Medicine
Permanent URI for this communityhttp://repository.kln.ac.lk/handle/123456789/12
This repository contains the published and unpublished research of the Faculty of Medicine by the staff members of the faculty
Browse
3 results
Search Results
Item The Effect of intestinal nematode infections on atopic diseases in children(Allergy and Immunology Society of Sri Lanka, 2009) Amarasekera, N.D.D.M.; Gunawardena, N.K.; de Silva, N.R.; Douglas, J.; O'Hehir, R.; Weerasinghe, A.BACKGROUND : The effect of helminth infections on atopic diseases and allergic sensitization is controversial. Little is known about the effect of infection on atopic diseases in children living in areas where both intestinal nematodes and Toxocara infections are prevalent. OBJECTIVE : To examine the association between atopic diseases and helminth infection among children exposed to both intestinal nematodes and Toxocara. METHODS: Children attending grade 5 (age group 9-11 years) in 17 schools in the Western Province of Sri Lanka were recruited. The association of atopic diseases (asthma, rhinitis, eczema) with active intestinal nematode infections (excreting eggs in faeces) and with exposure to Toxocara (specific IgG antibodies in serum) was investigated. A child was deemed sensitized if positive for at least one of the allergens tested (Dermatophagoides pteronyssinus, Blomia tropicalis, cockroach, cat epithelium, grass pollen), based on specific IgE levels in serum. RESULTS: A total of 640 children participated in the study; serum analysis was done in 203. Active intestinal nematode infection appeared to reduce the risk of atopic diseases (OR 0.47, P=0.016) whereas Toxocara exposure did not (OR 0.85 P=0.602). When specific IgE levels against Blomia tropicalis, the most common allergen in the study group (67.5%), were expressed as percentages of the total IgE levels for each child, infected children had significantly lower levels compared to uninfected children (P=0.001). CONCLUSIONS : Intestinal nematode infections seem to protect against atopic diseases in children in Sri Lanka. Polyclonal IgE synthesis may be involved in this protection.Item Allergic sensitization in children(The Sri Lanka College of Paediatricians, 2008) Amarasekera, N.D.D.M.; Gunawardena, N.K.; de Silva, N.R.; Weerasinghe, A.BACKGROUND :Allergic sensitization is considered a significant risk factor for the development of atopic diseases. Appropriate allergen avoidance measures can be taken only when the pattern of sensitization to allergens in a particular population is known. No data is available regarding allergic sensitization among Sri Lankan children. OBJECTIVE: To identify the common allergens causing sensitization in a selected group of schoolchildren. DESIGN, SETTING AND METHOD: A cross-sectional study was carried out in 640 children in grade 5 (age group 9-11 years), from 17 schools in the Western Province. Data regarding atopic diseases was collected using the International Study of Asthma and Allergies in Childhood (ISAAC) questionnaire. Specific IgE was estimated by ImmunoCAP method for five common aeroallergens (the dust mites Dermatophagoides pteronyssinus and Blomia tropicalis, cockroach, cat epithelium and dander, grass pollen) in a sub-sample of 203. RESULTS: Aeroallergen sensitivity was detected in 163 (80.3%) children. No significant difference for sensitization between boys and girls was noted (P= 0.549). The pattern of allergens in the two groups was similar. Mite allergen sensitivity was the most prevalent (B. tropicalis 84.0%, D. pteronyssinus 69.9%), followed by cockroach (67.5%), cat dander (46.0%) and grass pollen (35.6%). Twenty seven (13.3%) children were sensitized to all allergens tested; 28 (13.8%) children were sensitized to only one allergen; and 68.7% were sensitized to both B. tropicalis and D. pteronyssinus. Children with rhinitis or eczema (but not those with asthma) were significantly more likely to show sensitization to cat dander than asymptomatic controls (P=0.02 and P=0.002 respectively), but not to other allergens. The likelihood of being sensitized to one allergen was well correlated with sensitization to other allergens as evident by the significant correlation coefficients. CONCLUSION: Mites and cockroaches were the most common aeroallergens causing sensitization among schoolchildren in the Western Province.Item Reduced risk of atopic diseases among schoolchildren infected with intestinal Nematodes(Federation of Immunology Societies of Asia-Oceania, 2008) Amarasekera, N.D.D.M.; Gunawardena, N.K.; de Silva, N.R.; Pathmeswaran, A.; Douglass, J.; O’Hehir, R.; Weerasinghe, A.BACKGROUND: The effect of helminth infections on atopic diseases and allergic sensitization is controversial. Little is known about the effect of infection on atopic diseases in children living in areas where both intestinal nematodes and Toxocara infections are prevalent. OBJECTIVE : To examine the association between atopic diseases and helminth infection among children exposed to both intestinal nematodes and Toxocara. METHODS: Children attending grade 5 (age group 9-11 years) in 17 schools in the Western Province of Sri Lanka were recruited. The association of atopic diseases (asthma, rhinitis, eczema) with active intestinal nematode infections (excreting eggs in faeces) and with exposure to Toxocara (specific IgG antibodies in serum) was investigate. A child was deemed sensitized if positive for at least one of the allergens tested (Dermatophagoides pteronyssinus, Blomia tropicalis, cockroach, cat epithelium, grass pollen), based on specific IgE levels in serum. RESULTS : A total of 640 children participated in the study; serum analysis was done in 203. Active intestinal nematode infection appeared to reduce the risk of atopic diseases (OR 0.47, P=0.0I6) whereas Toxocara exposure did not (OR 0.85, P=0.602). When specific IgE levels against Blomia tropicalis, the most common allergen in the study group (67.5%), were expressed as percentages of the total IgE levels for each child, infected children had significantly lower levels compared to uninfected children (P=0.001). CONCLUSIONS : Intestinal nematode infections seem to protect against atopic diseases in children in the tropics. Polyclonal IgE synthesis may be involved in this protection.