Gibberellin-regulated
protein (GRP) is a new
allergen in peach
allergy, with an amino acid sequence very well conserved through several botanical species. We investigated the allergenicity of GRP in fruit
allergies other than peaches and identified the clinical characteristics of fruit
allergy patients with GRP sensitization. One hundred consecutive Japanese patients with fruit
allergies were enrolled in the present study. To identify the features of GRP sensitization, we selected patients with negative ImmunoCAP results for Bet v 1 homologs and
profilin, which are marker
allergens for pollen-
food allergy syndrome (PFAS), or
lipid transfer protein. These patients underwent specific
immunoglobulin E measurements by
enzyme-linked
immunosorbent assay (ELISA) and skin prick tests (SPT) using purified nPru p 7. Twenty of 100 consecutive patients with fruit
allergies had negative ImmunoCAP results for Bet v 1 homologs and
profilin. Thirteen (65.0%) of the 20 patients had positive ELISA and/or SPT results using nPru p 7, whereas one of the 20 patients had positive ImmunoCAP results for Pru p 3. In 13 nPru p 7-sensitized patients, the causative foods were peaches (92.3%), apricots (61.5%), oranges (46.2%) and apples (30.8%). Ten patients (76.9%) had multiple causative fruits. Frequent symptoms included facial
edema (92.3%) and laryngeal tightness (66.7%). In eight patients (61.5%), exercise or
aspirin intake enhanced the
allergic reaction onset as cofactors. The prevalence of GRP sensitization was high in Japanese fruit
allergy patients except for PFAS patients. In conclusion, GRP-sensitized patients may have
allergies to multiple fruits and may show peculiar characteristics such as facial swelling and cofactor dependence.