title: The serological diagnosis of human clonorchiasis by time-resolved fluoroimmunoassay based on GST2-specific IgG4 detection.
abstract: Due to its delayed fluorescence of a lanthanide chelate, high accuracy and low background the broad linear range, long fluorescent life-time and large Stoke's shift of europium chelates, the time-resolved fluorescence has been developed for higher sensitive immunoassay. In this article, a simple, sensitive and specific method-time-resolved fluoroimmunoassay (TRFIA) was adopted for immunoassay of clonorchiasis, and recombinant glutathione transferases 2 of Clonorchis sinensis (rCsGST2) was used as a diagnostic antigen. To evaluate this novel assay for clinical applications, 409 serum samples were investigated. The diagnostic accuracy of the antigen was evaluated by receiver-operating characteristic (ROC) analysis. The area under the ROC curve (AUC) was 0.965, 95% confidence interval (CI, 0.946, 0.985). To eliminate the random influence of ambient temperature, test parameters, photometric instruments and so on, the cut-off value was expressed as ratios between the fluorescence of sample and that of a well-defined negative control serum, and the deduced cut-off value was 9.3605. At the optimum cut-off criteria, the technique has a sensitivity of 95.80%, specificity of 93.60%. And the cross reactivity revealed that its cross reactivity with Schistosoma japonicum, round worm, hook worm, whip worm, and Toxoplasma gondii was 9.3, 8.3, 7.6, 9.8, and 5.0%, respectively. Kappa score of agreement between TRFIA and microscopic examination of stools was 0.892, P < 0.05. These combined results showed that our method is feasible and could be used for the clinical determination of clonorchiasis.
authors.affiliation: Department of Parasitology, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China.
authors.forename: Jin
authors.initials: J
authors.lastname: Xu
authors.forename: Lexun
authors.initials: L
authors.lastname: Wang
authors.forename: Chuanhuan
authors.initials: C
authors.lastname: Deng
authors.forename: Xuchu
authors.initials: X
authors.lastname: Hu
authors.forename: Ran
authors.initials: R
authors.lastname: Li
authors.forename: Tingjin
authors.initials: T
authors.lastname: Chen
authors.forename: Dan
authors.initials: D
authors.lastname: Ning
authors.forename: Yingsong
authors.initials: Y
authors.lastname: Wu
authors.forename: Yan
authors.initials: Y
authors.lastname: Huang
authors.forename: Xuerong
authors.initials: X
authors.lastname: Li
authors.forename: Zhongdao
authors.initials: Z
authors.lastname: Wu
authors.forename: Xinbing
authors.initials: X
authors.lastname: Yu
authors.forename: Yonglong
authors.initials: Y
authors.lastname: Li
mesh_terms: D000818:Animals; D003003:Clonorchiasis / Q000175:diagnosis*; D003004:Clonorchis sinensis / Q000201:enzymology; D003429:Cross Reactions; D015200:Fluoroimmunoassay / Q000379:methods*; D005982:Glutathione Transferase; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood*; D011994:Recombinant Proteins; D012680:Sensitivity and Specificity
chemical_list: D007074:Immunoglobulin G; D011994:Recombinant Proteins; D005982:Glutathione Transferase