All of the tests provide indicators, antibodies that are present, genetic markers that predispose us to conditions. These tests alone cannot make a diagnosis. It is the combination of lab work, examinations, symptoms, xrays and MRIs that provide the detail to put together a diagnosis. You might want to consider getting a second or third opinion. See a specialist in AS. Rheumatology is a vast field and sometimes it helps to see someone with more experience in the suspect condition.