POS1476 AUTOANTIBODY TRAJECTORIES ASSOCIATE WITH CLASSIFICATION AND TREATMENT RESPONSE IN LUPUS NEPHRITIS

Background Autoantibodies are a hallmark of lupus nephritis (LN). While there is known heterogeneity in autoantibody expression among LN patients, the association autoantibodies with subtypes and implications longitudinal changes not entirely understood. Objectives In this study, we quantified circulating Accelerating Medicines Partnership (AMP) cohort to identify novel serum biomarkers classification treatment response provide insights into pathogenesis LN. Methods SLE patients meeting ACR or SLICC criteria (n=268) indicated for kidney biopsy by urine protein/creatinine (UPCR) > 0.5 were recruited study as part AMP. Kidney biopsies evaluated renal pathologist according ISN/RPS classification, samples collected at time diagnostic 3-, 6-, 12-months post-biopsy. Serum against dsDNA, chromatin, ribosomal-P, Ro, La, Sm, SmRNP, RNP, Jo-1, Scl-70, centromere-B measured using BioPlex 2200 ANA kit (Bio-Rad Technologies, Hercules, CA), while anti-C1q positivity was determined ELISA (QUANTA Lite, Werfen, Bedford, MA). Clinical 12 months Abatacept Cyclophosphamide Combination Efficacy Safety Study definitions class III, IV, V, combination thereof baseline UPCR ratio >1.0. Results Most exhibited chromatin (78%) dsDNA (70%), SmRNP (63%), C1q (56%), RNP (54%), Sm (52%) (Figure 1A). Patients proliferative (class III+V, IV+V) had higher rates several autoantibodies, including those C1q, compared membranous V) Similarly, pure III IV) mixed III+V significantly titers these mesangial I II), membranous, advanced sclerosis VI) 1B-D). Furthermore, increased associated odds having Proliferative complete significant decline anti-dsDNA, Smith, ribosomal P 1F). Autoantibody levels remained relatively stable partial- non-responder well Figure 1. Conclusion exhibit heterogeneous profiles classification. Specifically, may serve noninvasive but LN, many routinely over time, such anti-Sm, response, suggesting possible role pathogenesis. addition, early response. REFERENCES: NIL. Acknowledgements: Disclosure Interests None Declared.