Age-related sensitization profiles for hazelnut (Corylus avellana) in a birch-endemic region.

BACKGROUND: Symptoms of hazelnut allergy seem related to geographic and possibly age variations in allergen recognition. OBJECTIVE: To investigate sensitization profiles of hazelnut allergy in different age groups in a birch-endemic region using component resolved diagnosis (CRD) by microarray. METHODS: Sixty-five patients with hazelnut allergy, 27 healthy control individuals tolerant to hazelnut, and 34 birch pollen allergic but hazelnut tolerant individuals were included. All blood samples were analyzed using ISAC microarray. RESULTS: Twenty-nine patients with hazelnut allergy suffered from a systemic reaction (17 preschool children with a median age of 2 years, six school children, and six adults), whereas 36 patients reported an oral allergy syndrome (OAS; three preschool and nine school children and 24 adults). In the hazelnut allergic preschool children with systemic reactions, 65% were sensitized to Cor a 9, 12% to Cor a 8, 18% to Cor a 1.04, 6% to Cor a 1.0101, and 29% to Bet v 1. Of the school-aged systemic reactors, 50% were sensitized to Cor a 9, 17% to Cor a 8, 50% to Cor a 1.04 and Cor a 1.0101, and 67% to Bet v 1. In adults with hazelnut allergy, 3.3% were sensitized to Cor a 9, 6.7% to Cor a 8, 90% to Cor a 1.04 and Bet v 1, and 87% to Cor a 1.0101. In regard to systemic reactors in this group, 17% were sensitized to Cor a 9, 33% to Cor a 8 and Cor a 1.0101, and 50% to Cor a 1.04 and Bet v 1. In the patients with OAS, irrespective the age group, all were sensitized to Bet v 1 and over 97% to Cor a 1.04 and Cor a 1.0101. No sensitization to Cor a 9 or Cor a 8 was found in patients with only an OAS. Of the patients with birch pollen allergy, tolerant to hazelnut, none were sensitized to Cor a 9 or Cor a 8, 56% to Cor a 1.0101, 82% to Cor a 1.04, and 92% to Bet v 1. In healthy controls, no sensitization to components of hazelnut, hazel pollen or birch pollen was demonstrable. CONCLUSION: Hazelnut allergy in a birch-endemic region exhibits age-related sensitization profiles with distinct clinical outcomes that can be identified using CRD. The majority of hazelnut allergic preschool and school children in a birch-endemic region show systemic reactions on consumption of processed hazelnut, mostly being sensitized to the hazelnut legumin-like allergen Cor a 9 but unrelated to birch pollen allergy. In contrast, adults generally suffer from an OAS apparently as a result of cross-reactivity between Cor a 1.04 from hazelnut and Bet v 1 from birch pollen.

Basophil activation reveals divergent patient-specific responses to thermally processed peanuts.

INTRODUCTION: The impact of processing on the allergenicity of peanut (Arachis hypogaea) proteins has traditionally been studied using immunoglobulin (Ig) E binding assay. However, as this technique does not assess the potential of an allergen to trigger basophils and mast cells, studies based on it can hardly be considered complete. We evaluated the effect of processing on peanut allergenicity using flow-cytometric quantification of in vitro basophil activation (basophil activation test [BAT]). PATIENTS AND METHODS: Basophils from 10 patients with severe peanut allergy and 3 peanut-tolerant individuals were stimulated with extracts from 5 raw and thermally processed peanut varieties. Data were compared using protein staining (sodium dodecyl sulfate-polyacrylamide gel electrophoresis [SDS-PAGE]) and IgE immunoblotting. RESULTS: Stimulation with different extracts resulted in patient-dependent and variety-dependent effects on basophil activation. SDS-PAGE revealed a considerable loss of identifiable bands, especially for the South Africa Common Natal, Argentina Runner, and US Virginia varieties. The results of IgE immunoblotting in patients were similar, irrespective of the responses observed in the BAT. CONCLUSIONS: The impact of thermal processing on the capacity of peanuts to trigger basophils seems highly divergent between patients and cannot be predicted using SDS-PAGE or IgE binding. BAT can be considered a complementary tool for the evaluation of food allergenicity.

Human basophils: a unique biological instrument to detect the allergenicity of food.

