FC062: Baseline Soluble Immune Checkpoints Predict Relapse Risk in PR3-Anca Vasculitis Following Rituximab Induction Therapy

Abstract BACKGROUND AND AIMS We investigated whether soluble immune checkpoints (sICPs) predict treatment-resistance, relapse risk and risk of infections in patients with antineutrophil cytoplasm antibody (ANCA)-associated vasculitis (AAV). METHOD Plasma levels of sICPs were measured by enzyme-linked immunosorbent assay from samples obtained at baseline and during follow-up from patients with AAV in the RAVE trial and were correlated with selected clinical outcomes. Log-rank test was used to evaluate survival benefits, and optimal cut-off values of the marker molecules were calculated using Yeldons J. RESULTS Among 95 patients receiving rituximab as induction therapy, lower soluble (s)Lag-3 (3000 pg/mL) were predictive of not achieving remission. Among patients with remission, 32.9% relapsed with a median relapse free survival of 5.64 months. Low baseline values of sTim-3 (