BACKGROUND Chronic deterioration of kidney graft function is related to inadequate immunosuppression (IS). A novel tool to assess the individual net state of IS in transplanted patients might be the monitoring of Torque teno virus (TTV) viral load. TTV is a non-pathogen virus detectable in almost all individuals. TTV level in the peripheral blood has been linked to the immune-competence of its host and should thus reflect IS after solid organ transplantation. METHODS TTV plasma load was quantified monthly by RT-PCR for a period of 1 year in 45 kidney-transplanted children. Post-transplant time was at least 3 months. The relation of the virus DNA levels to IS and transplant-specific clinical and laboratory parameters was analysed longitudinally. RESULTS TTV DNA was detectable in 94.5% of the plasma samples. There was a significant association with the post-transplant follow-up time as well as with the type of IS regimen, with lower virus loads in patients after longer post-transplant time and mTOR inhibitor-based IS. Furthermore, a significant positive correlation with the dose of prednisolone and mycophenolate mofetil was found. CONCLUSIONS TTV levels show an association/correlation with the strength of IS. Further studies are needed in order to evaluate TTV measurement as a tool for IS monitoring for hard clinical outcomes such as presence of donor-specific antibodies, rejections or infections-common consequences of insufficient or too intense IS.

中文翻译：

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Torque Teno 病毒载量反映了儿童肾移植患者的免疫抑制——一项初步研究。

背景肾移植物功能的慢性恶化与免疫抑制(IS)不足有关。一种评估移植患者 IS 个体净状态的新工具可能是监测 Torque Teno 病毒 (TTV) 病毒载量。TTV 是一种几乎在所有个体中均可检测到的非病原体病毒。外周血中的 TTV 水平与其宿主的免疫能力有关，因此应该反映实体器官移植后的 IS。方法 在 45 名肾移植儿童中，在为期 1 年的时间里，通过 RT-PCR 每月对 TTV 血浆负荷进行量化。移植后时间至少为 3 个月。纵向分析了病毒 DNA 水平与 IS 和移植特异性临床和实验室参数的关系。结果 在 94.5% 的血浆样本中可检测到 TTV DNA。与移植后随访时间以及 IS 方案类型有显着关联，移植后时间越长患者的病毒载量越低，以及基于 mTOR 抑制剂的 IS。此外，发现与泼尼松龙和霉酚酸酯的剂量显着正相关。结论 TTV 水平显示出与 IS 强度的关联/相关性。需要进一步研究以评估 TTV 测量作为 IS 监测硬临床结果的工具，例如供体特异性抗体的存在、排斥或感染——IS 不足或过强的常见后果。发现与泼尼松龙和霉酚酸酯的剂量显着正相关。结论 TTV 水平显示出与 IS 强度的关联/相关性。需要进一步研究以评估 TTV 测量作为 IS 监测硬临床结果的工具，例如供体特异性抗体的存在、排斥或感染——IS 不足或过强的常见后果。发现与泼尼松龙和霉酚酸酯的剂量显着正相关。结论 TTV 水平显示出与 IS 强度的关联/相关性。需要进一步研究以评估 TTV 测量作为 IS 监测硬临床结果的工具，例如供体特异性抗体的存在、排斥或感染——IS 不足或过强的常见后果。