BACKGROUND: Labeling of major food allergens is mandatory for the safety of allergic consumers. Although enzyme-linked immunosorbent assay, polymerase chain reaction, and mass spectrometry are sensitive and specific instruments to detect trace amounts of food proteins, they cannot measure the ability of food constituents to trigger activation of mast cells or basophils. AIM: We evaluated the basophil activation test as an instrument to determine the allergenic potential of trace amounts of food allergens in complex matrices. Peanut (Arachis hypogaea) allergy was selected as a proof-of-concept model. METHODS: The study population comprised 5 severely peanut-allergic patients (3 males/2 females; median age, 12 years) all sensitized to 3 major peanut allergens (Ara h 1, Ara h 2, and Ara h 3) and 5 peanut-tolerant individuals (2 males/3 females; median age, 8 years). Basophils from patients and controls were stimulated with pure peanut extract and blank and peanut-spiked (0.1, 0.01, and 0.001 ppm) biscuits (baking time 11, 16, 21, 26 minutes) and chocolate extracts. RESULTS: Blank biscuits and chocolate did not induce cell activation in patients or controls. A comparison between patients and controls showed significantly higher activation of basophils after stimulation with 0.1 and 0.01 ppm of peanut-spiked biscuit at all baking times and peanut-spiked chocolate (P < .05). CONCLUSIONS: The basophil activation test is a highly sensitive and specific tool to detect traces of functionally active food allergens. For biscuits, its accuracy seems independent of baking time. Furthermore, it allows even the most sensitive patients to be included in study protocols.

Sensitization profiles in birch pollen-allergic patients with and without oral allergy syndrome to apple: lessons from multiplexed component-resolved allergy diagnosis.

BACKGROUND: Component-resolved diagnosis (CRD) using microarray technology has recently been introduced into the field of clinical allergology. OBJECTIVE: To further validate the use of CRD by microarray technology in allergy diagnosis. METHODS: Thiry-seven patients allergic to birch pollen were included. The discriminative value of apple-specific IgE (sIgE), recombinant Mal d 1 (rMal d 1) sIgE, apple skin prick test and rMal d 1 on the microarray was assessed between patients with a birch-related oral allergy syndrome to apple (OAS(+), n=20) and healthy control individuals (HC, n=8) without a history of inhalant allergies or apple-induced OAS. An additional comparative analysis was carried out with individuals allergic to birch pollen allergy without OAS (OAS(-); n=17). RESULTS: rMal d 1 coupled to the microarray constitutes a discriminative marker between OAS(+) and HC with a sensitivity 95% and a specificity of 100%. However, in parallel with the traditional sIgE assay, 15 out of 17 OAS(-) individuals (88%) also displayed IgE reactivity to rMal d 1 coupled to the microarray. OAS(-) individuals are more frequently sensitized to mite (about three to four times), cat and dog dander (about two to three times) and grass pollen (about 1.5 times) as compared with OAS(+) patients. CONCLUSION: At first glance, CRD by microarray seems to be a reliable instrument in the diagnosis of apple-mediated OAS in birch pollen allergy. However, for discriminating between sensitization and a real allergy, micro-arrayed rMal d 1 offers no advantage over conventional quantification of rMal d 1 sIgE. Most interestingly, within a single run, birch pollen-allergic patients without OAS to apple were shown to display a broader sensitization to classical inhalant allergens than birch pollen-allergic patients with an apple-related OAS.

Component-resolved diagnosis from latex allergy by microarray.

BACKGROUND: A positive specific IgE (sIgE) result for latex does not always mirror the clinical situation and is frequently found in individuals without overt latex allergy. OBJECTIVE: We sought to investigate the potential of component-resolved diagnosis (CRD) of latex allergy by microarray and to assess whether the technique allows discriminating genuine allergy from asymptomatic sensitization. METHODS: Twenty-six healthy controls without a history of latex allergy with a negative latex sIgE and skin test, 22 latex-allergic patients with a compelling history of latex allergy with a positive latex sIgE and prick test and 20 latex-sensitized individuals with a frequent asymptomatic exposure to natural rubber latex-containing devices with a negative latex skin test but a positive sIgE were also included. CRD was performed with the ImmunoCAP ISAC microarray and traditional singleplexed ImmunoCAP. RESULTS: In all patients, the diagnosis of latex allergy could be established by the combination of recombinant latex components present on the microarray (Hev b 1, Hev b 3, Hev b 5 and Hev b 6.02). Over three-quarters of our patients were sensitized for Hev b 5 and/or Hev b 6.02. Some patients also displayed reactivity for Hev b 1 and/or Hev b 3. In contrast, none of the individuals sensitized to natural rubber latex or control individuals demonstrated IgE reactivity for rHev b 1, rHev b 3, rHev b 5 or rHev b 6.02. Three-quarters of the patients sensitized to latex displayed a positive microarray result for recombinant latex profilin (rHev b 8). In contrast to the results obtained by traditional ImmunoCAP for bromelain, almost no sensitization for cross-reactive carbohydrates was demonstrated by bromelain spotted on the microarray. CRD by traditional singleplexed ImmunoCAP showed highly comparable results. CONCLUSION: CRD by microarray is a reliable tool for diagnosing latex allergy. In addition, the technique allows discrimination between genuine allergy and sensitization. CRD by microarray can improve the diagnosis of IgE-mediated latex allergy by discriminating between genuine allergy and sensitization. CRD by microarray is a reliable tool to diagnose latex allergy. In addition, the technique allows discrimination between a genuine allergy and simple sensitization.

