P62 Poly-autoimmunity frequency in SLE patients from a tertiary hospital

Background/Purpose Poly-autoimmunity (PAI) is the presence of more than one Autoimmune Disease (AID) in one patient. The coexistence of Systemic Lupus Erythematosus (SLE) with other AIDs is a clinical challenge due to is one of the issues not yet elucidated in medical practice. We aimed to determine PAI frequency in the context of SLE patients reported in a tertiary hospital. Methods Cross-sectional observational study with systematic revision of electronic clinical records of SLE patients with other AIDs (from 2014 to 2018) was performed. Demographic, clinical and immunological data were collected. Results Of 261 SLE patients, 48 (18.39%) had PAI. Mean age was 51.19 (15.35) years (93.75% were female). 2 patients from the 48 (4.16%) had PAI with three AIDs. The 75% of cases developed SLE as the first AID. The mean age at diagnosis of the first AID was 35.52 (15.33) years and mean age at diagnosis of the second AID was 43.75 (16.31) years. A mean difference of 8.31 (9.24) years between the first and second AIDs debut was observed. The most frequent AIDs registered that go along with SLE are Antiphospholipid Syndrome (APS)(39.58%), Sjogren Syndrome (SS)(31.25%), and Rheumatoid Arthritis (RA) (16.67%). Moreover, in two cases a third AID was registered: SLE-SS-APS and SLE-APS-autoimmune-thyroiditis. In the SLE-APS group, SLE was the AID of debut in the 89.47% of cases, instead of SLE-RA group with a 62.5%. The SLE-APS group showed a 47.37% of cases with positive antiphospholipid antibodies and 64.71% positive lupus anticoagulant. In the SLE-RA group a 71.43% and 66.67% positive rheumatoid factor and antiCCP antibody was reported. Conclusions 18.39% of patients with PAI in our group of SLE patients was observed, mostly with the SLE as the first AID developed. The most frequent association of AIDs in SLE cases were with APS, SS and RA.