[Assay of circulating anti-insulin antibodies by radioimmunoprecipitation].

We report a radio-immunoprecipitation method for the measurement of circulating insulin antibodies using porcine, bovine or human radiolabeled insulin and precipitation of the bound fraction by a combined polyethylene glycol--second antibody method. The coefficient of variation for intra- and inter-assay is below 8,5 p. cent and 17 p. cent respectively. 100 insulin treated patients sera were tested in the three systems: the results showed a great scattering; for the same serum, the values obtained with porcine and human insulins are below that with bovine insulin. The data correlated statistically significantly with those found with a commercial kit (r = 0,97, n = 170, t = -4,91, p greater than 0,001).