title: Use of recombinant nucleoproteins in enzyme-linked immunosorbent assays for detection of virus-specific immunoglobulin A (IgA) and IgG antibodies in influenza virus A- or B-infected patients.
abstract: The nucleoprotein genes of influenza virus A/Netherlands/018/94 (H3N2) and influenza virus B/Harbin/7/94 were cloned into the bacterial expression vector pMalC to yield highly purified recombinant influenza virus A and B nucleoproteins. With these recombinant influenza nucleoproteins, enzyme-linked immunosorbent assays (ELISAs) were developed for the detection of influenza virus A- and B-specific immunoglobulin A (IgA) and IgG serum antibodies. Serum samples were collected at consecutive time points after the onset of clinical symptoms from patients with confirmed influenza virus A or B infections. Nucleoprotein-specific IgA antibodies were detected in 41.2% of influenza virus A-infected patients and in 66. 7% of influenza virus B-infected patients on day 6 after the onset of clinical symptoms. In serum samples taken on day 21 (influenza virus A-infected patients) or day 28 (influenza virus B-infected patients), nucleoprotein-specific IgA antibodies could be detected in 58.8 and 58.3% of influenza virus A- and B-infected patients, respectively. At the same time, IgG antibody rises were detected in 88.2% of influenza virus A-infected patients and in 95.8% of influenza virus B-infected patients. On comparison, hemagglutination inhibition assays detected antibody titer rises in 81.3 and 72.7% of patients infected with influenza viruses A and B, respectively. In contrast to the detection of nucleoprotein-specific IgG antibodies or hemagglutination-inhibiting antibodies, the detection of nucleoprotein-specific IgA antibodies does not require paired serum samples and therefore can be considered an attractive alternative for the rapid serological diagnosis of influenza.
authors.affiliation: WHO National Influenza Centre and Institute of Virology, Erasmus University Rotterdam, 3000 DR Rotterdam, The Netherlands. rmmelzwaan@viro.fgg.eur.nl
authors.forename: J T
authors.initials: JT
authors.lastname: Voeten
authors.forename: J
authors.initials: J
authors.lastname: Groen
authors.forename: D
authors.initials: D
authors.lastname: van Alphen
authors.forename: E C
authors.initials: EC
authors.lastname: Claas
authors.forename: R
authors.initials: R
authors.lastname: de Groot
authors.forename: A D
authors.initials: AD
authors.lastname: Osterhaus
authors.forename: G F
authors.initials: GF
authors.lastname: Rimmelzwaan
mesh_terms: D000818:Animals; D000914:Antibodies, Viral / Q000097:blood*; D004797:Enzyme-Linked Immunosorbent Assay; D005289:Ferrets; D006385:Hemagglutination Inhibition Tests; D006801:Humans; D007070:Immunoglobulin A / Q000097:blood*; D007074:Immunoglobulin G / Q000097:blood*; D009980:Influenza A virus / Q000276:immunology*; D009981:Influenza B virus / Q000276:immunology*; D007251:Influenza, Human / Q000276:immunology*; D019590:Nucleocapsid Proteins; D009698:Nucleoproteins; D011817:Rabbits; D011994:Recombinant Proteins / Q000276:immunology; D014758:Viral Core Proteins / Q000276:immunology*
chemical_list: D000914:Antibodies, Viral; D007070:Immunoglobulin A; D007074:Immunoglobulin G; D019590:Nucleocapsid Proteins; D009698:Nucleoproteins; D011994:Recombinant Proteins; D014758:Viral Core Proteins