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COMPLEMENT. Anna Tjandrawati Clinical Pathology Department Medical Faculty Padjadjaran University Hasan sadikin General Hosptital Bandung. COMPLEMENT. Definition : a system comprised of a groups of plasma and cell membrane proteins that play an important role in
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COMPLEMENT Anna Tjandrawati Clinical Pathology Department Medical Faculty Padjadjaran University Hasansadikin General Hosptital Bandung
COMPLEMENT Definition : a system comprised of a groups of plasma and cell membrane proteins that play an important role in host defense process. Components: • More than 30 proteins • Synthesized in the liver, macrophages and other cells
COMPLEMENT Functions : • Lysis of cells, bacteria, and viruses • Opsonization, which promotes phagocytosis of particulate antigens. • Regulate inflammatory and immune responses • Regulate the biologic activity of cells.
COMPLEMENT activation pathway • CLASSICAL PATHWAY • ALTERNATIVE PATHWAY • MANNAN BINDING LECTIN PATHWAY
COMPLEMENT activation • As a cascade • Numerous protein of the complement system are sequentially activated. • Activation typically refers to the conversion zymogen to an enzymatic form • The enzymatic form cleave other complement protein into two fragments
COMPLEMENT activation • Some fragments bind to receptors, while others bind to microbial surfaces • One complement fragment associates with intact protein to formcytocidal complexes that insert into the membranes of cells ( bacteria) resulting in bacteria destruction
C3 convertase classical pathway C3 convertase alternative pathway C5 convertase classical pathway C5 convertase alternative pathway
COMPLEMENT RECEPTORS, LIGANDS, AND BIOLOGICAL FUNCTION FOLLOWING RECEPTOR-LIGAND INTERACTION
Biological activity of complement • Inflammatory response : C3a, C4a, C 5a • - Anaphylatoxins • - Chemokines/Chemotaxis • Phagocytosis: C3b • - Opsonin • Elimination of immune complex: C3b • - Opsonin and receptors • Osmotic lysisbacteria:C5b6789 • - MAC(Membrane Attack Complex)
EVALUATING COMPLEMENT PATHWAYS Measurement of Overall Complement Activity CH50 and AH50 Measurement of Complement Components • Radial Immunodiffusion (RID) • Nephelometry rate nephelometry: an assay in which the rate of immune complex formation is measured