FRI0167 LONG TERM CLINICAL OUTCOME IN SYSTEMIC LUPUS ERYTHEMATOSUS PATIENTS FOLLOWED FOR MORE THAN 20 YEARS IN THREE ITALIAN TERTIARY REFERRAL CENTERS: THE MILAN SYSTEMIC LUPUS ERYTHEMATOSUS CONSORTIUM (SMILE) COHORT

Abstract

Background:the prognosis of Systemic lupus Erythematosus (SLE) patients has significantly improved over time, raising the need for more data about disease activity and damage accrual in the long term.Objectives:to investigate the risk of long term disease activity and to identify viable prognostic markers for disease flares in SLE patients with long standing diseaseMethods:data on SLE patients regularly followed at ASST PINI-CTO, Fondazione Ca’ Granda Policlinico and Ospedale San Raffaele, Milan (Milan Systemic Lupus Erythematosus Consortium, SMiLE, cohort) with disease duration ≥ 20 years, were retrospectively analyzed. Organ involvement as per the British Isles Lupus Assessment Group (BILAG) definitions was recorded along with achievement of clinical and complete remission (CR and CCR: clinical SLEDAI =0, PGA <0.5 and no prednisone or immunosuppression ± negative serology) and lupus low disease activity state (LLDAS) at 15 (T15) and 20 (T20) years of follow up. Damage accrual was estimated according to the SLE International Collaborating Clinics/American College of Rheumatology damage index (SDI).Results:data from 168 patients (table 1) were available for analysis. Remission (CR+CCR) and LLDAS were achieved in 22% and 61% at T15 and 25% and 71% at T20. LLDAS was not associated with a history of involvement in any BILAG domain, but it was inversely associated with treatment with mycophenolate at any time (50 vs 23% treated vs not treated; p=0.02). SDI>0 was found in 49% patients at T15 and in 71% at T20. LLDAS at T15 was associated with lower flare rates in the following five years (HR= 0.395, 95%, CI=0.239-0.653; Figure, left panel; p<0.001). The risk of flaring for LLDAS was largely comparable to CCR and CR (Figure, middle panel). In the T15-T20 timeframe, 37% of patients had a flare. Patients with both low complement and anti-dsDNA positivity at T15 had an increased risk of flaring compared to serologically inactive patients (HR=2.86, 95%, CI=1.572-5.19; Figure right panel). Flaring patients were more likely to show an increase in SDI from T15 to T20 (37% vs 9% in patients with stable SDI; p<0.001)Table 1.Demographic, laboratory and clinical characteristics of patients with SLECharacteristics(n=168)Demographic characteristicsFemale, n (%)150 (89.3)Age at diagnosis years, median (IQR)24 (18-32)Clinical and serological features during 15 years follow up, n (%)Musculoskeletal140 (83)Mucocutaneous135 (80)Constitutional114 (68)Haematological103 (61)Nephritis81 (48)Cardiopulmonary49 (29)NPSLE31 (18)Positive anti-dsDNA136 (81)Hypocomplementemia136 (81)Positive antiphospholipid73 (44)CR / CCR at T1513 (8) / 23 (14)CR / CCR at T2017 (10) / 25 (15)Conclusion:LLDAS is common in SLE patients with long disease duration although up to 37% of patients with 15-year disease duration may experience a flare during the following 5 years. The flare risk increases with failure to attain LLDAS at T15 and with active serology. Late flares associate with damage accrual.