Browsing by Author "Amarasekera, M."

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Immunoglobulin E in health and disease
(Asia Pacific Association of Allergy, Asthma and Clinical Immunology, 2011) Amarasekera, M.
The discovery of immunoglobulin E (IgE) was a breakthrough in the field of Allergy and Immunology. Our understanding of mechanisms of allergic reactions and the role of IgE in these disorders has paralleled to the discovery of treatment modalities for patients with allergy. Apart from allergic diseases, IgE is involved in pathogenesis of other disorders. Much controversy exists about the control of total IgE (tIgE) levels and allergen-specific IgE (sIgE) profiles in allergic individuals. This review aims at giving a comprehensive overview of IgE molecule and discussing the issues related to its importance in clinical setting.
Impact of helminth infection on childhood allergic diseases in an area in transition from high to low infection burden
(Asia Pacific Association of Allergy, Asthma and Clinical Immunology, 2012) Amarasekera, M.; Gunawardena, N.K.; de Silva, N.R.; Douglass, J.A.; O Hehir, R.E.; Weerasinghe, A.
BCKGROUND: The effect of helminth infections on allergic diseases is still inconclusive. Furthermore, the effect of helminth infections on childhood allergic diseases in a tropical area where prevalence of helminth infections has undergone dramatic changes is not well documented. OBJECTIVE: To investigate the relationship between allergic diseases and helminth infection in a cohort of schoolchildren in an area that has undergone dramatic changes in intensity of helminth infections. METHODS: Children attending grade 5 were recruited from 17 schools in Western Province of Sri Lanka. They were assessed for allergic diseases using the International Study of Asthma and Allergies in Childhood questionnaire. Their serum total IgE (tIgE) and allergen-specific IgE (sIgE) for five common aeroallergens were measured by ImmunoCAP® method and stools were examined for the presence of helminth infections. RESULTS: A total of 640 children (mean age 10 years) were recruited to the study. Of them, 33.7% had evidence of allergic disease and 15.5% had helminth infections. Majority of infections (68.9%) were of low intensity. A significant relationship between allergic disease and helminth infections was not observed, however, a trend toward protective role of helminth infections against allergic diseases was noted. Multivariate analysis showed helminth infections to be an independent predictor of high tIgE levels whereas allergic disease was not. Allergic sensitization (atopy) was a significant risk factor for allergic disease only among non-infected children (odds ratio 3.025, p = 0.022) but not in infected children. The ratio of sIgE to tIgE was higher in non-infected children. CONCLUSION: Though not significant, a reduced risk of allergy in helminth-infected children was observed in this population. A Decrease in intensity of helminth infections may have contributed to the reduced capacity of immune-modulation by helminths in this paediatric population.
Nutrition in early life, immune-programming and allergies: the role of epigenetics
(Allergy and Immunology Society of Thailand, 2013) Amarasekera, M.; Prescott, S.L.; Palmer, D.J.
Early life nutritional exposures are significant determinants of the development and future health of all organ systems. The dramatic rise in infant immune diseases, most notably allergy, indicates the specific vulnerability of the immune system to early environmental changes. The associated parallel rise in metabolic diseases including obesity, childhood type 2-diabetes and non-alcoholic fatty liver disease highlights the interplay between modern dietary patterns and increasing abnormalities of both immune and metabolic health. The low-grade inflammation that characterize these non-communicable diseases (NCDs) suggests a central role of the immune system in the pathogenesis of these conditions. Understanding how environmental influences disrupt the finely balanced development of immune and metabolic programing is of critical importance. Diet-sensitive pathways are likely to be crucial in these processes. While epigenetic mechanism provides a strong explanation of how nutritional exposures can affect the fetal gene expression and subsequent disease risk, other diet-induced tissue compositional changes may also contribute directly to altered immune and metabolic function. Although modern dietary changes are complex and involve changing patterns of many nutrients, there is also interest in the developmental effects of specific nutrients such as folic acid levels, which have clear epigenetic effects on programming. Here we examine the current knowledge of the nutritional-programming of immune health and how research into nutritional-epigenetics in the context of allergic disease as one of the earliest onset NCDs can expand our knowledge to discover the biological processes sensitive to nutritional exposures in early life to prevent later disease risk.
Prevalence of latex allergy among healthcare workers
(Versita co-published with Springer, 2010) Amarasekera, M.; Rathnamalala, N.; Samaraweera, S.; Jinadasa, M.
OBJECTIVES: The use of latex gloves has increased by several folds in the recent past due to concerns about blood-borne infections. Data from Asian countries with regard to latex allergy is scarce. The objective of this study was to determine the prevalence and risk factors of latex allergy among healthcare workers in a tertiary hospital in Sri Lanka. MATERIAL AND METHODS: A cross-sectional survey was carried out among different categories of employees in the hospital. A self-administered questionnaire was used to collect data related to latex allergy. RESULTS: A total of 524 employees was recruited and 62% responded to the questionnaire. Among them 49.2% wore gloves for more than 1 hour a day. Symptoms suggestive of latex allergy were reported by 53 (16.3%) subjects. A considerable proportion (11.4%) of workers had been suffering from latex allergy for more than 5 years. Nurses accounted for the highest prevalence for any job category, while the unit with the highest rate was the surgical ward. Duration in the service (OR = 1.006, P = 0.048) and wearing gloves for more than one hour a day (OR = 3.292, P = 0.004) were significant risk factors for latex allergy, but not atopy or family history of atopy. Seven employees noticed that they developed food allergy after assuming duties as healthcare personnel. CONCLUSIONS: Prevalence of latex allergy is high among healthcare workers in this study population. Environmental factors rather than genetic predisposition play the major role in the development of this condition.