Anaphylaxis after hamster bites--identification of a novel allergen

Laboratory Animal Bite Anaphylaxis: A National Survey: Part 1: Case Series and Review of the Literature

OBJECTIVE

This study documents previously unreported cases of laboratory animal bite anaphylaxis in animal laboratory facilities in the United States.

METHODS

An online survey was e-mailed to designated institutional officials at laboratory animal facilities identified by the National Institutes of Health Office of Laboratory Animal Welfare.

RESULTS

One hundred ninety eight organizations responded and 15 organizations indicated that workers had experienced anaphylaxis following an animal bite. Case report forms were completed by nine of these institutions for 14 cases, 13 for rodent bites, and one involving a needlestick from a horse. In half of the cases involving rodents, there was no prior history of animal allergy. All workers had uncomplicated recoveries. Treatment, testing, and work restrictions varied across cases.

CONCLUSIONS

While uncommon, anaphylaxis from laboratory animal bites occurs more frequently than suggested by the literature.

Occupational Animal Allergy

PURPOSE OF REVIEW

This review explores animal allergen exposure in research laboratories and other work settings, focusing on causes and prevention.

RECENT FINDINGS

(1) Consistent with the hygiene hypothesis, there is new evidence that early childhood exposure to pets produces changes in the gut microbiome that likely lead to a lower risk of allergy. (2) Anaphylaxis from laboratory animal bites occurs more frequently than suggested by prior literature. (3) Animal allergens represent an occupational hazard in a wide variety of work settings ranging from fields that work with animals to public settings like schools and public transportation where allergens are brought into or are present in the workplace. Exposure to animal allergens can result in allergy, asthma, and anaphylaxis. Animal allergy has been most studied in the research laboratory setting, where exposure reduction can prevent the development of allergy. Similar prevention approaches need to be considered for other animal work environments and in all settings where animal allergens are present.

Co-infection of the Siberian hamster (Phodopus sungorus) with a novel Helicobacter sp. and Campylobacter sp

We report the isolation of a novel helicobacter isolated from the caecum of the Siberian hamster (Phodopus sungorus). Sequence analysis showed 97% sequence similarity to Helicobacter ganmani. In addition, we report the co-infection of these Siberian hamsters with a Campylobacter sp. and a second Helicobacter sp. with 99% sequence similarity to Helicobacter sp. flexispira taxon 8 (Helicobacter bilis), a species isolated previously from patients with bacteraemia. Gross necropsy and histopathology did not reveal any overt pathological lesions of the liver and gastrointestinal tract that could be attributed to the Helicobacter or Campylobacter spp. infections. This is the first helicobacter to be identified in the Siberian hamster and the first report of co-infection of Helicobacter spp. and Campylobacter sp. in asymptomatic Siberian hamsters.

Male-specific submaxillary gland protein, a lipocalin allergen of the golden hamster, differs from the lipocalin allergens of Siberian and Roborovski dwarf hamsters

BACKGROUND

An increasing number of asthma cases upon exposure to hamsters and anaphylactic reactions following hamster bites are being reported, but the allergens responsible are still poorly characterized. In the Golden hamster, male-specific submaxillary gland protein (MSP), a lipocalin expressed in a sex- and tissue-specific manner in the submaxillary and lacrimal glands, is secreted in the saliva, tears and urine. The purpose of this study was to determine if MSP is an allergen, to identify IgE-reactive proteins of different hamster species and to analyse potential cross-reactivities.

METHODS

Fur extracts were prepared from four hamster species. Hamster-allergic patients were selected based on a history of positive IgE-test to hamster epithelium. The IgE-reactivity of patients' sera was investigated by means of immunoblot and ELISA. IgE-reactive proteins in fur extracts and the submaxillary gland were identified using anti-MSP antibodies, Edman sequencing or mass spectrometry. MSP was purified from Golden hamster and recombinant MSP was expressed in E. coli.

RESULTS

Four patients had IgE-antibodies against 20.5-kDa and 24-kDa proteins of Golden hamster fur extract, which were identified as MSP. IgE-reactive MSP-like proteins were detected in European hamster fur extract. Three patient sera showed IgE-reactive bands at 17-21 kDa in Siberian and Roborovski hamster fur extracts. These proteins were identified as two closely related lipocalins. Immunoblot inhibition experiments showed that they are cross-reactive and are different from MSP.

CONCLUSION

MSP lipocalin of the Golden hamster was identified as an allergen, and it is different from the cross-reactive lipocalin allergens of Siberian and Roborovski hamsters. Our findings highlight the need for specific tools for the in vitro and in vivo diagnosis of allergy to different hamster species.

[New pets, allergens and allergic dermatitis]

The number of household pets increased greatly during the twentieth century, with the numbers of new pets (NP, i.e. any pet other than cats and dogs) rising especially sharply over the last decade. Contact with such animals, whose owners do not always know how to look after them properly, expose the population to new risks such as trauma, infection and allergy. While the most common allergies are respiratory, allergic skin reactions, both immediate and delayed, may also result from contact with these new allergens. The animal itself or its environment may be the cause. Herein, we review NPs and reports of allergic dermatitis associated with them.

