Background

High viral loads are observed in Torque Teno Virus (TTV) infection after hematopoietic stem cell transplantation (HSCT). We aimed to analyze the kinetics of plasma TTV-DNA load in pediatric patients who received immunosuppressive therapy and developed infection complications in the first 100 days after HSCT.

Methods

As a patient group; 113 plasma samples taken from 33 pediatric HSCT recipients at a time interval after transplantation and as a control group; 38 plasma samples from 38 children without known chronic disease were included in the study. Viral nucleic acid isolation was performed by using the NucliSENS easyMAG (bioMerieux, France) system. A laboratory designed quantitative polymerase chain reaction process was performed on 7300 Real-Time PCR system (Applied Biosystems, CA, USA) with the amplification mixture containing primer and probe sequences for the UTR gene region.

Results

TTV-DNA was detected in all patient's samples and the median viral load was calculated as 7.67 Log₁₀ copies/mL (range: 2.84–9.59). In the control group, the TTV-DNA median viral load was calculated as 5.51 Log₁₀ copies/mL (range: 2.50–7.04), except for one negative sample. A significant difference was observed between the control group and the patient group in terms of TTV viral load levels. In nine patients, a median 2.15 Log₁₀ copies/mL viral load increase was observed at 31–60 days post-transplant compared to the pre-transplant period.

Conclusion

TTV-DNA levels should be closely monitored to understand the immune status of the first 100 days after transplantation and the effects of treatment regimens on patients with HSCT.

中文翻译：

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在儿童造血干细胞移植（HSCT）患者中研究Tenor Teno病毒（TTV）DNA作为免疫学和病毒学标记的研究。

背景

造血干细胞移植（HSCT）后，在扭矩Teno病毒（TTV）感染中观察到高病毒载量。我们的目的是分析在接受HSCT后的头100天内接受免疫抑制治疗并出现感染并发症的小儿患者血浆TTV-DNA负荷的动力学。

方法

作为患者群体；从33名儿科HSCT接受者中以移植后的时间间隔取113份血浆样品作为对照组；这项研究包括来自38名未患有慢性疾病的儿童的38个血浆样品。通过使用NucliSENS easyMAG（法国bioMerieux）系统进行病毒核酸分离。在7300 Real-Time PCR系统（Applied Biosystems，CA，美国）上进行了实验室设计的定量聚合酶链反应过程，扩增混合物中含有UTR基因区域的引物和探针序列。

结果

在所有患者样本中均检测到TTV-DNA，计算出的中位病毒载量为7.67 Log ₁₀拷贝/ mL（范围：2.84–9.59）。在对照组中，除一个阴性样品外，TTV-DNA的中位病毒载量计算为5.51 Log ₁₀拷贝/ mL（范围：2.50-7.04）。在TTV病毒载量水平方面，对照组和患者组之间存在显着差异。在9名患者中，与移植前相比，移植后31–60天的病毒载量平均增加了2.15 Log _10个拷贝/ mL。

结论

应密切监测TTV-DNA水平，以了解移植后前100天的免疫状况以及治疗方案对HSCT患者的影响。