Idoia Postigo

The major allergen of Alternaria alternata (Alt a 1) is expressed in other members of the Pleosporaceae family

There is general consensus regarding the scarce cross‐reactivity existing between Alternaria alternata and other allergenic moulds such as Aspergillus fumigatus, Penicillium notatum or Cladosporium herbarum. However, A. alternata has been shown to have a very significant level of allergenic cross‐reactivity with other fungi belonging to the Pleosporaceae family. To date, no biological identity or homologies with other proteins have been described for Alt a 1, and it remains unclear whether the major allergen Alt a 1 contributes to the cross‐reactivity shown for these moulds. Specific quantification of Alt a 1 in culture filtrates of Stemphylium botryosum, Ulocladium botrytis, Curvularia lunata, Alternaria tenuissima, C. herbarum, Penicillium chrysogenum and Asp. fumigatus, and immunoblotting using culture filtrate extracts from the above‐mentioned moulds and rabbit serum anti‐recombinant Alt a 1 have shown significant amounts of Alt a 1 in culture filtrates as well as antigenic components ranging from 14 to 20 kDa that strongly react with the specific serum for all taxonomically related species (Pleosporaceae family). No reactions were revealed in culture filtrates of Cladosporium, Penicillium and Aspergillus. These results restrict the cross‐reactivity phenomenon due to Alt a 1 to the scope of the taxonomical term of family.

Diagnostic value of Alt a 1, fungal enolase and manganese‐dependent superoxide dismutase in the component‐resolved diagnosis of allergy to pleosporaceae

Cite this as: I. Postigo, A. Gutiérrez‐ Rodríguez, J. Fernández, J. A. Guisantes, E. Suñén and J. Martínez, Clinical & Experimental Allergy, 2011 (41) 443–451.

Alternaria alternata allergens: Markers of exposure, phylogeny and risk of fungi-induced respiratory allergy

Alternaria alternata spores are considered a well-known biological contaminant and a very common potent aeroallergen source that is found in environmental samples. The most intense exposure to A. alternata allergens is likely to occur outdoors; however, Alternaria and other allergenic fungi can colonize in indoor environments and thereby increase the fungal aeroallergen exposure levels. A consequence of human exposure to fungal aeroallergens, sensitization to A. alternata, has been unequivocally associated with increased asthma severity. Among allergenic proteins described in this fungal specie, the major allergen, Alt a 1, has been reported as the main elicitor of airborne allergies in patients affected by a mold allergy and considered a marker of primary sensitization to A. alternata. Moreover, A. alternata sensitization seems to be a triggering factor in the development of poly-sensitization, most likely because of the capability of A. alternata to produce, in addition to Alt a 1, a broad and complex array of cross-reactive allergens that present homologs in several other allergenic sources. The study and understanding of A. alternata allergen information may be the key to explaining why sensitization to A. alternata is a risk factor for asthma and also why the severity of asthma is associated to this mold. Compared to other common environmental allergenic sources, such as pollens and dust mites, fungi are reported to be neglected and underestimated. The rise of the A. alternata allergy has enabled more research into the role of this fungal specie and its allergenic components in the induction of IgE-mediated respiratory diseases. Indeed, recent research on the identification and characterization of A. alternata allergens has allowed for the consideration of new perspectives in the categorization of allergenic molds, assessment of exposure and diagnosis of fungi-induced allergies.

Identification of allergens homologous to Alt a 1 from Stemphylium botryosum and Ulocladium botrytis

Several studies have demonstrated that proteins homologous to the Alt a 1 major allergen of Alternaria alternata are expressed in other members of the Pleosporaceae family. However, since no direct biochemical data have been reported concerning the presence of Alt a 1 allergen homologues capable of binding IgE in the excretion-secretion products of Stemphylium and Ulocladium, our objective was to explore their presence in Stemphylium botryosum and Ulocladium botrytis. S. botryosum and U. botrytis culture filtrate extracts were analyzed by two-dimensional (2D)-electrophoresis and 2D-immunoblotting using polyclonal rabbit antibodies raised against recombinant Alt a 1, as well as five human sera from patients allergic to Alternaria. Cross-reactivity immunoassays were performed by ImmunoCAP inhibition and 2D-immunoblotting inhibition. IgE-binding proteins recognized by the rabbit antiserum raised against Alt a 1, with apparent molecular weights of 17-18 kDa and isoelectric points of 4, were identified as Alt a 1-like proteins. Alt a 1 inhibited IgE-specific binding to the Alt a 1 homologues from S. botryosum and U. botrytis. In conclusion, it was demonstrated that allergens which are homologous to Alt a 1 are expressed in the excretory-secretory materials of the phylogenetically-related species S. botryosum and U. botrytis.

