曼氏裂头蚴实验感染小鼠吡喹酮治疗后血清IgG水平的变化

Serum IgG levels in mice experimentally infected with sparganum mansoni after treatment with praziquantel

目的观察曼氏裂头蚴实验感染小鼠吡喹酮治疗后血清IgG抗体水平的变化。方法将40只雄性昆明小鼠随机分为4组（每组10只）,1~3组分别经口接种1、5、1条裂头蚴,1组和2组于感染后3周应用吡喹酮灌胃治疗（总剂量2 800 mg/kg体重,3次/d,疗程3 d）,3组和4组分别为阳性和空白对照组。每周尾静脉采血,ELISA检测血清裂头蚴IgG抗体。治疗后18周剖杀,收集裂头蚴并计算减虫率。结果感染后3周,1条和5条裂头蚴感染小鼠的血清IgG抗体阳性率均为100%;两组小鼠治疗后1周血清IgG抗体水平快速升高,治疗后2周达峰值,然后开始下降,治疗后18周两组小鼠的血清IgG抗体阳性率分别为70%和100%,与治疗后5周相比无明显下降;减虫率分别为20%和0。检出的虫体平均长26.1 cm,比接种时虫体（平均长5 cm）均显著增长,其中36.21%（21/58）的虫体形成囊包。结论吡喹酮（2 800 mg/kg体重）对裂头蚴无明显杀虫作用,裂头蚴感染小鼠应用吡喹酮治疗后血清抗裂头蚴IgG水平无明显下降。

Objective To observe the changes in serum IgG levels in mice experimentally infected with sparganum mansoni after treatment with praziquantel.Methods Forty male Kunming mice were randomly divided into 4 groups（10 mice per group）.Groups 1-3 were orally inoculated with 1,5,and 1 sparganum,respectively.Groups 1 and 2 were treated with praziquantel（total dose of 2 800/kg body weight,three times/day for three days）3 weeks post infection（wpi）.Group 3 served as the positive control and group 4 served as the blank control.Blood samples were collected weekly and serum anti-sparganum antibody IgG was assayed with ELISA.All of the mice were sacrificed and dissected 18 weeks after treatment,the spargana were recovered and the worm reduction rate was determined.Results Mice infected with 1 or 5 spargana tested positive for serum antibody IgG at a rate of 100% at 3 wpi.The levels of serum anti-sparganum IgG increased rapidly 1 wpi and reached their peak 2 wpi,and then the IgG levels subsequently decreased.As late as 18 wpi two groups of mice still tested positive for serum antibody IgG at rates of 70% and 100%,respectively.The levels of IgG did not decrease markedly compared to those 5 wpi.The worm reduction rate was 20% and 0 in the two groups.Additionally,the recovered worms（mean length： 26.1cm） were clearly larger than the inoculated worms（mean length： 5 cm）,and 36.21%（21/58） of the recovered worms were encapsulated.Conclusion Praziquantel（2 800 /kg） has no evident killing effect on sparganum and after treatment with praziquantel there was no obvious drop in serum anti-sparganum IgG levels in mice infected with sparganum.