Background Critical illness induces immune disorders associated with an increased risk of hospital-acquired pneumonia (HAP) and acute respiratory distress syndrome (ARDS). Torque Teno Virus (TTV), from the Anelloviridae family, are proposed as a biomarker to measure the level of immunosuppression. Our objective was to describe the kinetics of TTV DNA loads and their association with critical-illness related complications. Methods We performed a longitudinal study in 115 brain-injured patients from a prospective cohort, collected endotracheal and blood samples at three time points (T1, T2, T3) during the two weeks post-admission in intensive care unit, and measured viral DNA loads using the TTV R-gene® kit (Biomerieux) and a pan-Anelloviridae in house qRT-PCR. Results TTV DNA was detected in the blood of 69, 71, and 64% of brain-injured patients at T1, T2 and T3 respectively. Time-associated variations of TTV and Anellovirus (AV) DNA loads were observed. Using a linear mixed-effects model, we found that HAP and ARDS were associated with lower blood AV DNA loads. Conclusion Our results show that HAP or ARDS in critically ill patients are associated to changes in AV DNA loads, and should be evaluated further as a biomarker of immune disorders leading to these complications.

中文翻译：

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脑损伤患者重症监护病房期间指环病毒载量动态与医院获得性肺炎的关联

背景 危重疾病会诱发免疫紊乱，并增加医院获得性肺炎 (HAP) 和急性呼吸窘迫综合征 (ARDS) 的风险。Torque Teno 病毒 (TTV) 属于指环病毒科，被提议作为测量免疫抑制水平的生物标志物。我们的目标是描述 TTV DNA 负载的动力学及其与危重疾病相关并发症的关联。方法 我们对前瞻性队列中的 115 名脑损伤患者进行了纵向研究，在入住重症监护病房后两周内的三个时间点（T1、T2、T3）收集气管内和血液样本，并测量病毒 DNA 载量使用 TTV R-gene® 试剂盒 (Biomerieux) 和泛指环病毒科内部 qRT-PCR。结果 T1、T2、T3 时脑损伤患者血液中检出 TTV DNA 的比例分别为 69%、71%、64%。观察到 TTV 和指环病毒 (AV) DNA 载量随时间的变化。使用线性混合效应模型，我们发现 HAP 和 ARDS 与较低的血液 AV DNA 载量相关。结论 我们的结果表明危重患者的 HAP 或 ARDS 与 AV DNA 载量的变化相关，应作为导致这些并发症的免疫紊乱的生物标志物进行进一步评估。