The double whammy of endogenous insulin antibodies in non-diabetic subjects

The presence of high affinity/avidity endogenous insulin antibodies in significant amounts in non-diabetic individuals could uniquely be a double whammy. Clinically it could trigger pathology, namely hypoglycaemia, and analytically it could cause erroneous and potentially misleading results (i.e., falsely high or falsely low) in the key biochemical parameters essential in the differential diagnosis of this pathology, namely serum insulin, proinsulin and even C-peptide. The purpose of this paper is to highlight the clinical and analytical sequelae of endogenous insulin antibodies in (a) delaying or even confusing the differential diagnosis of unexpected/unexplained hypoglycaemia, and (b) interfering in some immunoassays of pancreatic hormones (commercial or in-house).