弓形虫病IgM免疫吸附凝集试验（ISAGA）的建立

目的∶建立检测弓形虫 Ｉｇ Ｍ 抗体的免疫吸附凝集试验 （ Ｉ Ｓ Ａ Ｇ Ａ） 。方法∶ Ｕ 型微孔板以适宜浓度的羊抗人 Ｉｇ Ｍ 抗体包被， 用１ ％ 牛血清白蛋白封闭， 洗板后加入待测血清， 在３７ ℃孵育后洗涤， 加入弓形虫（ Ｒ Ｈ 株） 速殖子抗原悬液， 置３７ ℃过夜后观察结果。将其与丹麦的 Ｉ Ｓ Ａ Ｇ Ａ 和 Ｅ Ｌ Ｉ Ｓ Ａ 检测的结果以及玻片 Ｅ Ｉ Ａ 检测的结果作比较。结果∶本法与丹麦的试验检测丹麦孕妇４４ 份血清， 总符合率为９３２ ％ ；与玻片 Ｅ Ｉ Ａ 检测丹麦和上海孕妇６７ 份血清， 总符合率为９２５ ％ ， 两法的滴度之间明显相关 （γ＝ ０５８９ ， Ｐ＜ ０００１） ， Ｉ Ｓ Ａ Ｇ Ａ 滴度较玻片 Ｅ Ｉ Ａ 高１８ 倍； 用 Ｗ Ｈ Ｏ 国际生物标准化实验室提供的标准的抗弓形虫人血清定量测得其灵敏度为００８ Ｉ Ｕ／ ｍｌ。结论∶ Ｉｇ Ｍ Ｉ Ｓ Ａ Ｇ Ａ 具有敏感性、特异性高， 操作简便等优点， 不仅可作为弓形虫急性感染和慢性感染活动期的一种检测手段， 而且适用于弓形虫感染调查的大规模筛选。

Establishment of immunoglobulin M(IgM)-immunosorbent agglutination assay (ISAGA) for diagnosis of toxoplasmosis.

AIM: To establish an immunosorbent agglutination assay (ISAGA) for detection of IgM antibodies against Toxoplasma gondii. METHODS: In the ISAGA, wells of microtiter plates were coated with anti-human IgM antibodies and sealed with 1% bovine serum albumin. After the test sera were added and incubated, the plates were washed, T. gondii tachyzoite antigen suspension was added, and incubated overnight at 37 degrees C. The ISAGA results were evaluated by comparing with those detected by Danish ISAGA and ELISA and those detected by slide enzyme immunoassay (S-EIA). RESULTS: Forty-four sera from Danish pregnant women were tested by the IgM-ISAGA, 41(93.2%) were consistent with the Danish results. Sixty-seven sera from Danish and Shanghai pregnant women were detected by IgM-IgM-ISAGA and S-EIA, the total consistency rate was 92.5%. A significant correlation was found between the titers of the ISAGA and S-EIA, with a Pearson correlation coefficient of 0.589(P < 0.001). The titers of ISAGA were eighteen times higher than those of S-EIA. This method enables the detection of IgM antibodies as low as approximately 0.08 IU/ml. CONCLUSION: The IgM-ISAGA is therefore sensitive, specific, easy to perform, and is useful for mass screening and diagnosing recent Toxoplasma infection or reactivation.