Laboratory animal allergy

Residual profiles and health risk of indoor allergens in China

Exposure to indoor allergens is a principal risk factor for allergic diseases. However, most of the previous studies on indoor allergens focused on very limited kinds of allergens in China. Knowledge of the simultaneous exposure to multiple allergens is still lacking. In this study, the residual profiles of 8 allergens were investigated in 166 dust samples from 11 cities in China. The house dust mite allergens including Der p 1, Der f 1, and Der 2 were detected in the range of <0.02-283.83 μg/g dust. The concentrations of dog allergen Can f 1 and cat allergen Fel d 1 varied widely, from <0.84-22,896.46 μg/g dust for Can f 1 and from <0.02-6298.96 μg/g dust for Fel d 1. Cockroach allergen Bla g 2 was detected in 68% of the samples but at a low level with a maximum of 9.44 μg/g dust. Comparatively low detection frequencies were found for mouse allergen Mus m 1 as 37% and for fungi allergen Asp f 2 as 24%. The frequency of cleaning sheets/bedding was negatively correlated to the levels of house dust mite allergens. The presence of pets indoors was associated with higher levels of pet allergens and lower levels of house dust mite allergens and cockroach allergen. Risk evaluation reveals that at least 4 allergens were found in more than 80% of the rooms and more than 2 allergens with median/high risk were detected in 42% of the rooms, indicating that simultaneous exposure to multiple allergens is prevalent in China.

Horse allergy: Curly Horses can mediate immune tolerance

American Bashkir Curly Horses are claimed to be hypoallergenic, but this has not been clinically proven. In the present study, the effect of exposure to Curly Horses was investigated in 141 patients allergic to horses by measuring their lung function and nasal patency during Curly Horse contact. Continuous contact with Curly Horses, including riding and brushing, decreased the allergic riders' reactivity as measured by FEV1, PEF, and PNIF. Subsequent visits (up to 40 or more hours of riding) further reduced reactivity to the Curly Horses. Allergic events to horses occurred only in 72 out of 1312 riding hours, mainly in the first ten riding hours.In 41 out of the 141 patients, it was further investigated whether repeated exposure to Curly Horses could induce tolerance to other horses. Patients in the tolerance induction study were tested annually for horse allergy using a nasal provocation test. The tolerance induction study showed that exposure to Curly Horses induced immune tolerance to other horses in 88% of patients who completed the study.To understand the mechanism causing hypoallergenicity, we performed IgE immunoblots to determine whether Curly Horse hairs contain IgE binding proteins. However, no differences in IgE reactivity were found between Curly and non-Curly Horses. Moreover, the immune tolerance induction study patients did not show decreased IgE reactivity to hairs from Curly or non-Curly Horses even though patients had developed tolerance. However, we did find increasing levels of anti-horse IgG antibodies in the study patients.Overall, our data strongly suggests that continuous exposure to Curly Horses can induce immune tolerance, rendering these patients non-reactive to horses. The reason for the reduced clinical allergenicity of Curly Horses remains unclear, but the data suggest that blocking IgG antibodies may be of importance for immune tolerance development.

Automation of training and testing motor and related tasks in pre-clinical behavioural and rehabilitative neuroscience

Testing and training animals in motor and related tasks is a cornerstone of pre-clinical behavioural and rehabilitative neuroscience. Yet manually testing and training animals in these tasks is time consuming and analyses are often subjective. Consequently, there have been many recent advances in automating both the administration and analyses of animal behavioural training and testing. This review is an in-depth appraisal of the history of, and recent developments in, the automation of animal behavioural assays used in neuroscience. We describe the use of common locomotor and non-locomotor tasks used for motor training and testing before and after nervous system injury. This includes a discussion of how these tasks help us to understand the underlying mechanisms of neurological repair and the utility of some tasks for the delivery of rehabilitative training to enhance recovery. We propose two general approaches to automation: automating the physical administration of behavioural tasks (i.e., devices used to facilitate task training, rehabilitative training, and motor testing) and leveraging the use of machine learning in behaviour analysis to generate large volumes of unbiased and comprehensive data. The advantages and disadvantages of automating various motor tasks as well as the limitations of machine learning analyses are examined. In closing, we provide a critical appraisal of the current state of automation in animal behavioural neuroscience and a prospective on some of the advances in machine learning we believe will dramatically enhance the usefulness of these approaches for behavioural neuroscientists.

