The detection of autoantibodies to IgE in plasma of individuals infected with hookworm (Necator americanus) and the demonstration of a predominant IgG1 anti-IgE autoantibody response.
In this study we have demonstrated significantly elevated levels of circulating IgG autoanti-IgE antibody in hookworm infected individuals from Kebasob village on Karkar Island, Papua New Guinea. Although anti-IgE activity was demonstrable in IgG1, IgG3 and IgG4, IgG1 was by far the most important subclass of IgG anti-IgE in terms of frequency of detection (34/39; 87.2%) and magnitude of increase (P = 0.0000); with IgG3 (16/39; 41.0%) and IgG4 (15/39; 38.5%) antibodies being considerably less prevalent. Plasma levels of IgG1 anti-IgE (P = 0.0019) and IgG3 anti-IgE (P = 0.0034) showed significant correlations with total IgE concentrations, but not with IgE specific to excretory-secretory worm products; thus suggesting that anti-IgE synthesis is more related to polyclonal hyper IgE production than to antigen-specific IgE stimulation. No correlation was seen between IgG subclass anti-IgE levels and faecal egg counts or worm burden. Given that our data failed to show a negative or a positive correlation between anti-IgE and the degree of infection with hookworm, it is tempting to speculate that the main role of autoanti-IgE is to provide the host with protection against immune complex- and IgE-mediated hypersensitivity reactions to parasitic antigens.
Shakib
F
F
Department of Immunology, University of Nottingham, UK.
Pritchard
D I
DI
Walsh
E A
EA
Smith
S J
SJ
Powell-Richards
A
A
Kumar
S
S
Edmonds
P
P
D000293:Adolescent; D000328:Adult; D000818:Animals; D000909:Antibodies, Helminth / Q000276:immunology*; D001323:Autoantibodies / Q000032:analysis*; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D007073:Immunoglobulin E / Q000276:immunology*; D007074:Immunoglobulin G / Q000096:biosynthesis*; D008297:Male; D008875:Middle Aged; D017221:Necator americanus / Q000276:immunology*; D009332:Necatoriasis / Q000276:immunology*; D017455:Receptors, IgE / Q000276:immunology
D000909:Antibodies, Helminth; D001323:Autoantibodies; D007074:Immunoglobulin G; D017455:Receptors, IgE; D007073:Immunoglobulin E