免疫健全者重症肺炎后巨细胞病毒感染两例并文献复习

Cytomegalovirus Infection after Severe Pneumonia in Immunocompetent Subjects:A Two-case Report and Literature Review

目的总结免疫健全者重症肺炎后活动性巨细胞病毒感染的临床特征和诊治要点。方法报告2例于我院呼吸重症监护病房诊治的基础免疫健全宿主重症肺炎后巨细胞病毒活动性感染病例,并结合文献资料对该病的危险因素、临床特征和诊治要点进行分析。结果 2例患者均为老年患者,因"重症肺炎、Ⅰ型呼吸衰竭"入住我科,经有创机械通气、广谱抗生素抗感染、激素抗炎及支持治疗后体温正常,氧合改善,肺部渗出影吸收好转,成功脱机拔管。之后患者氧合进一步改善不明显,且肺部渗出影进展,外周血巨细胞病毒DNA转阳,加用更昔洛韦抗病毒治疗后氧合改善,肺部渗出影吸收。结合文献资料,在基础免疫健全者,重症肺炎后出现活动性巨细胞病毒感染的危险因素包括有创机械通气、糖皮质激素应用;临床特征为氧合恶化、肺部渗出影增多,而普通细菌、真菌培养无阳性发现;诊断试验包括外周血巨细胞病毒定量核酸扩增试验、巨细胞病毒pp65抗原检测和组织病理学检查;治疗方法推荐缬更昔洛韦片口服或更昔洛韦静脉滴注,疗程至少2周。结论巨细胞病毒活动性感染在基础免疫功能正常的危重症患者中频发,对于原发疾病为重症肺炎、接受有创机械通气及应用糖皮质激素的患者,需警惕巨细胞病毒肺炎的发生,及早诊断并给予相应的治疗,可改善该类患者的预后。

Objective To summarize the clinical features of cytomegalovirus infection after severe pneumonia in immunocompetent subjects.Methods Two cases of cytomegalovirus infection after severe pneumonia in immunocompetent subjects were reported and the literatures were reviewed.Results Two elderly patients were admitted to our Respiratory Intensive Care Unit for severe pneumonia and type Ⅰrespiratory failure.After treatment of invasive mechanical ventilation,broad-spectrum antibiotics and steroids,their body temperature became normal with improvement of oxygenation and lung infiltrates on chest radiograph.After extubation,their oxygenation deteriorated,with extensive lung infiltrates on chest X ray.Coincidently,their blood cytomegalovirus DNA became positive and then they were treated with parenteral ganciclovir for more than 2 weeks.After that,their oxygenation and chest radiograph returned to normal.Combined with the results of the related literature,invasive mechanical ventilation and use of corticosteroids could be the risk factors of immunocompetent subjects to develop cytomegalovirus infection after severe pneumonia.The clinical characteristics include deterioration of oxygenation and extensive lung infiltrates without positive pathogenic findings of bacteria and fungi.Quantitive nucleic acid amplification tests for blood cytomegalovirus DNA,cytomegalovirus pp65 antigenemia test and histology / immunohistochemistry are recommended diagnostic tools.Valganciclovir or intravenous ganciclovir are recommended as first-line treatment for at least 2 weeks.Conclusions Cytomegalovirus infection occurs frequently in immunocompe-tent subjects with critical illness.Cytomegalovirus pneumonia should especially be considered in patients with severe pneumonia,receiving mechanical ventilation and steroids.Early diagnosis and treatment may help improve the prognosis of these patients.