FRI0224 PREVALENCE OF SJÖGREN’S SYNDROME IN THE COMMUNITY OF MADRID
Authors: Jaime Barrio Cortes, Tomás Gómez Gascón, Mͣ Dolores Esteban Vasallo, Isabel Del Cura González, Juan Antonio López Rodríguez, Ana Clara Zoni, María Felicitas Domínguez Berjón
Journal: Annals of the Rheumatic Diseases (2019)

<h3>Background:</h3> Several studies on the epidemiology of autoimmune diseases performed within the past several decades revealed a prevalence of Sjögren Syndrome (SS) between 0.3% and 4.83% (1). More recent studies revealed a lower prevalence between 31/100,000 to 49/100,000 (2 3). The exact prevalence of SS is unknown due to the heterogeneity of the populations and geographic areas studied, the utilization of different diagnostic tests or the lack of a unique classification criteria for the disease. Also, the disease may have an insidious onset and a variable course with a broad spectrum of clinical manifestations, so the diagnosis may be delayed or SS patients may be missed and misclassified as other rheumatic disease. Besides, SS can occur alone (primary SS) or in association with other specific systemic autoimmune rheumatic diseases (secondary SS). <h3>Objectives:</h3> The aim of our study was to determine the prevalence of SS in the Community of Madrid (CM) and to describe the sociodemographic and clinical characteristics of these patients. <h3>Methods:</h3> Population-based cross-sectional study in the CM, Spain. The information source for SS cases was the Registry of rare diseases in the CM (SIERMA). A descriptive analysis of the main sociodemographic and clinical characteristics of SS cases was performed. Prevalence per 10,000 inhabitants in people with 18 years of age and over, stratified by sex and their 95% confidence intervals (CI) were calculated for 2015. The denominator was the people registered at the Population Register in the middle of the period (July 2015). <h3>Results:</h3> There were 4,778 cases of SS in SIERMA and 389 (8,1%) of them were already dead. 4434 (92.8%) were women. The median age was 64,7 years (15,4), and the maximum age was 103 years. The disease was most frequent in the sixth decade with 1079 cases (22,6%), in the seventh decade with 1120 cases (23,4%) and in the eighth decade with 935 cases (19,6). 3116 cases (65.2%) were classified as primary SS (pSS) and 1662 (34.8%) as secondary SS (sSS). Among the sSS the main rheumatological conditions associated were rheumatoid arthritis (58%), lupus (24,5%), systemic Sclerosis (10,5%); mixed connective tissue (4%), inflammatory muscle disease (2%) and vasculitis (1%). The prevalence of SS in adults (≥ 18 years of age) was 8.4/10,000 with a 95% CI: 8.2 – 8.7 (14.9% in women and 0,8% in men). The prevalence of pSS was 5.5/10,000 (CI 5,3 – 5,7) and for sSS was 2.8/10,000 (95%CI: 2.7-3). <h3>Conclusion:</h3> SS mainly affects females during the sixth, seventh and eight decades of life, and shows a female:male ratio of 9:1. Two out of three cases of SS identified were classified as pSS. The main rheumatological conditions associated were rheumatoid arthritis and lupus. The estimated prevalence of SS in the Community of Madrid population is lower than the observed in previous studies whereas the prevalence of pSS is similar than the observed in current studies. <h3>References:</h3> [1] Toms M, Logar D, Grmek M, Perkovic T, Kveder T. Prevalence of Sjögren's syndrome in Slovenia. Rheumatology. 1999;38:164–70. [2] Sardu C, Cocco E, Mereu A, Massa R, Cuccu A, Marrosu MG, et al. Population Based Study of 12 Autoimmune Diseases in Sardinia, Italy: Prevalence and Comorbidity. Ashour HM, editor. PLoS One [Internet]. 2012 Mar 2;7(3):e32487. Available from: http://dx.plos.org/10.1371/journal.pone.0032487 [3] Prevalencia de las enfermedades raras: Datos bibliográficos », Informes Periódicos de Orphanet, Serie Enfermedades Raras, Enero 2019, Número 1 : Listado por orden alfabético de enfermedades o grupo de enfermedades http://www.orpha.net/orphacom/cahiers/docs/ES/Prevalencia_de_las_enfermedades_raras_por_orden_alfabetico.pdf <h3>Disclosure of Interests:</h3> None declared