Mar Fernández-Nieto

Differences among Pollen-Allergic Patients with and without Plant Food Allergy

Background: A considerable number of pollen-allergic patients develops allergy to plant foods, which has been attributed to cross-reactivity between food and pollen allergens. The aim of this study was to analyze the differences among pollen-allergic patients with and without plant food allergy. Methods: Eight hundred and six patients were recruited from 8 different hospitals. Each clinical research group included 100 patients (50 plant food-allergic patients and 50 pollen-allergic patients). Diagnosis of pollen allergy was based on typical case history of pollen allergy and positive skin prick tests. Diagnosis of plant-food allergy was based on clear history of plant-food allergy, skin prick tests and/or plant-food challenge tests. A panel of 28 purified allergens from pollens and/or plant foods was used to quantify specific IgE (ADVIA-Centaur® platform). Results: Six hundred and sixty eight patients (83%) of the 806 evaluated had pollen allergy: 396 patients with pollen allergy alone and 272 patients with associated food and pollen allergies. A comparison of both groups showed a statistically significant increase in the food and pollen allergy subgroup in frequency of: (1) asthma (47 vs. 59%; p < 0.001); (2) positive skin test results to several pollens: Plantago,Platanus,Artemisia,Betula,Parietaria and Salsola (p < 0.001); (3) sensitization to purified allergens: Pru p 3, profilin, Pla a 1 – Pla a 2, Sal k 1, PR-10 proteins and Len c 1. Conclusion: Results showed relevant and significant differences between both groups of pollen-allergic patients depending on whether or not they suffered from plant-derived food allergy.

Glucoamylase: another fungal enzyme associated with baker's asthma.

BACKGROUND Aspergillus-derived enzymes are widely used as dough additives in the baking industry. These enzymes may give rise to immunoglobulin (Ig)E-mediated sensitization and occupational asthma. Glucoamylase (or amyloglucosidase) is an important industrial enzyme obtained from Aspergillus niger and used to provide fermentable sugars for yeast to improve loaf volume and texture. OBJECTIVE The aim of our study was to investigate the potential allergenic role of glucoamylase in bakers asthma. METHODS We report four subjects with work-related allergic respiratory symptoms who were exposed to glucoamylase and other starch-cleaving enzymes used as baking additives. The causative role of glucoamylase in work-related asthma was investigated by immunologic tests and specific inhalation challenges (SIC). Glucoamylase allergenic components were characterized by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and immunoblotting. RESULTS Skin prick tests to glucoamylase (10 mg/mL) gave a positive response in all patients. Further, a positive skin prick test to alpha-amylase was obtained in the four patients and to hemicellulase in two of them. SIC to glucoamylase elicited isolated early asthmatic responses in the three patients tested, and SIC to alpha-amylase elicited early asthmatic responses in two patients and a dual asthmatic response in another patient. Immunoblotting with glucoamylase showed several IgE-binding bands with molecular masses between 33 and 96 kD. IgE-inhibition assays showed scarce to moderate allergenic cross-reactivity between glucoamylase and alpha-amylase. CONCLUSIONS These bakers had developed IgE-mediated occupational asthma to glucoamylase and alpha-amylase. Fungal glucoamylase is widely used as a baking additive and this enzyme may give rise to allergic respiratory reactions among exposed workers.

Changes in Sputum Eicosanoids and Inflammatory Markers After Inhalation Challenges With Occupational Agents

BACKGROUND An increase in cysteinyl-leukotrienes (LTs) after specific inhalation challenge (SIC) with common allergens in patients with atopic asthma has been shown previously, but there are scarce data with occupational agents. We sought to determine whether there are differences in lower airway inflammatory markers and the production of cytokines and eicosanoids between patients with a positive or negative SIC response to occupational agents. METHODS Twenty-six patients with suspected occupational asthma and 13 healthy control subjects were studied. Spirometry, methacholine challenge, and sputum induction were performed at baseline and 24 h after SIC with occupational agents. Several cytokines and inflammatory mediators, including eicosanoids, were measured in sputum. RESULTS Twenty-six SICs were carried out with high-molecular-weight or low-molecular-weight agents, and the responses were positive in 18 patients. SIC elicited nine early asthmatic responses, two dual asthmatic responses, and seven isolated late asthmatic responses. Significant increments in sputum eosinophil counts were found only in patients with positive SIC responses compared with baseline values. Interleukin-10 levels were decreased in patients with positive and negative SIC responses compared to those in healthy control subjects. A significant increase (p < 0.05) in the LTC(4)/prostaglandin E(2) (PGE(2)) ratio was observed in patients after positive SIC responses compared to those with negative SIC responses. CONCLUSIONS Overexpression of LTC(4), relative underproduction of PGE(2), and greater airway eosinophilia were observed in patients with positive SIC responses.

