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Prof. Dr. U. Wahn. Prevention of asthma in childhood. Ulrich Wahn Department of Pediatric Pneumology and Immunology. Possible opportunities. Allergen avoidance Preventative Pharmakotherapy in high risk groups a) Cetirizin/Levocetiricin b) Desloratadin c) Pimecrolimus
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Prof. Dr. U. Wahn Prevention of asthma in childhood Ulrich Wahn Department of Pediatric Pneumology and Immunology
Possible opportunities • Allergen avoidance • Preventative Pharmakotherapy in high risk groups a) Cetirizin/Levocetiricinb) Desloratadinc) Pimecrolimus • Spec. Immunotherapy in pollen allergic children • SLIT in high risk infants • Primary prevention by modification of infant nutrition
Allergen avoidace • Dust mites • Pets • Novel tools
Prevalence of current wheeze from birth to age 13 years Wheezing at school age (5–7 years) Non-atopic Atopic Age (years) Illi S, et al. Lancet 2006
Early sensitization and allergenexposure to perennial allergens* andlung function at school age Not sensitized Sensitized/low exposure Sensitized/high exposure Mean±SD 160 140 120 100 80 60 40 20 0 p=0.003 p=0.020 p=0.018 p=0.001 p<0.001 p=0.003 p=0.025 FEV1(% FVC) FEV1(% predicted) MEF75(% predicted) MEF50(% predicted) MEF25(% predicted) FEV1 = forced expiratory volume in 1 second; FVC = forced vital capacity; MEF = maximal expiratory flow *Sensitization/exposure to mites and/or cats up to the age of 3 years Illi S, et al. Lancet 2006
Parental smoking and sensitization 27,7 Adj. OR and 95%CI No atopic parents 1 atopic parent 2 atopic parents No atopic parents 1 atopic parent 2 atopic parents No atopic parents 1 atopic parent 2 atopic parents Mother smoked regularly Only father smoked Mother smoked irregularly T. Keil et al, Allergy Allergy. 2010 Apr;65(4):482-90
Pharmacotherapeutic attempts • Cetiricin/Levocetericin • Desloratadin • Pimecrolimus
Placebo (n=252) Levocetirizine (n=252) EPAAC™ : Percentage of Subjects Who Developed Asthma at the end of the 18 Month Treatment Period 100 No significant differences between treatments 80 60 % of subjects who developed asthma 40 36.5% 37.3% 20 0
Clinical efficacy of immunotherapy • Early effect • reduction in symptoms/need for medication • Progressive effect • reduction in symptoms/need for medication • reduction in hyperresponsiveness/late phase response • Persistent effect • long-term reduced symptoms/need for medication • long-term reduced hyperresponsiveness/late phase response • Preventive effect • prevention of new sensitivities and exacerbation of disease (rhinitis into asthma)
Probability of New Onset of Wheeze in children with and without atopy Rochat et al, JACI 2010; 126: 1170-1175
PAT Study Period Maintenance dose: Grass: 20 µg Phl p5 Birch: 13 µg Bet v1 Follow up Follow up SIT AAAAI, 2006 In print, Allergy 2006 Möller et al. J Allergy Clin.Immunol. 2002;109:251-6.
All included No asthma Asthma *** Number 208 (205)* 163 42 Mean age (range) 10.7 (6 - 15) 10.7 (6 - 15) 10.6 (6 - 14) Sex M/F 138/70 (137/68)* 108/55 29/13 Mean years with 4.7(1 - 15)** 4.6(1 - 15)** 4.9(1 - 9)** hay fever (range) N=171 N=137 N=34 Demographic data at inclusion Methacholin e PC 20 Mean (range) 10.8 (0.03 - 16) 12.2 (0.16 - 16) 5.1 (0.03 - 16) Control/SIT f. 3 years 94/97 72/79 22/18 * Three patients dropped out of before baseline monitoring season (0 – season) ** Only patients with reliable information’s included ***Mild seasonal asthma during first season before randomization
Patient flow Patients included 205 SIT group 103 Control group 102 Asthma: 42 Continued for 3 years as controls 94 Continued for 3 years on SIT 97 Asthma: 40 Follow up at 5 years 83 Follow up at5 years 95 Asthma: 36 Follow up at10 years 68 Follow up at 10 years 79 Asthma: 30 Total follow up at 10 years: 147
Conjunctival provocation test 3 P<0.001 P<0.001 P<0.001 P<0.001 P<0.05 2,5 2 Control 1,5 Change from baseline (2 x log SQ) Active 1 0,5 0 1 2 3 5 10 Year
Rhinitis: Change from baseline (Visual analogue scores) 30 P=0.01 P<0.001 P<0.0001 P<0.0001 P<0.05 15 Control 0 Mean VAS Score Active -15 -30 1 2 3 5 10 Year Means adjusted for baseline difference
Development of asthma at 3 years N=151 (patients without asthma in season one) Odds-ratio = 2.52 (1.3 – 5.1) N=60 N=40 N=32 N=19
Development of asthma at 5 years N=142 (patients without asthma in season one) Odds-ratio = 2.68 (1.3 – 5.7) N=60 N=38 N=29 N=15
Development of asthma at 10 years N=117 (patients without asthma in season one) Odds-ratio = 2.48 (1.2 – 5.4) N=48 N=29 N=24 N=16
Recent evidence from high dose SLIT trials opens new avenues for early intervention studies in infants and young children
Onset pre-clinical early late clinical Number of Phl pmolecules recognized by IgE in 79 children with SAR by time from the onset of symptoms Onset = 2,575 mol Years/mol = 4,1 confidential 10-15 kU/l IgE to g6 2.5 – 3 molecules to be adjusted by AGE AT ONSET!!! Component Resolved Prophylaxis CRP early simplified (es-CRT) (too) complex late CRT 1,4 2,1 3,0 4,0 4,2
Prophylaxis of atopy and asthma in children (ITN) • Inclusion criteria: Children 12 – 30 months of age (n=200) Atopic dermatitis, sensitisation to food No sensitisation to aeroallergens Positive family history for atopy/asthma • Primary end points: Allergic sensitisation • Secondary end points: Current asthma 3 years after the end of intervention
Study Design Allergens (Cat, house dust mites, grass) EndpointAssessment (ITT/ PP) Randomisation (n=200) (age 12 – 30 month) Enrolment Placebo Follow-up 12 months of oral application
The child at risk for asthma Parental Phenotypes Atopy/Asthma Atopy/Asthma Filaggrin Mutation Filaggrin Mutation AD Wheeze InfantilePhenotypes Food Sensitization Food Sensitization Perennial aero-sensitization Perennial aero-sensitization Persistent asthmain adolescene
What are the studies we need? • Allergen-specific SLIT in young children at high risk for asthma with established sensitization to house dust mite • Allergen-specific mucosal tolerance induction at high risk for asthma prior to aeroallergen sensitization • Asthma prevention studies in established disease of the upper airways
Conclusion • Asthma prevention: challenge for pediatric allergist • Asthma prediction in high risk infants possible • Results of allergen avoidance strategies and pharmacotherapeutic interventions not very encouraging • Primary prevention in infance not sucessful • Immunotherapeutic interventions probably more promissing