Division of Nephrology and Dialysis, Department of Medicine III, Medical University of Vienna, Vienna, Austria.
Department of Pathology, Medical University of Vienna, Vienna, Austria.
Transplantation. 2021 Sep 1;105(9):2112-2118. doi: 10.1097/TP.0000000000003619.
Nonpathogenic torque teno viruses (TTVs) are highly prevalent in transplant recipients and associated with immunosuppression. Studies in kidney transplant patients have proposed assessment of TTV load for risk stratification of clinically overt graft rejection. The value of TTV quantification in the context of subclinical rejection has not been evaluated.
In this prospective trial, 307 consecutive kidney transplant recipients were subjected to per-protocol monitoring of plasma TTV. TTV was analyzed in the context of protocol biopsies (n = 82), scheduled 1 year posttransplantation.
TTV load at the time of biopsy was lower in recipients with rejection (n = 19; according to Banff, including borderline changes suspicious for acute T cell-mediated rejection) than those without rejection (n = 63) whereby each log increase in TTV copies/mL decreased the risk for rejection by 9% (risk ratio 0.91, 95% confidence interval, 0.85-0.97; P = 0.004). Development of chronic lesions (cg, cv, ci, ct, ah, ptcml) was associated with the number of days with a TTV load <1 × 106 copies/mL between months 3 and 12 posttransplant (β 0.07, 95% confidence interval, 0.01-0.14; P = 0.02).
This trial demonstrates an association between TTV and subclinical graft rejection in kidney transplant recipients. A TTV load <1 × 106 copies/mL suggests suboptimal immunosuppression.
非致病性扭转型病毒（TTV）在移植受者中高度流行，并与免疫抑制有关。在肾移植患者中的研究提出了评估 TTV 负荷以对临床明显移植物排斥进行风险分层的建议。TTV 定量在亚临床排斥中的价值尚未得到评估。
在这项前瞻性试验中，307 例连续肾移植受者接受了血浆 TTV 的方案监测。TTV 是在方案活检（n = 82）的背景下进行分析的，这些活检是在移植后 1 年进行的。
在有排斥反应的受者（n = 19；根据 Banff 标准，包括急性 T 细胞介导的排斥反应可疑的边界改变）中，活检时的 TTV 载量低于无排斥反应的受者（n = 63），其中 TTV 拷贝/mL 的每对数增加使排斥的风险降低 9%（风险比 0.91，95%置信区间，0.85-0.97；P = 0.004）。慢性病变（cg、cv、ci、ct、ah、ptcml）的发展与移植后 3 至 12 个月之间 TTV 载量<1×106 拷贝/mL 的天数有关（β 0.07，95%置信区间，0.01-0.14；P = 0.02）。
本试验表明 TTV 与肾移植受者的亚临床移植物排斥有关。TTV 载量<1×106 拷贝/mL 提示免疫抑制不足。
