IA2 Autoantibodies (Endocrine Sciences)

Also known as: IA2 Antibodies, ICA512 Autoantibodies, Tyrosine Phosphatase Autoantibodies

Clinical Use

Use

Type 1 diabetes is caused by the autoimmune destruction of insulin-producing pancreatic beta cells, leading to insulin deficiency. Serological markers, such as autoantibodies to tyrosine phosphatase (IA2), are pivotal in the prediction and diagnosis of type 1 diabetes as they appear long before clinical symptoms. These autoantibodies provide early evidence of the autoimmune process against pancreatic islet cells and are present in 50% to 75% of patients with type 1 diabetes at or before disease onset. Their presence, especially when combined with other antibodies like those against glutamic acid decarboxylase (GAD) and insulin, significantly enhances the predictive value for diabetes.

Special Instructions

Not provided.

Limitations

While the IA2 antibody test is a valuable tool for predicting type 1 diabetes, the presence of IA2 antibodies alone does not confirm the development of the disease. It is more indicative of an autoimmune process, and the predictive value is increased when combined with other autoantibodies. False positives may occur, and interpretation should include clinical correlation. In some cases, additional confirmatory tests may be necessary, and the test's sensitivity might vary based on the age of the onset of diabetes.

Test Details

Methodology

Immunoassay (ELISA)

Biomarkers

Tyrosine Phosphatase

Protein

IA2 Autoantibodies

Expression • Categorical (e.g., Positive / Negative / Indeterminate)

LOINC Codes

Order Codes

31209-0 - Islet Cell512 Ab Ser-aCnc

Result Codes

31209-0 - Islet Cell512 Ab Ser-aCnc

Result Turnaround Time

5-10 days

Specimen

Serum

Volume

1 mL

Minimum Volume

0.5 mL

Container

Red-top tube or gel-barrier tube

Collection Instructions

Transfer the serum into a LabCorp PP transpak frozen purple tube with screw cap (LabCorp No. 49482). Freeze immediately and maintain frozen until tested. Submit separate frozen specimens for each test requested.