Biomaterial Database

A novel assay for serum complement activity: C42 generation assay. 1999

E Kobayashi, and E Kitano, and H Kitamura

Department of Medical Technology, Osaka Prefectural College of Health Sciences, Osaka, Japan.

BACKGROUND In most clinics, laboratory tests for serum complement are limited to immunochemical determinations of C3 and C4 and are occasionally extended to the hemolytic titration of total complement functional activity (CH50). However, these tests are often not sufficient for the analysis of low CH50 serum. METHODS A novel assay for serum complement activity, the C42 generation assay, has been developed. The principle of this assay is based on the hemolysis of sensitized sheep erythrocytes (EA) by complement components in two sera: C42 (the classical pathway C3 convertase) is generated on EA by C1, C4 and C2 in the first serum, followed by a second reaction leading to hemolysis by C3-C9 supplied by the addition of the second serum in the presence of EDTA. RESULTS This methodology permits the evaluation of two distinct serum complement activities of a test serum. The combined activity of C1, C4 and C2, as well as the combined activity of C3-C9, can be estimated from the observed degrees of hemolysis. Information obtained from this assay is helpful for the analysis of test serum determined to have decreased CH50. Several clinical cases are presented in which this assay was utilized. CONCLUSIONS The C42 generation assay is another functional assay of serum complement which can provide information beyond that obtained from the typical serum CH50 assay. Since intermediate cells or isolated complement components are not necessary, this assay can be employed rapidly and economically in a clinical setting.

UI	MeSH Term	Description	Entries
D008180	Lupus Erythematosus, Systemic	A chronic, relapsing, inflammatory, and often febrile multisystemic disorder of connective tissue, characterized principally by involvement of the skin, joints, kidneys, and serosal membranes. It is of unknown etiology, but is thought to represent a failure of the regulatory mechanisms of the autoimmune system. The disease is marked by a wide range of system dysfunctions, an elevated erythrocyte sedimentation rate, and the formation of LE cells in the blood or bone marrow.	Libman-Sacks Disease,Lupus Erythematosus Disseminatus,Systemic Lupus Erythematosus,Disease, Libman-Sacks,Libman Sacks Disease
D003165	Complement System Proteins	Serum glycoproteins participating in the host defense mechanism of COMPLEMENT ACTIVATION that creates the COMPLEMENT MEMBRANE ATTACK COMPLEX. Included are glycoproteins in the various pathways of complement activation (CLASSICAL COMPLEMENT PATHWAY; ALTERNATIVE COMPLEMENT PATHWAY; and LECTIN COMPLEMENT PATHWAY).	Complement Proteins,Complement,Complement Protein,Hemolytic Complement,Complement, Hemolytic,Protein, Complement,Proteins, Complement,Proteins, Complement System
D003169	Complement Inactivator Proteins	Serum proteins that negatively regulate the cascade process of COMPLEMENT ACTIVATION. Uncontrolled complement activation and resulting cell lysis is potentially dangerous for the host. The complement system is tightly regulated by inactivators that accelerate the decay of intermediates and certain cell surface receptors.	Complement Cytolysis Inhibiting Proteins,Complement Cytolysis Inhibitor Proteins,Complement Inactivating Proteins,Serum Complement Inactivators,Complement Inactivators, Serum,Inactivating Proteins, Complement,Inactivator Proteins, Complement,Inactivators, Serum Complement,Proteins, Complement Inactivating,Proteins, Complement Inactivator
D003170	Complement Pathway, Alternative	Complement activation initiated by the interaction of microbial ANTIGENS with COMPLEMENT C3B. When COMPLEMENT FACTOR B binds to the membrane-bound C3b, COMPLEMENT FACTOR D cleaves it to form alternative C3 CONVERTASE (C3BBB) which, stabilized by COMPLEMENT FACTOR P, is able to cleave multiple COMPLEMENT C3 to form alternative C5 CONVERTASE (C3BBB3B) leading to cleavage of COMPLEMENT C5 and the assembly of COMPLEMENT MEMBRANE ATTACK COMPLEX.	Alternative Complement Pathway,Properdin Pathway,Alternative Complement Activation Pathway,Complement Activation Pathway, Alternative
D003171	Complement Pathway, Classical	Complement activation initiated by the binding of COMPLEMENT C1 to ANTIGEN-ANTIBODY COMPLEXES at the COMPLEMENT C1Q subunit. This leads to the sequential activation of COMPLEMENT C1R and COMPLEMENT C1S subunits. Activated C1s cleaves COMPLEMENT C4 and COMPLEMENT C2 forming the membrane-bound classical C3 CONVERTASE (C4B2A) and the subsequent C5 CONVERTASE (C4B2A3B) leading to cleavage of COMPLEMENT C5 and the assembly of COMPLEMENT MEMBRANE ATTACK COMPLEX.	Classical Complement Pathway,Classical Complement Activation Pathway,Complement Activation Pathway, Classical
D003184	Complement C7	A 93-kDa serum glycoprotein encoded by C7 gene. It is a polypeptide chain with 28 disulfide bridges. In the formation of MEMBRANE ATTACK COMPLEX; C7 is the next component to bind the C5b-6 complex forming a trimolecular complex C5b-7 which is lipophilic, resembles an integral membrane protein, and serves as an anchor for the late complement components, C8 and C9.	C7 Complement,Complement 7,Complement Component 7,C7, Complement,Complement, C7,Component 7, Complement
D005069	Evaluation Studies as Topic	Works about studies that determine the effectiveness or value of processes, personnel, and equipment, or the material on conducting such studies.	Critique,Evaluation Indexes,Evaluation Methodology,Evaluation Report,Evaluation Research,Methodology, Evaluation,Pre-Post Tests,Qualitative Evaluation,Quantitative Evaluation,Theoretical Effectiveness,Use-Effectiveness,Critiques,Effectiveness, Theoretical,Evaluation Methodologies,Evaluation Reports,Evaluation, Qualitative,Evaluation, Quantitative,Evaluations, Qualitative,Evaluations, Quantitative,Indexes, Evaluation,Methodologies, Evaluation,Pre Post Tests,Pre-Post Test,Qualitative Evaluations,Quantitative Evaluations,Report, Evaluation,Reports, Evaluation,Research, Evaluation,Test, Pre-Post,Tests, Pre-Post,Use Effectiveness
D006461	Hemolysis	The destruction of ERYTHROCYTES by many different causal agents such as antibodies, bacteria, chemicals, temperature, and changes in tonicity.	Haemolysis,Extravascular Hemolysis,Intravascular Hemolysis,Extravascular Hemolyses,Haemolyses,Hemolyses, Extravascular,Hemolyses, Intravascular,Hemolysis, Extravascular,Hemolysis, Intravascular,Intravascular Hemolyses
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia