title: Coassociations between IL10 polymorphisms, IL-10 production, helminth infection, and asthma/wheeze in an urban tropical population in Brazil.
abstract: BACKGROUND
  Helminth infections are associated with protection against allergies. It is postulated that IL-10 production after helminth infection suppresses skin hypersensitivity and increases IgG₄ production, protecting against allergies.
  
  
  OBJECTIVE
  We aimed to determine whether IL10 polymorphisms are associated with helminth infection and the risk of wheeze and allergy.
  
  
  METHODS
  Twelve IL10 single nucleotide polymorphisms were genotyped in 1353 children aged 4 to 11 years living in a poor urban area in Salvador, Brazil. Wheezing status, Ascaris lumbricoides and Trichuris trichiura infection, IL-10 production by peripheral blood leukocytes stimulated with A lumbricoides extract, serum total IgE levels, specific IgE levels, skin prick test responses to common aeroallergens, and IgG4 and IgE anti-A lumbricoides antibody levels were measured in all children. Association tests were performed by using logistic or linear regression when appropriate, including sex, age, helminth infection, and principal components for ancestry informative markers as covariates by using PLINK.
  
  
  RESULTS
  Allele G of marker rs3024496 was associated with the decreased production of IL-10 by peripheral blood leukocytes in response to A lumbricoides stimulation. Allele C of marker rs3024498 was negatively associated with helminth infection or its markers. Marker rs3024492 was positively associated with the risk of atopic wheeze, total IgE levels, and skin prick test responses to cockroach.
  
  
  CONCLUSIONS
  Our findings suggest that IL10 polymorphisms might play a role in the production of IL-10, helminth infection, and allergy. We hypothesize that polymorphisms related to protection against helminths, which would offer an evolutionary advantage to subjects in the past, might be associated with increased risk of allergic diseases.
authors.affiliation: Division of Allergy and Clinical Immunology, Johns Hopkins University, Baltimore, MD, USA.
authors.forename: Camila Alexandrina
authors.initials: CA
authors.lastname: Figueiredo
authors.forename: Maurício Lima
authors.initials: ML
authors.lastname: Barreto
authors.forename: Neuza Maria
authors.initials: NM
authors.lastname: Alcantara-Neves
authors.forename: Laura Cunha
authors.initials: LC
authors.lastname: Rodrigues
authors.forename: Philip John
authors.initials: PJ
authors.lastname: Cooper
authors.forename: Alvaro A
authors.initials: AA
authors.lastname: Cruz
authors.forename: Lain Carlos
authors.initials: LC
authors.lastname: Pontes-de-Carvalho
authors.forename: Denise C
authors.initials: DC
authors.lastname: Lemaire
authors.forename: Ryan
authors.initials: R
authors.lastname: dos Santos Costa
authors.forename: Leila D
authors.initials: LD
authors.lastname: Amorim
authors.forename: Candelaria
authors.initials: C
authors.lastname: Vergara
authors.forename: Nicholas
authors.initials: N
authors.lastname: Rafaels
authors.forename: Li
authors.initials: L
authors.lastname: Gao
authors.forename: Cassandra
authors.initials: C
authors.lastname: Foster
authors.forename: Monica
authors.initials: M
authors.lastname: Campbell
authors.forename: Rasika A
authors.initials: RA
authors.lastname: Mathias
authors.forename: Kathleen C
authors.initials: KC
authors.lastname: Barnes
mesh_terms: D000293:Adolescent; D000483:Alleles; D001249:Asthma / Q000453:epidemiology* / Q000209:etiology*; D001938:Brazil / Q000453:epidemiology; D002648:Child; D002675:Child, Preschool; D005260:Female; D023061:Gene Order; D008040:Genetic Linkage; D005838:Genotype; D006373:Helminthiasis / Q000150:complications*; D006801:Humans; D007223:Infant; D016753:Interleukin-10 / Q000096:biosynthesis* / Q000235:genetics*; D015810:Linkage Disequilibrium; D008297:Male; D011110:Polymorphism, Genetic; D020641:Polymorphism, Single Nucleotide; D012135:Respiratory Sounds / Q000209:etiology*; D014505:Urban Population
chemical_list: D016753:Interleukin-10