Medical and economic impact of misdiagnosis of drug hypersensitivity in hospitalized patients.

From the Division of Allergy-Immunology, Children’s Memorial Hospital, Northwestern University Feinberg School of Medicine, Chicago, Ill; the Department of Pediatrics, National Jewish Health, and the Department of Pediatrics, University of Colorado, Denver, Colo; and the Elliott and Roslyn Jaffe Food Allergy Institute, Mount Sinai School of Medicine, New York, NY. E-mail: j-pongracic@ northwestern.edu. Disclosure of potential conflict of interest: J. A. Pongracic is the chair of the Adverse Reactions to Foods committee for the American Academy of Allergy, Asthma & Immunology. S. A. Bock is employed by Boulder Valley Asthma and Allergy Clinic, is research affiliate faculty for National Jewish Health, and is on the medical advisory board for the Food Allergy and Anaphylaxis Network. S. H. Sicherer is a consultant for the Food Allergy Initiative; receives research support from the National Institute of Allergy and Infectious Diseases/National Institutes of Health and the Food Allergy Initiative; is a member of the American Academy of Allergy, Asthma & Immunology; is a section chair for the American Academy of Pediatrics; and is an advisor for the Food Allergy and Anaphylaxis Network.

IgE reactivity to latex allergens among sensitized healthcare workers before and after immunotherapy with latex

Background:  New IgE sensitizations to proteins in allergen extracts have been shown to occur during allergen‐specific immunotherapy (IT).

Suppressors of Cytokine Signaling 3 Expression in Eosinophils: Regulation by PGE2 and Th2 Cytokines

Asthma and nonasthmatic eosinophilic bronchitis (NAEB) are respiratory disorders characterized by a predominance of Th2 cells and eosinophilic inflammation. Suppressors of cytokine signaling (SOCS) proteins play an important role in Th2-mediated allergic responses through control of the balance between Th1 and Th2 cells, particularly, SOCS3 and SOCS5. The aim of this study was to analyze SOCS expression in human peripheral blood eosinophils from patients with asthma, NAEB and healthy controls. SOCS expression in eosinophils from subjects was demonstrated by different techniques. Results showed that expression of SOCS3 in eosinophils and CD4 T cells from patients was higher than in healthy subjects. In addition, we demonstrated that prostaglandin E2 (PGE2) and Th2 cytokines are able to upregulate SOCS3 production in eosinophils and attenuate its degranulation. In conclusion, eosinophils are able to transcribe and translate SOCS3 protein and can contribute to the regulation of the Th1/Th2 balance through SOCS3 production.

Asthma induced by latex from ‘Christmas flower’ (Euphorbia pulcherrima)

