title: Soluble CD23 levels are inversely associated with atopy and parasite-specific IgE levels but not with polyclonal IgE levels in people exposed to helminth infection.
abstract: BACKGROUND
  Protective acquired immunity against helminths and allergic sensitisation are both characterised by high IgE antibody levels. Levels of IgE antibodies are naturally tightly regulated by several mechanisms including binding of the CD23 receptor. Following observations that helminth infections and allergic sensitisation may co-present, the current study aims to investigate the relationship between the soluble CD23 (sCD23) receptor, parasite-specific IgE responses and allergic sensitisation in people exposed to the helminth parasite Schistosoma haematobium.
  
  
  METHODS
  A cohort of 434 participants was recruited in two villages with different levels of S. haematobium infection in Zimbabwe. Serum levels of the 25-kDa fragment of sCD23 were related to levels of schistosome infection intensity, allergen (house dust mite, HDM) and schistosome-specific IgE, total IgE and skin sensitisation to HDM.
  
  
  RESULTS
  sCD23 levels rose significantly with schistosome infection intensity but declined significantly with schistosome-specific IgE levels. Furthermore, sCD23 levels were negatively associated with skin sensitisation and IgE reactivity against HDM, but showed no relationship with total IgE.
  
  
  CONCLUSIONS
  The results are consistent with the suppression of parasite and allergen-specific IgE levels by sCD23. Further mechanistic studies will determine the relevance of this potential regulatory mechanism in the development of helminth-specific immune responses in atopic individuals.
authors.affiliation: Institute of Immunology and Infection Research, Centre for Immunity, Infection and Evolution, School of Biological Sciences, University of Edinburgh, Ashworth Laboratories, Edinburgh, UK.
authors.forename: Nadine
authors.initials: N
authors.lastname: Rujeni
authors.forename: Norman
authors.initials: N
authors.lastname: Nausch
authors.forename: Nicholas
authors.initials: N
authors.lastname: Midzi
authors.forename: Reginald
authors.initials: R
authors.lastname: Gwisai
authors.forename: Takafira
authors.initials: T
authors.lastname: Mduluza
authors.forename: David W
authors.initials: DW
authors.lastname: Taylor
authors.forename: Francisca
authors.initials: F
authors.lastname: Mutapi
mesh_terms: D000293:Adolescent; D000328:Adult; D000818:Animals; D000909:Antibodies, Helminth / Q000097:blood; D039741:Antigens, Dermatophagoides / Q000276:immunology; D002648:Child; D015331:Cohort Studies; D018450:Disease Progression; D000939:Epitopes / Q000276:immunology; D005260:Female; D006801:Humans; D006967:Hypersensitivity / Q000150:complications / Q000175:diagnosis / Q000276:immunology*; D007073:Immunoglobulin E / Q000097:blood; D008297:Male; D039981:Pyroglyphidae / Q000276:immunology; D017455:Receptors, IgE / Q000097:blood*; D012548:Schistosoma haematobium / Q000276:immunology* / Q000472:pathogenicity; D012553:Schistosomiasis haematobia / Q000150:complications / Q000175:diagnosis / Q000276:immunology*; D055815:Young Adult; D015030:Zimbabwe
chemical_list: D000909:Antibodies, Helminth; D039741:Antigens, Dermatophagoides; D000939:Epitopes; D017455:Receptors, IgE; D007073:Immunoglobulin E