An immunochemical method for assessing the function of the alternative complement pathway.
Activation of the alternative pathway of human complement (C) by soluble C activators resulted in a decrease of C9 antigen, measured by single radial immunodiffusion, concomitant with a decrease of C9 hemolytic activity. In the presence of ethylene glycol bis-(beta-aminoethylether)-tetraacetic acid (EGTA) and Mg2+, this decrease of C9 antigen in the presence of soluble activators such as dinitrophenylated bovine serum albumin depends mainly on the activation of the alternative C pathway. Therefore, an assay system to express the total activity of the alternative C pathway in human serum - the C9 depletion test (C9DT) -, was devised. C9DT showed significantly lower values for patients with systemic lupus erythematosus and rheumatoid arthritis than for control patients.
D000941:Antigens / Q000032:analysis; D001172:Arthritis, Rheumatoid / Q000276:immunology; D003167:Complement Activation; D003186:Complement C9 / Q000276:immunology; D003170:Complement Pathway, Alternative; D004140:Dinitrophenols; D006358:Hot Temperature; D006801:Humans; D007120:Immunochemistry; D007074:Immunoglobulin G; D007444:Inulin / Q000494:pharmacology; D012710:Serum Albumin, Bovine / Q000494:pharmacology; D015054:Zymosan / Q000494:pharmacology
D000941:Antigens; D003186:Complement C9; D004140:Dinitrophenols; D007074:Immunoglobulin G; C034638:dinitrophenyl-bovine serum albumin; D012710:Serum Albumin, Bovine; D007444:Inulin; D015054:Zymosan