Dams E T, Oyen W J, Boerman O C, Storm G, Laverman P, Koenders E B, van der Meer J W, Corstens F H
Department of Nuclear Medicine, University Hospital Nijmegen, The Netherlands.
J Nucl Med. 1998 Dec;39(12):2172-8.
Scintigraphic techniques are routinely used for the evaluation of the extent and severity of inflammatory bowel disease. Currently, the radiopharmaceutical of choice is 99mTc-hexamethyl propyleneamine oxime (HMPAO)-leukocytes. We studied the imaging potential of two recently developed 99mTc-labeled agents, polyethylene glycol (PEG)-coated liposomes and hydrazinonicotinate (HYNIC) IgG, in a rabbit model of acute colitis, and compared them with that of 99mTc-labeled, granulocyte-enriched (>90%), white blood cells.
Acute colitis was induced in rabbits by retrograde instillation of trinitrobenzene sulfonic acid. After 48 hr, 37 MBq of each radiopharmaceutical was administered intravenously. Gamma camera images were taken at 0, 1, 2, 4, 10 and 24 hr. At 4 and 24 hr postinjection, groups of rabbits were killed, and the uptake of the radiolabel in the dissected tissues was determined. For each affected 5-cm segment, the colitis index (CI, affected-to-normal-colon-uptake ratio) was calculated and correlated to the macroscopically scored severity of inflammation.
All three agents visualized the colitis lesions within 1 hr postinjection. The CI correlated with the severity of the abnormalities. With increasing severity, the CI at 4 hr postinjection for liposomes was 3.89+/-0.73, 4.41+/-0.47 and 5.76+/-0.65; for IgG 1.67+/-0.08, 3.92+/-0.44 and 6.14+/-0.65; and for granulocytes 2.90+/-0.09, 6.15+/-0.96 and 9.36+/-3.35. For liposomes, the CI further increased during 24-hr postinjection to 6.56+/-0.84, 8.50+/-0.53 and 10.61+/-1.34, respectively. The CI for the other two agents did not change significantly with time.
In this rabbit model, 99mTc-labeled granulocytes, IgG and liposomes all rapidly visualized colonic inflammation. Granulocytes and liposomes showed the highest CI. Technetium-99m-labeled PEG-liposomes may be an attractive alternative for labeled leukocytes to image inflammatory bowel disease, because they can be prepared off the shelf and no handling of blood is required.
闪烁扫描技术通常用于评估炎症性肠病的范围和严重程度。目前，首选的放射性药物是99mTc-六甲基丙烯胺肟（HMPAO）标记的白细胞。我们在急性结肠炎兔模型中研究了两种新开发的99mTc标记剂，聚乙二醇（PEG）包被的脂质体和肼基烟酸盐（HYNIC）IgG的成像潜力，并将它们与99mTc标记的、粒细胞富集（>90%）的白细胞进行比较。
通过逆行灌注三硝基苯磺酸诱导兔急性结肠炎。48小时后，静脉注射每种放射性药物37MBq。在0、1、2、4、10和24小时拍摄γ相机图像。在注射后4小时和24小时，处死兔组，测定解剖组织中放射性标记物的摄取。对于每个受影响的5厘米节段，计算结肠炎指数（CI，病变结肠与正常结肠摄取比），并将其与宏观评分的炎症严重程度相关联。
所有三种药物在注射后1小时内均能显示结肠炎病变。CI与异常严重程度相关。随着严重程度增加，注射后4小时脂质体的CI分别为3.89±0.73、4.41±0.47和5.76±0.65；IgG为1.67±0.08、3.92±0.44和6.14±0.65；粒细胞为2.90±0.09、6.15±0.96和9.36±3.35。对于脂质体，注射后24小时内CI进一步增加，分别为6.56±0.84、8.50±0.53和10.61±1.34。其他两种药物的CI随时间无明显变化。
在该兔模型中，99mTc标记的粒细胞、IgG和脂质体均能快速显示结肠炎症。粒细胞和脂质体的CI最高。99mTc标记的PEG脂质体可能是标记白细胞成像炎症性肠病的有吸引力的替代物，因为它们可以现成制备，无需处理血液。
