Anti-jo-1 antibody positive(+) without any muscle weak symptoms. muscle enzymes cpk, lungs xray test came back normal. last year diagnosed ulcerative colitis (p-anca+) what could be the reason for anti-jo-1 + without any other clinical symptom?

Cannot be precise, but would discuss with your doctor the possibility of an occult cancer, especially in the lung.

Dr Berman agreed

I wonder what the reason you had this antibody test done. This antibody test may be helpful when you have other features of myositis syndrome or interstitial lung disease but it is not highly specific, i.e. positive result does not mean you have one of these conditions. If the other works-up were negative, you have nothing to concern.