Biomaterial Database

Glomerular deposition of the complement C4 isotypes C4A and C4B in glomeruonephritis. 1996

K Lhotta, and A Schlogl, and F Kronenberg, and M Joannidis, and P Konig

Department of Internal Medicine, Innsbruck University Hospital and Instute of Medical Biology and Human Genetics, University of Innsbruck, Austria.

BACKGROUND Complement C4 is a component of the classical complement pathway, which is a major mediator of inflammation in many forms of glomerulonephritis. The two isoforms of C4-C4A and C4B-differ in their physicochemical and functional properties. METHODS The glomerular deposition of C4A and C4B was investigated in 39 cases of glomerulonephritis with classical pathway activation using isotype-specific monoclonal antibodies 99H7 (C4A) and 1288 (C4B) and indirect immunofluorescence. Complement C4 phenotypes of all patients were determined by agarose gel electrophoresis and immunoprecipitation. RESULTS Three biopsies contained only the isotype C4B. C4 phenotyping revealed complete C4A deficiency in these three patients. Both isotypes C4A and C4B were detected in 36 biopsies. In 19 (53%) thereof staining for both isotypes was identical. In the remaining 17 (47%), staining intensity of C4A predominated over C4B. The distribution of these two staining patterns did not differ between membranous glomerulonephritis and lupus nephritis. They were also independent of C4A and C4B allotypes including the presence or absence of null alleles at either gene locus. In no case was C4B staining stronger than C4A staining. Serum creatinine and proteinuria did not differ between patients with identical and C4A-dominant C4 deposition. CONCLUSIONS The most likely but still hypothetical explanation for predominance in glomerular deposition of C4A over C4B in many cases of immune complex-mediated glomerulonephritis is the greater affinity of C4A to protein-containing immune complexes as compared to C4B.

UI	MeSH Term	Description	Entries
D007668	Kidney	Body organ that filters blood for the secretion of URINE and that regulates ion concentrations.	Kidneys
D007678	Kidney Glomerulus	A cluster of convoluted capillaries beginning at each nephric tubule in the kidney and held together by connective tissue.	Glomerulus, Kidney
D008297	Male		Males
D008875	Middle Aged	An adult aged 45 - 64 years.	Middle Age
D011110	Polymorphism, Genetic	The regular and simultaneous occurrence in a single interbreeding population of two or more discontinuous genotypes. The concept includes differences in genotypes ranging in size from a single nucleotide site (POLYMORPHISM, SINGLE NUCLEOTIDE) to large nucleotide sequences visible at a chromosomal level.	Gene Polymorphism,Genetic Polymorphism,Polymorphism (Genetics),Genetic Polymorphisms,Gene Polymorphisms,Polymorphism, Gene,Polymorphisms (Genetics),Polymorphisms, Gene,Polymorphisms, Genetic
D003181	Complement C4	A glycoprotein that is important in the activation of CLASSICAL COMPLEMENT PATHWAY. C4 is cleaved by the activated COMPLEMENT C1S into COMPLEMENT C4A and COMPLEMENT C4B.	C4 Complement,C4 Complement Component,Complement 4,Complement C4, Precursor,Complement Component 4,Pro-C4,Pro-complement 4,C4, Complement,Complement Component, C4,Complement, C4,Component 4, Complement,Component, C4 Complement,Pro C4,Pro complement 4
D005260	Female		Females
D005455	Fluorescent Antibody Technique	Test for tissue antigen using either a direct method, by conjugation of antibody with fluorescent dye (FLUORESCENT ANTIBODY TECHNIQUE, DIRECT) or an indirect method, by formation of antigen-antibody complex which is then labeled with fluorescein-conjugated anti-immunoglobulin antibody (FLUORESCENT ANTIBODY TECHNIQUE, INDIRECT). The tissue is then examined by fluorescence microscopy.	Antinuclear Antibody Test, Fluorescent,Coon's Technique,Fluorescent Antinuclear Antibody Test,Fluorescent Protein Tracing,Immunofluorescence Technique,Coon's Technic,Fluorescent Antibody Technic,Immunofluorescence,Immunofluorescence Technic,Antibody Technic, Fluorescent,Antibody Technics, Fluorescent,Antibody Technique, Fluorescent,Antibody Techniques, Fluorescent,Coon Technic,Coon Technique,Coons Technic,Coons Technique,Fluorescent Antibody Technics,Fluorescent Antibody Techniques,Fluorescent Protein Tracings,Immunofluorescence Technics,Immunofluorescence Techniques,Protein Tracing, Fluorescent,Protein Tracings, Fluorescent,Technic, Coon's,Technic, Fluorescent Antibody,Technic, Immunofluorescence,Technics, Fluorescent Antibody,Technics, Immunofluorescence,Technique, Coon's,Technique, Fluorescent Antibody,Technique, Immunofluorescence,Techniques, Fluorescent Antibody,Techniques, Immunofluorescence,Tracing, Fluorescent Protein,Tracings, Fluorescent Protein
D005921	Glomerulonephritis	Inflammation of the renal glomeruli (KIDNEY GLOMERULUS) that can be classified by the type of glomerular injuries including antibody deposition, complement activation, cellular proliferation, and glomerulosclerosis. These structural and functional abnormalities usually lead to HEMATURIA; PROTEINURIA; HYPERTENSION; and RENAL INSUFFICIENCY.	Bright Disease,Kidney Scarring,Glomerulonephritides,Scarring, Kidney
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man