How do you approach incidental NXP-2 antibody positivity in patients without current clinical evidence of myositis or systemic autoimmune disease?

A positive anti-NXP2 antibody in an asymptomatic patient may indicate either a false positive or a subclinical form of dermatomyositis. The initial step is to review the testing method (e.g., ELISA, immunoblot). If possible, confirm the result with a different assay, ideally immunoprecipitation, tho...

Likely false +, but the question is, why was it tested? If + by 2 different labs or high titer, then watch the patient clinically for future development of autoimmunity. Otherwise, it is likely false +.