Five-year follow-up on the PAT study: specific immunotherapy and long-term prevention of asthma in children.
BACKGROUND
A 3-year course of specific immunotherapy (SIT) in children with hay fever to grass and/or birch pollen significantly reduced the risk of developing asthma. To investigate the long-term preventive effect, we performed a follow up--2 years after termination of immunotherapy.


METHODS
A total of 183 children, aged 6-14 years with grass and/or birch pollen allergy could be investigated 2 years after discontinuation of SIT or no treatment. Conjunctival provocation tests (CPTs) and methacholine bronchial provocation tests were carried out during the season and winter after 5 years. The development of asthma was assessed by clinical evaluation.


RESULTS
The significant improvement in hay fever and CPT results observed after 3 years of SIT persisted at the 5-year follow-up. No difference in bronchial responsiveness to methacholine was found after 5 years because of spontaneous improvement during the follow-up period in the control patients. The immunotherapy-treated children had significantly less asthma after 5 years as evaluated by clinical symptoms [odds ratio 2.68 (1.3-5.7)] in favor of SIT for prevention of development of asthma and significantly less patients reported an increase in asthma scores (P < 0.01).


CONCLUSIONS
Immunotherapy for 3 years with standardized allergen extracts of grass and/or birch shows long-term clinical effect and preventive effect on development of asthma in children with seasonal rhinoconjunctivitis.
Niggemann
B
B
Department of Pediatric Pneumology and Immunology, Charité, Berlin, Germany.
Jacobsen
L
L
Dreborg
S
S
Ferdousi
H A
HA
Halken
S
S
Høst
A
A
Koivikko
A
A
Koller
D
D
Norberg
L A
LA
Urbanek
R
R
Valovirta
E
E
Wahn
U
U
Möller
C
C
D000293:Adolescent; D000485:Allergens / Q000627:therapeutic use*; D052179:Antigens, Plant; D001249:Asthma / Q000453:epidemiology / Q000276:immunology / Q000517:prevention & control*; D029662:Betula / Q000276:immunology; D002648:Child; D003888:Desensitization, Immunologic; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D016017:Odds Ratio; D010940:Plant Proteins / Q000627:therapeutic use*; D006109:Poaceae / Q000276:immunology; D011058:Pollen / Q000276:immunology; D006255:Rhinitis, Allergic, Seasonal / Q000276:immunology / Q000628:therapy*
D000485:Allergens; D052179:Antigens, Plant; C076049:Phl p V protein, Phleum pratense; D010940:Plant Proteins; C061312:Bet v 1 allergen, Betula