Clinical value of morphine, pholcodine and poppy seed IgE assays in drug-abusers and allergic people.

BACKGROUND The diagnosis of anaphylactic reactions due to opiates during anaesthesia can be difficult, since in most cases various drugs may have been administered. Detection of specific IgE to poppy seed might be a marker for sensitisation to opiates in allergic people and heroin-abusers. This study assessed the clinical value of morphine, pholcodine and poppy seed skin-prick and IgE determination in people suffering hypersensitivity reactions during anaesthesia or analgesia and drug-abusers with allergic symptoms. METHODS We selected heroin abusers and patients who suffered severe reactions during anaesthesia and analgesia from a database of 23,873 patients. The diagnostic yield (sensitivity, specificity and predictive value) of prick and IgE tests in determining opiate allergy was analysed. RESULTS Overall, 149 patients and 200 controls, mean age 32.9 ± 14.7 years, were included. All patients with positive prick to opiates showed positive prick and IgE to poppy seeds, but not to morphine or pholcodine IgE. Among drug-abusers, 13/42 patients (31%) presented opium hypersensitivity confirmed by challenge tests. Among non-drug abusers, sensitisation to opiates was higher in people allergic to tobacco (25%), P<.001. Prick tests and IgE against poppy seed had a good sensitivity (95.6% and 82.6%, respectively) and specificity (98.5% and 100%, respectively) in the diagnosis of opiate allergy. CONCLUSIONS Opiates may be significant allergens. Drug-abusers and people sensitised to tobacco are at risk. Both the prick and specific IgE tests efficiently detected sensitisation to opiates. The highest levels were related to more-severe clinical profiles.

Profilin cross-reactive panallergen causes latex sensitization in the pediatric population allergic to pollen

BACKGROUND Component-resolved diagnostics (CRD) has been demonstrated to be an excellent new tool for improving the current diagnosis of allergies, and it allows differentiation between polysensitization and cross-reactivity. OBJECTIVE To demonstrate the role of cross-reactive pollen allergens in pediatric patients living in areas with large amounts of airborne grass pollen grains who are sensitive to grass pollen and latex. METHODS Serum samples were obtained from 106 children between 3 and 14 years of age diagnosed with allergies to pollen based on clinical history, skin prick tests, and specific immunoglobulin E (IgE). None of them had allergy symptoms to latex or fruits. From these 106 children, 56 patients revealed positive results to Phleum-specific major allergens but not to cross-reactive allergens. The other 50 patients who showed positive specific IgE to Phleum-specific major allergens and to cross-reactive pollen allergens also showed positive results to latex allergens. CRD was carried out by specific IgE quantification using a fluoro-enzyme immunoassay (ImmunoCAPT System). RESULTS Results demonstrated a positive significant relationship between the specific IgE to Hev b 8 and Phl p 12 and also between the specific IgE to Hev b 8 and latex extract in the group of patients sensitized to species-specific and cross-reactive Phleum allergens. Positive significant relationships were also found between profilin and avocado or peach sensitizations. No other latex allergens gave positive results. CONCLUSION The apparent sensitization to latex in pediatric patients allergic to grass pollen is caused by the cross-reactive profilin panallergen; however, it is appears not to be clinically relevant.

Bovine serum albumin contained in culture medium used in artificial insemination is an important anaphylaxis risk factor

OBJECTIVE To analyze the cause of the anaphylactic reaction after a standard artificial insemination process in a patient diagnosed with asthma. DESIGN Case report. SETTING Residencia Sanitaria Virgen de la Arrixaca (Murcia, Spain) and University of the Basque Country (Vitoria, Spain). PATIENT(S) A 30-year-old woman with a previous medical history compatible with respiratory allergy who suffered an anaphylactic reaction after an artificial insemination with spermatozoids in capable medium (Upgraded B2 INRA medium; Laboratories CCD, Paris, France). INTERVENTION(S) Cutaneous tests and specific IgE levels to inhalant allergens, grass and Olea pollens, and insemination medium were performed. MAIN OUTCOME MEASURE(S) Specific IgE levels to mammal epithelia and bovine serum albumin (BSA). RESULT(S) Skin prick tests were positive for inhalant allergens such as mites, cat, dog, horse, and rabbit epithelia, grasses and Olea pollens, and the insemination medium. The beta-lactamic tests were negative. The determination of specific IgE demonstrated positive values to mammal epithelia and mammal serum albumins including BSA. CONCLUSION(S) We report a case of an anaphylactic reaction to the BSA included in the insemination culture medium induced by a subclinical sensitivity to serum albumins of mammal epithelia. A previous testing with the medium is recommended and specific testing might be needed in women who have a history of animal epithelium allergies.

