Approach to the Diagnosis of Thin Basement Membrane Nephropathy in Females With the Use of Antibodies to Type IV Collagen

2001 ◽  
Vol 125 (5) ◽  
pp. 631-636
Author(s):  
Ginette Lajoie

Abstract Context.—Thin basement membrane nephropathy is recognized by a diffusely thin glomerular basement membrane (GBM) ultrastructurally. In contrast to Alport syndrome (AS), there is no GBM thickening, lamellation, or granular inclusions. Morphologically, there is overlap between thin basement membrane nephropathy and AS in female patients in whom there might be only thin GBM and no pathognomonic findings of AS. Objective.—To determine if the use of antibodies to collagen IV is helpful in making the distinction between thin basement membrane nephropathy and AS in female patients with primarily thin GBMs. Design.—We examined renal biopsies from 9 adult female patients with thin GBMs for the presence of α1, α3, α4, and α5 chains of type IV collagen by immunofluorescence. Results.—In 2 patients with segmental GBM staining, no suggestion for AS was found on physical examination or in their family history. In the remaining 7 patients with normal GBM staining, 4 had family members with end-stage renal disease of unknown etiology, raising the suspicion of X-linked or autosomal-recessive AS. Three patients were presumed to have thin basement membrane nephropathy. Conclusion.—Segmental GBM staining for α3, α4, and α5 chains of type IV collagen raises the suspicion of AS in the presence of adequate controls and other supporting evidence. Normal GBM staining for α3, α4, and α5 chains of type IV collagen, however, does not exclude AS.

2017 ◽  
Vol 6 (1) ◽  
pp. 1-7
Author(s):  
Elise Alexandra Kikis ◽  
Emily Holland Williams

Alport syndrome is a type IV collagen disease that affects the glomerular basement membrane of approximately one in every 5000 people. The disease was first described by A. Cecil Alport in 1927 as “a dominantly inherited hereditary nephritis.” The three genotypes of the disease are X-linked dominant, autosomal recessive, and autosomal dominant. The X-linked dominant genotype is the most common, accounting for 80% of all cases of Alport syndrome, affecting mainly men. The autosomal recessive and autosomal dominant types affect men and women equally. Alport syndrome is caused by mutations on the COL4A3, COL4A4, and COL4A5 genes, which code the ?3, ?4, and ?5 (IV) chains that make up type IV collagen molecules, an important component of basement membranes. Thus, Alport syndrome results in malformed basement membranes, with symptoms including renal impairment, hematuria, bilateral sensorineural hearing loss, and an abnormal structure of the glomerular basement membrane. Alport syndrome also often progresses to end-stage renal disease, especially in men with X-linked Alport syndrome. At this point, there is no cure for Alport syndrome. However, there are many successful treatments for its symptoms. Angiotensin-converting enzyme (ACE) inhibitors are often given to patients in the early stages of Alport syndrome. For patients with end-stage renal disease, dialysis or kidney transplants are considered the best course of action.


1998 ◽  
Vol 9 (8) ◽  
pp. 1433-1440
Author(s):  
K Nakanishi ◽  
K Iijima ◽  
N Kuroda ◽  
Y Inoue ◽  
Y Sado ◽  
...  

X-Linked Alport syndrome is caused by mutations in the type IV collagen alpha5 chain gene. Male patients usually develop end-stage renal disease, whereas female patients have more variable phenotypes from asymptomatic hematuria to end-stage renal disease. The variable phenotypes in female patients may be attributable to different X-chromosome inactivation patterns. Therefore, the correlation between disease severity and the degree of alpha5 chain expression in the epidermal basement membrane of female patients with X-linked Alport syndrome was examined. To estimate the disease severity in X-linked Alport syndrome, the ratios of protein to creatinine in single voided urine samples were used. Expression of the alpha5 chain in the epidermal basement membrane was examined by an indirect immunofluorescence method using an anti-alpha5 chain monoclonal antibody. A total of 25 female patients with X-linked Alport syndrome from 17 families was examined. Multiple regression analysis using disease severity as the response variable, and age, family history of nephritis, female and male family history of end-stage renal disease, serum creatinine concentration, and alpha5(IV) expression ratio in the epidermal basement membrane as explanatory variables showed that only alpha5(IV) expression ratio was a significant factor, and that it showed a highly significant negative association with disease severity (adjusted r2=0.71, P=0.0001). These findings suggest that variable alpha5 chain expression, possibly caused by different X-inactivation patterns, is responsible for the variable disease severity in female patients with X-linked Alport syndrome, and that immunohistochemical examination of alpha5 chain expression in the epidermal basement membrane may be a simple and useful method for predicting patient outcome.


2008 ◽  
Vol 136 (Suppl. 4) ◽  
pp. 323-326 ◽  
Author(s):  
Alenka Vizjak ◽  
Dusan Ferluga

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.


2021 ◽  
Vol 12 (2) ◽  
Author(s):  
Yuexin Wu ◽  
Yuyan Cao ◽  
Keren Xu ◽  
Yue Zhu ◽  
Yuemei Qiao ◽  
...  

