A Method for Quantitative Determination of Insulin Antibodies in Human Plasma

Abstract

A method is described for quantitative determination of the insulin binding capacity of human plasma. In this method the insulin binding capacity of non-iodinated insulin is determined. The determination is not influenced by free or antibody bound plasma insulin in the concentrations usually found. It is shown that under the condition used, equilibrium between free and antibody bound insulin is first attained after one week. It is also shown that repeated freezing and thawing of plasma results in a reduction of the insulin binding capacity. Lower detection limit for antibody determination estimated as upper 95 % control limit for pig and ox insulin was found to be 32 and 25 μunits/ml, respectively.

The Immunogenic Properties of Highly Purified Insulin Preparations. The Clinical Importance of Insulin-Binding Antibodies

“…In the introduction Ortved Andersen (1972) mentioned that most investigators found high antibody titres in patients with insulin résistent diabetes whereas the correlation between the insulin dose and antibody titres in non-resistent dia¬ betics was found to be less convincing. Korp 8c Levett (1973) found only small and inconstant alterations in the insulin requirement when they changed the treatment from monospecies to monocomponent insulin.…”

“…Ortved Andersen (1972) showed that the maximum binding capacity was reached after treatment for 9-12 months. Fig.…”

“…The insulin-binding capacity (IBC) of plasma was determined according to Ortved Andersen et al (1972). The lower detection limit (LDL), determined as the upper 95 "lo limit for the binding capacity of porcine insulin in poorly regulated non-treated diabetic patients, was found to be 32 «U/ml.…”

Insulin antibody determination: Theoretical and practical considerations

“…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]. Solid-phase immobilisation of insulin to plastic tubes [33], paper discs [34] or sepharose particles (as in the radioallergosorbent test -RAST) [35,36], or immobilisation of second antibody (as in the paper radioimmunosorbent test -PRIST) [37], have been used chiefly to document the much smaller amounts of IgE antibody in the circulation of insulin-treated patients.…”

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).…”