title: Immune responses in human necatoriasis: association between interleukin-5 responses and resistance to reinfection.
abstract: Cytokine and proliferative responses to Necator americanus infection were measured in a treatment-reinfection study of infected subjects from an area of Papua New Guinea where N. americanus is highly endemic. Before treatment, most subjects produced detectable interleukin (IL)-4 (97%), IL-5 (86%), and interferon (IFN)- gamma (64%) in response to adult N. americanus antigen. Pretreatment IFN- gamma responses were negatively associated with hookworm burden, decreasing by 18 pg/mL for each increase of 1000 eggs/gram (epg) (n=75; P<.01). Mean IFN- gamma responses increased significantly after anthelmintic treatment, from 166 to 322 pg/mL (n=42; P<.01). The intensity of reinfection was significantly negatively correlated with pretreatment IL-5 responses, decreasing by 551 epg for each 100 pg/mL increase in production of IL-5 (n=51; P<.01). These data indicate that there is a mixed cytokine response in necatoriasis, with worm burden-associated suppression of IFN- gamma responses to adult N. americanus antigen. Resistance to reinfection is associated with the parasite-specific IL-5 response.
authors.affiliation: School of Biology, University of Leeds, Leeds, United Kingdom. r.j.quinnell@leeds.ac.uk
authors.forename: Rupert J
authors.initials: RJ
authors.lastname: Quinnell
authors.forename: David I
authors.initials: DI
authors.lastname: Pritchard
authors.forename: Andrew
authors.initials: A
authors.lastname: Raiko
authors.forename: Alan P
authors.initials: AP
authors.lastname: Brown
authors.forename: Marie-Anne
authors.initials: MA
authors.lastname: Shaw
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000818:Animals; D000947:Antigens, Helminth / Q000276:immunology*; D002648:Child; D016207:Cytokines / Q000378:metabolism; D005260:Female; D006801:Humans; D015848:Interleukin-5 / Q000378:metabolism*; D008213:Lymphocyte Activation; D008297:Male; D008875:Middle Aged; D017221:Necator americanus / Q000276:immunology*; D009332:Necatoriasis / Q000276:immunology* / Q000469:parasitology; D010219:Papua New Guinea; D010270:Parasite Egg Count; D012008:Recurrence
chemical_list: D000947:Antigens, Helminth; D016207:Cytokines; D015848:Interleukin-5