Etude de la réponse lymphocytaire T dans l’allergie de l’enfant, au diagnostic et au cours de la désensibilisation

Abstract : Allergic diseases are steadily increasing steadily and especially in children. Allergen specific immunotherapy (desensitization) is the only curative treatment for which accurate diagnosis of allergy is essential. Currently, the presence of specific IgE diagnoses a sensitization to an allergen but not a clinically symptomatic allergy. In a first part, we studied the value of a functional test, the ELISpot (Enzyme-linked immunosorbent spot) in the diagnosis of allergy to house dust mites (HDM). The number of circulating HDM-specific IL-4 and IL-13 secreting T cells was associated with the presence of symptoms, regardless of specific IgE and was higher in severe rhinitis than in mild rhinitis. In addition, it varied according to the season with a peak in autumn and a peak in early spring (wet periods with greater allergen exposure). In a second part, we studied the value of ELISpot for the diagnosis of cow's milk allergy in children, confirmed by double blind placebo control food challenge. We found that the number of casein-specific IL-4 and IL -13 secreting T-cells was associated with allergy to cow's milk. It was also inversely correlated to the cow’s milk tolerated cumulative dose. Receiver-operating characteristic (ROC) curve of combined IL-4 and IL-13 analysis was generated. AUC was 0,98 (95% CI 0.90-1.06). For a cut-off of 10 IL-4- and 12 IL-13 secreting T-cells, sensitivity and negative predictive value were 100%.Finally, in the third part, we monitored antigen specific T-cell response in HDM allergic children treated with sublingual ITA (SLIT) on the one hand and subcutaneous ITA (SCIT) on the other hand, during one year. We found a decrease in HDM specific Th2 cells after 12 months of SLIT associated with an increase in HDM specific IL-10 secreting T-cells after 6 months of SLIT. In addition, regulatory T cells (CD4 + CD25hiCD127loFoxp3+) were increased after 12 months of SCIT. In conclusion, this work has allowed us to describe a functional test, the ELISpot, as a reliable tool for the diagnosis of mite allergy and cow's milk allergy in children. In addition, in HDM allergic children, a decrease of Th2 cells and an increase of IL-10 secreting T-cells was found in children treated with SLIT to HDM as well as an increase in Foxp3+ Treg in children treated with SCIT.
Document type :
Theses
Complete list of metadatas

https://tel.archives-ouvertes.fr/tel-00881757
Contributor : Abes Star <>
Submitted on : Friday, November 8, 2013 - 7:59:26 PM
Last modification on : Tuesday, July 9, 2019 - 10:36:06 PM
Long-term archiving on : Sunday, February 9, 2014 - 10:45:12 AM

File

va_michaud_benedicte.pdf
Version validated by the jury (STAR)

Identifiers

  • HAL Id : tel-00881757, version 1

Collections

Citation

Bénédicte Michaud. Etude de la réponse lymphocytaire T dans l’allergie de l’enfant, au diagnostic et au cours de la désensibilisation. Médecine humaine et pathologie. Université René Descartes - Paris V, 2013. Français. ⟨NNT : 2013PA05T025⟩. ⟨tel-00881757⟩

Share

Metrics

Record views

753

Files downloads

3445