Exogenous insulin antibody syndrome (EIAS): a clinical syndrome associated with insulin antibodies induced by exogenous insulin in diabetic patients

Abstract

Insulin has been used for diabetes therapy and has achieved significant therapeutic effect. In recent years, the use of purified and recombinant human insulin preparations has markedly reduced, but not completely suppressed, the incidence of insulin antibodies (IAs). IAs induced by exogenous insulin in diabetic patients is associated with clinical events, which is named exogenous insulin antibody syndrome (EIAS). The present review is based on our research and summarizes the characterization of IAs, the factors affecting IA development, the clinical significance of IAs and the treatments for EIAS.

Keywords: diabetes; exogenous insulin antibody syndrome; hyperglycaemia; hypoglycaemia; insulin antibodies.

Figure 1

Representative images of Scatchard plots of insulin antibodies in one of our patients with EIAS. The insulin antibodies-binding data showed bimodal distributions, suggesting two classes of antibodies characterized by the high-affinity/low-capacity and low-affinity/high-capacity sites (11). Bound: bound insulin, Free: free insulin.

Figure 2

A schematic drawing of IAs’ clinical significance. Massive volumes of insulin binding to the insulin antibodies, a marked increase in insulin resistance is induced, insulin antibodies could reduce insulin action, thus triggering hyperglycemia (‘tampon-like effect’). On the other hand, insulin antibodies could also enhance and prolong the pharmacodynamic action of insulin by serving as a carrier, when massive volumes of insulin become dissociated, free insulin increases all at once, thus leading to hypoglycaemia (‘reservoir-like effect’).