Myerowitz R L, Pasculle A W, Dowling J N, Pazin G J, Puerzer M, Yee R B, Rinaldo C R, Hakala T R
N Engl J Med. 1979 Nov 1;301(18):953-8. doi: 10.1056/NEJM197911013011801.
Eight immunosuppressed patients had pneumonia due to Pittsburgh Pneumonia Agent (PPA), a gram-negative, weakly acid-fast bacterium cultivatable only in embryonated eggs and guinea pigs and distinct from Legionella pneumophila. The diagnosis was established by isolation of the agent from lung or visualization of the organism in lung tissue. The clinical presentations, radiographic abnormalities and pathology were not specific. The most consistent feature associated with the disease was the recent institution of daily high-dose corticosteriod therapy in all patients. Five of the eight patients died despite broad-spectrum antibiotic and antituberculous therapy. Anti-microbial activity against PPA was demonstrated for sulfamethoxazole combined with trimethoprim, for rifampin and for erythromycin with an egg-protection assay. Serologic studies with an indirect fluorescent-antibody technic suggested that seroconversion or high titers may be a sensitive test for PPA disease. PPA appears to be a newly recognized cause of life-threatening bacterial pneumonia in immunosupressed patients.
8例免疫抑制患者感染了匹兹堡肺炎病原体（PPA），这是一种革兰氏阴性、弱抗酸菌，仅能在鸡胚和豚鼠中培养，与嗜肺军团菌不同。通过从肺中分离病原体或在肺组织中观察到该生物体来确诊。临床表现、影像学异常和病理学表现均不具有特异性。与该疾病相关的最一致特征是所有患者近期均开始每日大剂量使用皮质类固醇治疗。尽管接受了广谱抗生素和抗结核治疗，8例患者中有5例死亡。通过卵保护试验证明，磺胺甲恶唑联合甲氧苄啶、利福平和红霉素对PPA具有抗菌活性。采用间接荧光抗体技术进行的血清学研究表明，血清转化或高滴度可能是PPA疾病的一项敏感检测方法。PPA似乎是免疫抑制患者中一种新发现的危及生命的细菌性肺炎病因。
