日本血吸虫病肠相关与卵相关抗原血症检测的诊断互补性初报

A PRELIMINARY REPORT ON DIAGNOSTIC COMPLEMENTARITY OF GUT ASSOCIATED AND EGG ASSOCIATED ANTIGENEMIA IN SCHISTOSOMIASIS JAPONICA

应用经羟基磷灰石纯化，偶联长链生物素ＢＡＣＨ（Ｂｉｏｔｉｎａｍｉｎｏｃａｐｒｙｌｈｙｄｒａｚｉｄｅ）的两株主要识别卵相关不同表位的单克隆抗体建立检测灵敏度达微微克水平的硷性磷酸酶抗原捕获酶联试验（ＢＡ－ＡＰＥＬＩＳＡ），对粗制日本血吸虫卵抗原ＳＥＡｊ－ＴＣＡ的检测极限，２Ｈ１０－ＥＬＩＳＡ可达１—０．３ｎｇ／ｍｌ，仅有效地检出日本血吸虫种特异的卵抗原表位分子；而２Ｈ１－ＥＬＩＳＡ则达３．２ｎｇ／ｍｌ，亦能灵敏地检示曼氏血吸虫的卵抗原组分。两组试验反复试用于日本血吸虫病例及正常人群血样检测，显示有非常明显的ＯＤ消光读数差异。同时采用已建立的１Ｂ１０－ＡＰＥＬＩＳＡ检测肠相关ＣＡＡ系列，以平行检测的健康对照组消光ＯＤ均值＋３ＳＤ为阳性界值，对３组采自不同流行区的慢性或混合型病例同批血样进行肠相关ＣＡＡ及卵相关２Ｈ１０和２Ｈ１的二联或三联叠加检测，其累计检出率都得到不同程度的提高，尤以低度流行区的慢性病例组更为明显。

With Hyroxylapatite purified preparations and BACH(biotin aminocapryl hydrazide) biotinylated McAbs, 274 2H10 and 273 2H1,recognizing different egg associated epitopes, biotin avidin(BA)involved alkaine phosphatase (AP) ELISA with detecting sensi tivities reaching nanogram levels (10 -9 ) were set up. The detectable limit for crude preparations of Schistosoma japonicum SEAJ TCA in 2H10 ELISA achieved 1.0 3.2 ng/ml, in which only S. japonicum specific egg antigens were efficiently detected, whereas with 2H1 ELISA, which could detect SEA TCA of both S. japonicum and S. mansoni species, an end point of detecting 3.2 ng/ml was obtained. Repeated tests with human serum groups revealed very significant differences of extinction OD readings between patients and normal individuals. For detection combinations, a previously established anti CAA homologous AP ELISA system was parallelly used for gut associated antigenemia determinations. Taking the mean extinction OD reading of a parallel normal serum group plus 3 SD as corresponding cut off values, 3 patient groups (n=82,52,39) from different areas of transmission intensity were subjected to accumulating determinations for egg and gut associated antigenemiae. Improved detectabilities to variable extent were achieved in either of the 2 or 3 combinations. The study thus demonstrated that the diagnostic efficiency for human schistosomiasis could be improved by multi epitope detections for more than one target molecule using corresponding McAbs, especially in areas where the transmission intensity of the disease is comparatively lower.