POS0777 STUDY OF PERIPHERAL BLOOD B CELL IMMUNO-PHENOTYPING IN PATIENTS WITH LUPUS NEPHRITIS: PARAMETERS OF DISEASE ACTIVITY, REMISSION AND FLARE

Background B cells play a central role in systemic lupus erythematosus (SLE) pathogenesis connecting innate with adaptative immunity. Objectives To investigate the peripheral blood cell phenotype cohort of SLE patients renal involvement (LN-SLE) relation to disease activity and histological lesions compared healthy controls. Methods One hundred LN-SLE active involvement, 40 at onset (Early) 60 whom LN occurred after (Long) were enrolled. Thirty-seven controls included. Clinical, laboratory demographic data collected baseline 6 12 month follow-up. Disease was recorded using SLEDAI-2K. Ultrasound-guided biopsy has been performed for definition nephritic class according ISN/RPS classification. The memory immunophenotyping (IgD/CD27 classification) analyzed through flow cytometry. clarify key molecules activation, IL-6 BAFF serum levels assayed by Enzyme-linked immunosorbent assay (ELISA). Results According symptoms, there no differences distribution classes chronicity indices two groups. A direct correlation observed between index score creatinine whole (R=0.342; p < 0.01 ) Early (R=0.528; = Long (R=0.337; p=0.02 ). found be significantly higher anti-dsDNA positive than negative ones (6.6±4.8 vs 2.8±3.5; p=0.01 ), least one antiphospholipid antibody-APL positivity (6.8±4.8 5.1±4.8; p=0.05 Considering predictive biomarkers remission within months, presence (glomerulosclerosis fibrocellular crescents) APL antibodies associated failure achieving clinical remission, while 24h-UP ≤2750mg achievement [OR:2.6(95%CIs:1.1-5.8)]. Studying subset, lower percentage CD19 pos unswitched (IgD CD27 (6.8±5.5% 10.5±3.5%; p<0.01 11.1±12.0% 15.3±8.0%; 0.01, respectively) observed. In addition, we double-negative neg plasmablasts (CD27 CD38 [(CD27 IgD 10.0±8.7% 4.1±1.9%; )(CD27 4.4±5.3% 1.0±0.5%; )]. Furthermore, negatively correlated [(R=-0.327; p=0.03 R=-0.305; p=0.04 respectively] (R=0.302; <0.01). No subsets parameters. status months both groups had frequencies [(Remission:10.7±12.4% )(No-Remission:9.8±9.5% )] conversely rate [(Remission:11.5±10.0% ;NoRemission:9.6±6.7% ] [(Remission 5.2±6.7% 1.0±0.5; p=0.05; NoRemission:4.1±3.4 Conclusion This study suggests that injury chronic damage features do not depend on duration per se , but could months. reveals distinct subset when controls, confirming an alteration strengthening hypothesis pathogenetic played lymphocytes course LN. References [1]Obris că et al . Int J Mol Sci 2021;22(7):3766. [2]Zhu L al. Clin Rheumatol 2018;37(1):205-212. Disclosure Interests None declared