An immunochemical method for the quantitation of insulin antibodies

Insulin antibody determination: Theoretical and practical considerations

“…A consequence of Data derived using an immunochemical assay [30] and expressed in ~g/ 1. this is that there is less 'binding territory' left in which to discriminate between positive sera of different binding capacities. Second-antibody assays reduce this problem, the reagent being used either in standard excess [52] or at an optimal concentration for each individual serum [30]. The need to wash precipitates after phase separation introduces further error which can be obviated by incorporation of a volume marker, i.e.…”

“…22Na. Allowance is made for the 'free' 125I insulin which remains after removal of about 80% of the supematant, by determining 2eNa and a25I counts in the precipitate [30].…”

“…Generally, methods using non-specific methods of phase separation show higher levels of background binding. PEG and anti-IgG are probably the most widely used phase separants in current use [29,30]. Some workers have favoured competitive binding, e. g. between antibody and both labelled and unlabelled insulin [31] or between labelled insulin and a mixture of a standard guinea pig antibody and the human antibody under examination [32].…”

Immunogenicity of recombinant DNA human insulin

“…Such antibodies develop less often and in lower concentrations in individuals treated with highly purified porcine insulins than in individuals treated with less purified insulins [2,3]. Apart from trace amounts of proinsulin and other pancreatic peptides which may remain after extraction and purification of animal insulins, human insulin differs from porcine insulin only with regard to the terminal amino acid of the B chain [4].…”

Scintigraphic distribution of complexes of antiinsulin antibodies and 123I-insulin. In vivo studies in rats.

“…Virtually all diabetic patients treated with insulin develop circulating antibodies, and these are now routinely detected by a variety of techniques (1)(2)(3)(4)(5)(6)(7).…”