Allergy to rocuronium: from clinical suspicion to correct diagnosis.

BACKGROUND: Allergy to rocuronium can be life-threatening. Correct diagnosis is a prerequisite because of serious consequences of diagnostic error. OBJECTIVE: To assess skin testing, quantification of specific IgE (sIgE) and flow-assisted activation of basophils [basophil activation test (BAT)] in the diagnosis of rocuronium allergy. METHODS: This study comprises 104 curarized patients with a history of profound hypotension and severe bronchospasm immediately after induction of anaesthesia. All patients had skin tests, quantification of sIgE and BAT to rocuronium, together with investigations for all relevant compounds administered during anaesthesia that could have evoked the reaction. Diagnosis of rocuronium allergy was considered definite when the patient demonstrated a positive outcome for at least two of the three aforementioned tests. RESULTS: The positive predictive value for skin testing, BAT and sIgE was 98% (CI 95%: 92-99%), 97% (CI 95%: 88-100%) and 83% (CI 95%: 74-89%), respectively. The negative predictive value for skin testing, BAT and sIgE was 96% (CI 95%: 86-99%), 75% (CI 95%: 67-75%) and 72% (CI 95%: 58-83%), respectively. Cross-reactivity with vecuronium was documented in 69% of the patients. CONCLUSION: Skin testing merits the status of primary diagnostic investigation to document rocuronium allergy and cannot be substituted by quantification of sIgE or BAT. SIgE can offer a diagnostic advantage in cases where skin tests yield negative results. However, additional tests (e.g. BAT) are of capital importance in patients with negative skin tests and positive sIgE results to help in interpreting the clinical significance of a positive sIgE result. Optimal assessment of cross-reactivity between rocuronium and vecuronium implies both skin testing and BAT.

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.

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.

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.

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.

Pre- and post-natal exposure to antibiotics and the development of eczema, recurrent wheezing and atopic sensitization in children up to the age of 4 years.

BACKGROUND: Little data are available on the relationship between indirect antibiotic exposure of the child in utero or during lactation and allergic diseases. On the other hand, several studies have been conducted on the association with direct post-natal antibiotic exposure, but the results are conflicting. OBJECTIVE: The aim of this study was to investigate pre- and post-natal antibiotic exposure and the subsequent development of eczema, recurrent wheeze and atopic sensitization in children up to the age of 4 years. METHODS: We conducted an aetiologic study in 773 children based on a prospective birth cohort project in which environmental and health information were collected using questionnaires. Antibiotic exposure was assessed as maternal antibiotic intake during pregnancy and during lactation and as medication intake of the child. The chronology of exposures and outcomes was taken into account during the data processing. At the age of 1 and 4 years, a blood sample was taken for the quantification of specific IgE. RESULTS: Prenatal antibiotic exposure was significantly positively associated with eczema, whereas no association was found with recurrent wheeze and atopic sensitization. We found a positive, although statistically not significant, association between antibiotic exposure through breastfeeding and recurrent wheeze. Neither eczema nor atopic sensitization was significantly associated with antibiotic exposure through breastfeeding. Finally, we observed a negative association between the use of antibiotics in the first year of life and eczema and atopic sensitization, and also between antibiotic use after the first year of life and recurrent wheeze, eczema and atopic sensitization. CONCLUSION: Indirect exposure to antibiotics (in utero and during lactation) increases the risk for allergic symptoms in children, while direct exposure to antibiotics appears to be protective. The biological mechanisms underlying these findings still need to be elucidated.

Two novel proteins expressed by the venom glands of Apis mellifera and Nasonia vitripennis share an ancient C1q-like domain.

An in-depth proteomic study of previously unidentified two-dimensional polyacrylamide gel electrophoresis spots of honey bee (Apis mellifera, Hymenoptera) venom revealed a new protein with a C1q conserved domain (C1q-VP). BlastP searching revealed a strong identity with only two proteins from other insect species: the jewel wasp, Nasonia vitripennis (Hymenoptera), and the green pea aphid, Acyrthosiphon pisum (Hemiptera). In higher organisms, C1q is the first subcomponent of the classical complement pathway and constitutes a major link between innate and acquired immunity. Expression of C1q-VP in a variety of tissues of honey bee workers and drones was demonstrated. In addition, a wide spatial and temporal pattern of expression was observed in N. vitripennis. We suggest that C1q-VP represents a new member of the emerging group of venom trace elements. Using degenerate primers the corresponding gene was found to be highly conserved in eight hymenopteran species, including species of the Aculeata and the Parasitica groups (suborder Apocrita) and even the suborder Symphyta. A preliminary test using recombinant proteins failed to demonstrate Am_C1q-VP-specific immunoglobulin E recognition by serum from patients with a documented severe bee venom allergy.

T cell signal transducer and activator of transcription (STAT) 4 and 6 are affected by adalimumab therapy in rheumatoid arthritis.

OBJECTIVES: TNF-alpha inhibition therapy affects the systemic immune response in rheumatoid arthritis by influencing T cell subtypes (Th1, Th2, Treg), but its effect on the intracellular signal transduction in T cells remains largely unexplored. Here we studied the activation of Th1-associated signalling molecule STAT4 and Th2-associated STAT6 in CD4+ T cells. METHODS: Eight rheumatoid arthritis patients were studied before and after 12 weeks of adalimumab therapy and compared to 8 healthy individuals. Peripheral blood mononuclear cells (PBMC) were analysed flow cytometrically either directly after isolation or after 24 hours of anti-CD3/anti-CD28 stimulation, to determine spontaneous and IL-4/IL-12-induced STAT4 and STAT6 phosphorylation in CD4+ T cells. Cytokine production by stimulated PBMC was measured in the supernatant using a cytometric bead array. Non-parametric statistical tests were applied. RESULTS: After adalimumab therapy, phospho-STAT6 increased, both in freshly isolated and anti-CD3/anti-CD28-stimulated CD4+ T cells. The STAT6 response to brief IL-4 stimulation did not change. In healthy individuals and adalimumab-treated patients, anti-CD3/anti-CD28 induced the phosphorylation of STAT4, but not in untreated patients. IFN-gamma production in untreated patients was significantly lower than in healthy individuals or adalimumab-treated patients. In contrast, the production of IL-4, IL-6 and IL-12 was not influenced. CONCLUSIONS: Adalimumab therapy increases Th2-associated STAT6 phosphorylation and restores the activation-induced STAT4 phosphorylation to the levels in healthy individuals. This advocates against a pro-inflammatory effect of Th1-associated STAT4 and might provide an explanation for the influence of TNF inhibition therapy on the systemic T cell response in rheumatoid arthritis.

Monosensitivity to pangasius and tilapia caused by allergens other than parvalbumin.

Fish allergy is one of the most common food allergies in populations where fish is a major part of the diet. Most fish-allergic patients react to the panallergen parvalbumin present in multiple fish species. Our aim was to investigate the clinical case of a patient with oral allergy syndrome to pangasius and Nile tilapia but tolerance of other fish and seafood. The temporal relationship between fish consumption and allergic symptoms, the positive skin prick tests, and the basophil activation test results for both fish species strongly supported the diagnosis of an immunoglobulin (Ig) E-mediated allergy. This was confirmed by the detection of specific IgE to 18-kDa and 45-kDa proteins in immunoblot analysis. Notably, the patient was not sensitized to parvalbumin, as shown by enzyme-linked immunosorbent assay using purified allergens. Cross-reactivity between fish species can result from sensitization to allergens other than parvalbumin. This case report emphasizes the applications of flow cytometry-assisted analysis in the diagnosis of food allergy.