A sensitive non-isotopic assay for GAD65 autoantibodies

Evaluation of Two Nonisotopic Immunoassays for Determination of Glutamic Acid Decarboxylase and Tyrosine Phosphatase Autoantibodies in Serum

“…The recovery, CV WR , and CV T near the cutoff value were similar in the RBA and ELISA and were comparable to the intra-and interassay CVs obtained previously (10 ). The diagnostic accuracies of the RBA and ELISA were also satisfactory, with the latter being slightly better.…”

Slowly progressive insulin-dependent (type 1) diabetes positive for anti-GAD antibody ELISA test may be strongly associated with a future insulin-dependent state

“…Another possible reason for the GADA test result mismatch lies in the fact that the GADA-RIA test requires a single wash step in the measuring process, possibly leading to a non-specific response and a false-positive result, particularly in the lower GADA range, in contrast to the 3 wash steps in GADA-ELISA test [12,13]. Furthermore, a lower binding affinity of GADA to GAD65 protein may exist in SPIDDM within a lower GADA range and may not be detected by GADA-ELISA kit, for reasons unknown.…”

“…As a result, the GADA-ELISA test consistently achieved higher sensitivity and specificity levels than the GADA-RIA test (sensitivity/specificity: 74-90%/94-98% for ELISA and 70-86%/92-98% for RIA) in all four programs (taken from the manufacturer's data sheets of the two kits; RSR Ltd.). Behind this background, the GADA-ELISA assay may rely on the autoantibody forming a bridge between immobilized GAD65 on the plate and biotinylated GAD65 in the solution with detection by streptavidin peroxidase [12,13]. In fact, it is believed that the bridging conformation favors the recognition of high-affinity antibodies, contributing to the good specificity [14].…”

Reactivity to N-Terminally Truncated GAD65(96–585) Identifies GAD Autoantibodies That Are More Closely Associated With Diabetes Progression in Relatives of Patients With Type 1 Diabetes

“…RBAs are still widely used for the prediction and characterization of type 1 diabetes despite the advent of highquality alternative assay formats such as the bridging ELISA (19) and electrochemiluminescence assay (20). Advantages of RBAs include their relatively low cost, high sensitivity, good flexibility, small serum volume requirement, and proven track record in diabetes prediction as well as the wide availability of equipment and reagents.…”