Proceedings of the 2024 Childhood Arthritis and Rheumatology Research Alliance (CARRA) Annual Scientific Meeting

NSAIDshort (n=32) NSAIDlong (n=62) Secondline (n=70) P value Overall (n=164) Mean number out of 6 regions affected ( SD) 1.22 ( 0.608) 1.31 ( 0.561) 2.06 ( 1.03) <0.001 1.61 ( 0.890) Symmetric involvement in the same bone, n (%) 5 (16%) 14 (23%) 51 (73%) <0.001 70 (43%) Mean days on NSAID monotherapy, days ( SD) 175 ( 26.5) 725 (512) 441 (536) <0.001 497 (511) Number of NSAIDs Trialed, n (%) <0.001 0 0 (0%) 0 (0%) 2 (3%) 2 (1%) 1 30 (94%) 28 (45%) 17 (24%) 75 (46%) 2 2 (6%) 32 (52%) 45 (64%) 79 (48%) 3 or more 0 (0%) 3 (3%) 6 (9%) 8 (5%) Patients with complications, n (%) Vertebral height loss 0 (0%) 8 (13%) 14 (20%) 0.0215 22 (13%) Amplified pain 0 (0%) 3 (5%) 10 (14%) 0.02 13 (8%) Patients in each disease activity state at study end date, n (%) Active disease 0 (0%) 7 (11%) 14 (20%) 0.024 21 (13%) Inactive disease on treatment 2 (6%) 11 (18%) 20 (29%) 0.0285 33 (20%) Remission 30 (94%) 44 (71%) 36 (51%) <0.001 110 (67%)Table 2 (Abstract A1) Linear regression modeling with AIC-based variable selection comparing the NSAID-short and NSAID-long groups Study Variable Coefficient P-value Unifocal disease at diagnosis -0.386 0.029 Number of regions affected -0.225 0.141 Onset to treatment interval 0.000 0.162 On average, patients with unifocal disease at diagnosis require 47.11% less days of total NSAID monotherapy treatment than patients with multifocal disease at diagnosis.P-values here correspond to a one-way ANOVA for numeric variables and chi-squared test for categorical variables A3 Tubulointerstitial inflammation is associated with end-stage renal disease in pediatric lupus nephritis,