Christmas flower or poinsettia [Euphorbia pulcherrima (Ep)] is widely used as an ornamental plant during Christmas season in many countries. It belongs to the family Euphorbiaceae that includes other allergenic plants such as Hevea brasiliensis (Hb) or rubber tree. There are few reports of contact dermatitis induced by this plant (1, 2). We studied a 6-year-old male who presented with rhinitis and asthma upon exposure to several poinsettia plants for two consecutive Christmas seasons. He clearly improved when he was out of his apartment. At the time of the first study he did not suffer from any other respiratory symptoms. Three years after the first Christmas-related episode, he developed mild rhinoconjunctivitis during spring time. He was able to eat banana, kiwifruit and chestnut without any ill effects. He had never eaten avocado. Red and green leaves and latex from Ep, and natural rubber latex were extracted in phosphate-buffered saline (PBS), dialysed in a 3.5-kDa cut-off dialysis membrane and freeze-dried, that was later reconstituted at a concentration of 10 to 1 mg/ml (25 mg of protein per 100 mg of raw material). Healthy, atopic and rubber latex (H. brasiliensis) allergic patients were studied as controls. The patient had positive skin-prick test (SPT) to grass pollen and to Ep red leaves (5 mm)and latex extracts (7 mm),whereas it was negative to green leaf extract and other common aeroallergens in our area. Natural rubber latex extract fromHb elicited a 2-mm wheal. Prick-prick tests with kiwifruit, banana, avocado and chestnut were negative. In five healthy control patients, SPT with Ep extracts were negative, but were positive in five of eight patients diagnosed with rhinitis and asthma induced by latex fromHb. Baseline PC20 methacholine was 14.3 mg/ml. Pre-challenge induced sputum samples showed no eosinophils. Both performed as previously described (3). After parent’s consent, bronchial challenge by tidal volume method with Ep extract at a concentration of 0.31 mg/ml elicited an isolated immediate asthmatic response, with a 20% fall in forced expiratory volume (FEV)1. Twenty-four hours after the specific bronchial challenge, PC20 methacholine decreased to 2.5 mg/ml and 5% of eosinophils was seen in induced sputum sample. Rubbing and latex glove use test were negative. In one patient diagnosed with rhinitis and asthma induced by Hb latex, who also had a positive SPT to Ep, the bronchial challenge test with Ep extract was negative. Total IgE was 703 kU/l. Specific IgE (Pharmacia CAP System, Uppsala, Sweden) was positive to Ep latex (6.65 kU/l), Hb latex (8.24 kU/l), banana (6.28 kU/l) and chestnut (9.3 kU/l). ImmunoCAP inhibition experiments demonstrated a high degree of allergenic cross-reactivity between latex extracts of Hb and Ep. IgE immunoblots performed under reducing conditions revealed major IgEbinding bands in the Ep latex extract (Fig. 1). The most intense reaction was observed at 36, 25 and 19 kDa bands. Patient’s serum also revealed several IgEbinding bands in the Hb extract (Fig. 1). Case reports of IgE-mediated rhinitis and asthma induced by latex from ornamental plants, and dust samples from the floor, such as Ficus benjamina, have been previously described (4). To the best of our knowledge, this is the first case report of IgE-mediated rhinitis and asthma induced by latex of Christmas flower or poinsettia. Although extensive in vitro cross-reactivity with natural rubber latex and related fruits was demonstrated, the patient had no symptoms with these products.

Characterization of Allergens in Four South American Snake Species

A 55-year-old herpetologist developed rhinitis, asthma, urticaria and anaphylaxis when handling 4 different viper snake venoms. Allergen characterizations were done using SDS-PAGE, IgE immunoblotting and IgE inhibition experiments. The most prominent immunoreactive proteins were analyzed by MALDI-TOF mass spectrometry, and peptide identity was demonstrated by homology with known peptide sequences. SDS-PAGE showed several protein bands ranging from 5 to 99 kDa in each of the 4 snake venoms. Immunoblotting demonstrated 4 IgE-binding bands in the Bothrops extract of about 60, 28, 14 and 7 kDa. The bands of 28 and 14 kDa were also present in Lachesis muta. Two IgE-binding proteins of about 50 and 35 kDa were found in Bothrops atrox and L. muta, respectively. A strong inhibition of IgE binding to immobilize Bothrops asper proteins was observed after preabsorption of sera with B. asper, B. atrox,Bothrops xanthograma and L. muta extracts. MALDI-TOF analysis showed a 14-kDa phospholipase and the 60- and 28-kDa proteins showed significant similarity with metalloproteinases. In this report we have characterized the snake venom allergens that can elicit IgE-mediated symptoms.

Occupational allergy in a researcher due to Ole e 9, an allergenic 1,3-β-glucanase from olive pollen

