豚鼠模型中结核菌素纯蛋白衍生物量效关系比较研究

Comparison of dose-effect relationship for purified protein derivative of tuber culin in guinea pig model

目的在不同分枝杆菌致敏豚鼠模型中研究结核菌素纯蛋白衍生物(purified protein derivative of tuberculin,TB-PPD)的量效关系。方法将受试豚鼠随机分成6组:结核分枝杆菌H37Rv活菌致敏组、结核分枝杆菌临床株CMCC 94757、94754、94766致敏组、卡介苗(Bacillus Calmette-Guérin vaccine,BCG)致敏组和灭活结核分枝杆菌H37Rv致敏组。各组豚鼠分别于左侧大腿腹股沟皮下注射相应致敏原,5~6周后,所有豚鼠于脊柱两侧皮内注射20 IU/m L TB-PPD和50 IU/m L TB-PPD各0.1 m L;于注射后24 h、48 h观察和记录局部硬结的纵径与横径,计算平均值。结果所有组别豚鼠接受两种规格TB-PPD皮试后,无论是24 h还是48 h,局部硬结反应直径均大于10 mm,全部阳性,阳转率均为100%。5 IU TB-PPD皮试反应强度高于2 IU TB-PPD,存在明显的剂量效应关系。其中,24 h结果显示:2 IU TB-PPD和5 IU TB-PPD在H37Rv活菌致敏组、94766致敏组、灭活H37Rv致敏组皮试反应大小差异无统计学意义(t=2.291、P=0.071;t=2.722、P=0.053;t=1.76、P=0.153),其余3组5 IU TB-PPD皮试反应强度高于2 IU TB-PPD,差异均有统计学意义(t=4.098、P=0.015;t=4.811、P=0.009;t=3.068、P=0.037)。48 h硬结反应和24 h、48 h平均硬结反应结果均显示:在各致敏组豚鼠模型中5 IU TB-PPD皮试反应强度均高于2 IU TB-PPD,皮试反应大小均有统计学差异(t=3.471、P=0.018;t=3.371、P=0.020;t=6.216、P=0.003;t=5.244、P=0.006;t=3.959、P=0.017;t=4.674、P=0.010;t=4.824、P=0.008;t=3.794、P=0.019;t=3.857、P=0.018;t=2.86、P=0.046;t=3.539、P=0.024;t=3.365、P=0.028)。结论各组豚鼠致敏模型中5 IU TB-PPD的效价均明显高于2 IU TB-PPD,存在较为明显的量效关系。各种感染状态下,虽然高剂量制品可诱导更强的迟发型超敏(delayed type hypersensitivity,DTH)反应,但低剂量制品也不影响其阳性检出率。

Objective To evaluate the dose-effect relationship for purified protein derivative of tuberculin（ TB-PPD） in guinea pig models sensitized by different mycobacteria. Methods The guinea pigs were randomly divided into six groups including H37 Rv,94757,94754,94766,BCG and inactivated H37 Rv,and immunized with corresponding allergens,after5-6 weeks given intradermal injections with 0.1 m L 20 IU/m L TB-PPD and 50 IU/m L TB-PPD,respectively. Skin reactions defined by diameter and internal transverse were read after 24 and 48 hours,and the means of them counted as the reaction diameter. Results All guinea pigs responded to PPD with positive skin reactions,no matter 24 h or 48 h,the reaction diameters were more than 10 mm,but the response intensity of 5 IU TB-PPD was greater than 2 IU TB-PPD. The test showed for both 2 IU TB-PPD and 5 IU TB-PPD after 24 h,there were no a statistical difference（ t = 2. 291,P = 0. 071; t = 2. 722,P =0.053; t = 1.76,P = 0.153） between H37 Rv,94766 and inactivated H37 Rv,but statistical difference（ t = 4. 098,P = 0. 015; t = 4. 811,P = 0. 009; t = 3. 068,P = 0. 037） between other groups. The skin test results（ after 48 h） and the average reaction（ after 24 h,48 h） showed there were statistical differences（ t = 3.471,P = 0.018; t = 3.371,P = 0.020; t = 6.216,P = 0.003; t = 5.244,P = 0.006; t = 3.959,P = 0.017; t =4.674,P = 0.010; t = 4.824,P = 0.008; t = 3.794,P = 0.019; t = 3.857,P = 0.018; t = 2.86,P = 0.046; t = 3.539,P =0.024; t = 3.365,P = 0.028） in every groups. Conclusion In each model group the effect of the 5 IU TB-PPD was obviously higher than that of 2 IU TB-PPD,so there was presence a dose-effect relationship. Although the high dose can induce a stronger reaction（ delayed type hypersensitivity,DTH） under a variety of infections,but the low dose can not interfere with the positive detection rate.