Basophils response to Pru p 3 and Ara h 9 in patients sensitised to peach under specific immunotherapy

Rationale

In Southern Europe Pru p3 is the primary sensitizer of plants fruit and it is responsible of severe reactions. Specific immunotherapy (SIT) brings a new perspective to treat those patients. There is a lack of knowledge regarding cellular responses that include changes in the basophil activation during the IT. We aim to analyse early changes in the basophil response to Pru p 3 and other related allergen (Ara h 9) after the first month of sublingual immunotherapy (SLIT).

Methods

Forty-six peach allergic patients confirmed by positive specific IgE determined by skin prick test or fresh peach (prick-by-prick), ImmunoCAP IgE and/or a double blind placebo control food challenge with peach. Basophil reactivity was determined by the basophil activation test (BAT) with Pru p 3 and Ara h 9 at two concentrations, 1 and 0.1 µg/ml, before and after 1month of SLIT.

Results

Twenty one patients evaluated (45%) performed anaphylaxis and 25 (55%) urticaria and/or angioedema. The 82,6% showed sensitization to other plant foods proteins and 69,5% showed sensitization to pollens. The BAT was done in 25 patients with first month of SLIT completed. The 28% patients have an increase of Pru p 3 reactivity. The 36% patients showed same reactivity after first month and 36% presented a decreased reactivity to Pru p3. Similar results were obtained for Ara h 9 in those patients.

Conclusion

Preliminary result disclosed that percentage of patients who underwent changes in BAT reactivity to Pru p3 and Ara h 9 was similar. There have been no differential clinical pattern in the groups studied after one month of SLIT. The BAT shows a good correlation between both Pru p 3 and Ara h 9.