OP0092 OPTIMIZING A DEFINITION OF LUPUS LOW DISEASE ACTIVITY STATE (LDA) FOR DAILY CLINICAL PRACTICE: SLE-DAS LDA VS LLDAS

Abstract

Background:The Lupus Low Disease Activity State (LLDAS)[1] is a proposed target for the management of Systemic Lupus Erythematosus (SLE). However, the LLDAS definition is cumbersome to apply, as it requires comparison with manifestations in the previous visit, scoring of Systemic Lupus Erythematosus disease activity index (SLEDAI), Physician Global Assessment (PGA), treatment conditions and exclusion of additional features. The SLE disease activity score (SLE-DAS)[2] is a validated continuous measure with higher sensitivity to change and validity in predicting damage accrual as compared to SLEDAI-2K. SLE-DAS is quickly quantified with its online calculator. The SLE-DAS low disease activity (SLE-DAS LDA) was recently defined [3] and it is easier to apply than the LLDAS.Objectives:To compare the performance of SLE-DAS and LLDAS for defining LDA state in a real-life clinical setting.Methods:Cross-sectional study of SLE patients fulfilling ACR’97 and/or SLICC’12 classification criteria followed at an academic lupus clinic, from January to December 2019. Fulfillment of LLDAS and SLE-DAS LDA state was verified for each patient. The SLE-DAS LDA state was defined as (1) SLE-DAS ≤3.77[3] with (2) prednisolone dose ≤7.5 mg/day. The proportion of cases in LDA state using LLDAS and SLE-DAS LDA was compared with McNemar’s test. Agreement between LLDAS and SLE-DAS LDA was tested with Cohen’s Kappa coefficient.Results:We included 292 patients (86.6% female, mean age: 48.7±14.4 years, mean disease duration: 14.4±9.3 years). From these, 245 (83.9%) and 248 (85%) were in LDA according to LLDAS and SLE-DAS LDA, respectively. There was no statistically significant difference between LLDAS and SLE-DAS LDA (p=0.581 regarding the identification of patients in LDA. Agreement between these two sets of criteria was almost perfect (k=0.831, p<0.01).There were 13 discordant cases, fulfilling only the SLE-DAS LDA (n=8) or the LLDAS (n=5), and their manifestations of disease activity (excluding serologic features) are summarized in table 1.Patients fulfilling only SLE-DAS LDANumber of casesPGA (range)Active clinical manifestations (range)SLEDAI-2K (range)SLE-DAS (range)Prednisolone (range, mg/day)60.1-0.2Leukopenia 2.2-2.7x10^9/L1-31.46-3.030-2.520.2-0.3Thrombocytopenia 71-96x10^9/L1-31.97-2.860-5Patients fulfilling only LLDASNumber of casesPGA(range)Active clinical manifestations(range)SLEDAI-2K(range)SLE-DAS(range)Prednisolone(range, mg/day)20.2-0.4Arthritis (2-4/28 swollen joints)44,41-5.310-510.5Panniculitis (face and torso)35,53010.1Generalized rash45,01510.4Leukopenia 2.1x10^9/L Thrombocytopenia 62x10^9/L24,990Conclusion:A LDA state, by either definition, was achieved by most patients in this real-life setting. LLDAS and SLE-DAS LDA identify almost exactly the same population. The SLE-DAS LDA definition is easier to apply and hence might be the optimal definition for use in daily clinical practice.