How Allergen Extracts Are MadedFrom Source Materials to Allergen Extracts Mammalian raw materials used to produce allergen extracts Enrique Fernández-Caldas, PhD * , y ; Bárbara Cases, PhD * ; David El-Qutob, MD, PhD z ; Jose Fernando Cantillo, PhD x * Inmunotek SL, Madrid, Spain y University of South Florida College of Medicine, Tampa, Florida z Unit of Allergy, University Hospital of La Plana in Vila-Real, Castellon, Spain x Institute for Immunological Research, University of Cartagena, Cartagena, Columbia A R T IC L E IN F O Article history: Received for publication March 29, 2016. Received in revised form August 12, 2016. Accepted for publication August 22, 2016. A B ST R AC T Objective: To provide information about the complexity of skin-derived mammalian allergen extracts and recent advances made in their characterization and production. Data Sources: Original and review articles (involving nonfood allergy to mammals) published in indexed journals were searched in the PubMed database. Study Selections: Studies were selected with the following criteria: novelty, species of the study, and date of publication. Results: The information provided will help in the understanding and the selection of the appropriate allergen source materials for the preparation of extracts for the diagnosis and treatment of allergic respi- ratory diseases induced by the inhalation of skin-derived mammalian allergens. The data presented herein suggest the presence of cross-reactive and species-specific allergens in extracts prepared from different mammalian dander. Dander should be strongly considered in the preparation of allergenic extracts not only of cats and dogs but also of other mammalian species. Conclusion: New methods should be developed to estimate the relative quantities of specific allergens in the extracts. The current knowledge illustrates the complexity of these extracts, and more efforts should be undertaken to fully understand the wide spectrum of mammalian allergens. Ó 2016 American College of Allergy, Asthma & Immunology. Published by Elsevier Inc. All rights reserved. Introduction The scope of this article is to provide information about the complexity of skin-derived mammalian allergen extracts and recent advances made in their characterization and production. The information provided will help in the understanding and selection of the appropriate allergen source materials for the preparation of extracts for the diagnosis and treatment of allergic respiratory diseases induced by the inhalation of skin-derived mammalian allergens. The data presented herein suggest the presence of cross- reactive and species-specific allergens in extracts prepared from different mammalian dander. Dander should be strongly consid- ered in the preparation of allergenic extracts not only of cats and dogs but also of other mammalian species. New methods should be developed to estimate the relative quantities of specific allergens in the extracts. The current knowledge illustrates the complexity of these extracts, and more efforts should be undertaken to fully un- derstand the wide spectrum of mammalian allergens. The inhalation of skin-derived mammalian allergens is a com- mon cause of allergic sensitization and acute and chronic allergic respiratory symptoms worldwide. Sensitization and symptoms may occur at home and the workplace. The most common mammalian allergens are derived from cats, dogs, horses, cows, and rodents. 1 Occupational allergy to rodents is frequent among labo- ratory workers. The most common rodents that induce allergic sensitization and symptoms are guinea pigs, rabbits, mice, and rats. Airborne allergen from different mammalian species can also be detected in the ambient air in farms, animal facilities, 2e4 and homes. 5 Sensitization to mouse pelt and urine is also common in inner-city children with asthma in the United States. 6,7 Humans may get exposed to rodent allergens (rats, mice, guinea pigs, hamsters, and gerbils) in homes and occupational settings. 8,9 It has been reported that mouse allergens are detectable in settle dust 10,11 and bedrooms of children with or without asthma. 12 The major, currently identified mouse and rat allergens are Mus m 1 and Rat n 1, respectively. These allergens belong to the lipocalin family, secreted in mouse urine, but can also be present in mouse hair Reprints: Enrique Fernández-Caldas, PhD, Inmunotek SL, Calle Punto Mobi, 5 Alcalá de Henares, Madrid 28805, Spain; E-mail: efcaldas@inmunotek.com. Disclosures: Authors have nothing to disclose. Contents lists available at ScienceDirect http://dx.doi.org/10.1016/j.anai.2016.08.024 1081-1206/Ó 2016 American College of Allergy, Asthma & Immunology. Published by Elsevier Inc. All rights reserved. Ann Allergy Asthma Immunol 119 (2017) 1e8