Markers of Atopy in Children With Presumed Early Exposure to Allergens, Unhygienic Conditions, and Infections
Condition: Atopic Diseases
MeSH terms: Infections
Study type: Observational

Summary: 
      There are many studies regarding possible causes of increasing trend in frequency of allergic
      diseases in the last three decades. Main causes of this trend are: decrease of infectious
      diseases frequency, improvement in life level, changes in diet and lactic acid bacterias
      elimination from digestive tract. Primary Purpose of this study is to compare the prevalence
      of atopy and atopic diseases in two child populations: foster care and reference children and
      - to define risk and protective factors for the development of atopy.
    

Detailed description: 
      There are many studies regarding possible causes of increasing trend in frequency of allergic
      diseases in the last three decades. Main causes of this trend are: decrease of infectious
      diseases frequency, improvement in life level, changes in diet and lactic acid bacterias
      elimination from digestive tract. Less exposition to microbes can lead to the disturbance in
      optimal balance between Th1 and Th2 lymphocytes, prevalence of Th2 cytokines and excessively
      high production of IgE. Decreased exposure to microbes has resulted in the loss of main
      source of immune provocation, and a consequent increase in pathogenic immune responses and
      their associated diseases. Molecular interactions between immunocytes and microbes are
      mediated largely by Toll-like receptors (TLRs) on host cells and a diversity of ligands
      produced by viruses, bacteria and fungi.

      Many studies confirm the protective role of some viral, bacterial or parasite infections
      against atopy development.

      The studied group consisted of 500 children, living in all the ten community foster homes in
      Lodz. The reference group consisted of 500 children, living with their parents at home,
      recruited from primary care centres.

      Primary Purpose of this study is to compare the prevalence of atopy and atopic diseases in
      two child populations: foster care and reference children and - to define risk and protective
      factors for the development of atopy.

      Secondary Purpose is the genotyping and cytometric study - to define risk and protective
      factors for the development of atopy.

      Primary outcome measures: skin prick test results with 18 allergens, peripheral blood
      eosinophil count, level of total and specific IgE in children with positive skin-test results
      were secondary and point, spirometry, medical history and physical examination.

      Secondary outcome measures: included symptoms of asthma and other allergic diseases, lung
      function, parental allergy only for children from reference group, family history including
      life conditions in very early childhood, and markers of allergy such as total IgE serum
      concentration and eosinophil blood count, expression of TLR2, TLR4, TLR7, TLR9, examining the
      serum samples for specific antibodies to Toxocara sp, Toxoplasma gondi, Ascaris lumbricoides,
      DNA.
    

Observational model: Cohort
Time perspective: Retrospective
Sampling method: Non-Probability Sample
Study population: 
        Children.
      
Biospecimen description: 
      whole blood samples
    
Keywords: atopy; atopic diseases; children; orphanages