Loading...
Respiratory atopic disease, Ascaris-immunoglobulin E and tuberculin testing in urban South African children
Respiratory atopic disease, Ascaris-immunoglobulin E and tuberculin testing in urban South African children
Obihara, C.C. Beyers, N. Gie, R.P. Hoekstra, M.O. Fincham, J.E. Marais, B.J. Lombard, C.J. Dini, L.A. Kimpen, J.L.L.
Obihara, C.C.
Beyers, N.
Gie, R.P.
Hoekstra, M.O.
Fincham, J.E.
Marais, B.J.
Lombard, C.J.
Dini, L.A.
Kimpen, J.L.L.
Abstract
Background Epidemiological relation of intestinal helminth infection and atopic disease, both
associated with a T-helper (Th) 2 immune response, is controversial, as it has been reported
that helminth infection may either suppress or pre-dispose to atopic disease. This relation has
not been tested in an area with a high burden of Mycobacterium tuberculosis (MTB) infection,
a known Th1-stimulating infection.
Objective To study the association of intestinal helminth infection and atopic disease in a
community where helminth infection is endemic and MTB infection is high.
Methods Three-hundred and fifty-nine randomly selected children aged 6–14 years from a
poor urban suburb were tested with allergy questionnaire, skin prick test (SPT) to common
aeroallergens, Ascaris-specific IgE (Ascaris-sIgE), fecal examination for pathogenic intestinal
helminths and tuberculin skin testing (TST). Histamine bronchoprovocation was tested in the
group of children aged 10 years and older. Results were corrected for demographic variables,
socioeconomic status, parental allergy, environmental tobacco smoke (ETS) exposure in the
household, recent anthelminthic treatment and for clustering in the sampling unit.
Results Ascaris-sIgE was elevated in 48% of children, Ascaris eggs were found in 15% and
TST was positive in 53%. Children with elevated Ascaris-sIgE had significantly increased risk
of positive SPT to aeroallergens, particularly house dust mite, atopic asthma (ever and recent),
atopic rhinitis (ever and recent) and increased atopy-related bronchial hyper-responsiveness.
In children with negative TST (o10 mm), elevated Ascaris-sIgE was associated with
significantly increased risk of atopic symptoms (adjusted odds ratio (ORadj) 6.5; 95%
confidence interval (CI) 1.9–22.4), whereas in those with positive TST (X10 mm) this
association disappeared (ORadj 0.96; 95% CI 0.4–2.8).
Conclusions These results suggest that immune response to Ascaris (Ascaris-sIgE) may be a
risk factor of atopic disease in populations exposed to mild Ascaris infection and that MTB
infection may be protective against this risk, probably by stimulation of anti-inflammatory
networks.
Description
Date
2006
Journal Title
Journal ISSN
Volume Title
Publisher
Blackwell Publishing Ltd.
Collections
Research Projects
Organizational Units
Journal Issue
Keywords
Ascaris specific IgE , Atopic disease
Citation
Obihara CC, Beyers N, Gie RP, Hoekstra MO, Fincham JE, Marais BJ, et al. Respiratory atopic disease, Ascaris-immunoglobulin E and tuberculin testing in urban South African children. CLINICAL AND EXPERIMENTAL ALLERGY