Both anti-glomerular basement membrane (GBM) disease and the anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) are common causes of pulmonary-renal syndrome. Organizing pneumonia (OP), a special pattern of interstitial lung disease, is extremely rare either in AAV or anti-GBM disease. We report an old woman presented with OP on a background of co-presentation with both ANCA and anti-GBM antibodies.
Female ; Humans ; Antibodies, Antineutrophil Cytoplasmic ; Organizing Pneumonia ; Autoantibodies ; Glomerulonephritis ; Anti-Glomerular Basement Membrane Disease ; Pneumonia ; Anti-Neutrophil Cytoplasmic Antibody-Associated Vasculitis/complications*

Anti–glomerular basement membrane (GBM) nephritis is characterized by circulating anti-GBM antibodies and crescentic glomerulonephritis (GN) with deposition of IgG along the GBM. In a limited number of cases, glomerular immune complexes have been identified in anti-GBM nephritis. A 38-year-old female presented azotemia, hematuria, and proteinuria without any pulmonary symptoms. A renal biopsy showed crescentic GN with linear IgG deposition along the GBM and mesangial IgA deposition. The patient was diagnosed as concurrent anti-GBM nephritis and IgA nephropathy. Therapies with pulse methylprednisolone and cyclophosphamide administration were effective. Concurrent cases of both anti-GBM nephritis and IgA nephropathy are rare among cases of anti-GBM diseases with deposition of immune complexes. This rare case of concurrent anti-GBM nephritis and IgA nephropathy with literature review is noteworthy.
Adult ; Anti-Glomerular Basement Membrane Disease ; Antibodies ; Antigen-Antibody Complex ; Azotemia ; Basement Membrane ; Biopsy ; Cyclophosphamide ; Female ; Glomerulonephritis ; Glomerulonephritis, IGA ; Hematuria ; Humans ; Immunoglobulin A ; Immunoglobulin G ; Methylprednisolone ; Nephritis ; Proteinuria

Alport syndrome (ATS) is an inherited glomerular disease caused by mutations in one of the type IV collagen novel chains (α3, α4, and α5). ATS is characterized by persistent microscopic hematuria that starts during infancy, eventually leading to either progressive nephritis or end-stage renal disease. There are 3 known genetic forms of ATS, namely X-linked ATS, autosomal recessive ATS, and autosomal dominant ATS. About 80% of patients with ATS have X-linked ATS, which is caused by mutations in the type IV collagen α5 chain gene, COL4A5. Although an 80% mutation detection rate is observed in men with X-linked ATS, some difficulties do exist in the genetic diagnosis of ATS. Most mutations are point mutations without hotspots in the COL4A3, COL4A4, and COL4A5 genes. Further, there are insufficient data on the detection of COL4A3 and COL4A4 mutations for their comparison between patients with autosomal recessive or dominant ATS. Therefore, diagnosis of ATS in female patients with no apparent family history can be challenging. Therefore, in this study, we used whole-exome sequencing (WES) to identify mutations in type IV collagen in 2 girls with glomerular basement membrane structural changes suspected to be associated with ATS; these patients had no relevant family history. Our results revealed de novo c.4688G>A (p.Arg1563Gln) and c.2714G>A (p.Gly905Asp) mutations in COL4A5. Therefore, we suggest that WES is an effective approach to obtain genetic information in ATS, particularly in female patients without a relevant family history, to detect unexpected DNA variations.
Child ; Collagen Type IV ; Diagnosis ; DNA ; Exome ; Female ; Glomerular Basement Membrane ; Hematuria ; Humans ; Kidney Failure, Chronic ; Korea ; Male ; Nephritis ; Nephritis, Hereditary ; Point Mutation

C3 glomerulopathy is a renal disorder involving dysregulation of alternative pathway complement activation. In most instances, a membranoproliferative pattern of glomerular injury with a prevalence of C3 deposition is observed by immunofluorescence microscopy. Dense deposit disease (DDD) and C3 glomerulonephritis (C3GN) are subclasses of C3 glomerulopathy that are distinguishable by electron microscopy. Highly electron-dense transformation of glomerular basement membrane is characteristic of DDD. C3GN should be differentiated from post-infectious glomerulonephritis and other immune complex-mediated glomerulonephritides showing C3 deposits.
Complement Activation ; Complement Pathway, Alternative ; Dichlorodiphenyldichloroethane ; Glomerular Basement Membrane ; Glomerulonephritis ; Glomerulonephritis, Membranoproliferative ; Microscopy, Electron ; Microscopy, Fluorescence ; Pathology ; Prevalence

