Interference of Exogenous Insulin on Insulin Detection Test by Electrochemiluminescence Immunoassay

Objective To explore the interference of exogenous insulin therapy on insulin detection test by electrochemical luminescence immunoassay (ECLIA). Methods Insulin level was determined by ECLIA. According to the requirements of EP7-A2 of American Society for Clinical Laboratory Standards Institute Standards, paired difference experiment was conducted to evaluate the interference of 8 kinds of exogenous insulin on insulin detection, dose effect experiment was conducted to determine the relationship between exogenous insulin concentration and interference degree. Results When the interfering substance concentrations were ≤250 μU/mL, Gansulin N?, Gansulin R?, Humulin R?，Novolin R? and Lantus? all showed linear positive interference, while Levemir? showed a linear negative interference in high concentrations insulin and non-interfering in low concentrations insulin, Humalog? and Novo Rapid? showed non-interference in insulin detection. Conclusion The use of different exogenous insulin may have different interference on insulin measurement, which need laboratorians and physicians notice to avoid misdiagnosis.