Referral strategies for early diagnosis of axial spondyloarthritis.

The spectrum of HLA-B27-associated inflammatory spine diseases is referred to as axial spondyloarthritis (axSpA). AxSpA encompasses established ankylosing spondylitis (AS) but also nonradiographic axSpA, and can be classified according to the Assessment of SpondyloArthritis international Society classification criteria for axSpA. Specific and effective therapy for axSpA includes education, physiotherapy, NSAIDs and biologic agents, as appropriate. Patients with axSpA, however, are often diagnosed late in the course of the disease. As specific therapy is available, the effective identification of those individuals who are likely to have axSpA among patients with chronic back pain in primary care and their subsequent referral to a rheumatologist for establishing a correct diagnosis is worth pursuing. Candidate referral parameters that can easily be applied to patients with chronic back pain and age at onset ≤ 45 years (the target population) include inflammatory back pain (IBP) and positivity for HLA-B27. Following diagnostic work-up by a rheumatologist, these referral parameters, either alone or in combination, have led to the diagnosis of as many as 33-45% of patients within this target population with axSpA, 41-62% of whom had undiagnosed AS. Thus, educating primary care physicians on the value of IBP and HLA-B27 testing within this target population, and referral to a rheumatologist if one of these parameters is positive, is a promising approach to reduce the long delay in diagnosing patients with axSpA.