title: [Analysis of larval excretory-secretory antigen and its immunodiagnosis of Angiostrongyliasis cantonensis infection].
abstract: OBJECTIVE
  To analyze the diagnostic value of larval excretory-secretory antigen in Angiostrongylus cantonensis (LESA) infection.
  
  
  METHODS
  A.cantonensis larvae harvested from mice brain were cultured in vitro. The LESA and the adult worm antigens of A.cantonensis (AWA) were collected and analyzed using SDS-PAGE and Western blotting. Two ELISA systems were established using the two antigens (LESA-ELISA and AWA-ELISA) to detect the serum spectra from different sources.
  
  
  RESULTS
  SDS-PAGE and Western blotting displayed fewer protein and antigen bands for LESA than for the adult antigen. Two distinct bands of LESA (with relative molecular masses of 40 000 and 26 000) showed reactivity with the sera from patients with A. cantonensis infection. The serum levels of IgG and IgM antibodies to LESA increased at the beginning of infection in mice, reaching the peak on day 5 after infection and decreased on day 10. Compared with AWA-ELISA, LESA-ELISA showed a lower seropositive ratio in suspected patients with A.cantonensis, with also a lower cross-positive ratio in patients with schistosomiasis and clonorchis sinensis.
  
  
  CONCLUSIONS
  LESA possesses fewer antigen reaction bands than AWA. Although with a slightly lower positive ratio than AWA, LESA has a higher specificity for detecting serum antibodies in suspected cases of A.cantonensis infection, and therefore shows a potential for the diagnosis of angiostrongyliasis especially in the early stage and in current infection.
authors.affiliation: Department of Parasitology, School of Public Health and Tropical Medicine, Southern Medical Universtiy, Guangzhou 510515, China. zxcongufo@163.com
authors.forename: Xin
authors.initials: X
authors.lastname: Zhang
authors.forename: Min
authors.initials: M
authors.lastname: Liu
authors.forename: Yaxin
authors.initials: Y
authors.lastname: Wu
authors.forename: Zexun
authors.initials: Z
authors.lastname: Mo
authors.forename: Haoxian
authors.initials: H
authors.lastname: Shen
authors.forename: Daixiong
authors.initials: D
authors.lastname: Chen
authors.forename: Hua
authors.initials: H
authors.lastname: Li
mesh_terms: D017185:Angiostrongylus cantonensis / Q000276:immunology*; D000818:Animals; D000947:Antigens, Helminth / Q000276:immunology*; D004797:Enzyme-Linked Immunosorbent Assay; D006801:Humans; D007814:Larva / Q000276:immunology; D051379:Mice; D008807:Mice, Inbred BALB C; D051381:Rats; D017207:Rats, Sprague-Dawley; D017206:Strongylida Infections / Q000175:diagnosis* / Q000469:parasitology*
chemical_list: D000947:Antigens, Helminth