Renal Molecular Imaging of Mesangial Cell Function with Tc-99m-Tilmanocept

家长资助摘要 2017年，国际糖尿病联合会估计，全球糖尿病患病率将 从2015年的4.15亿增加到2040年的6.42亿。大约40%的糖尿病患者 糖尿病肾病（DN）。这些人中有20%不遵循慢性病的典型路径， 肾脏疾病，这是一个缓慢的几十年增加的蛋白尿和血清肌酐，目前的标准- 用于监测慢性肾脏病（KD）。因此，对于常规治疗存在未满足的临床需求。 在慢性KD的第一个十年期间进行监测。 我们建议将系膜细胞功能的外部成像作为糖尿病肾病的生物标志物。我们 推理基于以下内容。系膜细胞基质（MCM）扩张是糖尿病肾病的组织学标志， 肾病，其先于患者的肾小球滤过率降低或白蛋白尿增加。 此外，糖尿病肾病的所有临床表现与MCM扩张高度相关。 目前不存在对系膜细胞敏感的成像、血清或尿液生物标志物 功能目前的显像剂和生物标志物仅对肾小球滤过、有效肾血浆 血流量或蛋白尿，当治疗干预无效时，这些蛋白尿在疾病后期发生改变。 我们提出了一项Tc-99 m-tilmanocept的1期临床试验，它在肝脏和肾脏中积累。 其分子机制是与CD 206结合，CD 206位于细胞内固定的巨噬细胞的细胞表面。 肝脏和肾脏的系膜细胞。我们目前的初步数据包括人体SPECT/CT和 大鼠肾皮质的microPET图像。此外，我们提出的证据的敏感性MCM膨胀通过Tc- db/db小鼠（一种公认的糖尿病肾病疾病模型）的99 m-tilmanocept动态成像。 我们提出了一项开放标签研究，以调查在两个剂量水平（2.0和20 nmol）的生物分布 Tc-99 m-替马诺塞我们将在每个剂量下研究5组（每组10名受试者）：1）晚期DN，2）早期DN，3） 无肾脏疾病的糖尿病，4）有KD的晚期高血压（HTN），和5）无KD的HTN。研究 将包括30分钟动态，随后是30分钟肾脏SPECT/CT，以及定期血液和尿液采样。 动态成像将产生血浆清除半衰期以及肝脏和肾脏蓄积率; SPECT/CT将 产生心脏、肝脏、肾皮质、肾髓质的SUV。我们还将计算膀胱积聚。 我们期望肾图和生物分布数据反映以下病理：第1组，重度 MCM膨胀; G2，轻度MCM膨胀; G3和GS，无MCM膨胀;以及G4，低MCM膨胀。 这项研究是FDA批准Tc-99 m-tilmancoept作为肾脏成像的必要的第一步。 剂该研究还将提供DN患者中MCM扩张的成像敏感性证据， 对HTN患者不敏感。如果将Tc-99 m-tilmanocept肾图作为“一线”肾图，则需要此服务。 糖尿病患者的诊断测试。

Parent Grant Summary In 2017 the International Diabetes Federation estimated that the worldwide prevalence of diabetes would increase from 415 million in 2015 to 642 million in 2040. Approximately 40% of individuals with diabetes develop diabetic nephropathy (DN). Twenty percent of these individuals do not follow the typical path toward chronic kidney disease, which is a slow multi-decade increase in albuminuria and serum creatinine, the current standard- of-care for surveillance of chronic kidney disease (KD). Consequently, there is an unmet clinical need for routine surveillance during the first decade of chronic KD. We propose external imaging of mesangial cell function as a biomarker for diabetic nephropathy. Our reasoning is based on the following. Mesangial cell matrix (MCM) expansion is a histologic hallmark of diabetic nephropathy, which precedes the reduction of a patient's glomerular filtration rate or increase in albuminuria. Additionally, all the clinical manifestations of diabetic nephropathy are highly correlated with MCM expansion. There currently does not exist an imaging, serum, or urine biomarker that is sensitive to mesangial cell function. Current imaging agents and biomarkers are only sensitive to glomerular filtration, effective renal plasma flow, or albuminuria, which are altered late in the disease when therapeutic intervention is not effective. We propose a Phase 1 clinical trial of Tc-99m-tilmanocept, which accumulates in the liver and kidneys. The molecular mechanism is binding to CD206, which resides on the cell surface of fixed macrophages within the liver and mesangial cells within the kidney. We present preliminary data consisting of human SPECT/CT and rat microPET images of renal cortex. Additionally, we present evidence of sensitivity to MCM expansion via Tc- 99m-tilmanocept dynamic imaging of db/db mice, an accepted disease model of diabetic nephropathy. We propose an open-label study to investigate the biodistribution at two dose levels (2.0 & 20 nmol) of Tc-99m-tilmanocept. We will study 5 groups at each dose (10 subjects each): 1) Advance DN, 2) early DN, 3) diabetes with no kidney disease, 4) advanced hypertension (HTN) with KD, and 5) HTN without KD. The study will include a 30-min dynamic followed be a 30-min kidney SPECT/CT, and periodic blood and urine sampling. Dynamic imaging will yield plasma clearance half-lifes, and liver and kidney accumulation rates; SPECT/CT will yield SUVs for the heart, liver, renal cortex, renal medulla. We will also calculate urinary bladder accumulation. We expect the renograms and biodistribution data to reflect the following pathology: Group 1, severe MCM expansion; G2, mild MCM expansion; G3 & GS, no MCM expansion; and G4, low MCM expansion. This study is the necessary first step toward FDA-approval of Tc-99m-tilmancoept as a kidney imaging agent. The study will also provide evidence of imaging sensitivity to MCM expansion in DN patients, and insensitivity to patients with HTN. This senerio will be required if Tc-99m-tilmanocept renograms as "first-line" diagnostic test for diabetic patients.