弓形体IgG抗体亲和力指数在胎儿宫内感染中的临床意义

Clinical Evaluation of Fetus Intrauterine Infection in Immunoglobulin G Avidity Index to Toxoplasma.

【目的】探讨弓形体(toxoplasma,TOX)IgG抗体亲和力指数,判断弓形体感染孕妇宫内感染的概率。【方法】ELISA法检测中晚期孕妇弓形体特异性抗体IgM和IgG,并对150例TOX-IgM或TOX-IgG阳性孕妇的胎儿或新生儿脐血进行TOX-IgM检测;采用尿素变性试验检测弓形体感染孕妇TOX-IgG抗体亲和力指数(avidity index,AI)。【结果】孕妇弓形体IgM抗体阳性和IgG抗体阴性58例;弓形体IgM和IgG抗体阳性22例;弓形体IgM抗体阴性和IgG抗体阳性70例。胎儿或新生儿IgM阳性44例。原发性感染宫内感染率高于继发性感染(P<0.05),活动性感染宫内感染率高于非活动性(P<0.01),AI≤30%宫内感染率高于AI>30%(P<0.01)。【结论】IgG抗体亲和力指数AI≤30%结合IgM阳性有助于提高判断弓形体宫内感染的发生率。

[Objective] To explore the action of IgG antibodies avidity index in fetus intrauterine infection of pregenant women to toxoplasmosis infection. [Methods] TOX-IgM and TOX-IgG of 150 pregnant women in second or third trimester and their newborn infants/fetus were studied by ELISA assay, and TOX-IgG antibodies avidly index of pregnant women were measured by urea denaturalization trial. [Results] In maternity, we found TOX-IgM positive and TOX-IgG positive, 58 sera; TOX-IgM positive and TOX-IgG negative, 22 sera; TOX-IgM negative and TOX-IgG nega- tive, 22 sera. In their newborn infants/fetus, we also found TOX-IgM positive, 44 sera. Intrauterine infection rate of pri- mary infection was higher than that of recurrent infection （p（0.05）. Intrauterine infection rate of activity infection was higher than that of stillness infection （P（0.01）. Intrauterine infection rate of AI≤30% was higher than that of AI〉30% （P〈0.01）. [Conclusion] Combination of TOX-IgG antibodies avidiy index （AI≤30%） and TOX-IgM positive may be helpful for diagnosis of intrauterine infection.