AB0733 Which Chronic Back Pain (CBP) Characteristics Are Associated with A Positive HLA-B27 in Patients with Suspected Axial Spondyloarthritis (AXSPA)? Results from the Esperanza Cohort

Background CBP is nowadays the starting point for the ASAS classification criteria for axSpA. Later, two possible entry criteria based on complementary examinations (HLA-B27 and imaging) are considered. However, CBP is a very prevalent symptom so it is necessary to identify those characteristics more likely resulting in a positive complementary test. Objectives To evaluate which inflammatory characteristics of CBP are associated with the presence of HLA-B27 in patients with suspected axSpA. Methods Baseline dataset from the EsPeranza cohort ( Results A total of 270 (41%) patients were HLA-B27+. Table shows results for the association between individual and combined IBP characteristics with HLA-B27+. Awakening at 2nd half of night (OR=1.53;p Conclusions Awakening at second half of night and good response to NSAIDs are both related to positive HLA-B27 in patients with suspected axSpA although they are less specific than the existing criteria to define IBP. The most specific criteria for a positive HLA-B27 are the ASAS criteria. Acknowledgements The EsPeranza Program has been supported by an unrestricted grant from Pfizer Disclosure of Interest None declared DOI 10.1136/annrheumdis-2014-eular.1814