Unraveling the Diagnosis of Kiwifruit Allergy: Usefulness of Current Diagnostic Tests.

OBJECTIVES: To determine the usefulness of the in vitro and in vivo methods used in the diagnosis of kiwifruit allergy and to specifically assess the impact of seed proteins on sensitivity. METHODS: We performed skin prick tests (SPTs) using various commercial extracts, homemade pulp, and seed extracts and prick-prick tests with kiwifruit on 36 allergic patients. The presence of specific IgE (sIgE) was assessed using the ImmunoCAP (kiwifruit extract), ELISA (Act d 1, Act d 2), ISAC, and FABER assays. Immunoblotting of seed extract was carried out, and a single-blind oral food challenge was performed with whole seeds in seed-sensitized individuals. RESULTS: The prick prick test with kiwifruit demonstrated the highest diagnostic capacity (81.8% sensitivity and 94.1% specificity) among the in vivo tests. The sIgE levels measured using ImmunoCAP (kiwifruit extract) showed a similar sensitivity to that of global ISAC and FABER (63.9%, 59.5%, and 58.3%, respectively). Act d 1 was the major allergen. Sensitization to Act d 1 was associated with positive sIgE results to whole kiwifruit extract detected by ImmunoCAP (P<.000). A positive SPT result to kiwifruit seeds was associated with severe symptoms induced by kiwifruit (P=.019) as a marker of advanced disease, but not with clinically relevant sensitization. Challenge testing with kiwifruit seeds performed on 8 seed-sensitized patients yielded negative results. CONCLUSION: Sensitization to Act d 1 is associated with a positive result in conventional diagnostic techniques, whereas kiwifruit seed sensitization does not increase the sensitivity of the diagnostic techniques evaluated.

Are basophil activation and sulphidoleukotriene determination useful tests for monitoring patients with peach allergy receiving sublingual immunotherapy with a Pru p 3-enriched peach extract?

INTRODUCTION: Treatment of food allergy essentially consists of food avoidance, but immunotherapy with food is emerging as a new therapeutic option. OBJECTIVE: To evaluate clinical improvement and immunological changes in patients with peach allergy following sublingual immunotherapy (SLIT) with a Prup3 quantified peach extract. METHODS: A randomized, double-blind, placebo-controlled clinical trial with peach SLIT was conducted. We assessed clinical efficacy after 6 months of treatment by means of double-blind, placebo-controlled oral challenges with peach and also evaluated immunological changes (basophil activation test [BAT] and determination of sulphidoleukotriene production) following stimulation with peach peel and pulp, rPrup3, rMald 1, and rMal d 4 stimulation. We also measured specific IgE and IgG4 to Pru p3. RESULTS: After 6 months of SLIT (T6), the active group showed a 3-fold improvement in tolerance to Prup3 and a significant increase in IgE to rPrup3 and in sLT production following stimulation with peach peel and rPrup3. There was also a significant increase in BAT results after stimulation with rPrup3 at 1 month of SLIT (T1). Statistically significant between-group differences were only observed for BAT with peach peel and pulp at T1 and T6 and for BAT with rPru p3 at T6. No changes were observed in BAT with rMal d 1 or rMal d 4 or in IgG4 levels to nPrup3. CONCLUSIONS: SLIT with a Pru p 3 quantified peach extract is clinically effective and leads to an increase in basophil activation and sulphidoleukotriene production following stimulation with rPru p3 and peach peel in the first months of treatment.

Sublingual immunotherapy in peach allergy: monitoring molecular sensitizations and reactivity to apple fruit and Platanus pollen.

BACKGROUND: Peach allergy is prevalent, persistent, and potentially severe and as such is a target for immunotherapy. Our aims were to evaluate the profile of sensitization to Rosaceae allergens and the effects of sublingual peach immunotherapy on immunoglobulin (Ig) E levels to these allergens, to monitor for neosensitizations, and to check if this treatment modified other Rosaceae fruit and pollen-related sensitizations. METHODS: A double-blind placebo-controlled trial was conducted on 56 peach-allergic patients who received, sublingually, a standardized peach extract quantified in mass units of Pru p 3, or placebo for 6 months. IgE to recombinant (r) Mal d 1, rMal d 4, rPru p 3, and natural (n) Art v 3 and skin prick test (SPT) reactivity to Platanus pollen and apple extracts evaluated before treatment (T0), after 1 month (T1) and after and 6 months (T6) were recorded. RESULTS: In total, 18.5% of patients recognized rMal d 1, 83.3%, rPru p 3, 24.1%, rMal d 4, and 25.9% nArt v 3. IgE to Pru p 3 rose from T0 to T1 in both the active group (P = .003) and the placebo group (P = .022), and remained elevated at T6 in the active group (P = .001). IgE to other purified allergens did not change significantly and no relevant neosensitizations were detected. SPT reactions to peach decreased from T0 to T6 in the active group (P < 0.05). Reactivity to peach (T1 and T6) and apple (T6) was lower in the active group than in the control group. CONCLUSIONS: The main allergen was Pru p 3. Changes in rPru p 3 IgE levels and in peach and apple extract SPT were induced by sublingual immunotherapy.

Randomized double-blind, placebo-controlled trial of sublingual immunotherapy with a Pru p 3 quantified peach extract.

BACKGROUND: Peach allergy is highly prevalent in the Mediterranean area; it is persistent and potentially severe, and therefore a prime target for immunotherapy. We aimed to study the efficacy and safety of sublingual immunotherapy (SLIT) with a peach extract quantified in mass units for Pru p 3, the peach lipid transfer protein. METHODS: Randomized, double-blind, placebo-controlled (DBPC) clinical trial. The main efficacy outcome was the change in the response to a DBPC food challenge (DBPCFC) with peach. Secondary efficacy outcomes were the changes in skin prick test (SPT), and in specific immunoglobulin E (IgE) and IgG(4) to Pru p 3. Tolerance was assessed with a careful recording of adverse events. RESULTS: After 6 months of SLIT, the active group tolerated a significantly higher amount of peach (three- to ninefold), presented a significant decrease (5.3 times) in SPT, and a significant increase in IgE and IgG(4) to Pru p 3. No significant changes were observed within the placebo group. Statistically significant inter-group differences were only observed in the SPT and IgG(4) responses. No serious adverse events were reported. Systemic reactions were mild, and observed with a similar frequency in both groups. Local reactions were significantly more frequent in the active group (three times) and 95% of them restricted to the oral cavity. CONCLUSION: In this first exploratory clinical trial, SLIT for peach allergy seems to be a promising therapeutic option that could modify the clinical reactivity of the patients to peach intake and the underlying immunological response with a good tolerance.