Early diagnosis of disseminated adenovirus infection associated with hematopoietic stem cell transplantation by quantitative PCR

一名接受骨髓移植(BMT)的17岁男性死于多器官衰竭。我们用实时荧光定量聚合酶链式反应对他的血清和尿液样本进行了腺病毒(ADV)基因组检测。ADV DNA拷贝数先在尿液中增加，然后在血清中增加，与其临床病程密切相关。12岁女性发展为危及生命的肺炎并噬血细胞综合征。我们不能通过抗体效价或培养来确定病原体。然而，肺组织中ADV的PCR检测呈阳性，实时荧光定量PCR分析证实了这一诊断。我们对7例接受骨髓移植的患者的血清和尿液样本进行了时间历程的实时定量PCR检测。通过这一分析，7名患者中有3名被确认为播散性ADV感染。3例患者骨髓移植后1~2周尿液ADV DNA均阳性，4~6周血清ADV DNA>105拷贝/ml。2例BMT前血清ADV拷贝数>10 3拷贝/ml的患者发生播散性ADV感染，1例17岁接受BMT的女性患者出现顽固性腹泻和高热。粪便中ADV抗原快速检测试验呈阳性，但由于该ADV中存在9个碱基替换，用常规的ADV引物进行聚合酶链式反应无法检测到ADV DNA。用7型ADV特异性引物进行聚合酶链式反应分析，确诊为ADV感染，定量检测ADV拷贝数是早期诊断播散性ADV感染的有力手段。骨髓移植前血清ADV拷贝阳性和骨髓移植后尿液ADV拷贝阳性的患者发生播散性ADV感染的风险较高。使用这项技术，我们可以在肺等活组织标本中检测到ADV。然而，由于ADV经常发生突变，在进行PCR分析时必须注意假阴性结果。

A 17-year-old male who had undergone bone marrow transplantation (BMT) died of multiple organ failure. We evaluated his serum and urine samples for adenovirus (AdV) genome using real-time PCR retrospectively. AdV DNA copy numbers, increasing at first in urine followed by in serum, were closely related with his clinical course.A 12-year-old female developed life-threatening pneumonia with hemophagocytic syndrome. We could not pin down pathogen with antibody titer or culture. However, PCR assay of lung tissue was positive for AdV and real-time PCR analysis confirmed this diagnosis.We evaluated serum and urine samples of 7 patients received BMT for AdV genome using real-time PCR in time course retrospectively. With this analysis 3 of 7 patients were confirmed to have disseminated AdV infection. In all of these 3 patients, AdV DNA was found to be positive in urine at one or two weeks after BMT and those were to be more than 10^5 copies/ml in serum at 4 to 6 weeks after BMT. 2 patients, who were found to have more than 10^3 copies/ml AdV in serum before BMT, developed disseminated AdV infection.A 17-year-old female who was received BMT developed intractable diarrhea and spiky fever. Rapid AdV antigen detection test was positive in stool, however, PCR using conventional primers for AdV failed to detect AdV DNA because of 9 base substitutions in this AdV. She was confirmed to have AdV infection by PCR analysis using AdV type 7 specific primers.Quantification of AdV copies is powerful method for early diagnosis of disseminated AdV infection. Patients who are positive for serum AdV copies before BMT and found to be positive for urine AdV copies after BMT are high risk of developing disseminated AdV infection. Using this technique we can detect AdV in biopcied specimens such as lung. However we have to pay attention for false negative results in PCR analysis because AdV has mutations frequently.