Rapid assays for detection of anti-islet autoantibodies: Implications for organ donor screening

The purpose of the current study was to develop and evaluate rapid assays f or autoantibodies to GAD65 (GAA), ICA512bdc/IA-2 (ICA512AA), and insulin (m icroLAA, mIAA) as a potential tool for identification of cadaveric pancreas donors who were at high risk for developing diabetes. The study included 1 54 new onset diabetic, prediabetic, and healthy control subjects. Subjects were evaluated for all three autoantibodies in three separate assays: (1) s tandard (std) assay with a 24-h or 72-h incubation at 4 degreesC (combined GAA/ICA512AA or mIAA, respectively), (2) rapid assay with 1-h room temperat ure (RT) incubation, and (3) rapid assay with 2-h RT incubation. The serum samples from 777 organ donors were also evaluated for all three autoantibod ies and all the positive samples from standard assay evaluated with the 1-h incubation assay. Simple linear regression analyses revealed excellent cor relation between the standard assay and the rapid assays for all three auto antibodies, as follows: (1) GAA: std vs. 1 h (R-2=0.85) and std vs. 2 h (R- 2=0.83), (2) ICA512AA: std vs. 1 h (R-2=0.85) and std vs. 2 h (R-2=0.84), a nd (3) mIAA: std vs. Ih (R-2=0.70) and std vs. 2 h (R-2=0.64). Comparison o f assay correlation rates between subject cohorts revealed no significant d ifferences. Compared to their respective standard assays, the 1-h RT GAA as say missed 3.2% and identified an additional 1.3% of samples, the 1-h RT IC A512AA assay had no discordant samples, and the 1-h RT mIAA assay missed 7. 1% and identified an additional 5.8% of samples. We analysed a series of 77 7 stored serum samples from cadaveric donors. Two of 777 (0.25%) were posit ive for two autoantibodies (both GAA and ICA512AA) and 23 of 777 (3.0%) one autoantibody (11 IAA; 12 GAA). The rapid analysis for all three autoantibo dies could be completed in less than 3 h with comparable concordance rates to the more time-consuming standard assays, making these assays an attracti ve option for organ donor screening to identify potential pancreata for imm unopathogenetic research. (C) 2001 Academic Press.