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Keywords:

  • grass pollen;
  • immunotherapy;
  • rhinitis;
  • rhinoconjunctivitis;
  • transcutaneous

In Europe, allergen specific immunotherapy (SIT) administered by subcutaneous route has gradually fallen out of favour (1). Sublingual immunotherapy has declared safe and effective (2). Transcutaneous immunization is a new strategy to induce Ag-specific tolerance (3). To the best of our knowledge, no previous studies have investigated the efficacy of SIT using transcutaneous immunization by a skin patch set to induce high immune tolerance for the prevention of seasonal allergic rhinoconjunctivitis symptoms.

This prospective double blind randomized trial was achieved in January 2008 as suggested by European Medicine Agency guidelines (4) before the onset of the pollen season. 15 children (nine males, six females) received grass transcutaneous immunotherapy (gTCIT) and 15 (ten males, five females) received placebo.

End point prick test was carried out before and after treatment and the results were expressed as the percentage of the mean wheal diameter provoked by the allergen compared with that provoked by histamine.

Active adhesive patch containing 25–30 mg of vaccine with approx. 11.25 μg of major grass pollen allergens, was placed on the patient’s back and removed after 24 h. The grass pollen extract (SARM srl, Guidonia-Rome, Italy; specific activity of approx. 90 μg/ml of each of the major grass pollen allergens) was mixed (50%) with vaseline (excipient: salicylic acid <3% p.v.). The gTCIT was repeated once a week from 5th February to 19 April 2008 (12 weeks).

Daily intensity of eight rhinoconjunctivitis symptoms was rated according to a four grade scale. Oral antihistamine drug assumption was recorded on the diary card as a score of one and the mean number of drug assumptions per week for each week of the pollen season was thus calculated. Grass pollen count per m3 of air was taken continuously.

Intra-group evolution was performed with Wilcoxon signed ranks or Friedman tests and intergroup with the Mann–Whitney U-test. Group differences were examined with general linear models (GLMs). Two-sided exact tests were used and P-values of <0.05 were considered significant.

The two groups were well matched for age and duration of the disease, the mean age was similar in the two treatment groups: 7.57 ± 3.67 years in placebo groups, 9.20 ± 4.22 years in active groups (U = 84.5, = ns).

No children showed systemic reactions or local reactions.

There were no statistically significant differences in the endpoint prick tests between the two groups before and after treatment (before: placebo group 158.07 ± 57.111, active group: 142.31 ± 53.503, U = 95.5, P = ns; after: placebo group 145.09 ± 60.403, active group: 143.27 ± 55.069, U = 94.0, P = ns).

Significant increases were found in the placebo group concerning nasal obstruction (χ2 = 10.711, = 0.003), dyspnoea (χ2 = 9.071, = 0.007), ocular itching (χ2 = 8.791, = 0.010) and ocular redness (χ2 = 9.455, = 0.006). In the active group, only ocular itching increased significantly (χ2 = 7.850, = 0.015).

General linear models revealed statistically significant differences between the two groups, particularly in rhinorrhea (F = 7.911, = 0.009), nasal obstruction (F = 10.593, = 0.003), dyspnoea (F = 4.876, = 0.036) and ocular tearing (F = 4.478, = 0.044). Moreover, a significant reduction in antihistamine intake was recorded in the active group (F = 6.239, = 0.019). Figure 1 shows the mean weekly symptoms and medication score for each group during the entire pollen season.

image

Figure 1.  Mean weekly symptoms and medication score for each group during the entire pollen season.

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Nowadays, transcutaneous delivery is commonly employed for drug administration.

Our results demonstrate that gTCIT was effective in reducing symptoms and the use of antihistamine in selected children with grass pollen rhinoconjunctivitis and that this new SIT could become a valid alternative to traditional treatment.

References

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  2. References
  • 1
    Bousquet J, Lockey R, Malling HJ. Allergen immunotherapy: therapeutic vaccines for allergic diseases. A WHO position paper. J Allergy Clin Immunol 1998;102:558562.
  • 2
    Wilson DR, Lima MT, Durham SR. Sublingual immunotherapy for allergic rhinitis: systematic review and meta-analysis. Allergy 2005;60:412.
  • 3
    Ghoreishi M, Dutz JP. Tolerance induction by transcutaneous immunization through ultraviolet-irradiated skin is transferable through CD4+ CD25+ T regulatory cells and is dependent on host-derived IL-10. J Immunol 2006;176:26352644.
  • 4
    Committee for Medicinal Products for Human Use (CHMP) and Efficacy Working Party (EWP): Concept Paper on the preparation of a guideline on the clinical development of products for specific immunotherapy for the treatment of allergic diseases. In: 18504/2006: EMEA/CHMP/EWP; 2006.