秧猪胆吸虫（Ov）感染可引发包括胆道进化性间质纤维化（APF）和最严重的并发症胆管细胞癌（CCA）在内的几种胆管疾病表现。单核细胞迁移到感染部位并分化为组织巨噬细胞，表达和释放细胞因子、活性氧物质和生长因子等分子。TLR4+单核细胞被归类为具有促肿瘤表型，分泌促进肿瘤的因子。本研究旨在研究单核细胞在棘吸虫病发病机制中的作用。我们运用流式细胞术测量了Ov感染携带或不携带APF的患者周围血液中TLR4+单核细胞的数量，并与健康非Ov感染的对照组进行了比较。我们首次发现，与无纤维化患者和健康个体相比，APF患者循环TLR4+单核细胞数量增高。有趣的是，当我们测量这些单核细胞的活性氧物质时，发现APF患者的ROS产量增加。我们推测，这些TLR4+单核细胞过度产生ROS可能导致周围组织过度损伤，从而促进胆道进化性间质纤维化发展的病理过程。 版权所有（c）2023 Kanin Salao，Chakrit Thapphan，Tran Duong Thai，Kiatichai Faksri，Sutas Suttiprapa，Sirikachorn Tangkawattana，Banchob Sripa B，Steven W Edwards。

Opisthorchis viverrini (Ov) infection can lead to several disease manifestations of the bile duct including advanced periductal fibrosis (APF) and the most severe complication, cholangiocarcinoma (CCA). Monocytes migrate to the infection site and differentiate into tissue macrophages to express and release molecules such as cytokines, reactive oxygen species, and growth factors. TLR4+ monocytes are classified as having a pro-tumor phenotype and secrete tumor-promoting factors. The aim of this study is to investigate the role of monocytes in the pathogenesis of opisthorchiasis.We used flow cytometry to measure the number of TLR4+ monocytes in the circulating blood of Ov infected patients with or without APF compared to healthy, non-Ov-infected controls.We found, for the first time, that patients with AFP have elevated numbers of circulating TLR4+ monocytes when compared to patients without fibrosis and healthy individuals. Intriguingly, when we measured ROS from these monocytes, we found increased ROS production in patients with APF.We propose that excessive production of ROS from these TLR4+ monocytes may lead to excessive injury of surrounding tissue and hence contribute to the pathological processes that lead to the development of advanced periductal fibrosis.Copyright (c) 2023 Kanin Salao, Chakrit Thapphan, Tran Duong Thai, Kiatichai Faksri, Sutas Suttiprapa, Sirikachorn Tangkawattana, Banchob Sripa B, Steven W Edwards.