Cargando…

Environmental determinants of total IgE among school children living in the rural Tropics: importance of geohelminth infections and effect of anthelmintic treatment

BACKGROUND: The environmental factors that determine the elevated levels of polyclonal IgE observed in populations living in the Tropics are poorly understood but may include geohelminth infections. We investigated the association between geohelminth infections and total IgE levels in school childre...

Descripción completa

Detalles Bibliográficos
Autores principales: Cooper, Philip J, Alexander, Neal, Moncayo, Ana-Lucia, Benitez, Susana M, Chico, Martha E, Vaca, Maritza G, Griffin, George E
Formato: Texto
Lenguaje:English
Publicado: BioMed Central 2008
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2459155/
https://www.ncbi.nlm.nih.gov/pubmed/18588694
http://dx.doi.org/10.1186/1471-2172-9-33
_version_ 1782157403513421824
author Cooper, Philip J
Alexander, Neal
Moncayo, Ana-Lucia
Benitez, Susana M
Chico, Martha E
Vaca, Maritza G
Griffin, George E
author_facet Cooper, Philip J
Alexander, Neal
Moncayo, Ana-Lucia
Benitez, Susana M
Chico, Martha E
Vaca, Maritza G
Griffin, George E
author_sort Cooper, Philip J
collection PubMed
description BACKGROUND: The environmental factors that determine the elevated levels of polyclonal IgE observed in populations living in the Tropics are poorly understood but may include geohelminth infections. We investigated the association between geohelminth infections and total IgE levels in school children in rural tropical Ecuador, and assessed the effect on IgE of repeated anthelmintic treatments over a period of 12 months. The study was nested within a cluster-randomized study that randomized 68 schools to receive either 400 mg of albendazole every 2 months over a year or no treatment. We studied random samples of children completing follow-up and representing four groups stratified by the presence of geohelminth infection at baseline and treatment allocation. We measured levels of total IgE and anti-A. lumbricoides IgG (used as a measure of past and current geohelminth infectious exposure) in blood samples collected at the start of the study and after 12 months. RESULTS: We observed elevated levels of total IgE (compared to standard reference values) at the start of the study in this population of school children (geometric mean, 1,004 IU/mL, range 12 to 22,608 IU/mL)) and baseline IgE levels were strongly associated with parameters of geohelminth infection but not with age, nutritional and socioeconomic status. After 12 months, levels of IgE fell significantly in the treatment (by 35.1%) and no treatment (by 10.4%) groups, respectively, but the fall was significantly greater in the treatment group. Falls in IgE were independently associated with albendazole treatment, having a baseline geohelminth infection and with high baseline levels of anti-A. lumbricoides IgG. Increases in IgE at 12 months were associated with the presence of geohelminth infections and increasing levels of anti-A. lumbricoides IgG at 12 months independent of treatment allocation. CONCLUSION: The data provide evidence that geohelminth infections are an important determinant of total IgE in school children in the rural Tropics and that periodic anthelmintic treatments over 12 months are associated with reductions in IgE. The failure of anthelmintic treatment to reduce IgE levels to that considered normal in industrialized countries may be attributed to continued exposure of children to geohelminths or to the effects of infections in early life in programming a long-lasting Th2-biassed immunity.
format Text
id pubmed-2459155
institution National Center for Biotechnology Information
language English
publishDate 2008
publisher BioMed Central
record_format MEDLINE/PubMed
spelling pubmed-24591552008-07-12 Environmental determinants of total IgE among school children living in the rural Tropics: importance of geohelminth infections and effect of anthelmintic treatment Cooper, Philip J Alexander, Neal Moncayo, Ana-Lucia Benitez, Susana M Chico, Martha E Vaca, Maritza G Griffin, George E BMC Immunol Research Article BACKGROUND: The environmental factors that determine the elevated levels of polyclonal IgE observed in populations living in the Tropics are poorly understood but may include geohelminth infections. We investigated the association between geohelminth infections and total IgE levels in school children in rural tropical Ecuador, and assessed the effect on IgE of repeated anthelmintic treatments over a period of 12 months. The study was nested within a cluster-randomized study that randomized 68 schools to receive either 400 mg of albendazole every 2 months over a year or no treatment. We studied random samples of children completing follow-up and representing four groups