scholarly journals Spectrum of collagen type IV nephropathies: From thin basement membrane nephropathy to Alport syndrome

2008 ◽  
Vol 136 (Suppl. 4) ◽  
pp. 323-326 ◽  
Author(s):  
Alenka Vizjak ◽  
Dusan Ferluga
Keyword(s):  
Basement Membrane ◽  
Glomerular Basement Membrane ◽  
Alport Syndrome ◽  
Type Iv Collagen ◽  
Mutation Screening ◽  
Glomerular Sclerosis ◽  
Collagen Type Iv ◽  
Dominant Type ◽  
Thin Basement Membrane Nephropathy ◽  
Type Iv

Alport syndrome and thin basement membrane nephropathy are common causes of persistent familial haematuria. They are associated with various mutations in type IV collagen genes. Mutations in genes, coding for ?5 chain of collagen IV, cause X-linked Alport syndrome, whereas mutations in genes for ?3 and ?4 chains can cause the autosomal recessive and autosomal dominant type of Alport syndrome or benign familial haematuria with thin basement membrane nephropathy. In view of the wide spectrum of phenotypes, an exact diagnosis is sometimes difficult to achieve. Few studies of genotype-phenotype correlations in Alport syndrome have shown that various types of mutations may be a significant predictor of the severity of disease. Histopathologic findings in Alport syndrome vary from normal kidney to nonspecific focal segmental and global glomerular sclerosis with characteristic ultrastructural finding of thickening and splitting of the glomerular basement membrane. Thin basement membrane nephropathy is characterized by diffuse thinning of the glomerular basement membrane on an ultrastructural level, while by light microscopy glomeruli are mostly unremarkable. Because of present limitations of mutation screening techniques, kidney biopsy with mandatory ultrastructural analysis and immunohistochemistry examination for type IV collagen ? chains remains a standard approach for establishing diagnosis and determining the mode of transmission of the disease.

Alport Syndrome and Thin Glomerular Basement Membrane Nephropathy: A Practical Approach to Diagnosis

2009 ◽  
Vol 133 (2) ◽  
pp. 224-232 ◽  
Author(s):  
Mark Haas
Keyword(s):  
Electron Microscopy ◽  
Basement Membrane ◽  
Renal Biopsy ◽  
Glomerular Basement Membrane ◽  
Alport Syndrome ◽  
Autosomal Recessive ◽  
Type Iv Collagen ◽  
The Past ◽  
Type Iv ◽  
Pathologic Features

Abstract Context.—Alport syndrome and thin glomerular basement membrane nephropathy (TBMN) are genetically heterogenous conditions characterized by structural abnormalities in the glomerular basement membrane and an initial presentation that usually involves hematuria. Approximately 40% of patients with TBMN are heterozygous carriers for autosomal recessive Alport syndrome, with mutations at the genetic locus encoding type IV collagen α3 [α3(IV)] and α4 chains. However, although the clinical course of TBMN is usually benign, Alport syndrome, particularly the X-linked form with mutations in the locus encoding the α5 chain of type IV collagen [α5(IV)], typically results in end-stage renal disease. Electron microscopy is essential to diagnosis of TBMN and Alport syndrome on renal biopsy, although electron microscopy alone is of limited value in distinguishing between TBMN, the heterozygous carrier state of X-linked Alport syndrome, autosomal recessive Alport syndrome, and even early stages of X-linked Alport syndrome. Objectives.—To review diagnostic pathologic features of each of the above conditions, emphasizing the need for immunohistology for α3(IV) and α5(IV) in addition to electron microscopy to resolve this differential diagnosis on a renal biopsy. The diagnostic value of immunofluorescence studies for α5(IV) on a skin biopsy in family members of patients with Alport syndrome also is reviewed. Data Sources.—Original and comprehensive review articles on the diagnosis of Alport syndrome and TBMN from the past 35 years, primarily the past 2 decades, and experience in our own renal pathology laboratory. Conclusions.—Although Alport syndrome variants and TBMN do not show characteristic light microscopic findings and can be difficult to differentiate from each other even by electron microscopy, using a combination of electron microscopy and immunohistology for α3(IV) and α5(IV) enables pathologists to definitively diagnose these disorders on renal biopsy in most cases.

scholarly journals Mutation in alpha 5(IV) collagen chain gene in nonfamilial hematuria.

