Division of Gastroenterology and Hepatology, Mayo Clinic, Rochester, Minnesota, USA.
Department of Radiology, Mayo Clinic, Rochester, Minnesota, USA.
Neurogastroenterol Motil. 2024 May;36(5):e14762. doi: 10.1111/nmo.14762. Epub 2024 Feb 20.
Animal models and human data have suggested macrophage-driven immune dysregulation in diabetic gastroparesis (DG). Translocator protein (TSPO) upregulation has been suggested to indicate activated state of macrophages and ER176 is a high affinity third generation TSPO-specific radioligand. The aim of this study was to determine feasibility of dynamic C-ER 176 PET to identify macrophage activation in DG.
Twelve patients, all females, were recruited (4 DG, 4 diabetics, and 4 healthy volunteers) for C-ER 176 PET/CT scanning. The standardized uptake value (SUV) in the gastric fundus, body, pylorus, and descending part of the duodenum were compared between three groups using Kruskal-Wallis test to perform the comparisons, and a p-value of 0.05 was considered statistically significant.
Age was comparable among the three groups with a median of 53 years. The uptake was higher in pylorus in diabetics compared to DG and healthy (SUV healthy 4.6 ± 0.2, diabetics 8.4 ± 4.1, DG 5.5 ± 1.0, p = 0.04). The uptake was similar in gastric fundus (9.0 ± 1.6, 13.1 ± 8.3, 7.8 ± 1.9 respectively, p = 0.3), body (7.7 ± 1.9, 13 ± 9.2, 7.8 ± 1.9 respectively, p = 0.8), and duodenum (6.2 ± 2.1, 9.5 ± 6.8, 7.0 ± 1.8 respectively, p = 0.6). No correlation was observed between SUV uptake and either HbA1C or fasting blood glucose.
Female diabetic gastroparesis patients did not demonstrate increased TSPO ligand C-ER 176 uptake in the stomach. Possible explanations include lack of specificity of ligand for specific macrophage phenotypes in DG, sex effect, or small sample size. Further studies investigating non-invasive ways of analyzing immune dysregulation in neurogastrointestinal disorders are warranted.
动物模型和人体数据表明，糖尿病性胃轻瘫（DG）中存在巨噬细胞驱动的免疫失调。转位蛋白（TSPO）上调表明巨噬细胞处于激活状态，ER176 是一种高亲和力的第三代 TSPO 特异性放射性配体。本研究旨在确定动态 C-ER176 PET 识别 DG 中巨噬细胞激活的可行性。
招募了 12 名女性患者（4 名 DG、4 名糖尿病患者和 4 名健康志愿者）进行 C-ER176 PET/CT 扫描。使用 Kruskal-Wallis 检验比较三组胃底、体、幽门和十二指肠降部的标准化摄取值（SUV），p 值<0.05 为有统计学意义。
三组年龄相仿，中位数为 53 岁。糖尿病患者的幽门 SUV 高于 DG 和健康者（健康者 4.6±0.2、糖尿病患者 8.4±4.1、DG 患者 5.5±1.0，p=0.04）。胃底 SUV 相似（分别为 9.0±1.6、13.1±8.3、7.8±1.9，p=0.3）、体部（分别为 7.7±1.9、13±9.2、7.8±1.9，p=0.8）和十二指肠（分别为 6.2±2.1、9.5±6.8、7.0±1.8，p=0.6）。SUV 摄取与 HbA1C 或空腹血糖均无相关性。
女性糖尿病性胃轻瘫患者的胃 TSPO 配体 C-ER176 摄取无增加。可能的解释包括配体在 DG 中对特定巨噬细胞表型缺乏特异性、性别影响或样本量小。进一步研究需要探索非侵入性方法来分析神经胃肠疾病中的免疫失调。
