MAPS & ITEC Cohorts: 6-8 Years Follow-up
Condition: Immunotherapy; Allergy and Immunology; Asthma
MeSH terms: Asthma
Study type: Interventional
Phase: Phase 2

Summary: 
      This study represents the follow-up, age 6-8 years, of children recruited at birth into two
      cohorts. The first cohort, the Mite Allergen Prevention Study (MAPS) was a double-blind,
      randomized controlled trial of the use of house dust-mite immunotherapy in the primary
      prevention of atopy and asthma. The Immune Tolerance in Early Childhood (ITEC) cohort is a
      separate observational cohort following up infants at high risk of atopy and correlating
      atopic disease development with epigenetic markers.
    

Detailed description: 
      There is an epidemic of allergic disease in childhood and current preventative strategies
      have failed to demonstrate effectiveness outside of isolated trials. In a previous study, the
      efficacy of sublingual immunotherapy (SLIT) with house dust mite in preventing the
      development of allergic sensitisation in infants was assessed. The long term objective was to
      assess the effect of the intervention on the subsequent development of asthma. The hypothesis
      is that high dose oral immunotherapy will induce immune tolerance and reduce development of
      allergic sensitisation and later clinical asthma and allergy. A total of 111 infants at high
      risk of allergy (with ≥2 first degree relatives affected by asthma or allergy) but with no
      evidence of allergic sensitisation at recruitment were recruited. These infants were
      randomised at 6 months of age to receive a year of active HDM (House dust-mite) allergen
      extract delivered as SLIT or placebo intervention. At 18 months of age, there was a
      significant reduction in cumulative allergic sensitisation in the SLIT intervention group and
      a trend for reduction in allergic symptoms. They have also been followed up at 3 years of
      age. The data currently being analysed.

      Additionally, an observational cohort (Immune Tolerance in Early Childhood, ITEC) was
      recruited at birth with the same inclusion criteria as the interventional one and assessed in
      the same way up to 3 years. This cohort has provided additional control data and samples to
      utilise in the analyses.

      This proposed study is the 6-8 year follow up of these interventional and observational
      cohorts. The aim of the 6-8 year assessment is to assess the efficacy of prophylactic oral
      immunotherapy with HDM allergen in preventing the later development of asthma. The hypothesis
      is that high dose oral immunotherapy will induce immune tolerance and reduce development of
      allergic sensitisation and later clinical asthma and allergy. Participants will be assessed
      6-8 years after finishing the intervention. The assessment will include a questionnaire, skin
      prick testing to the common aeroallergens and food allergens and lung function. Families and
      study investigators will both be blinded to participants' original treatment allocations. An
      additional aim is to investigate the epigenetic and immune mechanisms involved in the
      development of asthma and allergy and how allergen immunotherapy influence this process.
    

Intervention name(s): House dust-mite SLIT; Normal saline
Intervention type(s): Drug; Drug
Intervention description(s): received 2000 standard treatment units of glycerinated HDM allergen extract (ALK-AbellÓ) per day. Normal saline was administered to the placebo group. 11 µg of HDM allergen (equal parts of Dermatophagoides pteronyssinus and Dermatophagoides farinae) administered twice daily as oral drops.; Normal saline administered in same frequency and manner as intervention
Other intervention name(s): glycerinated HDM allergen extract (ALK-AbellÓ); Normal saline placebo control
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Quadruple (Participant, Care Provider, Investigator, Outcomes Assessor)
Primary purpose: Prevention
Keywords: Atopy; Early childhood; House Dust-mite; Sublingual immunotherapy