Peanut-specific IgE antibodies in asymptomatic Ghanaian children possibly caused by carbohydrate determinant cross-reactivity

Abstract

BackgroundThe prevalence of peanut allergy has increased in developed countries, but little is known about developing countries with high peanut consumption and widespread parasitic infections.ObjectiveWe sought to investigate peanut allergy in Ghana.MethodsIn a cross-sectional survey among Ghanaian schoolchildren (n = 1604), data were collected on reported adverse reactions to peanut, peanut sensitization (serum specific IgE and skin reactivity), consumption patterns, and parasitic infections. In a subset (n = 43) IgE against Ara h 1, 2, 3, and 9 as well as cross-reactive carbohydrate determinants (CCDs) was measured by using ImmunoCAP. Cross-reactivity and biological activity were investigated by means of ImmunoCAP inhibition and basophil histamine release, respectively.ResultsAdverse reactions to peanut were reported in 1.5%, skin prick test reactivity in 2.0%, and IgE sensitization (≥0.35 kU/L) in 17.5% of participants. Moreover, 92.4% of those IgE sensitized to peanut (≥0.35 kU/L) had negative peanut skin prick test responses. Schistosoma haematobium infection was positively associated with IgE sensitization (adjusted odds ratio, 2.29; 95% CI, 1.37-3.86). In the subset IgE titers to Ara h 1, 2, 3, and 9 were low (<1.3 kU/L), except for 6 moderately strong reactions to Ara h 9. IgE against peanut was strongly correlated with IgE against CCDs (r = 0.89, P < .0001) and could be almost completely inhibited by CCDs, as well as S haematobium soluble egg antigen. Moreover, IgE to peanut showed poor biological activity.ConclusionsParasite-induced IgE against CCDs might account largely for high IgE levels to peanut in our study population of Ghanaian schoolchildren. No evidence of IgE-mediated peanut allergy was found.

Coping with cross-reactive carbohydrate determinants in allergy diagnosis

“…A link to hymenoptera stings is o en discussed [17], whereas the increased risk for anti-CCD IgE development among heavy drinkers supposedly does not explain the whole phenomenon [18]. An interesting link to the physiological function of IgE may be posed by a study, which found increased anti-CCD IgE as a result of parasite infection [19].…”

Component-Resolved IgE Profiles in Austrian Patients with a Convincing History of Peanut Allergy

“…A recent study showed that asymptomatic peanut-sensitized children from sub-Saharan Africa had IgE almost exclusively specific to cross-reactive carbohydrate determinants (CCDs) induced by glycoproteins from parasitic Schistosoma species [15]. …”

Consensus communication on early peanut introduction and the prevention of peanut allergy in high-risk infants

“…Extrapolating the currently estimated prevalence, this translates to nearly 100,000 new cases annually (in the United States and United Kingdom), affecting some 1 in 50 primary school-aged children in the United States, Canada, the United Kingdom, and Australia. A similar rise in incidence is now being noted in developing countries, such as Ghana [1][2][3][4][5][6].…”