Cut-off matters in the interpretation of myositis antibodies by line immunoassay

Establishment of local cut-offs and cross-reference ANA findings can significantly enhance the assay's performance and increase the confidence in interpreting MAs results by LIA. It is important to be aware of the low PPV for most MAs in real-world cohorts; thus, the investigation of MAs should be approached as confirmatory or differential diagnosis rather than a screening tool in IIMs.