Steroid-resistant nephrotic syndrome (SRNS) has long been a challenge for clinicians due to its poor responsiveness to immunosuppressants, and rapid progression to end-stage renal disease. Identifying a monogenic cause for SRNS may lead to a better understanding of podocyte structure and function in the glomerular filtration barrier. This review focuses on genes associated with slit diaphragm, actin cytoskeleton, transcription factors, nucleus, glomerular basement membrane, mitochondria, and other proteins that affect podocyte biology.
Actin Cytoskeleton ; Biology ; Diaphragm ; Glomerular Basement Membrane ; Glomerular Filtration Barrier ; Immunosuppressive Agents ; Kidney Failure, Chronic ; Mitochondria ; Nephrotic Syndrome ; Podocytes ; Proteinuria ; Transcription Factors

Biopsy ; Female ; Glomerular Basement Membrane ; metabolism ; Hashimoto Disease ; metabolism ; pathology ; Humans ; Kidney Diseases ; metabolism ; pathology ; Middle Aged ; Proteinuria ; metabolism ; pathology ; Sjogren's Syndrome ; metabolism ; pathology

OBJECTIVETo explore the clinical and pathological features and the diagnosis of childhood Alport syndrome (AS).

METHODSA retrospective analysis was performed on clinical data of 91 children with AS.

RESULTSHematuria was observed in all 91 patients, of whom 86 were accompanied with proteinuria. Sixty-one children with X-Linked AS (XL-AS) had positive family history. Renal biopsy was performed on 82 children. Mild to moderate mesangial proliferation was observed in 74 cases. Small amounts of immune complexes deposits in the glomerular mesangial area were observed in 48 cases. Glomerular basement membrane (GBM) attenuation, thickening and layering were observed in 53 cases by electron microscopy (EM). In 63 cases receiving renal tissue type IV collagen α3 and α5 chain immunofluorescence detection, 58 were diagnosed with AS, including 53 cases of XL-AS and 5 cases of autosomal recessive AS. In 91 cases of AS, 58 were diagnosed as AS by renal tissue type IV collagen α3 and α5 chain immunofluorescence, 21 were diagnosed by EM, one was diagnosed by skin biopsy, and 12 were diagnosed by gene detection. Six novel mutations of COL4A5 gene were found. Forty-five cases were misdiagnosed before the diagnosis of AS. Forty-one of the 45 cases received steroids and/or immunosuppressant therapy.

CONCLUSIONSThe clinical manifestations and pathological changes are not specific in children with AS, resulting in a higher rate of misdiagnosis. Typical lesions of GBM under EM are only observed in a part of patients. There is a high novel mutation rate of COL4A5 in the detected AS children.

Child ; Child, Preschool ; Collagen Type IV ; genetics ; Diagnostic Errors ; Female ; Glomerular Basement Membrane ; pathology ; Humans ; Male ; Nephritis, Hereditary ; diagnosis ; genetics ; pathology ; Retrospective Studies

PURPOSE: Thin glomerular basement membrane nephropathy (TBMN) is, along with the IgA nephropathy, the most common cause of asymptomatic hematuria in Korean children. TBMN is usually a benign renal disease not requiring treatment and is associated with a good prognosis, but some cases hematuria is indicative of a state of progressive renal insufficiency. We aimed to retrospectively evaluate clinical manifestations and renal prognosis of patients with TBMN. METHODS: Among the 428 renal biopsies performed on children at Yeungnam University Hospital between January 2000 and February 2017, 167 patients were diagnosed as having TBMN. We retrospectively investigated 167 pediatric patients and identified 59 children with follow-up duration >3 years. RESULTS: Among 59 patients, there were 33 boys and 26 girls. Mean age of onset of hematuria was 7.18±2.64 years, and mean time from onset of disease until a renal biopsy was performed was 2.48±2.10 years. There were no clinical features or laboratory findings among studied children to indicate decreased renal function during follow-up; however, one case progressed to chronic kidney disease (CKD) due to an unknown cause. There were seven patients among these related a positive family history of hematuria or renal insufficiency. CONCLUSION: Although almost all patients had normal renal functions during follow-up, there were one patient who progressed to CKD and seven patients with family history of hematuria or renal insufficiency. Moreover, four among the 428 patients over 17 years underwent repeat renal biopsies, which showed results different from their earlier biopsies.Thus, large-scales studies may be required to determine long-term prognosis of TBMN in children, and further evaluation for Alport syndrome in TBMN cases is essential.
Age of Onset ; Biopsy ; Child* ; Female ; Follow-Up Studies ; Glomerular Basement Membrane* ; Glomerulonephritis, IGA ; Hematuria ; Humans ; Nephritis, Hereditary ; Prognosis* ; Renal Insufficiency ; Renal Insufficiency, Chronic ; Retrospective Studies*

