Table 1.

Number of sera samples tested on ELISA for both case samples and health controls (HC) and the number of samples with a co-efficient variance of equal to or less than 20%.

Autoantibody	+MSA Sample Number	HC Sample Number	+MSA sample with ++CV ≤20%	HC sample with ++CV ≤20%	Pre-defined positive cut-off (au)
Mi2	20	63	19	63	53
MDA5	20	63	20	62	32
ARS* MSA	76	120	70	100	25
Jo1	22	66	21	61	25
EJ	10	54	7	50	25
KS	3	47	2	47	25
PL-7	21	65	21	60	25
PL-12	20	64	19	58	25

^*Aminoacyl tRNA synthetase myositis specific antibodies combined (Jo1, EJ, KS, PL7, PL12).

⁺Myositis specific antibody samples.

⁺⁺Co-efficient of variation.