Mitigating the impact of antidrug antibodies against insulin on ELISA assay

Abstract: Diabetes has, in the past three decades, surged immensely. Because of this, new insulin analogues are constantly in the making.  In clinical studies, the presence of antidrug antibodies can prove a challenge when measuring insulin. In order to overcome the interference from antidrug antibody complexes on the total insulin measurement in human serum, several pre-treatment methods on insulin and polyclonal antibodies spiked samples were tried using ELISA analysis. Several different methods were tried, acid dissociation using a glycine buffer with and without ethanol in different concentrations, high ionic strength dissociation using MgCl2, Polyethylene glycol (PEG) and filtration. The best results were found when using the acid dissociation technique. Using glycine promising results were achieved, especially when 20 % ethanol was added to the acid mixture. Pre-treatment using PEG, MgCl2 and filtration was unsuccessful with the methods used. The main goal was reached through the use of glycine with the addition of 20% ethanol for acid dissociation. The proposed method still leaves significant room for optimisation and needs further verification on real patient samples. However, it is a good step in the direction of a global methodology using ELISA to overcome antidrug antibody interference for total insulin measurement in human serum.