SAT0612 FREQUENCY OF POLYAUTOIMMUNITY IN A TERTIARY HOSPITAL
Authors: Elena Grau García, Jose Ivorra Cortés, Jorge Juan Fragio-Gil, Roxana Gonzalez Mazario, Marta De la Rubia Navarro, Cristobal Pávez Perales, Paloma Valentina Castillo Dayer, Cristina Alcañiz Escandell, Inmaculada Chalmeta Verdejo, Luis Gonzalez Puig, Isabel Martínez Cordellat, Rosa Negueroles Albuixech, Jose Eloy Oller Rodríguez, Francisco Miguel Ortiz Sanjuan, Elvira Vicens Bernabeu, Carmen Nájera Herranz, Inés Cánovas Olmos, Borja García Sousa, Jose Andrés Román Ivorra
Journal: Annals of the Rheumatic Diseases (2019)

<h3>Background:</h3> Polyautoimmunity (PAI) is the presence of more than one Autoimmune Disease (AID) in one patient. PAI have been reported in different AIDs as systemic lupus erythematosus (SLE) (33-45%), rheumatoid arthritis (RA) (13-23%), systemic sclerosis (SSc) (10-43%) or Sjögren Syndrome (SS) (32-52%). On the other hand, Multiple Autoimmune Syndrome (MAS) where three or more AIDs coexisting in one patient has been reported. <h3>Objectives:</h3> To determine PAI frequency in the context of AIDs reported in a tertiary hospital. <h3>Methods:</h3> Cross-sectional observational study with systematic revision of patients' electronic clinical records with AIDs (from 2014 to 2018). We selected those patients who had two or more diagnosis of AIDs. Demographic, clinical and immunological data were collected. <h3>Results:</h3> Of 1854 patients with AIDs, 96 (5.17%) had PAI. Mean age was 56±15 years and 93.75% were female. 7 patients from the 96 (0.4%) also had MAS. The mean age at diagnosis of the first AID was 39.03±15.93 years and mean age at diagnosis of the second AID was 48.16±15.04 years. A mean difference of 9.17±10.18 years between first and second AIDs debut was observed. The most frequent AIDs registered are shown in table 1. Antiphospholipid syndrome (APS), Sjögren syndrome (SS), Systemic lupus erythematosus (SLE), Systemic sclerosis (SSc), Rheumatoid arthritis (RA), Psoriasic arthritis (PsA), Inflammatory bowel disease (IBD), Autoimmune hypothyroidism (AHyp), Celiac disease (CD), Diabetes mellitus type 1 (DM-1), Autoimmune hepatitis (AHep). The most frequent PAI cases registered were RA-SS (N=23), SLE-APS (N=17), SLE-SS (N=11), AR-IBD (N=7), RA-SLE (N=5), RA-CD (N=5), SS-SSc (N=4) and PsA-IBD (N=4). In the total group of 1854 patients with AIDs, SLE with PAI was present in 41 (2.21%) patients, SS with PAI in 42 (2.26%), RA with PAI in 46 (2.48%) and APS with PAI in 23 (1.2%). Moreover, SS was present in the 4.21% of SLE patients and in the 2.48% of RA patients. In contrast, APS was present in the 6.51% of SLE patients, being de of 7.64 (17.62) years the difference between the onset of the first AID and the second AID. In the MAS group an AHyp-SLE-APS in 2 patients was observed, as well as 1 patient with SLE-SS-Aps, 1 with SS-RA-APS, 1 with RA-vasculitis-AHyp and 1 with SS-Ahyp-Ahep. <h3>Conclusion:</h3> A 5.17% frequency of patients with PAI in our group of AID patients was observed, mostly women. APS, SS and SLE respectively were the diseases that most PAI showed. The most frequent association of AID diseases in PAI cases were RA-SS, APS-SLE and SS-SLE. We found a rather lower frequency compared with those published in the literature, possibly due to the putative bias of retrospective studies and the geographical differences of PAI patients. <h3> Disclosure of Interests:</h3> None declared