Islet Cell Antibody Panel (ICAP includes GAD, IA2 & ZT8)

Department of Immunology

Notes

• Antibodies recognising the islet cell antigens glutamic acid decarboxylase (GAD 65), Zinc Transporter 8 (ZnT8) and the insulinoma antigen 2 (IA-2) are present in up to 90% of newly diagnosed patients with type 1 diabetes.
• Anti-GAD antibodies in high titre are also associated with the stiff-person syndrome (60% sensitivity), a rare neurological disease characterised by muscle rigidity and spasms.
• Test performed by Department of Clinical Chemistry, Royal Devon and Exeter Hospital.

Sample Requirements

Clotted blood. (No patient preparation or special handling required)

Adult

5ml Gold-top SST tube or 3.5ml Rust-top gel tube (Trust users only)

Paediatric

1ml Serum Sample

Turnaround Times

3 weeks

Time limit for add-on

3 days

Reference Range

GAD Positive: >= 11 U/mL

IA-2 Positive: >= 7.5 U/mL

ZnT8 age >= 30 years Positive: >= 10 U/mL

ZnT8 age <30 years Positive: >= 65 U/mL