Servicio de Farmacología Clínica and UGC Aparato Digestivo, Instituto de Investigación Biomédica de Málaga-IBIMA, Hospital Universitario Virgen de la Victoria, Universidad de Málaga, Málaga, Spain.
Centro de Investigación Biomédica en Red en el Área Temática de Enfermedades Hepáticas y Digestivas (CIBERehd), Madrid, Spain.
Clin Pharmacol Ther. 2021 Dec;110(6):1604-1612. doi: 10.1002/cpt.2423. Epub 2021 Oct 3.
The identification of specific HLA risk alleles in drug-induced liver injury (DILI) points toward an important role of the adaptive immune system in DILI development. In this study, we aimed to corroborate the role of an adaptive immune response in DILI through immunophenotyping of leukocyte populations and immune checkpoint expressions. Blood samples were collected from adjudicated DILI (n = 12), acute viral hepatitis (VH; n = 13), acute autoimmune hepatitis (AIH; n = 9), and acute liver injury of unknown etiology (n = 15) at day 1 (recognition), day 7, and day >30. Blood samples from patients with nonalcoholic fatty liver disease (NAFLD; n = 20) and healthy liver controls (HLCs; n = 54) were extracted at one time point. Leukocyte populations and immune checkpoint expressions were determined based on cell surface receptors, except for CTLA-4 that was determined intracellularly, using flow cytometry. At recognition, DILI demonstrated significantly higher levels of activated helper T-cell (P < 0.0001), activated cytotoxic T-cells (P = 0.0003), Th1 (P = 0.0358), intracellular CTLA-4 level in helper T-cells (P = 0.0192), and PD-L1 presenting monocytes (P = 0.0452) than HLC. These levels approached those of HLC over time. No significant differences were found between DILI and VH. However, DILI presented higher level of activated helper T-cells and CTLA-4 than NAFLD and lower PD-L1 level than AIH. Our findings suggest that an adaptive immune response is involved in DILI in which activated CD4+ and CD8+ play an important role. Increased expression of negative immune checkpoints is likely the effect of peripheral tolerance regulation.
在药物性肝损伤 (DILI) 中，特定 HLA 风险等位基因的鉴定表明适应性免疫系统在 DILI 发展中起着重要作用。在这项研究中，我们旨在通过白细胞群体和免疫检查点表达的免疫表型来证实适应性免疫反应在 DILI 中的作用。在第 1 天（识别期）、第 7 天和第 >30 天，从经裁决的 DILI（n=12）、急性病毒性肝炎（VH；n=13）、急性自身免疫性肝炎（AIH；n=9）和原因不明的急性肝损伤（n=15）患者中采集血液样本。还在一个时间点从非酒精性脂肪性肝病（NAFLD；n=20）患者和健康肝对照（HLC；n=54）中提取血液样本。基于细胞表面受体，使用流式细胞术确定白细胞群体和免疫检查点表达，除了 CTLA-4 是在细胞内确定的。在识别期，与 HLC 相比，DILI 表现出显著更高水平的活化辅助性 T 细胞（P<0.0001）、活化细胞毒性 T 细胞（P=0.0003）、Th1（P=0.0358）、辅助性 T 细胞中的细胞内 CTLA-4 水平（P=0.0192）和 PD-L1 呈递单核细胞（P=0.0452）。这些水平随着时间的推移而接近 HLC。在 DILI 和 VH 之间未发现显著差异。然而，与 NAFLD 相比，DILI 表现出更高水平的活化辅助性 T 细胞和 CTLA-4，而 PD-L1 水平低于 AIH。我们的研究结果表明，适应性免疫反应参与了 DILI，其中活化的 CD4+和 CD8+发挥了重要作用。负免疫检查点的表达增加可能是外周耐受调节的结果。
