Test Overview
Insulin-I125 binding capacity
The presence of insulin antibody indicates either long-term insulin injection or autoimmune insulin antibody. Insulin resistance, defined as a state in which the daily insulin requirement exceeds 200 units/day for more than two days, may be associated with elevated anti-insulin antibody titers and insulin-binding capacity. Elevated insulin-binding alone, however, is not pathognomonic of insulin resistance, a complex phenomenon which may be due to a number of different causes such as ketosis or hormone antagonism. Stable diabetics, who are characterized as requiring infrequent changes in insulin doses, may have significant circulating concentrations of high avidity antibodies, whereas 'unstable' diabetics, who require frequent changes in insulin dose, may have lower concentrations.
< 5.0 uU/mL (Negative)
* Reference ranges may change over time. Please refer to the original patient report when evaluating results.
Test Details
3-10 days
- Anti-insulin Antibodies
Specimen Requirements
Collect specimen in an SST (preferred) or red top tube. Centrifuge, aliquot serum into a plastic vial, and freeze within 1 hour of collection. No radioactive isotopes should be administered within 24 hours prior to venipuncture.
Additional Information
Insulin antibodies occur in the serum of many insulin-treated diabetic patients and act as a insulin-transporting proteins, thereby preventing degradation of insulin. Formation of the antibody-antigen complex is a reversible process; insulin may dissociate from the complex and thus exert its physiologic action by binding to appropriate cell receptors. The most common type of anti-insulin antibody is IgG, but it has now been found in five classes of immunoglobulins in insulin-treated patients. These immunoglobulins may be responsible for allergic manifestations (especially IgE) and for insulin resistance (especially IgM). Test sent to Mayo Medical Laboratories.