Sensitive non-isotopic assays for autoantibodies to IA-2 and to a combination of both IA-2 and GAD65

Novel prokaryotic expression of thioredoxin-fused insulinoma associated protein tyrosine phosphatase 2 (IA-2), its characterization and immunodiagnostic application

“…The parameters of sensitivity (58.3 %), relative sensitivity (59.5 %) and specificity (94.9 %), although lower than those for RBA, are more than acceptable for use as a first line screening method for assessing humoral markers. It is difficult to compare the performance of this assay with those of previous studies where IA-2A is detected because in those studies different antigens were used, as well as different patient populations and healthy control individuals (with variables such as number, ethnicity and, possibly, sample matrix) [62, 63, 74–77]. The lower sensitivity showed by CL- b ELISA, in comparison with RBA, could be a consequence of partial denaturation of TrxIA-2 ic when adsorbed onto the surface of polystyrene microplates.…”

“…The protocol employed was based on those previously described [62–65]. White Polystyrene microplates (96 F Maxisorp white microwell, Thermoscientific, Rockford, IL, USA) were coated ON at 4 °C with 40.0 ng of purified TrxIA-2 ic per well, washed three times with PBS, blocked for 1.5 h with 200 μL of blocking solution, and washed five times.…”

Estudio de autoanticuerpos en el inicio de la diabetes autoinmune en nuestro medio mediante ELISA

“…Recientemente se ha diseñado un método ELISA para determinación conjunta de GAD e IA-2, parece ser que con buenos resultados. Obtienen un 85% de positivos con el ensayo combinado GAD-65/IA-2 25,26 .…”

Autoimmunity and Immunotherapy of Type 1 Diabetes

“…In fact, the binding of phogrin autoantibodies could be totally blocked if adding ICA512 to sera positive for both ICA512 and phogrin, while the binding of ICA512 antibodies cannot be fully blocked with phogrin (Savola, 2000). IA-2As can be evaluated by radioligand-binding assay and ELISA (Bonifacio et al, 2001;Chen et al, 2005a;Kotani et al, 2002); whereas, RIAs performed much better than ELISAs, as was found for GAD65A assays (Verge et al, 1998).…”

“…Association with other autoantibodies increases the test specificity, with a decrease in sensitivity however (Thivolet & Carel, 1996). ICA levels that exceed 80 JDF (Juvenile Diabetes Foundation) units at the time of diagnosis despite better beta-cell function are associated with short clinical remission (Zamaklar et al, 2002), and include 53% of disease 7 located on chromosome 2q31.1 and chromosome 10p11.23, respectively (Bennett et al, 2005). GAD1 mRNA has been reported to be translated into GAD67, which is not detected in human islets (Karlsen et al, 1991), but is predominantly found in mouse islets Velloso et al, 1994).…”