With chronic inflammatory diseases such as arthritis affecting the spine, a major clinical problem is that disease can advance over years with unrecognized persisting inflammation. Recently, we discovered that elevated concentration of certain substances in blood considered together, are highly associated with persisting local inflammation. This study will use data gathered from the blood chemistry analysis of 286 spinal arthritis patients followed for up to 12 years. Artificial Intelligence techniques will be used to help discern and analyze the data patterns in ways superior to previous methods. Patterns observed with the highest associations with persistent inflammation will be used to develop a suite of lab tests to assist diagnosis, define intensity of persisting inflammation and patients’ responses to drug therapy. It is envisaged that a successful suite of tests could also be used to assess presence and amount of inflammation in other chronic diseases such as chronic inflammatory bowel disease.