Test Directory

This test is crucial for differentiating between T1D and T2D. It is important to note that classifying diabetes type can be challenging at the time of presentation, and misdiagnosis can occur in approximately 40% of adults with new T1D.

Identifying individuals affected by stage 1 T1D is important for applying eligibility criteria to drugs, such as Teplizumab, which have demonstrated the ability to delay the transition of stage 1 to stage 3 T1D in clinical trials.

IA-2 has some distinctive features. Its presence is associated with more-advanced islet autoimmunity and faster progression to stage 3 T1D.

Specimen Type: Serum

Preferred Collection Container: Red Top, Plain

Alternate Collection Container: Gold Top, Serum Separator

Desired Volume: 2 mL

1. Collect a red top, plain tube via venipuncture.

1. Separate serum from cells.
2. Transfer 2 mL of serum to a clear aliquot tube (screw cap).

Fasting specimen is preferred.

Transport to the laboratory refrigerated.

• Gross hemolysis
• Grossly lipemic
• Grossly icteric

See patient report.

T1D is classified into three stages, with stages 1 and 2 considered presymptomatic. Since the presence of stage 1 and 2 T1D requires at least two islet autoantibodies, relying solely on IA-2 as a screening test limits the ability to make an accurate diagnosis. Professional organizations, including the American Diabetes Association (ADA), recommend using tests for all four islet cell autoantibodies: IAA, glutamic acid decarboxylase (GAD65), Zinc Transporter 8 (ZnT8), and islet cell antigen 2 antibody (IA-2).