title: Assessment of anti-streptokinase antibody levels in human sera using a microradioimmunoassay procedure.
abstract: A high capacity, quantitative radioimmunoassay procedure has been developed to measure IgG antibodies to streptokinase (SK) in human serum. Results showed that the use of low concentrations of 125I-SK (100 ng/ml) and ambient temperature incubation conditions minimised degradation of the target labelled antigen and afforded antibody binding values which could be confidently related to the native intact SK protein. SK-complexed to plasminogen was also shown to retain the equivalent antigenic activity of native SK. Comparison of the absolute anti-SK levels with streptokinase resistance titres demonstrated that the two measurements of antibody correlated statistically but afforded quantitatively poor agreements. A survey of IgG levels to SK in sera from 93 normal healthy volunteers showed that all individuals displayed readily measurable anti-SK antibodies, with some 80% having IgG concentration capable of binding in excess of 1 microgram SK per ml serum.
mesh_terms: D000906:Antibodies / Q000032:analysis*; D004351:Drug Resistance; D005342:Fibrinolysis; D006801:Humans; D007074:Immunoglobulin G / Q000032:analysis; D066298:In Vitro Techniques; D010958:Plasminogen / Q000378:metabolism; D011863:Radioimmunoassay / Q000379:methods*; D013300:Streptokinase / Q000097:blood / Q000276:immunology* / Q000494:pharmacology
chemical_list: D000906:Antibodies; D007074:Immunoglobulin G; D010958:Plasminogen; D013300:Streptokinase