Axial spondyloarthritis criteria and modified NY criteria: issues and controversies

The Assessment of Spondyloarthritis International Society (ASAS) classification criteria for axial spondyloarthritis (axSpA) developed in 2009 was a major step forward, since the 1984 modified New York (mNY) criteria for classification of ankylosing spondylitis (AS) were too insensitive to identify patients with early signs of axial inflammation. In the absence of “diagnostic” criteria for either axSpA or AS, both of these “classification” criteria are routinely used in clinical practice to diagnose patients. However, there is a real danger of “misdiagnosis” if classification criteria are applied erroneously by ticking “yes” or “no” boxes in an undiagnosed patient. This concern was raised and discussed at the FDA Arthritis Advisory Committee meeting in June 2013, and the committee warned that if TNF inhibitors are approved to treat axSpA, such misdiagnosis could lead to serious consequences. To gauge the SPARTAN members’ familiarity with these criteria and these issues surrounding them, as well as to investigate how they are using these criteria in daily practice, two questionnaires (one each for mNY and ASAS axSpA criteria) were sent to the “full” members of SPARTAN before the annual meeting. The results showed that more than 60 % of the responders used these criteria most of the time in practice to help them diagnose a patient, and nearly three fourth of responders agreed with the FDA Advisory Committee and would like to see some objective signs before prescribing TNF inhibitors to axSpA patients. A majority of responders looked at the sacroiliac joint x-rays themselves to diagnose sacroiliitis, even though they had difficulty in grading the x-rays. In a live vote at the meeting, 88 % of the members suggested that SPARTAN should engage in either modifying the existing criteria or develop new diagnostic criteria for axial spondyloarthritis.