As the world is severely affected by COVID-19 pandemic, the use of chloroquine and hydroxychloroquine in prevention or for the treatment of patients is allowed in multiple countries but remained at the center of much controversy in recent days. This review describes the properties of chloroquine and hydroxychloroquine, and highlights not only their anti-viral effects but also their important immune-modulatory properties and their well-known use in autoimmune diseases, including systemic lupus and arthritis. Chloroquine appears to inhibit in vitro SARS virus' replication and to interfere with SARS-CoV2 receptor (ACE2). Chloroquine and hydroxychloroquine impede lysosomal activity and autophagy, leading to a decrease of antigen processing and presentation. They are also known to interfere with endosomal Toll-like receptors signaling and cytosolic sensors of nucleic acids, which result in a decreased cellular activation and thereby a lower type I interferons and inflammatory cytokine secretion. Given the antiviral and anti-inflammatory properties of chloroquine and hydroxychloroquine, there is a rational to use them against SARS-CoV2 infection. However, the anti-interferon properties of these molecules might be detrimental, and impaired host immune responses against the virus. This duality could explain the discrepancy with the recently published studies on CQ/HCQ treatment efficacy in COVID-19 patients. Moreover, although these treatments could be an interesting potential strategy to limit progression toward uncontrolled inflammation, they do not appear per se sufficiently potent to control the whole inflammatory process in COVID-19, and more targeted and/or potent therapies should be required at least in add-on.

由于世界受到新冠肺炎 (COVID-19) 大流行的严重影响，多个国家允许使用氯喹和羟氯喹来预防或治疗患者，但近年来仍成为许多争议的焦点。这篇综述描述了氯喹和羟氯喹的特性，不仅强调了它们的抗病毒作用，还强调了它们重要的免疫调节特性以及它们在自身免疫性疾病（包括系统性狼疮和关节炎）中的众所周知的用途。氯喹似乎可以抑制体外SARS 病毒的复制并干扰 SARS-CoV2 受体 (ACE2)。氯喹和羟氯喹会阻碍溶酶体活性和自噬，导致抗原加工和呈递减少。它们还干扰内体 Toll 样受体信号传导和核酸的胞质传感器，从而导致细胞活化减少，从而降低 I 型干扰素和炎症细胞因子的分泌。鉴于氯喹和羟氯喹具有抗病毒和抗炎特性，使用它们来对抗 SARS-CoV2 感染是合理的。然而，这些分子的抗干扰素特性可能是有害的，并且会损害宿主对病毒的免疫反应。这种二元性可以解释最近发表的关于 CQ/HCQ 对 COVID-19 患者治疗效果的研究的差异。此外，尽管这些治疗可能是一种有趣的潜在策略，可以限制炎症向不受控制的进展，但它们似乎并没有出现。本身足够有效地控制 COVID-19 的整个炎症过程，并且至少应该需要更有针对性和/或有效的治疗方法。