重组巨细胞病毒多肽检测特异性 IgG 抗体 及抗体亲合力指数的评价.

Objective To investigate whether cytomegalovirus (CMV) recombinant polypeptides expressed in prokaryotic cells were suitable for detecting CMV-specific IgG antibodies and the IgG avidity index (AI). Methods Four genes of CMV, phosphoprotein 150 (pp150), pp28, non-structural protein pp52, and glycoproteins B (gB) were cloned and expressed in E. coli, respectively. Purified recombinant polypeptides, pp150, pp28, pp52, and gB were used to es‑ tablish the ELISA method to detect the specific IgG antibodies. CMV IgG in 126 positive and 74 negative serum samples were determined together with imported CMV IgG ELISA kit. Based on the results of CMV IgG detection in indirect ELISA, we further determined CMV IgG AI based on recombinant polypeptides pp150/2, pp150/3 and pp150/4 with higher positive and negative coincident rates. The CMV IgG AI was detected in eight primarily infected patients and seven latently-infected patients and we compared the results with those of the imported test kit. Results We prepared eight recombinant CMV polypeptides, including pp150/1, pp150/2, pp150/3, pp150/4, pp28, pp52/1, pp52/2, and gB. Compared with CMV IgG ELISA kit, recombinant polypeptide pp150/4 showed the highest positive coincident rate (90. 9%), fol‑ lowed by pp150/3 (89. 7%), pp150/2 (88. 9%) and pp150/1 (80. 2%). Of eight serum samples from primarily infected patients with AI of 15. 3% ‒ 29. 8% measured by imported test kit, four showed AI < 30% and the other four samples showed AI > 30% (39. 0%‒60. 4%) based on polypeptide pp150/4. In addition, of seven serum samples from latently-infected patients with AI of 59. 6%‒92. 3% measured by imported test kit, two showed AI of 22. 9% and 25. 1% respectively determined by recombinant CMV polypeptides. Statistically significant differences were found in the results of AI determined by recombinant CMV polypeptides and imported test kit (all P<0. 05). Similarly, the results of CMV IgG AI established based on recombinant polypeptide pp150/2 or pp150/3 were significantly different from those detected by imported test kit (all P<0. 05). Conclusion Recombinant polypeptide pp150 has good antigenicity, and can be used to detect CMV IgG in indirect ELISA, but it is not suitable for detection of CMV IgG AI. [ABSTRACT FROM AUTHOR]

目的 探讨大肠杆菌重组巨细胞病毒（CMV）多肽是否适合于检测 CMV特异性 IgG抗体以及 IgG抗体亲 合力指数（AI）。方法 利用分子克隆技术克隆CMV的pp150、pp28、pp52和gB这4种基因，大肠杆菌分别表达这些 基因，重组蛋白多肽纯化后，建立检测特异性IgG抗体的ELISA方法，与进口ELISA试剂盒同时检测126例CMV IgG 阳性和74例CMV IgG阴性血清。根据重组抗原ELISA检测CMV IgG的结果，选取阳性和阴性符合率均相对较高的重 组抗原pp150/2、pp150/3和pp150/4，进一步检测8例明确原发感染的婴幼儿血清、7例确定为潜在感染的儿童血清的 CMV IgG AI，并与进口试剂检测结果比较。结果 制备了 8 种 CMV 重组抗原，包括 pp150/1、pp150/2、pp150/3、 pp150/4、pp28、pp52/1、pp52/2和gB。与进口试剂盒相比，检测CMV IgG抗体时重组抗原pp150/4的阳性符合率最 高（90. 9%），其次为多肽pp150/3（89. 7%）、pp150/2（88. 9%）和pp150/1（80. 2%）。与进口ELISA试剂盒比较，重组 多肽pp150检测CMV IgG抗体的阳性率差异无统计学意义（P均>0. 05）。8例经进口试剂确定为原发感染血清的AI 值为15. 3%～29. 8%；以重组抗原pp150/4检测时，4例AI值<30%，4例AI值>30%（39. 0%～60. 4%），与进口试剂检 测值比较差异有统计学意义（P均<0. 05）。7例明确为潜在感染的血清进口试剂AI值为59. 6%～92. 3%，2例经重 组抗原检测AI值分别为22. 9%和25. 1%，与进口试剂检测结果比较差异有统计学意义（P均<0. 05）。同样，利用重 组抗原pp150/2和pp150/3检测的IgG AI值与进口试剂盒检测值比较差异有统计学意义（P均<0. 05）。结论 重组 多肽pp150具有良好的抗原性，可用于检测CMV IgG抗体，但不适合于CMV IgG AI检测。 [ABSTRACT FROM AUTHOR]