1995 ◽  
Vol 6 (2) ◽  
pp. 264-268
Author(s):  
K Kitagawa ◽  
K Nakanishi ◽  
K Iijima ◽  
H Nishio ◽  
Y Sado ◽  
...  
Keyword(s):  
Polymerase Chain Reaction ◽  
Basement Membrane ◽  
Glomerular Basement Membrane ◽  
Alport Syndrome ◽  
Type Iv Collagen ◽  
Chain Reaction ◽  
Col4a5 Gene ◽  
Abnormal Expression ◽  
Type Iv ◽  
Polymerase Chain

Alport syndrome is an inherited disorder characterized by progressive nephritis with ultrastructural basket-weave changes of the glomerular basement membrane and neurosensory deafness. Mutations in the COL4A5 gene encoding the Type IV collagen alpha 5 chain have been reported to occur in patients with X-linked Alport syndrome. A girl with hematuric nephritis, characteristic basket-weave glomerular basement membrane changes, and abnormal expression of the Type IV collagen alpha 5 chain immunohistochemically, but no family history of nephritis, was identified. Mutation detection enhancement gel electrophoresis of the polymerase chain reaction-amplified exons of COL4A5 from this patient revealed a sequence variant in the exon 50 region. Sequence analysis of her polymerase chain reaction product demonstrated a single-base (C; nucleotide 4728 from the 5' end) deletion in exon 50. This novel mutation alters the reading frame and introduces a translation stop codon that would be expected to result in a noncollagenous domain with only 209, instead of the normal 229, amino acid residues. Gene tracking with restriction enzyme AfIIII demonstrated that her mother was normal. These findings represent a new mutation of the X-linked Alport syndrome in this patient and demonstrate that a COL4A5 gene mutation causes the abnormal expression of Type IV collagen alpha 5 chain protein.

scholarly journals Possible Implication of Intermolecular Epitope Spreading in the Production of Anti-Glomerular Basement Membrane Antibody in Anti-Neutrophil Cytoplasmic Antibody-associated Vasculitis

2021 ◽  
Author(s):  
Yuka Nishibata ◽  
Mayu Nonokawa ◽  
Yuto Tamura ◽  
Rio Higashi ◽  
Ku Suzuki ◽  
...  
Keyword(s):  
Basement Membrane ◽  
Glomerular Basement Membrane ◽  
Immunofluorescent Staining ◽  
Enzyme Linked Immunosorbent Assay ◽  
Collagen Type Iv ◽  
Normal Kidney ◽  
Type Iv ◽  
Formalin Fixed Paraffin ◽  
Formalin Fixed Paraffin Embedded ◽  
Α3 Subunit

Abstract ObjectiveAnti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) is sometimes complicated by anti-glomerular basement membrane (GBM) disease. Proteases, including elastase, released from neutrophils activated by ANCA are implicated in the pathogenesis of AAV. Epitopes of anti-GBM antibody exist in the α3-subunit non-collagenous (NC1) domain of collagen type IV [Col (IV)]. This region, called α3(IV)NC1, is structurally cryptic. This study aimed to determine the production mechanism of anti-GBM antibody in AAV.MethodsWe first examined whether α3(IV)NC1 could be revealed by the digestion of formalin-fixed, paraffin-embedded (FFPE) normal kidney sections and Col (IV) by proteases, including neutrophil elastase, using immunohistochemistry (IHC) and enzyme-linked immunosorbent assay (ELISA). Next, the reveal of α3(IV)NC1 and the infiltration of CD11c+ macrophages in the affected kidneys were evaluated by IHC and immunofluorescent staining using FFPE sections. Finally, the production of anti-GBM antibody in AAV rats was determined by ELISA.Resultsα3(IV)NC1 was revealed by the digestion of FFPE normal kidney sections and Col (IV) by proteases. Although the reveal of α3(IV)NC1 was observed in sclerotic glomeruli regardless of causative diseases, CD11c+ macrophages near α3(IV)NC1 were characteristics of AAV. Anti-GBM antibody was produced subsequent to ANCA in some AAV rats. IHC demonstrated the reveal of α3(IV)NC1 in affected renal tissues and the infiltration of CD11c+ macrophages around the sites.ConclusionThe collective findings suggest that, in AAV, proteases released from neutrophils activated by ANCA digest Col (IV) and result in the reveal of α3(IV)NC1, CD11c+ macrophages present GBM epitopes, and then the host’s immune system produce anti-GBM antibody.

scholarly journals Albumin contributes to kidney disease progression in Alport syndrome

