FRI0577 ANTIPHOSPHOLIPID SYNDROME SECONDARY TO PEDIATRIC SYSTEMIC LUPUS ERYTHEMATOSUS. EXPERIENCE IN A THIRD-LEVEL HOSPITAL IN MEXICO CITY
Authors: Erika Sifuentes, Alejandra Ramirez, M. A. Yamazaki-Nakashimada, F. Rivas-Larrauri
Journal: Annals of the Rheumatic Diseases (2019)

<h3>Background</h3> Antiphospholipid syndrome (APS) is a multisystemic autoimmune disease that is characterized by thromboembolic events, pregnancy morbidity and other manifestations in the presence of elevated titers of antiphospholipid antibodies.(1) APS can be either primary, occurring as an isolated clinical entity, or secondary to other diseases including infections, malignancy or autoimmunity, the latter associated in particular with systemic lupus erythematosus (SLE).(1) Patients with SLE can produce a great variety of autoantibodies, including the so called antiphospholipid antibodies (aPLs), such as lupus anticoagulant (LA); anti-cardiolipin antibodies (aCL) or anti-β<sub>2</sub>Glycoprotein-I antibodies (anti-β<sub>2</sub>GPI).(2) These aPLs have been described in 20-40% of SLE patients. <h3>Objectives</h3> To report frequency of patients with antiphospholipid syndrome secondary to pediatric systemic lupus erythematosus (pSLE) at National Institute of Pediatrics in Mexico City from 2005-2016. In addition, describe their clinical manifestations and laboratory features. <h3>Methods</h3> Retrospective study that included all pediatric systemic lupus erythematosus (pSLE) patients diagnosed at National Institute of Pediatrics in Mexico City from 2005 to 2016. We then identified patients with positive antiphospholipid antibodies (aPLs) and/or clinical manifestation of antiphospholipid syndrome (APS). Demographic, clinical and laboratory features were extracted from their clinical records. Study approved by the local Ethics Committee. <h3>Results</h3> Over the 12-year study period, we collected 295 patients with a new diagnosis of pediatric systemic lupus erythematosus (pSLE). Eighty patients (27.11%) had at least a positive antiphospholipid antibody (aPL) or a clinical manifestation of antiphospholipid syndrome (APS). Figure 1 shows our study population. Of these 80 patients, 75 (93.75%) had a positive aPL at moment of pSLE. With respect to the remaining 5 cases, 3 of them developed a positive aPL during follow-up, while the remaining 2 cases presented a clinical feature of APS simultaneously to pSLE diagnosis and their serology persisted negative during follow-up. Twenty (25%) patients had a clinical manifestation associated to APS. Concerning these patients, 11 (55%) patients presented clinical features of APS at time of pSLE diagnosis, 6 (30%) patients developed it during follow-up and the remaining 3 (15%) patients had previous history of a clinical manifestation associated to APS prior to pSLE diagnosis. Nevertheless, 2 of these 20 patients never reported positive antiphospholipid antibodies. According to clinical manifestations 11 (55%) patients had venous thrombosis, 7 (35%) patients with arterial thrombosis, one patient identified with chorea and one showed evidence of thrombosis in a skin biopsy. Characteristics of the patients are shown in Table 1. <h3>Conclusion</h3> Antiphospholipid syndrome (APS) secondary to pediatric systemic lupus erythematosus (pSLE) is a very common entity and is increasingly diagnosed. This study allowed us to report frequency and describe clinical manifestations of pSLE patients presenting with secondary APS from Mexico City. Antiphospholipid antibodies (aPLs) were positive in 27% of cases with pSLE. And more than 90% of cases had positive aPLs at moment of pSLE diagnosis, which is why we strongly agree with international recommendations of performing aPLs screening simultaneously to pSLE diagnosis. <h3>References</h3> [1] Meroni PL, Argolini LM, Pontikaki I, P.l M, L.m A, I P. What is known about pediatric antiphospholipid syndrome?Expert Rev Hematol. 2016;9(10):977–85. [2] Taraborelli M, Lazzaroni MG, Martinazzi N, Fredi M, Cavazzana F. The role of clinically significant antiphospholipid antibodies in systemic lupus erythematosus. Reumatismo. 2016;68(3):137–43. <h3>Disclosure of Interests</h3> None declared