Frequent occurrence of T cell-mediated late reactions revealed by atopy patch testing with hypoallergenic rBet v 1 fragments

Abstract

Background: Late allergic reactions are common in the course of allergen-specific immunotherapy and even occur with allergy vaccines with reduced IgE reactivity.

Objective: We sought to study atopy patch test (APT) reactions and T-cell responses to the recombinant birch pollen allergen Bet v 1 and recombinant hypoallergenic T-cell epitope-containing Bet v 1 fragments in patients with birch pollen allergy with and without atopic dermatitis (AD).

Methods: A clinical study was conducted in 15 patients with birch pollen allergy with AD (group 1), 5 patients with birch pollen allergy without AD (group 2), 5 allergic patients without birch pollen allergy (group 3), and 5 nonallergic subjects (group 4) by performing skin prick tests and APTs with rBet v 1 and hypoallergenic rBet v 1 fragments. T-cell, cutaneous lymphocyte antigen (CLA)(+) and CCR4(+) T-cell and cytokine responses were studied by thymidine uptake, carboxyfluorescein diacetate succinimidyl ester staining, and Luminex technology, respectively.

Results: rBet v 1 and hypoallergenic rBet v 1 fragments induced APT reactions in not only most of the patients with birch pollen allergy with AD (11/15) but also in most of those without AD (4/5). Patients with birch pollen allergy with AD had higher Bet v 1-specific proliferation of CLA(+) and CCR4(+) T cells compared with patients with birch pollen allergy without AD. There were no differences in Bet v 1-specific CLA(+) and CCR4(+) proliferation and cytokine secretion in patients with and without APT reactions.

Conclusion: Hypoallergenic rBet v 1 fragments induce T cell-dependent late reactions not only in patients with birch pollen allergy with AD but also in those without AD, which can be determined based on APT results but not based on in vitro parameters.

Keywords: Allergy; CCR4; T-cell proliferation; allergen; atopy patch testing; birch pollen allergy; cutaneous lymphocyte antigen; late-phase reaction; rBet v 1; rBet v 1 fragments; recombinant hypoallergens; specific immunotherapy.

Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.

Figures

FIG 1

Study design. Four groups of subjects, group 1 (patients with birch pollen allergy with AD, n = 15), group 2 (patients with birch pollen allergy with rhinoconjunctivitis without AD, n = 5), group 3 (allergic patients without birch pollen allergy and without AD, n = 5), and group 4 (nonallergic subjects, n = 5), were subjected to SPTs and APTs.

FIG 2

T-cell proliferation toward rBet v 1 or F1+F2. Shown are PBMC proliferations (y-axes: stimulation indices as box-and-whisker plots showing minimum, quartiles, median, and maximum values) in response to rBet v 1 or the rBet v 1 fragments (F1+F2) for study groups 1 to 4 (upper panel) and (lower panel) for patients with birch pollen allergy with positive APT reactions (group A), patients with birch pollen allergy with negative APT reactions (group B), and subjects without birch pollen allergy with negative APT reactions (group C). Significant differences between the groups are indicated.

FIG 3

Activation of CLA+ or CCR4+CD3+ cells by rBet v 1 or F1+F2 with carboxyfluorescein diacetate succinimidyl ester staining. A and B, Shown are the stimulation indices as box-and-whisker plots showing minimum, quartiles, median, and maximum values in response to rBet v 1 (Fig 3, A) or to the rBet v 1 fragment mix (F1+F2; Fig 3, B) for study groups 1 to 4. C and D, Results for patients with birch pollen allergy with positive APT reactions (Fig 3, A), patients with birch pollen allergy with negative APT reactions (Fig 3, B), and subjects without birch pollen allergy with negative APT reactions (Fig 3, C) in response to rBet v 1 and F1+F2, respectively. Significant differences between the groups are indicated. The horizontal dashed line represents the cutoff for positive proliferation (stimulation index > 1).