2016 ◽  
Vol 311 (1) ◽  
pp. F120-F130 ◽  
Author(s):  
George Jarad ◽  
Russell H. Knutsen ◽  
Robert P. Mecham ◽  
Jeffrey H. Miner
Keyword(s):  
Kidney Disease ◽  
Basement Membrane ◽  
Glomerular Basement Membrane ◽  
Alport Syndrome ◽  
Transforming Growth Factor ◽  
Kidney Diseases ◽  
Serum Triglyceride ◽  
Transforming Growth Factor Β ◽  
Collagen Type Iv ◽  
Albumin Concentration

Alport syndrome is a familial kidney disease caused by defects in the collagen type IV network of the glomerular basement membrane. Lack of collagen-α3α4α5(IV) changes the glomerular basement membrane morphologically and functionally, rendering it leaky to albumin and other plasma proteins. Filtered albumin has been suggested to be a cause of the glomerular and tubular injuries observed at advanced stages of Alport syndrome. To directly investigate the role that albumin plays in the progression of disease in Alport syndrome, we generated albumin knockout ( Alb−/−) mice to use as a tool for removing albuminuria as a component of kidney disease. Mice lacking albumin were healthy and indistinguishable from control littermates, although they developed hypertriglyceridemia. Dyslipidemia was observed in Alb+/− mice, which displayed half the normal plasma albumin concentration. Alb mutant mice were bred to collagen-α3(IV) knockout ( Col4a3−/−) mice, which are a model for human Alport syndrome. Lack of circulating and filtered albumin in Col4a3−/−; Alb−/− mice resulted in dramatically improved kidney disease outcomes, as these mice lived 64% longer than did Col4a3−/−; Alb+/+ and Col4a3−/−; Alb+/− mice, despite similar blood pressures and serum triglyceride levels. Further investigations showed that the absence of albumin correlated with reduced transforming growth factor-β1 signaling as well as reduced tubulointerstitial, glomerular, and podocyte pathology. We conclude that filtered albumin is injurious to kidney cells in Alport syndrome and perhaps in other proteinuric kidney diseases, including diabetic nephropathy.

IDENTIFICATION OF ??3, ??4, AND ??5 CHAINS OF TYPE IV COLLAGEN AS ALLOANTIGENS FOR ALPORT POSTTRANSPLANT ANTI-GLOMERULAR BASEMENT MEMBRANE ANTIBODIES

2000 ◽  
Vol 69 (4) ◽  
pp. 679-684 ◽  
Author(s):  
Raghu Kalluri ◽  
Adriana Torre ◽  
Charles F. Shield ◽  
Eric D. Zamborsky ◽  
Michelle C. Werner ◽  
...  
Keyword(s):  
Basement Membrane ◽  
Glomerular Basement Membrane ◽  
Type Iv Collagen ◽  
Type Iv

scholarly journals Glomerular Basement Membrane Selective Permeability in Short-term Streptozotocin-induced Diabetic Rats

2000 ◽  
Vol 1 (1) ◽  
pp. 19-30 ◽  
Author(s):  
Michele Doucet ◽  
Irene Londoño ◽  
Amparo Gómez-Pascual ◽  
Moise Bendayan
Keyword(s):  
Basement Membrane ◽  
Glomerular Basement Membrane ◽  
Type Iv Collagen ◽  
Serum Proteins ◽  
Diabetic Rats ◽  
Glomerular Permeability ◽  
Structural Alterations ◽  
Early Stages ◽  
Type Iv ◽  
Basement Membrane Thickening

In diabetes, the glomerular basement membrane undergoes thickening and structural alterations with loss of glomerular permselectivity properties. However, the onset of the alterations at early phases of diabetes is unclear. Aiming to determine the functional and structural alterations of the glomerular wall in the early stages of diabetes, we have studied the distribution of endogenous circulating albumin and type IV collagen in the glomerular basement membrane, using the immunocytochemical approach. The streptozotocin-injected hyperglycemic rat was our animal model. Renal tissues were examined after 10 days, 2, 4 and 6 months of hyperglycemia. Upon immunogold labelings, changes in the glomerular permeability to endogenous albumin were found altered as early as upon ten days of hyperglycemia. In contrast, no structural modifications were detected at this time point. Indeed, glomerular basement membrane thickening and an altered type IV collagen labeling distribution were only observed after four months of hyperglycemia, suggesting that functional alterations take place early in diabetes prior to any structural modification. In order to evaluate the reversibility of the glomerular alterations, two-month-old diabetic animals were treated with insulin. These animals showed a significant restoring of their glomerular permselectivity. Our results suggest a link between glycemic levels and alteration of glomerular permeability in early stages of diabetes, probably through high levels of glycated serum proteins.

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