Olive (Olea europaea) pollen allergy is one of the most important causes of seasonal respiratory disease in Mediterranean countries (1). To date, 10 olive pollen allergens have been characterized (2). We report on a 30-year-old man who was born and lives in Madrid, smoker and without a previous personal history of atopy. He started working with olive pollen allergens in a laboratory research 10 years ago. In particular, he spent 5 years (from 2000 to 2005) manipulating Ole e 9-allergen and derivative recombinant products, being daily highly exposed to these molecules. In 2005, he started to suffer from nasoconjunctival pruritus, sneezing proxysms, nasal running, conjunctival redness and palatal itching while handling fractions enriched in 35–55 kDa protein components of olive pollen extract. Symptoms always appeared at the workplace and concomitantly with the manipulation of such batches of olive pollen proteins. The patient controlled the symptoms with antihistamines, remaining asymptomatic out of the workplace, even during the olive pollination season in Madrid. He ate plant-derived foods without experiencing any adverse reaction. Skin prick test with a commercially available battery of common aeroallergens (ALKAbelló SA, Madrid, Spain) were positive to Olea europaea eliciting a wheal of 5 mm (diameter) and negative to pollens from other trees, grasses or weeds, moulds, and cat and dog epithelia. Olive pollen extract was separated by SDS-PAGE gels under nonreducing conditions and immunostained with the patient s serum (Fig. 1A). A single IgEreactive band of 45 kDa molecular mass was detected. Immunoblotting performed with purified olive pollen allergens were negative in all the cases except for purified Ole e 9-allergen (Fig. 1A). To confirm Ole e 9 as the IgE-reactive allergen in olive pollen extract, IgE-inhibition experiments with the purified antigen were performed in immunoblotting (Fig 1B). When the patient s serum was preadsorbed to purified Ole e 9, the IgE binding to the 45 kDa protein in olive pollen extract was nearly abolished. Skin prick tests were carried out with purified olive pollen allergens such as Ole e 1 (0.50 lg/ml), profilin Ole e 2 (0.50 lg/ml), polcalcin Ole e 3 (0.50 lg/ml) and 1,3-b-glucanase Ole e 9 (0.27 lg/ml). Ole e 9 was the single-tested allergen able to elicit a positive response (6 mm of diameter) indicating the capability of this molecule to trigger the release of inflammatory mediators, thus demonstrating the biological activity of Ole e 9 in the patient. Three control subjects were skin tested with Ole e 9 and showed negative response. Ole e 9 is a 1,3-b-glucanase that has been described as a major allergen in areas such as Jaén (Spain) (3) where olive pollen concentrations reach values up to 10 000 grains/m. In contrast, patients living in Madrid (pollen counts up to 300 grains/m) are notably less sensitized to this molecule, and they are always co-sensitized to Ole e 1. In our study, the component-resolved diagnosis (CRD) (4) showed that the patient presented an unusual sensitization pattern to Olea europaea components as patients exclusively sensitized to Ole e 9 have not been described. The fact that the patient was not sensitized to Ole e 1, which is a diagnostic marker for sensitization to Oleaceae pollens (5), strongly suggests that the patient sensitization occurred at the workplace because of the daily overexposure to Ole e 9-allergen. A L L E R G Y 2 0 0 8 : 6 3 : 7 8 4 – 7 9 1 • a 2 0 0 8 T H E A U T H O R S • J O U R N A L C O M P I L AT I O N a 2 0 0 8 B L A C K W E L L M U N K S G A A R D • C O N T R I B U T I O N S T O T H I S S E C T I O N W I L L N O T U N D E R G O P E E R R E V I E W, B U T W I L L B E R E V I E W E D B Y T H E A S S O C I AT E E D I T O R S •

New developments in work-related asthma

ABSTRACT Introduction: Work-related asthma includes two subtypes: occupational asthma or asthma caused by specific agents (sensitizers or irritants) in the workplace, and work-exacerbated asthma or pre-existing asthma worsened by workplace exposures. Areas covered: This review provides an update on the definitions and the clinical features of the different work-related asthma subtypes as well as new insights into their etiology and the pathophysiological mechanisms involved. The diagnosis of work-related asthma should be made on objective basis using a constellation of clinical, physiologic and allergologic tests. Specific inhalation challenge with the suspected occupational agent(s) remains as the reference standard for diagnosis. A literature search was performed using the following terms: work-related asthma, occupational asthma, work-exacerbated asthma, irritant-induced asthma and etiological agents. Expert commentary: Studies focusing on the biological effects and mechanisms of environmental exposures in the development of sensitizer-induced or irritant-induced asthma in various workplace settings are of greatest interest. An integrative approach that combines clinical parameters with component-resolved diagnosis as well as inflammatory biomarkers appears to be very promising. Occupational allergy provides a good opportunity to understand the complex relationships between exposure to allergens in the workplace, interaction with genes and the co-exposures to other factors in the working environment.