title: The determination of the complement components C1q, C4 and C3 in serum and cerebrospinal fluid by radioimmunoassay.
abstract: Non-competitive 2-site radioimmunoassays (RIA) for the determination of the complement proteins C1q, C4 and C3 in cerebrospinal fluid (CSF) are described. The quantitative results of the RIAs were the same as those obtained by other assay methods: radial immunodiffusion and turbidimetry and, in the case of C4, the haemolytic assay. The concentrations of the complement proteins in paired CSF and serum samples from a group of 60 patients were measured, as well as those of albumin and IgG. The ratios (concentration in CSF)/(concentration in serum) of the complement proteins correlated poorly with that of albumin. In contrast, the ratio of IgG was significantly correlated with that of albumin. The ratios of the complement proteins were higher than might be expected on the basis of their molecular masses. This suggests that these proteins may be synthesized within the normal central nervous system.
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D003166:Complement Activating Enzymes / Q000097:blood / Q000134:cerebrospinal fluid* / Q000592:standards; D015922:Complement C1q; D003176:Complement C3 / Q000134:cerebrospinal fluid* / Q000592:standards; D003181:Complement C4 / Q000134:cerebrospinal fluid* / Q000592:standards; D004355:Drug Stability; D005260:Female; D006801:Humans; D005779:Immunodiffusion; D008297:Male; D008875:Middle Aged; D011863:Radioimmunoassay / Q000592:standards; D012015:Reference Standards; D012016:Reference Values
chemical_list: D003176:Complement C3; D003181:Complement C4; D015922:Complement C1q; D003166:Complement Activating Enzymes