title: Immuno-PCR for detection of antigen to Angiostrongylus cantonensis circulating fifth-stage worms.
abstract: BACKGROUND
  Definitive diagnosis of infestation with Angiostrongylus cantonensis is difficult because the parasitic nematode is undetectable in the cerebrospinal fluid (CSF) of one-half of afflicted patients and the diagnostic sensitivity of ELISA for circulating worm antigens in patient sera is low. We studied immuno-PCR as a diagnostic tool.
  
  
  METHODS
  We studied 30 controls and 60 afflicted patients (30 confirmed by parasitologic analysis of CSF). We used a monoclonal antibody to capture circulating A. cantonensis antigens in serum samples. A DNA label generated by PCR amplification with biotinylated primer was bound by use of streptavidin to a biotinylated third antibody. Circulating antigens sandwiched by monoclonal antibody were detected by PCR amplification of the DNA label.
  
  
  RESULTS
  The detection limit of the ELISA was 100-1000 times higher than that of the immuno-PCR. The concentrations of circulating antigens in patients were markedly higher than those in controls (Wilcoxon rank-sum test, P <0.001). At a cutoff of 0.1 ng/L, sensitivity and specificity for immunodiagnosis of patients with angiostrongyliasis by immuno-PCR were 98% (95% confidence interval, 91-99%) and 100% (93-100%), respectively. The test was positive in all parasitologically confirmed cases.
  
  
  CONCLUSIONS
  Immuno-PCR is a promising technique for diagnosis of A. cantonensis infestation.
authors.affiliation: Department of Medical Technology, Fooyin University, 151 Chinhsuen Road, Ta-Liao Hsiang, Kaohsiung, Taiwan, ROC. Chmiye@cc.kmu.edu.tw
authors.forename: Soi-Moi
authors.initials: SM
authors.lastname: Chye
authors.forename: Shiu-Ru
authors.initials: SR
authors.lastname: Lin
authors.forename: Ya-Lei
authors.initials: YL
authors.lastname: Chen
authors.forename: Lee-Yi
authors.initials: LY
authors.lastname: Chung
authors.forename: Chuan-Min
authors.initials: CM
authors.lastname: Yen
mesh_terms: D017185:Angiostrongylus cantonensis / Q000276:immunology*; D000818:Animals; D000911:Antibodies, Monoclonal; D000947:Antigens, Helminth / Q000097:blood* / Q000134:cerebrospinal fluid; D006801:Humans; D007118:Immunoassay / Q000379:methods; D008581:Meningitis / Q000097:blood / Q000134:cerebrospinal fluid / Q000469:parasitology; D016133:Polymerase Chain Reaction / Q000379:methods; D012680:Sensitivity and Specificity; D017206:Strongylida Infections / Q000097:blood / Q000134:cerebrospinal fluid / Q000175:diagnosis
chemical_list: D000911:Antibodies, Monoclonal; D000947:Antigens, Helminth