B cells modulate mouse allergen-specific T cells in nonallergic laboratory animal-care workers

Understanding the mechanisms of allergen-specific immune modulation in nonallergic individuals is key to recapitulate immune tolerance and to develop novel allergy treatments. Herein, we characterized mouse-specific T cell responses in nonallergic laboratory animal-care workers before and after reexposure to mice. PBMCs were collected and stimulated with developed peptide pools identified from high-molecular-weight fractions of mouse allergen extracts. Sizable CD4 T cell responses were noted and were temporarily decreased in most subjects upon reexposure, with the magnitude of decrease positively correlated with time of reexposure but not the duration of the break. Interestingly, the suppression was specific to mouse allergens without affecting responses of bystander antigens. Further, PBMC fractioning studies illustrated that the modulation is unlikely from T cells, while B cell depletion and exchange reversed the suppression of responses, suggesting that B cells may be the key modulators. Increased levels of regulatory cytokines (IL-10 and TGF-β1) in the cell culture supernatant and plasma mouse-specific IgG4 were also observed after reexposure, consistent with B cell–mediated modulation mechanisms. Overall, these results suggest that nonallergic status is achieved by an active, time-related, allergen-specific, B cell-dependent regulatory process upon reexposure, the mechanisms of which should be detailed by further molecular studies.

Mechanisms of Particles in Sensitization, Effector Function and Therapy of Allergic Disease

Humans have always been in contact with natural airborne particles from many sources including biologic particulate matter (PM) which can exhibit allergenic properties. With industrialization, anthropogenic and combustion-derived particles have become a major fraction. Currently, an ever-growing number of diverse and innovative materials containing engineered nanoparticles (NPs) are being developed with great expectations in technology and medicine. Nanomaterials have entered everyday products including cosmetics, textiles, electronics, sports equipment, as well as food, and food packaging. As part of natural evolution humans have adapted to the exposure to particulate matter, aiming to protect the individual's integrity and health. At the respiratory barrier, complications can arise, when allergic sensitization and pulmonary diseases occur in response to particle exposure. Particulate matter in the form of plant pollen, dust mites feces, animal dander, but also aerosols arising from industrial processes in occupational settings including diverse mixtures thereof can exert such effects. This review article gives an overview of the allergic immune response and addresses specifically the mechanisms of particulates in the context of allergic sensitization, effector function and therapy. In regard of the first theme (i), an overview on exposure to particulates and the functionalities of the relevant immune cells involved in allergic sensitization as well as their interactions in innate and adaptive responses are described. As relevant for human disease, we aim to outline (ii) the potential effector mechanisms that lead to the aggravation of an ongoing immune deviation (such as asthma, chronic obstructive pulmonary disease, etc.) by inhaled particulates, including NPs. Even though adverse effects can be exerted by (nano)particles, leading to allergic sensitization, and the exacerbation of allergic symptoms, promising potential has been shown for their use in (iii) therapeutic approaches of allergic disease, for example as adjuvants. Hence, allergen-specific immunotherapy (AIT) is introduced and the role of adjuvants such as alum as well as the current understanding of their mechanisms of action is reviewed. Finally, future prospects of nanomedicines in allergy treatment are described, which involve modern platform technologies combining immunomodulatory effects at several (immuno-)functional levels.

Exposição prolongada a animais de laboratório está associada ao aumento de casos de asma

Resumo Objetivo: descrever o resultado do acompanhamento de trabalhadores sensibilizados a animais de laboratório que prolongaram sua exposição. Métodos: após um período de aproximadamente 7 anos, entramos em contato com todos os indivíduos com sensibilização alérgica ocupacional detectada em estudo anterior. Um questionário foi aplicado para situação ocupacional atual, relação entre alergia e a decisão de deixar o trabalho ou exposição e para asma, sibilância, rinite, sintomas cutâneos e dispneia noturna. Resultados: dos 74 indivíduos com sensibilização ocupacional, 45 responderam ao questionário na segunda avaliação e 37 ainda estavam expostos. Ao comparar os dados da primeira avaliação com os da avaliação atual, observou-se um aumento na frequência de asma. Na primeira avaliação, entre todos os sensibilizados (n = 74), 27,0% responderam sim a ambas as questões “Você tem ou já teve asma?” e “A asma foi diagnosticada por um médico?”. Na segunda avaliação, 7 anos depois, dos 37 sujeitos que ainda estavam expostos, 51,3% responderam sim a essas questões (OR: 2,80; IC95%: 1,23-6,38; p = 0,013). Não houve mudança na frequência de respostas positivas às outras perguntas. Conclusão: os dados demonstram aumento da frequência de asma entre trabalhadores com sensibilização ocupacional que prolongam a exposição a animais de laboratório.

