单克隆抗体74D_(11)、SJA_(111)检测慢性日本血吸虫病循环抗原的研究

本研究用双抗夹心ＥＬＩＳＡ法检测慢性日本血吸虫病人血清循环抗原，观察血吸虫感染家兔血清循环抗原的动态变化。该方法采用兔抗ＡＷＡ－ＩｇＧ作包被抗体，抗日本血吸虫成虫和虫卵单抗ＳＪＡ１１１和７４Ｄ１１组合作Ⅱ抗，１７２例经粪孵毛蚴确诊的血吸虫病人中，１３６例循环抗原阳性（７９．１％），其中轻度（毛蚴数＜５只／２０克粪）、中度（６－２０）、重度（大于２０）感染者循环抗原阳性率分别为７３．４％、８７．７％、９２．８％，检测６５例健康献血员，２０例肺吸虫病人，１２例华支睾吸虫病人，１０倒包虫病人，交叉反应率依次为１．５％、５％、０％、０％，４２例经吡喹酮治疗后的血吸虫病人用该方法复查，治后３月和６月随访粪孵毛蚴阴转者中，循环抗原阴转率分别为７８．０％和９２．１％，考核疗效明显优于检测循环抗体。用单抗ＳＪＡ１１１检测感染家兔循环抗原动态变化，循环抗原于感染后３—４周可检出，７周达高峰，以后逐渐消退，而循环抗体（ＩｇＧ）推迟１周出现，８－９周达高峰。实验结果表明，血吸虫病血清ＣＡｇ阳性率与感染度有关，可在早期检出，检测方法具有较高敏感性和特异性，可用于早期诊断和疗效考核。

DETECTION OF CIRCULATING ANTIGEN IN SERA FROM PATIENTS WITH CHRONIC SCHISTOSOMIASIS JAPONICA USING MONOCLONAL ANTIBODY 74D_(11) AND SJA_(111)

Circulating antigen (CAg) in patients with chronic schistosomiasis japonica were detected by sandwichELISA and the dynamic changes of circulating antigen of rabbit infected with schistosomiasis were observed.In this research work. rabbit anti-Schistosoma japonicum adult worm (AWA-IgG)was used as coated antibody and the combination of two monoclonal antibodies SJA111 and 74D11 as second antibody. Among 172 cases of schistosomiasis confirmed by stool hatching method,CAg positive rate was 79. 1% (136/172). CAg positiverates were 73. 4%, 87. 7% and 92. 8% respectively in cases with light, medium and heavy infection intensity.The cross reaction rates for 65 normal individuals, 12 cases of clonorchiasis sinensis,20 cases of paragonimiasis skrjabini and 10 alveolar echinococcosis were 1. 5%, 5%. 0%, 0% respectively. For 42 cases treated withpraziquantel,CAg negative rates were 78. 0% and 92. 1% respectively 3 and 6 months after treatment. CAgand CAb dynamic changes were observed in rabbits experimentally infected with S. japonicum:CAg could be detected in 3-4 weeks after infection,up to peak in 7 weeks after infection and then gradually declined;however circulating antibody(IgG)could be detected 1 week later than CAg and up to peak in 8-9 weeks after infection. The results showed ti,at CAg positive rate in sera of schistosomiasis patients was associated with intensity of infection and CAg could be found in early stage of infection. This method could be used for early diagnosis and therapeautic evaluation with high sensitivity and specificity.