PURPOSE: Thin glomerular basement membrane nephropathy (TBMN) is, along with the IgA nephropathy, the most common cause of asymptomatic hematuria in Korean children. TBMN is usually a benign renal disease not requiring treatment and is associated with a good prognosis, but some cases hematuria is indicative of a state of progressive renal insufficiency. We aimed to retrospectively evaluate clinical manifestations and renal prognosis of patients with TBMN. METHODS: Among the 428 renal biopsies performed on children at Yeungnam University Hospital between January 2000 and February 2017, 167 patients were diagnosed as having TBMN. We retrospectively investigated 167 pediatric patients and identified 59 children with follow-up duration >3 years. RESULTS: Among 59 patients, there were 33 boys and 26 girls. Mean age of onset of hematuria was 7.18±2.64 years, and mean time from onset of disease until a renal biopsy was performed was 2.48±2.10 years. There were no clinical features or laboratory findings among studied children to indicate decreased renal function during follow-up; however, one case progressed to chronic kidney disease (CKD) due to an unknown cause. There were seven patients among these related a positive family history of hematuria or renal insufficiency. CONCLUSION: Although almost all patients had normal renal functions during follow-up, there were one patient who progressed to CKD and seven patients with family history of hematuria or renal insufficiency. Moreover, four among the 428 patients over 17 years underwent repeat renal biopsies, which showed results different from their earlier biopsies.Thus, large-scales studies may be required to determine long-term prognosis of TBMN in children, and further evaluation for Alport syndrome in TBMN cases is essential.
Age of Onset ; Biopsy ; Child* ; Female ; Follow-Up Studies ; Glomerular Basement Membrane* ; Glomerulonephritis, IGA ; Hematuria ; Humans ; Nephritis, Hereditary ; Prognosis* ; Renal Insufficiency ; Renal Insufficiency, Chronic ; Retrospective Studies*

BACKGROUND: Dipeptidyl peptidase-4 (DPP-4) inhibitors are widely used in the treatment of patients with type 2 diabetes and have proven protective effects on diabetic kidney disease (DKD). Whether DPP-4 inhibitors have renoprotective effects on insulin-deficient type 1 diabetes has not been comprehensively examined. The aim of this study was to determine whether gemigliptin, a new DPP-4 inhibitor, has renoprotective effects in streptozotocin (STZ)-induced type 1 diabetic mice. METHODS: Diabetes was induced by intraperitoneal administration of a single dose of STZ. Mice with diabetes were treated without or with gemigliptin (300 mg/kg) for 8 weeks. Morphological changes of the glomerular basement membrane (GBM) were observed by electron microscopy and periodic-acid Schiff staining. In addition, we measured blood glucose and urinary albumin excretion and evaluated fibrotic markers using immunohistochemical staining, quantitative reverse transcription polymerase chain reaction analysis, and Western blot analysis. RESULTS: Gemigliptin did not reduce the blood glucose levels of STZ-treated mice. In gemigliptin-treated mice with STZ, a significant reduction in urinary albumin excretion and GBM thickness was observed. Immunohistological examination revealed that gemigliptin attenuated renal fibrosis induced by STZ and decreased extracellular matrix protein levels, including those of type I collagen and fibronectin, and Smad3 phosphorylation. In cultured rat renal cells, gemigliptin inhibited transforming growth factor β-stimulated type I collagen and fibronectin mRNA and protein levels via down-regulation of Smad3 phosphorylation. CONCLUSION: Our data demonstrate that gemigliptin has renoprotective effects on DKD, regardless of its glucose-lowering effect, suggesting that it could be used to prevent DKD, including in patients with type 1 diabetes.
Animals ; Blood Glucose ; Blotting, Western ; Collagen Type I ; Diabetes Mellitus, Type 1 ; Diabetic Nephropathies ; Down-Regulation ; Extracellular Matrix ; Fibronectins ; Fibrosis ; Glomerular Basement Membrane ; Humans ; Mice* ; Microscopy, Electron ; Phosphorylation ; Polymerase Chain Reaction ; Rats ; Reverse Transcription ; RNA, Messenger ; Streptozocin ; Transforming Growth Factors