Fig. 6.
Islet autoantigen-specific B cell responses in slow progressors, measured by ELISpot, are increased to proinsulin but not GAD or IA-2. B cell responses to the indicated islet autoantigens were quantified using an ELISpot assay to detect secreted IgG. Background responses were determined in the absence of islet autoantigens. Results are shown as the number of background-subtracted spots per 4 × 105 input PBMCs. Counts were averaged over at least six wells for each condition. ELISpot counts are shown for: (a) GAD at 0.8 μg/ml and 1.6 μg/ml; (b) IA-2 at 0.8 μg/ml and 1.6 μg/ml; (c) proinsulin at 10 μg/ml and 50 μg/ml. Horizontal lines indicate median values. Red squares denote slow progressors who tested seropositive for a single islet autoantibody at the time of immune cell analysis. *p < 0.05 for slow progressors vs healthy donors (determined using the Mann–Whitney U test). Bgd, background; HD, healthy donors; SP, slow progressors