title: European Sero-Epidemiology Network 2: standardisation of immunoassay results for pertussis requires homogeneity in the antigenic preparations.
abstract: A standardisation process, already developed during the earlier European Sero-Epidemiology Network (ESEN) project, was employed with a more robust algorithm to harmonise results of pertussis serological assays performed in 12 European and non-European countries. Initially, results from each country's own assay were compared with those obtained at the reference laboratory by means of an in-house pertussis toxin (PT)-based ELISA: seven countries used in-house or commercial PT-ELISAs; the other countries used assays based on Bordetella pertussis whole cell extracts (WCE) (three countries) or on combined PT-FHA (filamentous haemagglutinin) antigenic preparations (two countries). The WCE assays, although admitted for diagnostic purposes, confirmed their low correlation with the PT-ELISAs and their results could not be used for standardisation; the PT-FHA ELISAs gave results that were suitable for standardisation in one country but unsatisfactory in the other; the use of purified PT in serological assays confirmed its better reliability than other preparations and all PT-ELISAs results could be calibrated against those of the reference centre. In the standardisation process two high-titre cut-offs indicative of likelihood of recent infection (from within 4 weeks of disease onset up to 1 year after) were included for evaluations as they are suggested to be more useful, for the sero-epidemiological assays of immunity to pertussis, than the cut-off of protection, commonly employed, but still not defined for pertussis. Providing PT-ELISAs are used, standardisation of pertussis assay results is always possible and, when standardisation is performed, evaluation and comparison of the impact of different interventions can be also allowed, by measuring at the distribution of high antibody titres in the populations.
authors.affiliation: Department of Hygiene and Microbiology 'G. D'Alessandro', University of Palermo, Palermo, Italy. chiogia@unipa.it
authors.forename: Anna
authors.initials: A
authors.lastname: Giammanco
authors.forename: Antony
authors.initials: A
authors.lastname: Nardone
authors.forename: Richard
authors.initials: R
authors.lastname: Pebody
authors.forename: George
authors.initials: G
authors.lastname: Kafatos
authors.forename: Nick
authors.initials: N
authors.lastname: Andrews
authors.forename: Alfredo
authors.initials: A
authors.lastname: Chiarini
authors.forename: Susanna
authors.initials: S
authors.lastname: Taormina
authors.forename: Fernando
authors.initials: F
authors.lastname: de Ory
authors.forename: Katarina
authors.initials: K
authors.lastname: Prosenc
authors.forename: Bohumir
authors.initials: B
authors.lastname: Krize
authors.forename: Hans
authors.initials: H
authors.lastname: Hallander
authors.forename: Margaretha
authors.initials: M
authors.lastname: Ljungman
authors.forename: Esther
authors.initials: E
authors.lastname: Marva
authors.forename: Athanassios
authors.initials: A
authors.lastname: Tsakris
authors.forename: Darina
authors.initials: D
authors.lastname: O'Flanagan
authors.forename: François
authors.initials: F
authors.lastname: Schneider
authors.forename: Algirdas
authors.initials: A
authors.lastname: Griskevicius
authors.forename: Robert
authors.initials: R
authors.lastname: Vranckx
authors.forename: Ildiko
authors.initials: I
authors.lastname: Karacs
mesh_terms: D000907:Antibodies, Bacterial / Q000097:blood*; D000942:Antigens, Bacterial; D001886:Bordetella pertussis / Q000276:immunology*; D002138:Calibration; D005060:Europe; D006801:Humans; D007118:Immunoassay / Q000592:standards; D010567:Pertussis Vaccine / Q000276:immunology; D014917:Whooping Cough / Q000517:prevention & control*
chemical_list: D000907:Antibodies, Bacterial; D000942:Antigens, Bacterial; D010567:Pertussis Vaccine