O-2 role of immune checkpoints and activated helper and cytotoxic t-cells in drug-induced liver injury (dili)

Introduction Idiosyncratic DILI is a challenging condition, believed to involve the immune system. This hypothesis is supported by various identified HLA risk alleles. Objectives To evaluate a potential role of the immune system in DILI through leukocyte immunophenotyping. Methods Blood samples were collected from adjudicated DILI (n=12) and viral hepatitis (VH, 13) at day 1 (recognition), 7 and >30. A single blood sample was extracted from healthy liver controls (HLC, 54). Leukocyte populations and immune checkpoint expressions were determined based on cell surface receptors, except for CTLA-4 that was determined intracellularly, using multiparametric flow cytometry. Results No differences were detected in leukocytes, lymphocytes or neutrophils counts at day 1. However, DILI (0.57 × 10E09/L, p=0.037) and HV (1.41 × 10E09/L, p Conclusion Our findings suggest that an adaptive immune response is involved in DILI in which activated CD4+ and CD8+ play important roles. Increased expression of negative immune checkpoints and ligands reflects restoration of immune homeostasis. Funding:PI16/01748, PI19/00883, CIBERehd-ISCIII