title: Age-dependent impairment of IgG responses to glycosylphosphatidylinositol with equal exposure to Plasmodium falciparum among Javanese migrants to Papua, Indonesia.
abstract: Immune responses directed at glycosylphosphatidylinositol (GPI) anchors of Plasmodium falciparum may offer protection against symptomatic malaria. To independently explore the effect of age on generation of the anti-GPI IgG response, we measured serum anti-GPI IgGs in a longitudinal cohort of migrant Javanese children (6-12 years old) and adults (> or = 20 years old) with equivalent numbers of exposures to P. falciparum in Papua, Indonesia. While the peak response in adults was achieved after a single infection, comparable responses in children required > or = 3-4 infections. Significantly fewer children (16%) than adults (41%) showed a high (optical density > 0.44) anti-GPI IgG response (odds ratio [OR] = 3.8, 95% confidence interval [CI] = 2.3-6.3, P < 0.0001), and adults were more likely to show a persistently high response (OR = 5.5, 95% CI = 1.0-56.8, P = 0.03). However, the minority of children showing a strong response were significantly less likely to experience symptoms with subsequent parasitemia compared with those with a weak response (OR = 4.0, 95% CI = 1.1-13.8, P = 0.02). This effect was not seen among high- and low-responding adults (OR = 1.2, 95% CI = 0.5-2.8, P = 0.60). Host age, independent of cumulative exposure, apparently represents a key determinant of the quantitative and qualitative nature of the IgG response to P. falciparum GPI.
authors.affiliation: United States Navy Medical Research Unit 2, Jakarta, Indonesia. sarah.hudson-keenihan@adelaide.edu.au
authors.forename: Sarah N
authors.initials: SN
authors.lastname: Hudson Keenihan
authors.forename: Sutanti
authors.initials: S
authors.lastname: Ratiwayanto
authors.forename: Saraswati
authors.initials: S
authors.lastname: Soebianto
authors.lastname: Krisin
authors.forename: Harijani
authors.initials: H
authors.lastname: Marwoto
authors.forename: Gowdahalli
authors.initials: G
authors.lastname: Krishnegowda
authors.forename: D Channe
authors.initials: DC
authors.lastname: Gowda
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Bangs
authors.forename: David J
authors.initials: DJ
authors.lastname: Fryauff
authors.forename: Thomas L
authors.initials: TL
authors.lastname: Richie
authors.forename: Sanjai
authors.initials: S
authors.lastname: Kumar
authors.forename: J Kevin
authors.initials: JK
authors.lastname: Baird
mesh_terms: D000328:Adult; D000375:Aging / Q000276:immunology*; D000818:Animals; D000953:Antigens, Protozoan / Q000097:blood / Q000276:immunology*; D002648:Child; D004641:Emigration and Immigration; D005260:Female; D017261:Glycosylphosphatidylinositols / Q000097:blood* / Q000276:immunology*; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood / Q000276:immunology*; D007214:Indonesia / Q000208:ethnology; D016778:Malaria, Falciparum / Q000276:immunology*; D008297:Male; D010963:Plasmodium falciparum / Q000276:immunology*; D012307:Risk Factors
chemical_list: D000953:Antigens, Protozoan; D017261:Glycosylphosphatidylinositols; D007074:Immunoglobulin G