荷人型淋巴瘤裸鼠“冷抗体”封闭前后放免治疗与显像

Radio-immunotherapy and imaging of "cold antibody" before and after blocking on nude mice bearing human lymphoma

目的探讨用"冷抗体"封闭前后131I-Rituximab对荷人淋巴瘤裸鼠的治疗与显像效果。方法建立荷人淋巴瘤裸鼠模型,病理示B细胞非霍奇金淋巴瘤且肿瘤细胞表面CD20抗原阳性率95%以上,实验分显像与治疗研究。显像研究中将荷瘤裸鼠随机分为3组,每组5只,分别为18F-FDG组、131I-Rituximab组、"冷抗体"封闭后131I-Rituximab组,后两组于第2、4、7、11、16天做SPECT显像,并做相应药物分布;治疗研究中将荷瘤裸鼠随机分为5组,3只/组,分别为Rituximab 50μg组、Rituximab 100μg组、131I-Rituximab组、"冷抗体"封闭后131I-Rituximab组、空白对照组,观察各组肿瘤生长情况,第15天后处死,常规病理分析。结果肿瘤在PET/CT上未见明显摄取18F-FDG;在T/NT值最高期间,131I-Rituximab组肿瘤未见显像,而"冷抗体"封闭后131I-Rituximab组在第7天肿瘤可见显像。治疗中"冷抗体"封闭后131I-Rituximab组抑瘤率高于其他各组,组织病理学显示有效。结论"冷抗体"封闭后放射免疫治疗的淋巴瘤抑制率最好,优于单纯放射免疫治疗及免疫治疗。"冷抗体"封闭组放免显像优于未封闭组放免显像。

Objective To investigate the effect of ^131I-labeled Rituximab in radio-immunotherapy and imaging of nude mice bearing human lymphoma before and after ＂cold antibody＂ blocking. Methods The BALB/C mice model bearing human non Hodgkin lymphoma was established. The positive rate of tumor cell surface CD20 was 95% upwards. Lymphoma bearing nude mice were randomly divided into 3 groups （5 mice in every group）, i.e. ^18F-FDG group, ^131I-Rituximab group and ^131 I-Rituximab group with ＂cold antibody＂ block, the latter two groups underwent SPECT scanning on the 2nd, 4th, 7th, 11th and 16th day in imaging study, while the treatment study was divided into 5 groups （3 mice in every group） including Rituximab 50 μg group, Rituximab 100 μg group, ^131I-Rituximab group and ^131I-Rituximab group with ＂ cold antibody＂ block. After 15 d, the tumor inhibition rate was calculated, then the mice were sacrificed to get tumor tissues for histological examination. Results Obvious uptake of 18F-FDG in tumor was not seen on PET/CT. When T/NT value was high, tumor was not shown in ^131I-Rituximab group, but was seen in 13, I Rituximab group with ＂cold antibody＂ block on the 7th day. Tumor inhibiting effect of ^131I-Rituximab group with ＂cold antibody＂ block was the highest among all five treatment groups, also he verified from histological examination. Conclusion Lymphoma inhibiting effect of taking radio-immunotherapy with ＂cold antibody＂ block is superior to radio-immunotherapy and immunotherapy. Radio-immunoimaging with ＂cold antibody＂ block is better than dedicate radio-immunoimaging.