AbstractLiver cirrhosis remains major health problem. Despite the progress in diagnosis of asymptomatic early-stage cirrhosis, prognostic biomarkers are needed to identify cirrhotic patients at high risk developing advanced stage disease. Liver cirrhosis is the result of deregulated wound healing and is featured by aberrant extracellular matrix (ECM) remodeling. However, it is not comprehensively understood how ECM is dynamically remodeled in the progressive development of liver cirrhosis. It is yet unknown whether ECM signature is of predictive value in determining prognosis of early-stage liver cirrhosis. In this study, we systematically analyzed proteomics of decellularized hepatic matrix and identified four unique clusters of ECM proteins at tissue damage/inflammation, transitional ECM remodeling or fibrogenesis stage in carbon tetrachloride-induced liver fibrosis. In particular, basement membrane (BM) was heavily deposited at the fibrogenesis stage. BM component minor type IV collagen α5 chain expression was increased in activated hepatic stellate cells. Knockout of minor type IV collagen α5 chain ameliorated liver fibrosis by hampering hepatic stellate cell activation and promoting hepatocyte proliferation. ECM signatures were differentially enriched in the biopsies of good and poor prognosis early-stage liver cirrhosis patients. Clusters of ECM proteins responsible for homeostatic remodeling and tissue fibrogenesis, as well as basement membrane signature were significantly associated with disease progression and patient survival. In particular, a 14-gene signature consisting of basement membrane proteins is potent in predicting disease progression and patient survival. Thus, the ECM signatures are potential prognostic biomarkers to identify cirrhotic patients at high risk developing advanced stage disease.


2021 ◽  
Vol 80 (Suppl 1) ◽  
pp. 1434.1-1434
Author(s):  
K. Wójcik ◽  
A. Masiak ◽  
Z. Zdrojewski ◽  
R. Jeleniewicz ◽  
M. Majdan ◽  
...  

Background:ANCA associated vasculitides (AAV) are a heterogeneous group of rare diseases with unknown etiology and the broad clinical spectrum ranging from life-threatening systemic disease, through single organ involvement to minor isolated skin changes. Unfortunately the clinical classification, ANCA specificity or genetic characteristics alone is not able to categorize AAV patients in a satisfactory manner. As a consequence advanced statistical techniques were used to identify and stratify AAV subphenotypes [1, 2]. Here we have analyzed influence of the ANCA type on clinical manifestations and demographic characteristics in various types of AAV, based on data from the POLVAS registryObjectives:We decided to retrospectively analyze a large cohort of Polish AAV patients deriving from several referral centers – members of the Scientific Consortium of the Polish Vasculitis Registry (POLVAS) – and concentrate on demographic and clinical characteristics of anti-PR3 and anti-MPO positive patients regardless of their clinical diagnosis.Methods:We conducted a systematic multicenter retrospective study of adult patients diagnosed with AAV between Jan 1990 and Dec 2016. Patients were enrolled by 9 referral centers. We analyzed dichotomous variables: gender; ANCA status – anti-PR3+ or anti-MPO+, ANCA negative; organ involvement - skin, eye, ENT, respiratory, heart, GI, renal, urinary, CNS, peripheral nerves and polytomous variable (number of relapses), supported by quantitative covariates (e.g., age at diagnosis, CRP at diagnosis, maximal serum creatinine concentration ever)[3].Results:MPO-positive patients (both GPA and EGPA phenotype) were older at the time of diagnosis with a substantial percentage diagnosed > 65 years of age, and with high rate of renal involvement. Interestingly, while in the whole group of patients diagnosed with EGPA male to female ratio was 1:2, the MPO+ EGPA patients showed M:F ratio of 1:1.The analysis of ANCA negative AAV reveled significant differences in GPA, ANCA negative group is characterized with significantly lower frequency of renal involvement compared to rest GPA (11,5% vs 63,7%) p<0,05 what should be emphasized ANCA negative AAV never lead to ESRD (end stage renal disease) or even transient dialysis.Conclusion:ANCA specificity is indispensable as a separate variable in any clinically relevant analysis of AAV subcategories. MPO+ group is characterized by older age at time of diagnosis, male to female ration 1:1, kidney involvement, and shows more homogenous clinical phenotype than PR3+ AAV patients. In our group ANCA negative AAV never lead to ESRD (end stage renal disease) or even transient dialysis.References:[1]Mahr A, Specks U, Jayne D. Subclassifying ANCA-associated vasculitis: a unifying view of disease spectrum. Rheumatol Oxf Engl 2019;58:1707–9. https://doi.org/10.1093/rheumatology/kez148.[2]Wójcik K, Biedroń G, Wawrzycka-Adamczyk K, Bazan-Socha S, Ćmiel A, Zdrojewski Z et al. Subphenotypes of ANCA-associated vasculitis identified by latent class analysis. Clin Exp Rheumatol. 2020 Sep 1. Epub PMID: 32896241.[3]Wójcik K, Wawrzycka-Adamczyk K, Włudarczyk A, Sznajd J, Zdrojewski Z, Masiak A, et al. Clinical characteristics of Polish patients with ANCA-associated vasculitides—retrospective analysis of POLVAS registry. Clinical Rheumatology. 1 wrzesień 2019;38(9):2553–63.Disclosure of Interests:None declared


Biochemistry ◽  
1983 ◽  
Vol 22 (21) ◽  
pp. 4940-4948 ◽  
Author(s):  
Robert S. MacWright ◽  
Virginia A. Benson ◽  
Katherine T. Lovello ◽  
Michel Van der Rest ◽  
Peter P. Fietzek

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