed these podocyte markers. The ultrastructure revealed that podocytes in MGB showed tight junctions without foot process formations, which indicated incomplete differentiation. These results suggest that a set of podocyte differentiation markers are occasionally diversely expressed, and raise the possibility that expression of these markers is insufficient to determine the state of terminal differentiation in podocytes.

Localization of intercellular adherens junction protein p120 catenin during podocyte differentiation.

To reveal the role of cadherin complex in podocyte differentiation, the present study describes the localization of the cadherin complex, including p120 catenin (p120ctn), in the developing and in the aminonucleoside nephrosis (PAN nephrosis) rat kidney, by immunofluorescence microscopy and immunogold electron microscopy. p120ctn and beta-catenin were co-localized at the apical part of lateral cell membranes in presumptive podocytes of the S-shaped body, and their localization shifted to the basal margin of lateral cell membranes in the capillary loop stage. There was no expression of the cadherin complex at the slit diaphragm, the intercellular junction of mature podocytes. After the regression of the podocyte junctional structure in PAN nephrosis, the cadherin complex was not re-expressed. The dynamic changes in the localization of the cadherin complex suggest that the it plays an important role during podocyte differentiation, including the rearrangement of the intercellular junction and the formation of the slit diaphragm.

Podocytes, parietal cells, and glomerular pathology: the role of cell cycle proteins.

Podocytes are highly differentiated cells that play a central role in glomerular function. Cell cycle quiescence sustained by the tight regulation of cell cycle molecules seems to be the basis of podocyte differentiation, as reflected in reciprocal expression of cyclins and cyclin kinase inhibitors (CKIs) during glomerulogenesis, concurrent with the expression of podocyte-specific markers. In addition, cell cycle re-entry by podocytes, accompanied by down-regulation of CKIs, leads to either nuclear division without cytokinesis or to marked cell proliferation, both of which result in heavy proteinuria and progressive glomerulosclerosis. These observations suggest that proper cell cycle regulation in podocytes is pivotal for their role in glomerular function and that dysregulation of this system plays a role in glomerular pathology. This review discusses the role of cell cycle molecules in the differentiation, function, and pathology of podocytes.