Christiane Lehners

Allergic cross-reactions between cat and pig serum albumin: Study at the protein and DNA levels

After observing a patient allergic to cat dander and pork but devoid of other allergies, we prospectively screened patients known to be allergic to cat for a second sensitization to pork. After collecting the sera of 10 young patients found to contain specific IgE to cat dander and pork, we undertook this study to detect the possible cross‐reactive allergen, define its molecular characteristics, and evaluate its clinical relevance. Through immunoblotting techniques, cat and porcine serum albumin were found to be jointly recognized molecules. These findings were further analyzed by specific anti‐albumin IgE titrations and cross‐inhibition experiments. Cat serum albumin cDNA was obtained from cat liver, and the corresponding amino acid sequence was deduced and compared to the known porcine and human serum albumin sequences. Inhibition experiments showed that the spectrum of IgE reactivity to cat serum albumin completely contained IgE reactivity to porcine serum albumin, suggesting that sensitization to cat was the primary event. In two cohorts of cat‐allergic persons, the frequency of sensitization to cat serum albumin was found to lie between 14% and 23%. Sensitization to porcine albumin was found to lie between 3% and 10%. About 1/3 of these persons are likely to experience allergic symptoms in relation to pork consumption. Sensitization to cat serum albumin should be considered a useful marker of possible cross‐sensitization not only to porcine serum albumin but also to other mammalian serum albumins.

IgE antibodies of fish allergic patients cross‐react with frog parvalbumin

Background:  The major allergens in fish are parvalbumins. Important immunoglobulin (Ig)E cross‐recognition of parvalbumins from different fish species has been shown. Recently frog parvalbumin α has been found to be responsible for a case of IgE‐mediated anaphylaxis triggered by the ingestion of frog meat. The aim of this study was to investigate whether IgE antibodies of fish allergic persons cross‐react with frog parvalbumin and to appreciate its clinical relevance.

Identification of a new major dog allergen highly cross-reactive with Fel d 4 in a population of cat- and dog-sensitized patients

From the Christian Doppler Laboratory for Allergy Research, Division of Immunopathology, Department of Pathophysiology and Allergy Research, Center for Pathophysiology, Infectiology and Immunology, Medical University of Vienna, Vienna, Austria; the Department for Biotechnology, Institute for Applied Genetics and Cell Biology, University of Natural Resources and Applied Life Sciences, Vienna, Austria; the Department for Biotechnology, Institute for Applied Microbiology, University of Natural Resources and Applied Life Sciences, Vienna, Austria. E-mail: rudolf.valenta@meduniwien.ac.at. *I. Swoboda is currently at the Section of Molecular Biotechnology, University of Applied Science, Campus Vienna Biocenter, Vienna, Austria. This work was supported by a research grant from the Christian Doppler Association and Biomay (Vienna, Austria). Disclosure of potential conflict of interest: The authors declare that they have no relevant conflicts of interest.

Two galactose-α-1,3-galactose carrying peptidases from pork kidney mediate anaphylactogenic responses in delayed meat allergy

Serum IgE antibodies directed at galactose‐α‐1,3‐galactose (α‐Gal) are associated with a novel form of delayed anaphylaxis occurring upon consumption of red meat or innards. Pork kidney is known as the most potent trigger of this syndrome, but the culprit allergens have not yet been identified. The aim of this study was the identification and characterization of pork kidney proteins mediating delayed anaphylactic reactions through specific IgE to α‐Gal.

Identification and isolation of a Fel d 1–like molecule as a major rabbit allergen

BACKGROUND Rabbits are increasingly kept as domestic pets. Several rabbit allergens have been characterized. However, their sequences are still elusive, and none of these molecules are available for diagnosis. OBJECTIVE We sought to isolate major allergens from the rabbit Oryctolagus cuniculus and to investigate their importance in sensitized patients. METHODS Proteins were extracted from rabbit hair, and IgE-reactive proteins were purified by using sequential chromatography. Allergens were characterized by means of N-terminal sequencing and mass spectrometry. IgE reactivity to a new allergen was analyzed in sera of 35 patients sensitized to rabbits in a domestic setting. A model of the crystal structure of the isolated proteins was constructed. RESULTS A new IgE-reactive allergen, Ory c 3, was identified as rabbit lipophilin. The molecule that belongs to the secretoglobin family is a heterodimer of 18 to 19 kDa composed of 2 polypeptide chains, CL2 and AL. CL2 has a predicted N-linked glycosylation site confirmed by using mass spectrometry. Of the 35 patients with rabbit allergy studied, 27 (77%) had IgE to both the glycosylated and deglycosylated Ory c 3 heterodimer. Allergenicity of Ory c 3 was confirmed by using skin prick tests and the basophil activation assay. Modeling of the structure revealed a marked homology to Fel d 1, the major cat allergen. However, no IgE cross-reactivity was detected between Fel d 1 and Ory c 3. CONCLUSION The rabbit lipophilin heterodimer AL-CL2 has been identified as a major rabbit allergen. After Fel d 1, Ory c 3 is the second mammalian secretoglobin shown to be a major allergen.

Evaluation of two new recombinant guinea-pig lipocalins, Cav p 2 and Cav p 3, in the diagnosis of guinea-pig allergy.

Cite this as: C. Hilger, K. Swiontek, S. Kler, C. Diederich, C. Lehners, L. Vogel, S. Vieths and F. Hentges, Clinical & Experimental Allergy, 2011 (41) 899–908.

Food allergy to chicken meat with IgE reactivity to muscle α-parvalbumin

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Allergy to hamster - 4 case reports

Background Hamsters are increasingly popular as domestic pets. Different species can be found in the domestic setting: the Syrian (golden) hamster (Mesocricetus auratus), the European hamster (Cricetus cricetus), the Siberian hamster (Phodopus sungorus) and the Rhoborovski hamster (Phodopus roborovskii). Several cases of asthma upon contact with hamsters and anaphylaxis following hamster bites have been described, but the allergen(s) responsible are either unidentified or poorly characterized. In the Syrian hamster, salivary lipocalins were found to be specifically expressed in male submandibular glands. MSP (male specific submandibular salivary gland protein) is detectable in saliva as two major forms of 20.5 and 24 kDa. The objectives of the present study were to determine if MSP is an allergen, to analyse IgE reactive proteins in different hamster fur extracts and to determine patient reactivity to different extracts.