Irene Mittermann1, Sheron Dzoro1, Pia Gattinger1, Maresa Botha2, Wisdom Basera3, Heidi E Facey-Thomas2, Ben Gaunt4,5, Jon Genuneit6, Claudia L Gray3, Carol Hlela7, Sabine Flicker1, Nonhlanhla Lunjani2, Avumile Mankahla4, Jordache Ramjith8,9, Rudolf Valenta1,10,11,12, Michael E Levin2,13. 1. Division of Immunopathology, Department of Pathophysiology and Allergy Research, Center for Pathophysiology, Infectiology and Immunology, Medical University of Vienna, Vienna, Austria. 2. Division of Paediatric Allergy, Department of Paediatrics, University of Cape Town, Cape Town, South Africa. 3. School of Public Health and Family Medicine, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa. 4. Eastern Cape Department of Health, Zithulele Hospital, Mqanduli, South Africa. 5. Institute of Epidemiology and Medical Biometry, Ulm University, Ulm, Germany. 6. Pediatric Epidemiology, Department of Pediatrics, Medical Faculty, Leipzig University, Leipzig, Germany. 7. Department of Dermatology, University of Cape Town, Cape Town, South Africa. 8. Department for Health Evidence, Biostatistics Research Group, Radboud Institute for Health Sciences, Radboud University Medical Center, Nijmegen, The Netherlands. 9. Division of Epidemiology & Biostatistics, School of Public Health & Family Medicine, University of Cape Town, Cape Town, South Africa. 10. NRC Institute of Immunology FMBA of Russia, Moscow, Russia. 11. Laboratory of Immunopathology, Department of Clinical Immunology and Allergy, Sechenov First Moscow State Medical University, Moscow, Russia. 12. Karl Landsteiner University for Health Sciences, Krems, Austria. 13. INVIVO Planetary Health Network, Research subgroup of the Worldwide Universities Network.
Abstract
BACKGROUND: Allergens can act as disease-triggering factors in atopic dermatitis (AD) patients. The aim of the study was to elucidate the molecular IgE sensitization profile in children with and without AD living in urban and rural areas of South Africa. METHODS: Specific IgE reactivity was assessed in 166 Black South African children aged 9-38 months using a comprehensive panel of microarrayed allergens. According to clinical characterization children fell in four groups, urban AD cases (n = 32), urban controls (non-AD, n = 40), rural cases (n = 49) and rural controls (non-AD, n = 45). RESULTS: IgE reactivity to at least one of the allergens was detected in 94% of urban and 86% of rural AD children. House dust mite (HDM; 81% urban, 74% rural AD) and animal-derived allergens (50% urban, 31% rural AD) were the most frequently recognized respiratory allergens, whereas IgE to pollen allergens was almost absent. Urban AD children showed significantly higher frequency of IgE reactivity (50%) to mouse lipocalin, Mus m 1, than rural AD children (12%). The most frequently recognized food allergens were from egg (63% urban, 43% rural AD), peanut (31% vs 41%), and soybean (22% vs 27%), whereas milk sensitization was rare. α-gal-specific IgE almost exclusively occurred in rural children (AD: 14%, non-AD: 49%). CONCLUSION: Molecular allergy diagnosis detects frequent IgE sensitization to HDM, animal but not pollen allergens and to egg, peanut, and soy, but not milk allergens in African AD children. Urban AD children reacted more often to Mus m 1, whereas α-gal sensitization is more common in rural children likely due to parasite exposure.
BACKGROUND: Allergens can act as disease-triggering factors in atopic dermatitis (AD) patients. The aim of the study was to elucidate the molecular IgE sensitization profile in children with and without AD living in urban and rural areas of South Africa. METHODS: Specific IgE reactivity was assessed in 166 Black South African children aged 9-38 months using a comprehensive panel of microarrayed allergens. According to clinical characterization children fell in four groups, urban AD cases (n = 32), urban controls (non-AD, n = 40), rural cases (n = 49) and rural controls (non-AD, n = 45). RESULTS: IgE reactivity to at least one of the allergens was detected in 94% of urban and 86% of rural AD children. House dust mite (HDM; 81% urban, 74% rural AD) and animal-derived allergens (50% urban, 31% rural AD) were the most frequently recognized respiratory allergens, whereas IgE to pollen allergens was almost absent. Urban ADchildren showed significantly higher frequency of IgE reactivity (50%) to mouse lipocalin, Mus m 1, than rural AD children (12%). The most frequently recognized food allergens were from egg (63% urban, 43% rural AD), peanut (31% vs 41%), and soybean (22% vs 27%), whereas milk sensitization was rare. α-gal-specific IgE almost exclusively occurred in rural children (AD: 14%, non-AD: 49%). CONCLUSION: Molecular allergy diagnosis detects frequent IgE sensitization to HDM, animal but not pollen allergens and to egg, peanut, and soy, but not milk allergens in African AD children. Urban ADchildren reacted more often to Mus m 1, whereas α-gal sensitization is more common in rural children likely due to parasite exposure.