title: Parasite-specific antibody and cellular immune responses in human infected with Necator americanus and Oesophagostomum bifurcum.
abstract: In this study parasite-specific antibody, cellular reactivity and Thl-type or Th2-type cytokine responses were investigated in humans concurrently infected with Necator americanus and Oesophagostomum bifurcum. The prospects for O. bifurcum-specific serodiagnosis based on IgG4 and IgE were evaluated. IgG4 showed low specificity for O. bifurcum due to antigen cross-reactivity with N. americanus, while IgE specifically distinguished between hookworm and O. bifurcum, and, in doubly infected patients, levels of O. bifurcum-specific as well as N. americanus-specific IgE were significantly elevated compared to those with N. americanus mono-infections. Cellular immunity was not strictly dominated by a Thl- or Th2- type reactivity. In co-infected patients cellular unresponsiveness to parasite antigens was observed, while cellular production of tumour necrosis factor alpha (TNF-alpha) and gamma-interferon (IFN-gamma) was greater in those doubly infected. Th2-type cytokines (interleukin-5 and interleukin-10) were produced in equal amounts by peripheral blood mononuclear cells from individuals with mono- and coinfections. Such mixed Thl-type and Th2-type immune responsiveness associated with persisting gastrointestinal parasitic nematodes may reflect a state of infection at which parasite-induced inflammatory and enteropathogenic responses co-exist, and furthermore, helminth coinfection will not only suppress parasite-specific cellular responsiveness but may also direct cytokine production towards a "permissive Th1-type cytokine profile" that favours parasite persistence.
authors.affiliation: Department of Parasitology, Faculty of Medicine, University of Leiden, The Netherlands.
authors.forename: D S
authors.initials: DS
authors.lastname: Pit
authors.forename: A M
authors.initials: AM
authors.lastname: Polderman
authors.forename: S
authors.initials: S
authors.lastname: Baeta
authors.forename: H
authors.initials: H
authors.lastname: Schulz-Key
authors.forename: P T
authors.initials: PT
authors.lastname: Soboslay
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000818:Animals; D000909:Antibodies, Helminth / Q000097:blood / Q000276:immunology*; D000918:Antibody Specificity; D000947:Antigens, Helminth / Q000276:immunology; D002648:Child; D016207:Cytokines / Q000378:metabolism; D005260:Female; D006801:Humans; D007111:Immunity, Cellular; D007073:Immunoglobulin E / Q000097:blood; D007074:Immunoglobulin G / Q000097:blood; D008297:Male; D008875:Middle Aged; D017221:Necator americanus / Q000276:immunology*; D009332:Necatoriasis / Q000150:complications / Q000276:immunology* / Q000469:parasitology; D009814:Oesophagostomiasis / Q000150:complications / Q000276:immunology* / Q000469:parasitology; D009815:Oesophagostomum / Q000276:immunology*; D013601:T-Lymphocytes / Q000276:immunology / Q000378:metabolism
chemical_list: D000909:Antibodies, Helminth; D000947:Antigens, Helminth; D016207:Cytokines; D007074:Immunoglobulin G; D007073:Immunoglobulin E