stratified by the presence of geohelminth infection at baseline and treatment allocation. We measured levels of total IgE and anti-A. lumbricoides IgG (used as a measure of past and current geohelminth infectious exposure) in blood samples collected at the start of the study and after 12 months. RESULTS: We observed elevated levels of total IgE (compared to standard reference values) at the start of the study in this population of school children (geometric mean, 1,004 IU/mL, range 12 to 22,608 IU/mL)) and baseline IgE levels were strongly associated with parameters of geohelminth infection but not with age, nutritional and socioeconomic status. After 12 months, levels of IgE fell significantly in the treatment (by 35.1%) and no treatment (by 10.4%) groups, respectively, but the fall was significantly greater in the treatment group. Falls in IgE were independently associated with albendazole treatment, having a baseline geohelminth infection and with high baseline levels of anti-A. lumbricoides IgG. Increases in IgE at 12 months were associated with the presence of geohelminth infections and increasing levels of anti-A. lumbricoides IgG at 12 months independent of treatment allocation. CONCLUSION: The data provide evidence that geohelminth infections are an important determinant of total IgE in school children in the rural Tropics and that periodic anthelmintic treatments over 12 months are associated with reductions in IgE. The failure of anthelmintic treatment to reduce IgE levels to that considered normal in industrialized countries may be attributed to continued exposure of children to geohelminths or to the effects of infections in early life in programming a long-lasting Th2-biassed immunity. BioMed Central 2008-06-27 /pmc/articles/PMC2459155/ /pubmed/18588694 http://dx.doi.org/10.1186/1471-2172-9-33 Text en Copyright © 2008 Cooper et al; licensee BioMed Central Ltd. http://creativecommons.org/licenses/by/2.0 This is an Open Access article distributed under the terms of the Creative Commons Attribution License ( (http://creativecommons.org/licenses/by/2.0) ), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
spellingShingle Research Article
Cooper, Philip J
Alexander, Neal
Moncayo, Ana-Lucia
Benitez, Susana M
Chico, Martha E
Vaca, Maritza G
Griffin, George E
Environmental determinants of total IgE among school children living in the rural Tropics: importance of geohelminth infections and effect of anthelmintic treatment
title Environmental determinants of total IgE among school children living in the rural Tropics: importance of geohelminth infections and effect of anthelmintic treatment
title_full Environmental determinants of total IgE among school children living in the rural Tropics: importance of geohelminth infections and effect of anthelmintic treatment
title_fullStr Environmental determinants of total IgE among school children living in the rural Tropics: importance of geohelminth infections and effect of anthelmintic treatment
title_full_unstemmed Environmental determinants of total IgE among school children living in the rural Tropics: importance of geohelminth infections and effect of anthelmintic treatment
title_short Environmental determinants of total IgE among school children living in the rural Tropics: importance of geohelminth infections and effect of anthelmintic treatment
title_sort environmental determinants of total ige among school children living in the rural tropics: importance of geohelminth infections and effect of anthelmintic treatment
topic Research Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2459155/
https://www.ncbi.nlm.nih.gov/pubmed/18588694
http://dx.doi.org/10.1186/1471-2172-9-33
work_keys_str_mv AT cooperphilipj environmentaldeterminantsoftotaligeamongschoolchildrenlivingintheruraltropicsimportanceofgeohelminthinfectionsandeffectofanthelmintictreatment
AT alexanderneal environmentaldeterminantsoftotaligeamongschoolchildrenlivingintheruraltropicsimportanceofgeohelminthinfectionsandeffectofanthelmintictreatment
AT moncayoanalucia environmentaldeterminantsoftotaligeamongschoolchildrenlivingintheruraltropicsimportanceofgeohelminthinfectionsandeffectofanthelmintictreatment
AT benitezsusanam environmentaldeterminantsoftotaligeamongschoolchildrenlivingintheruraltropicsimportanceofgeohelminthinfectionsandeffectofanthelmintictreatment
AT chicomarthae environmentaldeterminantsoftotaligeamongschoolchildrenlivingintheruraltropicsimportanceofgeohelminthinfectionsandeffectofanthelmintictreatment
AT vacamaritzag environmentaldeterminantsoftotaligeamongschoolchildrenlivingintheruraltropicsimportanceofgeohelminthinfectionsandeffectofanthelmintictreatment
AT griffingeorgee environmentaldeterminantsoftotaligeamongschoolchildrenlivingintheruraltropicsimportanceofgeohelminthinfectionsandeffectofanthelmintictreatment