Vereecken K.,Institute of Tropical Medicine |
Kanobana K.,Institute of Tropical Medicine |
Wordemann M.,Institute of Tropical Medicine |
Junco Diaz R.,National Institute of Hygiene Epidemiology and Microbiology |
And 7 more authors.
Pediatric Allergy and Immunology
Total serum IgE (tIgE), allergen-specific IgE (sIgE), and skin prick test (SPT) are commonly used markers for atopy and atopic disease. The association between these measures and their relationship to clinical symptoms differs in affluent and non-affluent countries. We investigated the role of intestinal helminth infections in observed variations in atopic markers and asthma, and possible diagnostic and epidemiological consequences. A cross-sectional study was conducted in Cuban schoolchildren (n=1285; 4-14yrs). Atopy was determined by SPT, sIgE, and tIgE; asthma by International Study of Asthma and Allergies in Childhood questionnaire; and intestinal helminth infections by stool examination. Percentages of tIgE, sIgE, and SPT positives were 88.9%, 25.5%, and 16.5%, respectively. Asthma was found in 20.8%, and helminth infections in 20.9% of the children. All three atopic markers were significantly associated with each other and with asthma. Median tIgE levels were higher in helminth-infected than in uninfected children, irrespective of their status of atopy/asthma. Discordant results between SPT and sIgE were observed in 22.6% of the children. Among SPT positives, 41% were sIgE negative. The proportion of SPT negatives among sIgE positives was 74% in helminth-infected and 58.4% in uninfected children (p<0.05). Helminth infections affected tIgE levels, reconfirming the limited value of tIgE for diagnosis of atopy and asthma in tropical areas. Higher frequencies of sIgE than positive SPTs were observed, especially in helminth-infected children. This corresponds with current hypothesis on the role of helminths in atopy. However, the observed proportion of sIgE negatives among children with positive SPT suggests that other mechanisms may also be involved. © 2012 John Wiley & Sons A/S. Source