2070 – CentAK® anti-GAD65 M

Highlights

• Use of recombinant human glutamic acid decarboxylase (GAD65)
• Quantitative determination of the antibody activity
• Results expressed in U/mL
• High diagnostic sensitivity and specificity
• High precision within the measurement range
• CE marked

Intended Purpose

The CentAK^® anti-GAD₆₅ M is a quantitative immunoassay for the determination of antibodies against glutamic acid decarboxylase (GAD₆₅) in human serum. The CentAK^® anti-GAD₆₅ M is intended as an aid in the diagnosis of autoimmune diabetes mellitus type 1 in conjunction with other clinical and laboratory findings. The immunoassay is designed for manual professional in vitro diagnostic use.

Diagnostic Relevance

Diabetes mellitus type 1 is a chronic autoimmune disease in which the insulin-producing beta cells of the islets of Langerhans in the pancreas are destroyed. The consequence of this destruction is a reduced insulin production, which results in high blood sugar levels as diabetes mellitus. Genetic predispositions and viral infections are considered risk factors, but the exact causes have not yet been fully clarified.

The destruction of the insulin-producing beta cells of the pancreas is based on the presence of islet cell antibodies (ICA), which are directed against different antigens of the pancreatic islet cells, such as glutamic acid decarboxylase (GAD65), tyrosine phosphatase (insulinoma-associated antigen 2, IA2), the zinc transporter 8 (ZnT8) and against insulin. Islet cell antibodies (ICA) can be detected in 70 – 80 % of patients with diabetes mellitus. The different antibodies usually appear months to years before the occurrence of elevated blood sugar levels and are therefore also considered important prognostic markers to identify patients with an increased risk of developing diabetes mellitus type 1. The combined detection of antibodies against GAD65, IA2, ZnT8 and insulin is considered an important method for diagnosing diabetes mellitus type 1 at the onset of the disease.

Glutamic acid decarboxylase (GAD) catalyzes the synthesis of the neurotransmitter GABA in the brain and in the beta cells. Two isoforms of the enzyme are known: GAD65 with a molecular weight of 65 kDa and GAD67 with 67 kDa, respectively. Antibodies directed against GAD65 are observed in the majority of patients with diabetes mellitus type 1 and in a large number of individuals in the prediabetic phase. In contrast, antibodies directed against both GAD isoforms are found in patients with the very rare neuromuscular Stiff-man syndrome.