The allergen profile of beech and oak pollen

BACKGROUND: Beech and oak pollen are potential allergen sources with a world-wide distribution. OBJECTIVE: We aimed to characterize the allergen profile of beech and oak pollen and to study cross-reactivities with birch and grass pollen allergens. METHODS: Sera from tree pollen-allergic patients with evidence for beech and oak pollen sensitization from Basel, Switzerland, (n=23) and sera from birch pollen-allergic patients from Vienna, Austria, (n=26) were compared in immunoblot experiments for IgE reactivity to birch (Betula pendula syn. verrucosa), beech (Fagus sylvatica) and oak (Quercus alba) pollen allergens. Subsequently, beech and oak pollen allergens were characterized by IgE inhibition experiments with purified recombinant and natural allergens and with allergen-specific antibody probes. Birch-, beech- and oak pollen-specific IgE levels were determined by ELISA. RESULTS: Beech and oak pollen contain allergens that cross-react with the birch pollen allergens Bet v 1, Bet v 2 and Bet v 4 and with the berberine bridge enzyme-like allergen Phl p 4 from timothy grass pollen. Sera from Swiss and Austrian patients exhibited similar IgE reactivity profiles to birch, beech and oak pollen extracts. IgE levels to beech and oak pollen allergens were lower than those to birch pollen allergens. CONCLUSION: IgE reactivity to beech pollen is mainly due to cross-reactivity with birch pollen allergens, and a Phl p 4-like molecule represented another predominant IgE-reactive structure in oak pollen. The characterization of beech and oak pollen allergens and their cross-reactivity is important for the diagnosis and treatment of beech and oak pollen allergy

Allergy diagnosis from symptoms to molecules, or from molecules to symptoms: a comparative clinical study

Abstract Background Classical allergy diagnostic workup “from symptoms to molecules” comprises 1) clinical investigation, 2) skin prick- and IgE- testing, and recently, 3) molecular allergy testing. We aimed to examine the diagnostic fidelity of the alternative approach “from molecules to symptoms”, which was recently suggested in the EAACI Molecular Allergology User’s Guide, in a retrospective clinical study. Methods Records from 202 patients with clinically suspected allergic sensitizations were extracted from files at two sites applying either the “ISAC-first” workup with IgE-testing by immuno-solid phase allergen chip ISAC112 followed by selected skin prick tests (SPT) or the “SPT-first” starting with SPT followed by the microarray test. Results In the ISAC-first procedure significantly less SPTs were performed during allergy diagnosis (median 4 vs. 14). By SPT in 19% of patients in the ISAC-first group and in 34% in the SPT-first group additional respiratory allergens (p = 0.014) were detected not positive in ISAC microarray. By ISAC microarray test 18% additional sensitizations were found in the ISAC-first, and 32% in SPT-first cohort (p = 0.016). For food allergens 13 and 12% additional sensitizations were detected by the microarray not detected by SPT in the two groups (p = 0.800). No additional food allergen was found by SPT in the ISAC-first group, while in 6% of the cases in the SPT-first group detected sensitizations were negative in the microarray. Discussion The ISAC-first approach followed by (fewer) SPTs meets the demands for a patient’s tailored diagnostic work-up and therefore can be considered equivalent to the conventional way using the skin prick test as first screening tool, followed by IgE diagnosis. Conclusions For the diagnostic verification of clinically suspected allergy, the novel concept “from molecules to clinic” offers a reliable diagnostic workup in shorter time. Due to lower skin test numbers it is especially applicable for young children and seniors, in atopic patients, and whenever skin tests get difficult or unreliable

Elevated oxytocin and noradrenaline indicate higher stress levels in allergic rhinitis patients: Implications for the skin prick diagnosis in a pilot study