From respiratory sensitization to food allergy: Anaphylactic reaction after ingestion of mushrooms (Agaricus bisporus)

We report a case of a 38-year-old mold-allergic patient who developed episodes of generalized urticaria and systemic anaphylactic shock immediately after ingesting button mushrooms. A manganese-dependent superoxide dismutase (MnSOD) and a NADP-dependent mannitol dehydrogenase (MtDH) from Agaricus bisporus mushroom were identified as patient-specific IgE-binding proteins. Cross-reactivity between A. bisporus MnSOD and mold aeroallergens was confirmed. We conclude that prior sensitization to mold aeroallergens might explain severe food reactions to cross-reacting homologs mushroom proteins.

Characterisation of Alternaria alternata manganese-dependent superoxide dismutase, a cross-reactive allergen homologue to Asp f 6.

It is well known that Alternaria alternata presents a significant level of allergenic cross-reactivity with several other phylogenetically related and non-related allergenic moulds. To improve the molecular diagnosis, the identification and characterisation of all clinically relevant allergens, including both species-specific and cross-reacting proteins, is required. In this study we report the molecular and immunological characterisation of the A. alternata manganese-dependent superoxide dismutase (Alt a MnSOD) and its cross-reactivity with Asp f 6, a diagnostic marker allergen in allergic bronchopulmonary aspergillosis (ABPA). The cDNA coding for Alt a MnSOD sequence was isolated by RACE and PCR. Alt a MnSOD is a protein of 191 amino acids that presented significant homology and potential cross-reactive epitopes with Asp f 6. The recombinant protein was produced in Escherichia coli and the immunoreactivity was evaluated in patient sera. Immunoblotting analyses showed that seven of sixty-one A. alternata-sensitised patient sera and two ABPA patient sera reacted with the recombinant Alt a MnSOD. The native counterpart contained in both A. alternata and Aspergillus fumigatus extracts inhibited IgE binding to the recombinant molecule. The allergen was named Alt a 14 by the official Allergen nomenclature subcommittee. Thus, Alt a 14 is a relevant allergen in A. alternata sensitisation that may be used to improve diagnostic procedures. Evidence of cross-reactivity between Asp f 6 and Alt a 14-recognition by ABPA patient sera suggest the existence of an Alt a 14-mediated mechanism that, similar to Asp f 6, may be related to the pathogenesis of ABPA.

IgE-Mediated Allergic Reactions after the First Administration of Glatiramer Acetate in Patients with Multiple Sclerosis

Background: Immediate adverse reactions to glatiramer acetate (GA), a drug used in the treatment of patients with multiple sclerosis (MS), have been poorly investigated. We studied 3 MS patients who presented adverse reactions following GA administration. Two of them experienced severe anaphylactic reactions after the first administration and the other an eyelid edema upon reintroduction 6 months after GA withdrawal. Methods: Skin prick tests (SPT) to GA and mannitol were performed on all 3 patients and in 10 atopic controls. Specific IgE (sIgE) levels to GA, myelin basic protein (MBP) and MBP fragments were assessed in all 3 patients, 6 MS patients treated with GA for more than 6 month and 10 healthy donors. Specific IgG (sIgG) to GA was also quantified in the three study groups. Both sIgE and sIgG were determined by means of the UniCAP 100 assay. Results: SPT and sIgE to GA were positive only in the 3 patients with adverse reactions while sIgE to mannitol was negative in all. sIgE tests against MBP and its fragments were negative in all individuals. Similar levels of sIgG to GA were found in all studied subjects. Conclusion: These results demonstrate the significance of sIgE in allergic reactions to GA presented by these patients and suggest the importance of strict surveillance during administration of the first GA doses.