Multicentric reticulohistiocytosis associated arthritis responding to anti-TNF and methotrexate.

We present a patient with therapy resistant multicentric reticulohistiocytosis (MRH). MRH is a rare granulomatous, multisystem disease characterised most frequently by disfiguring papulonodular skin lesions and sometimes a destructive polyarthritis, though any organ can be involved. Abnormal histiocytic reactions to an undetermined stimulus (possibly an associated mycobacterial infection, auto immune process or neoplastic process) have been proposed as an underlying mechanism. The diagnosis is confirmed by histopathology of the cutaneous nodules and/or synovial membrane by the presence of CD68-positive histiocytes and multinucleated giant cells with an eosinophilic 'ground-glass' cytoplasm. Recent studies have identified TNFalpha and other inflammatory cytokines to be highly expressed in the synovium and synovial fluid of affected joints in patients with MRH. Based on these findings, we treated our patient with infliximab in combination with methotrexate with marked improvement of morning stiffness, tender and swollen joint count, visual analogue scale and health assessment questionnaire after his third infusion. However, the nodules did not markedly resolve. When treating patients with MRH with TNFa neutralizing drugs, one has to keep the possible association with malignancy in 15-30% of cases in mind and these products should be used with caution.

Vanishing tumour of the colon ascendens due to acquired type II C1-inhibitor deficiency.

We present a patient with recurrent bouts of angioedema of the lips, throat and extremities with a negative familial history for angioedema. Laboratory results confirmed an angioedema due to acquired C1-INH deficiency (or acquired angioedema, AAE). As AAE can result from underlying disease, further investigation toward malignancy was initiated. A CT-scan of the abdomen disclosed a circumferential tumour of the proximal segment of the colon ascendens which disappeared by the time an ileocolonoscopy was executed. Angioedema of the bowel has been widely reported in hereditary angioedema, whereas it is anecdotal in AAE.

Macadamia nut allergy: 2 case reports and a review of the literature.

We report on 2 patients with anaphylaxis rom Macadamia nut. Temporal relationship between consumption of the nut strongly suggested the diagnosis. Clinical suspicion was supported by the presence of positive specific IgE and/or the positive skin test and/or and the basophil activation test.

Component-resolved allergy diagnosis by microarray: potential, pitfalls, and prospects.

Diagnosis of IgE-mediated allergies is not always straightforward, as traditional tests can yield equivocal or negative results and provocation tests are hampered by several practical and ethical limitations. During the last decades two new in vitro techniques have entered the field of allergy diagnosis, that is, flow-assisted analysis of allergen-specific activated basophils and component-resolved diagnosis (CRD). This review focuses on component-resolved allergy diagnosis by microarray that has evolved from recent advances in molecular allergology and biochip technology. The technique allows a comprehensive analysis of individual sensitization profiles with multiplexed purified and recombinant allergens within a single run using only a minute amount of serum, providing information that largely exceeds the output from current sIgE capturing tools. Actually, multiplexing allows identification of diagnostic patterns that may facilitate the formulation of diagnostic algorithms. Although CRD by microarray sounds promising, the diagnostic performance requires further intensive assessment before it can enter mainstream application. In our opinion, the technique should currently be considered a complementary diagnostic tool rather than a first-line choice.

Angioedema beyond histamine: an educational case series.

Angioedema constitutes an important clinical problem that can cause significant morbidity and mortality. Correct management requires a prompt recognition and treatment of the acute event and identification of the underlying cause. Many cases are caused by non-allergic reactions and do not result from mediator release by degranulating mast cells and basophils, but are related to accumulation of plasma and tissue bradykinin. This case series aims primarily to describe some important causes of non-allergic bradykinin-induced angioedema. Particular emphasis is put on clinical particularities, differential diagnosis, diagnostic approach and correct therapeutic management, as bradykinin-mediated angioedema is unresponsive to antihistamines.