Organ Transplantation Research Institute of Sun Yat-sen University, The Third Affiliated Hospital of Sun Yat-sen University, Guangzhou, Guangdong, China.
Department of Medical Ultrasound, The Third Affiliated Hospital of Sun Yat-sen University, Guangzhou, Guangdong, China.
Am J Transplant. 2019 Jan;19(1):259-268. doi: 10.1111/ajt.15105. Epub 2018 Sep 27.
Antibody-mediated rejection (AMR) has emerged as a major cause of renal allograft dysfunction. C4d, a specific marker for AMR diagnosis, was strongly recommended for routine surveillance; however, currently, C4d detection is dependent upon tissue biopsy, which is invasive and provides only local semi-quantitative data. Targeted ultrasound imaging has been used extensively for noninvasive and real-time molecular detection with advantages of high specificity and sensitivity. In this study, we designed C4d-targeted microbubbles (MB ) using a streptavidin-biotin conjugated method and detected C4d deposition in vivo in a rat model of AMR by enhanced ultrasound imaging. This noninvasive procedure allowed successful acquisition of the first qualitative image of C4d deposition in a wide renal allograft section, which reflected real-time C4d distribution in grafts. Moreover, we introduced normal intensity difference for quantitative analysis, which exhibited a nearly linear correlation with the grade of C4d deposition according to pathologic analysis. In addition, this approach showed no influence on survival rates and pathologic features in the microbubble injection groups, thereby demonstrating its safety. These findings demonstrated a simple, noninvasive, quantitative, and safe evaluation method for C4d, with the utility of this approach potentially preventing patients from having to undergo an invasive biopsy.
抗体介导的排斥反应（AMR）已成为肾移植功能障碍的主要原因。C4d 是 AMR 诊断的特异性标志物，强烈推荐用于常规监测；然而，目前 C4d 的检测依赖于组织活检，这是一种有创的方法，只能提供局部半定量数据。靶向超声成像已广泛用于非侵入性和实时分子检测，具有高特异性和敏感性的优点。在这项研究中，我们使用链霉亲和素-生物素偶联法设计了 C4d 靶向微泡（MB），并通过增强超声成像在 AMR 大鼠模型中体内检测到 C4d 沉积。这种非侵入性的方法成功地获得了第一个广泛的肾移植节段 C4d 沉积的定性图像，反映了移植物中实时 C4d 的分布。此外，我们引入了正常强度差异进行定量分析，根据病理分析显示与 C4d 沉积程度呈近乎线性相关。此外，这种方法对微泡注射组的生存率和病理特征没有影响，从而证明了其安全性。这些发现表明，C4d 的评估方法简单、非侵入性、定量和安全，该方法的实用性可能使患者免于进行有创性活检。
