AB0690 ANTIPHOSPHOLIPID ANTIBODIES AND SPONDYLOARTHRITIS. TRUTH OR MYTH? OUR RESULTS IN A THIRD LEVEL HOSPITAL.
Authors: I. González Fernández, C. Álvarez Castro, C. Moriano, E. Diez Alvarez, T. Pérez Sandoval, M. E. Vallejo Pascual
Journal: Annals of the Rheumatic Diseases (2020)

Background: The importance of antiphospholipid antibodies and their clinical involvement in thrombotic phenomena, isolated or associated with certain autoimmune diseases such as systemic lupus erythematosus, is known. However, in spondyloarthritis (SpA) there is little published data about it. Objectives: Identify the presence of antiphospholipid antibodies in patients diagnosed with SpA in the León University Assistance Complex and analyze its possible relationship with different clinical-epidemiological variables. Methods: Prospective observational study between January 1, 2019 and December 31, 2019 with consecutive sampling of patients diagnosed with SpA (New York criteria, ASAS) in our hospital between 1973 and 2018. Anticardiolipin antibodies, anti-B2 glycoprotein and Lupus anticoagulant (AL) were the requested antiphospholipid antibodies excluding cases of positivity for other causes (coagulopathy, liver disease) and repeating the determination at 12 weeks. The disease activity was assessed based on BASDAI and CRP level (taking as a cut-off point 5 mg/l, reference value of our hospital and ruling out elevation due to other intercurrent processes) in the last consultation. An attempt was made to link antiphospholipid antibodies with sex, disease activity, cardiovascular risk factors (CVRF), thrombotic events and taking anti-TNF. Results: 132 patients were included, of which 60.6% were men with a mean age of 49.35 ± 12.95 years. 84.8% were B27 positive. 88.6% met New York criteria. 43.2% had CVRF, highlighting arterial hypertension (HT) in 25%; dyslipidemia (DL) in 24.2%; Obesity in 3.8%, hyperuricemia in 3% and diabetes mellitus (DM) in 2.3%. 43.9% of the patients were being treated with an anti-TNF. Only 25% of patients had elevated CRP levels and 11.4% had BASDAI&gt; 4. 38.7% of the sample had positive antiphospholipid antibodies; of which 58.8% (22.7% of total patients) were confirmed. Of these, AL was the predominant in 90.2% of cases (34.9% of the total number of patients). Likewise, 10% of patients with repeated antiphospholipid antibodies met criteria for antiphospholipid syndrome (thrombi). It was observed in our sample that female sex can behave as a protective factor against the positivity of AL (p 0.002) and that elevated CRP levels show a statistically significant tendency to the presence of AL (since the first positive determination was related with a p 0.013). Conclusion: -According to our results, it seems important to determine antiphospholipid antibodies (especially AL) in patients with SpA, especially in order to avoid future thrombotic events. -There seems to be a trend between disease activity and the probability of presenting positive AL, however, more studies are needed to confirm this hypothesis. -The female sex, in our sample, can be considered a protection factor against this antibody. References: [1]Juanola X, Mateo L, Domench P, Bas J, Contreras Montserrat, Nolla JM, Roig-Escofet D. Prevalence of antiphospholipid antibodies in patients with ankylosing spondylitis . J Rheumatol 1995; 22: 1891-3. Disclosure of Interests: None declared