Happel Kyle I, Nelson Steve
Section of Pulmonary and Critical Care Medicine, Alcohol Research Center, Louisiana State University Health Sciences Center, 1901 Perdido Street, Suite 3205, New Orleans, LA 70112, USA.
Proc Am Thorac Soc. 2005;2(5):428-32. doi: 10.1513/pats.200507-065JS.
Bacterial pneumonia is the most common cause of lower respiratory tract infection in immunocompromised populations, including the alcohol-abusing patient. Furthermore, alcoholics are frequently infected with highly virulent respiratory pathogens and consequently experience increased morbidity and mortality from bacterial pneumonia. The resulting increase in health care resource use in these patients represents a significant public health concern. Host defense mechanisms are operant from the nasopharynx to the alveolus, many of which are adversely affected by excessive alcohol intake. Although the increased risk of oropharyngeal aspiration has been recognized for centuries, only recently have detailed studies of the mechanical, innate, and adaptive immune systems identified specific mechanisms throughout the aerodigestive tract whereby ethanol exposure renders the individual more susceptible to infection. In addition to directly inhibiting the ability of resident lung immune cells to kill bacteria, excessive ethanol use suppresses the normally protective acute inflammatory response to infection, resulting in the defective recruitment of additional innate immune cells. Additionally, ethanol disrupts the intricate interface that exists between innate and adaptive pulmonary immunity, further hindering the alcoholic host's ability efficiently to eliminate invading pathogens. Whether immunomodulatory therapies, designed to augment the immune response in such patients, will be effective adjunct therapy in such patients remains to be determined. This article reviews some of the key mechanisms of pulmonary host defense that are negatively impacted in the setting of alcohol abuse.
细菌性肺炎是免疫功能低下人群(包括酗酒患者)下呼吸道感染最常见的病因。此外,酗酒者经常感染高毒力的呼吸道病原体,因此细菌性肺炎导致的发病率和死亡率增加。这些患者医疗资源使用的增加成为一个重大的公共卫生问题。宿主防御机制从鼻咽部到肺泡都在发挥作用,其中许多机制会受到过量饮酒的不利影响。尽管口咽误吸风险增加几个世纪以来已为人所知,但直到最近,对机械、固有和适应性免疫系统的详细研究才确定了整个气道消化道中乙醇暴露使个体更易感染的具体机制。除了直接抑制肺部常驻免疫细胞杀灭细菌的能力外,过量饮酒还会抑制对感染正常起保护作用的急性炎症反应,导致额外固有免疫细胞的募集缺陷。此外,乙醇破坏了固有和适应性肺部免疫之间存在的复杂界面,进一步阻碍了酗酒宿主有效清除入侵病原体的能力。旨在增强此类患者免疫反应的免疫调节疗法是否会成为此类患者有效的辅助治疗方法仍有待确定。本文综述了在酒精滥用情况下受到负面影响的肺部宿主防御的一些关键机制。