Department of Rheumatology and Clinical Immunology, Graduate School of Medicine, Kyoto University, Kyoto, Japan.
Department of Advanced Medicine for Rheumatic Diseases, Graduate School of Medicine, Kyoto University, Kyoto, Japan.
Mod Rheumatol Case Rep. 2024 Jul 8;8(2):314-317. doi: 10.1093/mrcr/rxae016.
Avacopan, an orally administered C5a receptor antagonist, is effective in microscopic polyangiitis via the inhibition of neutrophil priming induced by C5a. However, the exact effect of avacopan on the production of myeloperoxidase antineutrophil cytoplasmic antibody (MPO-ANCA) is yet to be clearly established. This report presents a microscopic polyangiitis patient without major organ damage where high levels of MPO-ANCA persisted with high-dose steroid therapy and azathioprine, but the addition of avacopan led to a reduction in MPO-ANCA titres. The present case implies that avacopan-mediated inhibition of C5a may lead to a reduction in MPO-ANCA levels, thereby potentially ameliorating the pathophysiology of ANCA-associated vasculitis. Nevertheless, the impact of avacopan on MPO-ANCA production cannot be asserted solely based on this report; therefore, further examination is necessary through subgroup analysis using data from larger-scale studies.
阿伐考帕（一种口服 C5a 受体拮抗剂）通过抑制 C5a 诱导的中性粒细胞的预激活，在显微镜下多血管炎中有效。然而，阿伐考帕对髓过氧化物酶抗中性粒细胞胞质抗体（MPO-ANCA）的产生的确切影响尚未明确。本报告介绍了一例显微镜下多血管炎患者，其无主要器官损伤，大剂量类固醇和硫唑嘌呤治疗后仍存在高水平的 MPO-ANCA，但加用阿伐考帕后 MPO-ANCA 滴度降低。本病例提示 C5a 介导的阿伐考帕抑制可能导致 MPO-ANCA 水平降低，从而可能改善 ANCA 相关性血管炎的病理生理学。然而，不能仅根据本报告就断言阿伐考帕对 MPO-ANCA 产生的影响；因此，需要通过更大规模研究的数据进行亚组分析来进一步检查。
