基于宏基因组二代测序诊断15例鹦鹉热衣原体肺炎临床特征与诊治分析

Clinical features，diagnosis，and treatment of chlamydia psittaci pneumonia based on metagenomic next-generation sequencing: an analysis of 15 cases

摘要:

目的 探讨和分析少见鹦鹉热衣原体肺炎的临床特征、诊治及预后，以期提升临床相关学科领域对该病的认识。方法 回顾性研究赣南医学院第一附属医院2017年1月至2022年12月确诊的15例鹦鹉热衣原体肺炎患者的临床资料，总结并分析该病的临床特征、诊断与鉴别要点，同时检索国内外文献资料对鹦鹉热衣原体肺炎的最新诊疗进展予以系统性讨论。结果 纳入本研究的15例鹦鹉热衣原体肺炎患者中，男性10例（66.67％），女性5例（33.33％），年龄62（32～79）岁，禽类接触史14例（93.33％），基础疾病史8例（53.3％），转化为重症肺炎5例（33.33％）。15例患者中，白细胞计数（white blood cell count，WBC）正常8例（53.3％），WBC升高5例（33.3％），WBC减低2例（13.3％）；血红蛋白（hemoglobin，HGB）正常9例（60.0％），减低6例（40.0％）；中性粒细胞百分比（neutrophils，NE）升高13例（86.7％）；所有患者（100.0％）C反应蛋白（C-reactive protein，CRP）均显著升高；13例（86.67％）患者降钙素原（procalcitonin，PCT）升高；12例（80.0％）患者乳酸脱氢酶（lactate dehydrogenase，LDH）升高；11例（73.33％）肝功能异常；8例（53.33％）肾功能异常；6例（40.0％）凝血功能异常；13例（86.7％）电解质紊乱。此外，11例（73.33％）患者动脉血气分析显示不同程度血氧分压降低，8例（53.33％）氧合指数（oxygenation index，OI）低于300 mmHg，4例（26.67％）患者无明显呼吸困难，未进行动脉血气分析检查。本研究所有患者均已完善经支气管镜检查，并获取支气管肺泡灌洗液（bronchoalverolar lavage fluid，BALF）行宏基因组二代测序（metagenomic next-generation sequencing，mNGS）检测，检出的病原体除鹦鹉热衣原体外，所有患者均合并多种病原体感染。15例患者均已完善肺部电子计算机断层扫描（computed tomography，CT）等影像学检查，单侧肺部实变7例（46.67％），双侧实变8例（53.33％）；9例（60.0％）患者伴有胸腔积液，部分患者可以表现出多种影像学表现，包括实变影、磨玻璃影、团块样实变影、反晕征、纵隔和肺门淋巴结肿大等。15例鹦鹉热衣原体肺炎患者在确诊后均予规范抗感染治疗，其中5例重症肺炎患者中2例患者予体外膜肺氧合（extracorporeal membrane oxygenation，ECMO）辅助治疗，所有患者均未见治疗相关不良反应或不良事件，平均住院日为13.9 d。本研究所有患者未见死亡，均好转出院。结论 鹦鹉热衣原体肺炎临床特征及表现缺乏特异性，易出现重症化，经支气管肺泡灌洗液予mNGS检测可精准确诊，早期予四环素类及喹诺酮类抗生素可最大程度改善患者预后。

Abstract:

Objective To investigate the clinical features，diagnosis and treatment，and prognosis of rare chlamydia psittaci pneumonia，and to improve the understanding of this disease in related clinical fields.Methods A retrospective analysis was performed for the clinical data of 15 patients who were diagnosed with chlamydia psittaci pneumonia in The First Affiliated Hospital of Gannan Medical University from January 2017 to December 2022，and the clinical features，diagnosis，and key points for differential diagnosis were summarized and analyzed. Meanwhile，related articles in China and globally were searched to systematically discuss the latest advances in the diagnosis and treatment of chlamydia psittaci pneumonia.Results Among the 15 patients with chlamydia psittaci pneumonia included in this study，there were 10 male patients（66.67%） and 5 female patients（33.33%），with an aged of 62（32-79） years. Among these patients，14（93.33%） had poultry contact history，8（53.3%） had the history of underlying diseases，and 5（33.33%） developed severe pneumonia. Among the 15 patients，8 had normal white blood cell count（WBC）（53.3%），5 had elevated WBC（33.3%），and 2（13.3%） had a reduction in WBC；9（60.0%） had normal hemoglobin，and 6（40.0%） had a reduction in hemoglobin；13（86.7%） had an increase in the percentage of neutrophils； all patients（100.0%） had a significant increase in C-reactive protein；13（86.67%） had an increase in procalcitonin，and 12（80.0%） had an increase in lactate dehydrogenase；11（73.33%） had abnormal liver function，8（53.33%） had abnormal renal function，and 6（40.0%） had abnormal coagulation function；13（86.7%） had electrolyte disturbance. In addition，arterial blood gas analysis showed varying degrees of reduction in the partial pressure of blood oxygen in 11 patients（73.33%），and 8 patients（53.33%） had an oxygenation index lower than 300 mmHg； 4 patients（26.67%） had no obvious dyspnea and thus did not undergo arterial blood gas analysis. All patients in this study underwent bronchoscopy，with bronchoalveolar lavage fluid obtained for metagenomic next-generation sequencing（mNGS），and all patients were infected with multiple pathogens besides chlamydia psittaci. All 15 patients underwent lung CT and other imaging examinations，among whom 7（46.67%） had unilateral pulmonary consolidation and 8（53.33%） had bilateral pulmonary consolidation；9 patients（60.0%） also had pleural effusion，and some of them showed various imaging findings，including consolidation opacities，ground-glass opacities，mass opacities，reversed halo sign，and mediastinal and hilar lymph node enlargement. All 15 patients with chlamydia psittaci pneumonia received standard anti-infective therapy after diagnosis，and among the 5 patients with severe pneumonia，2 received ECMO adjuvant therapy. No treatment-related adverse reactions or adverse events were observed，with a mean length of hospital stay of 13.9 days. No death was observed，and all patients were discharged after improvement.Conclusion Chlamydia psittaci pneumonia lacks specific clinical features and manifestations and tends to develop into severe exacerbation，and mNGS detection of bronchoalveolar lavage fluid can help to achieve an accurate diagnosis. Early administration of tetracycline and quinolone antibiotics can improve the prognosis of patients to the greatest extent.