Table 3:

Results of index values.

	GADA-Index	COVID-19A-Index	IA-2A-Index	TGA-Index	ZnT8A-Index	IAA-Index
GADA high PC	1.000	1.0	0.000	0.001	0.004	0.001
GADA low PC	0.285	0.4	0.004	0.002	0.001	0.003
COVID-19A high PC	0.001	100.0	0.001	0.002	−0.001	−0.001
COVID-19A low PC	0.014	10.6	−0.001	0.001	0.000	0.000
IA-2A/ZnT8A PC	0.009	−0.3	1.000	0.003	1.000	0.001
TGA PC	0.018	0.0	0.003	1.000	−0.001	0.001
IAA high PC	0.002	0.1	−0.002	0.000	0.003	1.000
IAA low PC	0.002	−0.2	0.001	0.002	0.005	0.023
NC	0.000	0.0	0.000	0.000	0.000	0.000
sample1	0.424	0.0	−0.003	0.000	0.001	−0.002
sample2	−0.001	0.0	0.109	0.001	0.000	0.000
sample3	0.000	0.0	−0.002	1.355	−0.001	−0.001
sample4	−0.001	324.2	0.000	0.000	0.000	−0.001
sample5	0.001	−0.2	0.001	0.000	0.586	−0.001
sample6	−0.001	−0.2	−0.002	0.000	0.000	0.026
sample7	0.066	−0.2	0.224	0.000	0.010	0.032
sample8	−0.002	0.0	−0.004	0.001	−0.001	0.001
sample9	−0.001	0.0	−0.001	0.089	−0.001	0.038
sample10	−0.001	−0.1	−0.003	−0.001	0.000	0.001
sample11	0.003	0.1	0.105	0.000	0.000	0.000
sample12	0.001	0.0	−0.003	0.000	0.000	0.001
sample13	−0.002	202.5	0.001	0.000	−0.001	0.001
sample14	0.059	493.6	−0.002	0.000	−0.001	−0.001
sample15	−0.001	−0.2	−0.001	0.003	−0.002	0.000

Index values for each sample for all six antibodies were calculated against the corresponding positive and negative controls. An index value greater than the cutoff value was defined as positive, marked in dark bold. The bad duplicate CPS values in Table 1, row Dlinker 3-columns 5 and 6, led to a positive IA-2A index value of sample 11 (highlighted in grey), which was probably a falsepositive result.