Background & Aims The effects of acute stress on allergic symptoms are little understood. The intention of this clinical study was to study the effects of acute stress and related mediators in allergic rhinitis (AR), taking the wheal and flare reaction in skin prick testing (SPT) as a readout. Methods 19 healthy and 21 AR patients were first subjected to SPTs with grass pollen-, birch pollen- and house dust mite allergen extracts, histamine and negative control. Subsequently, participants were exposed to a standardized Trier Social Stress Test (TSST), followed by SPT on the contralateral forearm. Stress responders were identified based on the salivary cortisol levels and State-subscale of State-Trait-Anxiety Inventory (STAI-S). Blood samples were collected before and after TSST and adrenaline, noradrenaline, serotonin, oxytocin, platelet activating factor and prostaglandin D2 were analyzed by enzyme immunoassay (EIA). Results SPT results of 14/21 allergics and 11/19 healthy who responded with stress after TSST were evaluated. No significant differences regarding SPT to allergens or histamine before and after the stress test could be calculated at the group level. But, the wheal and flare sizes after TSST increased or decreased substantially in several individuals, and unmasked sensitization in one healthy person, which could not be correlated with any mediator tested. The most significant finding, however, was that, independent of TSST, the baseline levels of oxytocin and noradrenaline were significantly higher in allergics. Conclusion High baseline levels of noradrenaline points toward higher stress levels in allergic patients, which might be counterregulated by elevated oxytocin. Moreover, our data indicate that acute stress may have a significant influence on SPT fidelity in susceptible individuals

Verification of TSST-induced stress in study subjects.

<p><b>a)</b> Salivary cortisol (means ± SD, ng/ml) in allergics (n = 14) and non-allergics (n = 11) who responded after the TSST; grey data points before, black after TSST; <b>b)</b> results of State-Trait-Anxiety Inventory (STAI-S) for self-reported anxiety in allergic (n = 20) and non-allergic participants (n = 19) before (grey boxes) and after the TSST (black boxes) (means ± SD); ***p ≤ 0.001. *P ≤ 0.05.</p

Characterization and clinical description of study participants.

<p>Characterization and clinical description of study participants.</p

Changes in SPT wheal diameters before and after the TSST.

<p><b>a)</b> Box plots illustrating changes in wheal diameters before (grey boxes) and after TSST (black) in the allergic cohort, in mm (y-axis); <b>b)</b> Individual changes in SPT wheal diameters to birch pollen (BP) (n = 8), <b>c)</b> grass pollen (GP) (n = 8), <b>d)</b> house dust mite (HDM) (n = 10), before (Pre) and after the TSST (Post); black lines in <b>b)-d)</b> indicate subjects responding with >10% relative change of reactivity, grey: less than 10% change.</p

Comparison of SPT results in the allergic and healthy cohort before and after the TSST.

<p>Comparison of SPT results in the allergic and healthy cohort before and after the TSST.</p

SPT left and right forearm comparison.

<p>Evaluation of the reliability of SPT with allergen extracts in 14 grass pollen allergic rhinitis patients at visit 1 <b>(a)</b> and visit 2 <b>(b)</b>. Box plots indicate median of SPT wheal surface areas (cm²) on the left (grey boxes) or right forearm (black boxes). 5 preparations of grass pollen extracts were used: A) Staloral® 300 IR/mL Phleum pratense pollen exact; B) Oralair® 300IR 5-grass pollen extract SLIT tablet, diluted in 1ml 50% glycerin; C) Soluprick® <i>Phleum pratense</i> pollen exact for SPT; D) Grazax® Phleum pratense pollen extract SLIT tablet, diluted in 1ml 50% glycerine; E) Reference Greer® 10.000 BAU/mL Phleum pratense pollen extract in different dilutions (E0: concentrated, E1: 1:3, E2: 1:10, E3: 1:30); vehicle negative control (NC) and histamine 1mg/ml positive control (PC). **p ≤ 0.01.</p

Significantly higher baseline levels of noradrenaline and oxytocin in allergic patients.

<p>Samples of cortisol-responding allergics (n = 12) and non-allergics (n = 9) were tested before TSST (grey dots) or after (black) for <b>a)</b> plasma noradrenaline and <b>b)</b> oxytocin levels. Data are represented as means ± SD; *p≤ 0.05.</p