Insulinoma-associated Antigen 2/ Tyrosine Phosphatase (anti-IA2) antibodies
| Category | Immunology |
|---|---|
| Test background |
IgG antibodies to Insulinoma-associated antigen 2 (IA2) are detected in 50-70% of children and 30-50% adults with newly apparent diabetes mellitus type 1 (T1DM) with levels declining with increasing age. IA2 antibodies are most frequent in patients with HLA DR4/DQ8 haplotype. IA2 antibodies can be measured together with other markers of islet cell autoimmunity (insulin, GAD, ZNT8 antibodies) to predict the development and aid in the diagnosis of type 1 diabetes mellitus (T1DM). Two or more antibodies in combination increase the predictive value of disease development. Screening for diabetic autoantibodies is also used to distinguish between type 2 diabetes mellitus (T2DM) and latent autoimmune diabetes in adults (LADA) in the adult population. NICE Guidelines for the diagnosis of T1DM in adults (NG17) recommend measuring diabetes-specific autoantibodies at diagnosis and state that the false negative rate can be reduced if quantitative tests for two different diabetes specific antibodies are measured. This test is performed by ELISA. |
| Clinical Indications |
Diagnosis of type 1 diabetes mellitus (T1DM) |
| Reference range | <10 IU/ml |
| Sample & container required | Serum (rust top RST tube) |
| Sample volume | 5-10 mL blood (1 mL serum) |
| Turnaround time | 14 days |