Abstract：
BACKGROUND We report a case of diffuse alveolar hemorrhage (DAH) caused by Legionella pneumophila serogroup (SG) 1 and review the existing literature to identify risk factors and determine the prognosis of patients with Legionella pneumonia-associated DAH. CASE REPORT A 44-year-old woman was admitted to our hospital following the presentation of dyspnea for a few days. Chest computed tomography (CT) findings revealed \"crazy-paving\" pattern in the right upper lobe implicating DAH and consolidation in the lower lobe. Analysis of the bronchoalveolar lavage (BAL) fluid revealed DAH, with further analyses identifying L. pneumophila SG 1 as the causative agent. The patient was successfully treated with levofloxacin and a red blood cell transfusion and discharged on the 32nd day of hospitalization. A literature review of 6 reported cases (including our case) of Legionella pneumonia-associated DAH revealed that the median age of patients with DAH was 59 years (range, 44-75 years), involving female patients in 4 cases (67%) and the use of immunosuppressive drugs in 2 cases (33%). Three cases were BAL Legionella polymerase chain reaction (PCR)-positive and 4 cases were diagnosed using a urinary Legionella antigen test (one case was simultaneously PCR-positive). These infections were caused by L. pneumophila SG 1 in three cases and SG 3 in one case. Mechanical ventilation was used in 5 cases (83%) and one patient had an unfavorable prognosis. Steroids for DAH were used in 5 cases (83%), and 2 cases responded to this treatment. CONCLUSIONS Our case highlights that clinicians should be aware of Legionella spp. as a cause of DAH in an immunocompetent host with \"crazy-paving\" pattern on chest CT, and perform a urinary antigen test and BAL PCR for diagnosis.
摘要：
背景：我们报道一例由嗜肺军团菌血清群1（SG）引起的弥漫性肺泡出血（DAH），并回顾现有文献以确定军团菌肺炎相关DAH患者的危险因素和预后。病例报告一名44岁的妇女在出现呼吸困难几天后入院。胸部计算机断层扫描（CT）发现右上叶的“疯狂铺路”模式暗示了下叶的DAH和巩固。支气管肺泡灌洗液（BAL）分析显示DAH，进一步分析确定嗜肺乳杆菌SG1为病原体。患者成功接受左氧氟沙星和红细胞输注治疗，并在住院第32天出院。对6例军团菌肺炎相关DAH的报道（包括我们的病例）的文献回顾显示，DAH患者的中位年龄为59岁（范围，44-75岁），累及女性患者4例（67%），使用免疫抑制药物2例（33%）。3例BAL军团菌聚合酶链反应（PCR）阳性，4例使用尿军团菌抗原检测诊断（1例同时PCR阳性）。这些感染由3例嗜肺乳杆菌SG1和1例SG3引起。机械通气5例（83％），1例预后不良。5例（83％）使用类固醇治疗DAH，2例患者对此治疗有反应。结论我们的案例强调临床医生应该意识到军团菌。作为胸部CT上具有“疯狂铺路”模式的免疫能力宿主中DAH的病因，并进行尿抗原检测和BALPCR诊断。
