Cross-reactivity of three recombinant insulin analogs with five commercial insulin immunoassays

Several new insulin analogs that are prepared with recombinant DNA technology are available for clinical use [for a recent review, see Ref. (1)]. These agents have altered pharmacokinetics compared with regular human insulin. Insulin aspart (Novo-LogTM; Novo Nordisk Pharmaceuticals) is homologous with regular human insulin except for a single substitution of aspartic acid for proline at position B28. This single substitution reduces the molecule's tendency to form hexamers. Therefore, insulin aspart is absorbed more rapidly after subcutaneous injection and has both a faster onset of action and a shorter duration of action than regular insulin. A second short-acting recombinant insulin is insulin lispro (Humalog®; Eli Lilly and Company), which is a human insulin analog created by reversing the amino acids at positions 28 (Pro to Lys) and 29 (Lys to Pro) of the B chain. It is absorbed more rapidly than regular human insulin when administered subcutaneously and has a shorter duration of action.