直接免疫荧光法检测阴道毛滴虫

目的研究多克隆抗体直接免疫荧光法(directimmunofluorescenceassay,DFA)检测阴道毛滴虫的最佳反应条件及临床应用意义。方法确诊为阴道炎的患者取阴道分泌物,经培养收集虫体,稀释成悬液,制作抗原片。取阴道毛滴虫免疫山羊血清,按Marssall氏法用异硫氰酸荧光素(FITC)标记抗体,观察不同抗体稀释度(1:10～1:2560)、不同孵育时间(15,30,45,60,90,120min)、不同封闭剂(1％牛血清白蛋白,10％牛血清白蛋白及10％小牛血清)对DFA检测阴道毛滴虫的影响。对102例阴道炎患者标本分别用培养法、悬滴法和DFA作临床检验。结果抗体稀释度1:160、37℃孵育45min、封闭剂1％或10％牛血清白蛋白为最佳反应条件。检测102例临床标本,3种方法均阳性的16例,均阴性的68例。有13倒悬滴法、3例DFA检测阴性,而另2法阳性。1倒悬滴法阴性,DFA阳性,培养法未能证实。以培养法为标准,DFA敏感性为87.9％,特异性为98.6％。结论DFA可作为悬滴法的一种替代手段用于临床检验。

Detection of Trichomonas vaginalis with Direct Immunofluorescence Assay

OBJECTIVE: To detect Trichomonas vaginalis (Tv) by direct immunofluorescence assay (DFA) and discuss its clinical significance. METHODS: The parasites at a concentration of 3 x 10(5) cells/L were fixed by acetone on slides which were then blocked by 1% BSA (bovine serum albumin) or 10% BSA or 10% NCS (newborn calf serum) respectively, incubated with different dilution of polyclonal goat anti-Tv IgG (1:20-1:2,560) for different incubation time (15, 30, 45, 60, 90, 120 min). 120 clinical vaginal specimens were examined by direct immunofluorescence assay, the wet mount method and the in vitro cultivation. RESULTS: Blocked by 1% or 10% BSA, incubated at 37 degrees C for 45 min with a titer 1:160 of polyclonal antibody were the optimal conditions for direct immunofluorescence assay. Its sensitivity and specificity were 87.9% and 98.6% respectively in comparison with the in vitro cultivation method. CONCLUSION: Direct immunofluorescence assay is a useful alternative to the wet mount method which shows a lower sensitivity.