量化检测日本血吸虫循环抗原的初步研究

Preliminary study on quantitative determination of circulating Antigens of Schistosoma japonicum

目的探索量化检测日本血吸虫循环抗原的方法。方法用AWA-PcAb/MG2双抗体夹心ELISA(S-ELISA)检测SEA-TCA抗原,并根据测得的OD490值和相应抗原浓度计算回归方程式,再用该法和fSjc26GST-PcAb双抗体夹心ELISA方法检测急慢性日本血吸虫病人的血清循环抗原。并初步应用于检测流行区和传播阻断地区的人群血清循环抗原。结果AWA-PcAb/MG2双抗体夹心ELISA测得SEA-TCA浓度(y)与OD490值(x)呈明显的正相关(r=0.981,y=128.08x-46.95);血清循环抗原的平均含量,急性血吸虫病人(206.27±36.62 ng/ml)显著高于慢性血吸虫病人(122.88±75.13 ng/ml)。两组双抗体S-ELISA检测急性血吸虫病人循环抗原的阳性率均为100%(34/34),慢性血吸虫病人循环抗原的阳性率则分别为87.50%(70/80)和78.57%(63/80),特异性分别为90.74%(98/108)和92.59%(100/108)。用以上两法对流行区和传播阻断地区的人群血清进行循环抗原检测,其阳性率分别为34.52%(87/252)和9.72%(49/504),具有显著性差异。结论两组双抗体S-ELISA用于检测日本血吸虫循环抗原均有较好的效果,其中AWA-PcAb/MG2双抗体夹心ELISA能量化检测日本血吸虫循环抗原。

Objective To estabish a method for quantititive determination of circulating antigens of Schistosoma japonicum, levels of SEA-TCA of S .japonicum were detected by sandwich ELISA with AWA-PcAb/MG2 and a series of OD490 values were obtained. According to the OD490 values（X） and corresponding SEA-TCA concentrations（y）, a regression equation was deduced which was used to quantitative calculation of the positive rate and average content of serum circulating antigens in acute and chronic schistosomiasis detected by sandaich ELISA with AWA-PcAb/MG2 and rSj26GST-PcAb. Furthermore, detection of circulating antigens in serum from different epidemic areas was also carried out. Obviously positive correlation between concentration of SEA-TCA and OI）490 value was proved and the regression equation（r = 0. 981, y = 128.98x- 46.95） was deduced. On the basis of quantitative detection of serum circulating antigens in achistosomiasis, there was significant difference statistically bet-wen 34 acute cases（206.27 ± 36.62 ng/ ml） and 80 chronic ones（ 122.88 ± 75.13 ng/ml）. Comparison between rSjc26GST-PcAb and AWA-PcAb/MG2 S-ELISA for circulating antigens of Schistosoma japonicum detection showed the positive rates of 34 acute cases were both 100 % （34/34）, while those of chronic cases were 87.50 % （70/80） and 78.57 % （63/80）, respectively. Detection results from 180 normal people showed specificity of 90.74 % and 97.30 %, respectively. In the field research, positive rate of circulating antigens from middle epidemic area（34. 52 %, 87/252）was markedly higher than that from transmit blocking area（9.72 %, 49/504）. In conclusion, both rSjc26GST-PcAb and AWA-PcAb/MG2 S-ELISA were suitable for detecting circulating antigens. Moreover, AWA-PcAb/MG2 S-ELISA can be used for quantitative determination of circulating antigens of Schistosoma japonicum.