Molecular profiles of IgE to Phleum pratense in children with grass pollen allergy: implications for specific immunotherapy.
BACKGROUND
The so-called component-resolved immunotherapy of allergies proposes an immunization tailored to the molecular sensitization profiles of individual patients.


OBJECTIVE
We sought (1) to investigate the profiles of IgE sensitization to Phleum pratense in children with grass pollen allergy and (2) to define the compatibility of these profiles with a mixture of recombinant allergenic molecules of P pratense previously proposed for specific immunotherapy.


METHODS
We examined 200 children (age, 4-18 years; 126 boys) with allergic rhinitis, asthma, or both ascertained through validated questionnaires. Each child underwent skin prick testing (ALK-Abelló) and serum IgE assays (ImmunoCAP, Phadia) with 9 pollen extracts. Sera reacting against P pratense were tested for the individual molecules (rPhl p 1, rPhl p 2, rPhl p 4, nPhl p 4, rPhl p 5b, rPhl p 6, rPhl p 7, rPhl p 11, and Phl p 12). Through a combinatorial approach, the IgE individual sensitization profiles were matched against an experimental allergen-specific immunotherapy (SIT) preparation containing Phl p 1, Phl p 2, Phl p 5, and Phl p 6.


RESULTS
Among the 176 of 200 children with IgE sensitization to P pratense extract, 39 profiles of sensitization to the 8 allergenic molecules tested (cutoff, 0.35 kU/L) were identified. This high heterogeneity was reduced by considering only 6 or 4 P pratense molecules but not by increasing the cutoff levels of IgE positivity. The molecular profile of the experimental SIT preparation matched that of 7 (4%) of 176 patients only; the remaining 169 patients were classified in 4 mismatch categories: underpowered (29%), overpowered (32%), underpowered/overpowered (32%), and unrelated (3%).


CONCLUSIONS
IgE sensitization profiles to P pratense are highly heterogeneous. Molecularly designed SIT preparations tailored to patients' needs should consider this high heterogeneity and be driven by locally performed population studies.
Pediatric Allergology Unit, Sandro Pertini Hospital, Rome, Italy.
Salvatore
S
Tripodi
Tullio
T
Frediani
Sandra
S
Lucarelli
Francesco
F
Macrì
Giuseppe
G
Pingitore
Andrea
A
Di Rienzo Businco
Arianna
A
Dondi
Paola
P
Pansa
Giovanni
G
Ragusa
Riccardo
R
Asero
Diego
D
Faggian
Mario
M
Plebani
Paolo Maria
PM
Matricardi
D000293:Adolescent; D000485:Allergens / Q000008:administration & dosage* / Q000009:adverse effects; D002648:Child; D002675:Child, Preschool; D020650:Combinatorial Chemistry Techniques; D003888:Desensitization, Immunologic / Q000379:methods*; D005260:Female; D006801:Humans; D007073:Immunoglobulin E / Q000097:blood; D008297:Male; D031784:Phleum / Q000276:immunology*; D057285:Precision Medicine; D011994:Recombinant Proteins / Q000008:administration & dosage* / Q000009:adverse effects; D006255:Rhinitis, Allergic, Seasonal / Q000175:diagnosis / Q000276:immunology* / Q000628:therapy*; D012882:Skin Tests
D000485:Allergens; D011994:Recombinant Proteins; D007073:Immunoglobulin E