Molecular and immunological characterization of the first allergenic lipocalin in hamster: the major allergen from Siberian hamster (Phodopus sungorus)

The most frequent pet allergy is to cat and dog, but in recent years, it has become increasingly popular to have other pets, and the risk of exposure to new allergens is more prevalent. The list of new pets includes hamsters, and one of the most popular hamsters is the Siberian hamster (Phodopus sungorus). The aim of this study was the characterization and cloning of the major allergen from this hamster. The study of its allergenicity and cross-reactivity could improve the specific diagnosis and treatment for hamster-allergic patients. Thirteen Siberian hamster-allergic patients were recruited at the outpatient clinic. Protein extracts were prepared from the hair, urine, and salivary glands of four hamster species (European, golden, Siberian, and Roborovski). IgE-binding proteins were detected by immunoblotting and identified by mass spectrometry. The recombinant protein was produced in Escherichia coli and then purified by metal chelate affinity chromatography. The allergenic properties of the recombinant protein were tested by ELISA and immunoblotting, and biological activity was tested according to capacity for basophil activation. Three IgE-binding proteins were identified in extracts obtained from Siberian hamster hair, urine, and salivary glands. All proteins corresponded to the same protein, which was identified as a lipocalin. This lipocalin had no cross-reactivity with common and golden hamsters. The recombinant allergen was cloned and purified, showing similar IgE reactivity in vitro to Siberian hamster protein extracts. Also, the recombinant allergen was capable of producing biological activation in vivo. The major Siberian hamster allergen was cloned, and allergenic properties were characterized, providing a new tool for specific diagnosis of allergy to Siberian hamster.

Allergy to uncommon pets: new allergies but the same allergens

The prevalence of exotic pet allergies has been increasing over the last decade. Years ago, the main allergy-causing domestic animals were dogs and cats, although nowadays there is an increasing number of allergic diseases related to insects, rodents, amphibians, fish, and birds, among others. The current socio-economic situation, in which more and more people have to live in small apartments, might be related to this tendency. The main allergic symptoms related to exotic pets are the same as those described for dog and cat allergy: respiratory symptoms. Animal allergens are therefore, important sensitizing agents and an important risk factor for asthma. There are three main protein families implicated in these allergies, which are the lipocalin superfamily, serum albumin family, and secretoglobin superfamily. Detailed knowledge of the characteristics of allergens is crucial to improvement treatment of uncommon-pet allergies.

Animal lipocalin allergens

Lipocalins represent the most important group of inhalant animal allergens. For some of them, three-dimensional protein structures have been resolved, but their functions are still elusive. Lipocalins generally display a low sequence identity between family members. The characterization of new lipocalin allergens has revealed however that some of them display a high sequence identity to lipocalins from another species. They constitute a new group of potentially cross-reactive molecules which, in addition to serum albumins, may contribute to allergic cross-reactions between animal dander of different species. However, the clinical relevance of cross-reactivity needs to be assessed. Further studies are needed to understand which of these animal lipocalins are the primary allergens and which are cross-reacting molecules. The use of single, well characterized allergens for diagnosis will allow the identification of the sensitizing animal, which is a prerequisite for specific immunotherapy.

["NPAs": a new allergic risk?]

In recent years, to the list of classic pet animals (dogs and cats) as allergens we must now add the "new pet animals" (NPAs). This group of animals, referred to by the Anglo-Saxons as "pets", includes both those previously recognized (rabbit, guinea pig, hamster, birds) and the "truly new NPAs"; by general agreement "NPA" will include all animals other than cats and dogs. Some rather rare animals are regularly added to this list. The emergence of "NPAs" can be related to a social phenomenon, in particular, to the fashion and need for the exotic (http://www.aquadesign.be). They are a very diverse group: warm-blooded animals, spiders, batrachia (frogs, toads, salamanders, etc.) and reptiles. Besides the physical risks from their natural aggressive behaviour, the "NPAs" can be an allergic risk factor and this risk has a tendency to increase. Allergists and paediatricians have a role to play in the diagnosis and prevention of these allergies by giving advice on the choice of pet animals. This review concerns allergies to rodents, reptiles, batrachians, spiders, etc.

Animal bites and stings with anaphylactic potential

Anaphylaxis to animal bites and stings poses a significant medical risk of vascular or respiratory reactions that vary according to the patient's response and nature of the insult. Emergency Physicians frequently see patients who complain of an allergic reaction to an animal bite or sting. Although Hymenoptera stings, specifically those of wasps, bees, and hornets, account for the majority of these cases, other invertebrates and vertebrates are capable of causing allergic reactions and anaphylaxis. Many of the causative animals are quite unusual, and their bites and stings are not commonly appreciated as potential causes of anaphylaxis. We conducted a literature review to identify documented reports of anaphylaxis and anaphylactoid reactions to animal bites and stings. This summary is meant to heighten awareness of the diversity of animals that may cause anaphylaxis, hopefully leading to more rapid diagnosis and treatment of this dangerous condition. A diverse group of animals was found whose bites and stings cause anaphylaxis and anaphylactoid reactions. Some case summaries are presented. A potentially life-saving plan is to direct patients to proper follow-up care to prevent a future life-threatening reaction, including: prescribing epinephrine and antihistamines with proper instructions for their use; referral to an allergist to determine if skin testing, radioallergosorbent test, and immunotherapy are indicated; and reporting the case to state or local Poison Control Centers. In some cases it may be helpful to consult an entomologist or a pest control service for help in identification and elimination of certain offenders.