Identifying Beta Cell Dysfunction with Sensitive and Specific Proinsulin Chemiluminescent Assays
Studies have shown that deterioration of pancreatic beta cell function may be assessed by the measurement of proinsulin, the precursor of insulin and C-peptide. Research has shown proinsulin to be an important biomarker for secretory beta cell dysfunction, an indirect predictor of insulin resistance, and an independent cardiovascular risk factor due to inefficiencies of proinsulin processing affiliated with demands on the beta cell. However, the ability to distinguish between intact, total and the partially processed proinsulin species has been difficult to research.
In order to address this issue, ALPCO developed the STELLUX® Total Proinsulin ELISA and the STELLUX® Intact Proinsulin ELISA for the quantitative determination of total and intact proinsulin in human serum, plasma, and tissue culture supernatants (TC Sups) over a dynamic range of 5-3,000 pg/mL and superior sensitivities. These assays are FDA Class I Devices for In Vitro Diagnostic Use. They have been calibrated to the WHO Proinsulin 1st International Standard 09/296.
These assays have negligible cross-reactivity to human insulin (0.17% and <0.6%) and C-peptide (0% and <0.1%), and 100% cross-reactivity to intact proinsulin. The assays differ in cross-reactivity to Des (31,32) proinsulin, with 0.73% and 100% for the intact and total proinsulin assays, respectively.