Indications for Autoimmune Diabetes Mellitus Insulin Antibody Testing
- Most useful in establishing autoimmune etiology in previously diagnosed type I DM.
- Order at least two antibody tests; do not order individual antibody tests.
- For most cases, use Glutamic Acid Decarboxylase Antibody in combination with one or more of the following: IA-2 Antibody, Zinc Transporter 8 Antibody, Islet Cell Cytoplasmic Antibody, and Insulin Antibody.
Type 1 DM
- Patient should have diagnosed DM:
- Antibody testing is not useful for the diagnosis of DM.
- Testing is not recommended for evaluating autoimmune etiology in patients receiving insulin > two weeks, as insulin antibody formation may occur (false-positive test result possible).
- Most useful in newly diagnosed DM in children <18 years to establish autoimmune etiology.
- May be useful in difficult adult cases when it is unclear if patient has type 1 or 2 DM.
Type 2 DM
- No indication for routine evaluation or management.
- Not recommended for screening family members of patients with type 1 DM (risk prediction) except in research settings.
- Latent autoimmune DM in adults (LADA): differentiates LADA from type 2 DM.
- Genetic testing: identifies patients with DM for whom a genetic etiology is suspected (e.g., monogenic DM, maturity-onset diabetes of the young [MODY]). Lack of antibodies suggests a genetic disorder.
- Gestational diabetes mellitus (GDM):
- Screen women with history of GDM to identify those at high risk for progression to type 1 DM.
- No evidence to suggest test results alter outcomes or improve care when compared to intermittent hemoglobin A1c testing.
For additional information regarding testing strategies, refer to our Laboratory Test Directory.
- ARUP Consult Diabetes Mellitus
- New Guidelines for the Diagnosis of Diabetes Mellitus
Presented by Joely A. Straseski, PhD, MS, MT(ASCP), DABCC