Verification of instrument iFlash 1800, a chemiluminescence immunoassay method, by analysing IA-2 and ZnT8 autoantibodies in patients with type 1 diabetes

Sammanfattning

The Swedish healthcare system strives for better and complete diagnoses with the intent of keeping people safe to the best of their abilities. To do so, it is vital to correctly diagnose with confidence. In this study, we verify the instrument iFlash 1800, a chemiluminescence (CLIA) -method, by comparing it to the pre-existing, validated and verified instrument Gemini, which uses enzyme-linked immunosorbent assay (ELISA) -method. The reasoning behind this is because of the promising benefits of what the CLIA-method can offer quicker analysis, lower limits of detection and with a similar performance to that of Gemini. The comparison is performed using analysis of two autoantibody markers in serum, Islet Antigen 2 antibody (IA2) and Zinc Transporter 8 (ZnT8), which can indicate a debut of type 1 diabetes years before it fully becomes symptomatic. The results of this study showed that iFlash 1800 has a sensitivity of 83% and 77%, for IA-2 antibodies and ZnT8 antibodies, respectively. Both analysis had an overall estimate of 87% concerning agreement and a specificity of 100%. One questionable aspect was the comparison of lab result concentrations between ELISA and CLIA which were plotted against each other. An R-squared value of 55% for IA-2 and 75% for ZnT8 shows little to no confident answer that iFlash 1800 can replace ELISA at this time. However if more tests were to be analyzed and perhaps the instrument itself needs to be systematically calibrated, there is great potential for the instrument and how it can prevent longer queues and delay of treatment in the Swedish healthcare system.