Biological occupational allergy: Protein microarray for the study of laboratory animal allergy (LAA)

Background

Laboratory Animal Allergy (LAA) has been considered a risk for the workers since 1989 by the NIOSH. About one third of the Laboratory Animal Workers (LAWs) can manifest symptoms to LAA as asthma, rhinitis, conjunctivitis and cutaneous reactions. The prevalence of LAA-induced clinical symptoms has been estimated with a great variability (4-44%) also due to the different methodologies applied.

Objective

Evaluate the prevalence of IgE positivity to mouse and rat allergens in LAWs and assess which factors are predisposing to sensitization among subjects exposed to laboratory animals in the workplace.

Methods

One hundred LAWs were invited to fill out a questionnaire regarding current allergic symptoms, atopic history, home environment, previous and current occupational history. IgE reactivity versus specific allergens was evaluated with ImmunoCAP ISAC.

Results

Out of one hundred LAWs, 18% had a serum susceptibility to mouse and/or rat allergens and 42% reported to have occupational allergy symptoms. Combining the results acquired by ImmunoCAP ISAC and questionnaire, 17% of LAWs have been defined as LAWs-LAA positive since they present a positive IgE response and allergy symptoms, 1% LAWs-LAA sensitized, 25% LAWs-LAA symptomatic and 57% LAWs-LAA negative. Presence of previous allergy symptoms in work and life environment were significantly related to LAWs-LAA positive/sensitized.

Conclusions

The study aimed to define the immunological profile of LAWs using the proteomic array as an innovative approach in the study of environmental and occupational exposure to allergens. We suggested a definition of LAWs-LAA considering serum IgE response and presence of allergy symptoms. The proposed approach has the advantage to provide a standard methodology for evaluating the specific IgE responsiveness to animal allergens in specific workplace also considering the immunological profile of workers referred to exposure in life and occupational environment.

The development of methods to measure exposure to a major rabbit allergen (Ory c 1)

Rabbits are used as laboratory animal models and are also popular domestic pets. Allergic responses to rabbit allergens have been documented in both settings, and several rabbit allergens identified. We have purified an 18 kD protein extracted from rabbit fur that was shown by N-terminal sequencing and mass spectrometry (MS) to be a lipocalin, identical to that identified as an odorant binding protein and an allergen with the formal nomenclature of Ory c 1. De novo sequencing of the MS peptide fragments gave additional primary sequence data of this protein. Polyclonal antisera were raised against the purified protein and used to develop two types of immunoassay. Ory c 1 content was measured in used rabbit bedding and household dust samples from homes keeping rabbits as pets. Atmospheric sampling was also undertaken in an animal facility undertaking rabbit experimental work. Ory c 1 levels in house dust where rabbits were kept as pets were between undetectable–41,290 ng·g⁻¹, and in used bedding between 370–26,740 ng·g⁻¹. Significantly higher house dust levels were found where rabbits spent large amounts, or all of, their time indoors. Personal air sampler levels within the animal facility were between 65–216 ng·m⁻³. Low levels (0.8–2 ng·m⁻³) were found in the facility's changing rooms, but undetected in the entrance lobby, office and laundry. We believe that these immunochemical assays may be used to identify activities in the occupational and domestic setting which produce higher levels of exposure to rabbit allergens, and where measures to control exposure may be warranted to reduce potential risk of allergic outcomes.

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.

Laboratory Animal Bite Anaphylaxis: A National Survey: Part 2: Treatment Protocols

OBJECTIVE

This study documents current treatment protocols for laboratory animal bite anaphylaxis 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 eighty-nine organizations responded to the question of whether they had a treatment protocol with 32% indicating that they had a protocol. Having a case of anaphylaxis increased the likelihood of having a protocol (61%). Of those with a protocol, 58% included treatment with injectable epinephrine, if clinically indicated. Among all respondents, only 14% reported keeping injectable epinephrine at the location where animal work is performed.

CONCLUSIONS

A minority of responding organizations had protocols in place to address laboratory animal bite anaphylaxis. Organizations with workers at risk should consider implementing a protocol for assessment and treatment.

Indoor Environmental Interventions and their Effect on Asthma Outcomes

PURPOSE OF REVIEW

The use of environmental interventions to improve outcomes in asthmatics has long been an elusive goal. While numerous interventions have been studied, the results of clinical trials have been mixed. This review aims to identify combinations of interventions that have been proven to be effective and to propose a model for using them in a clinical setting.

RECENT FINDINGS

An NIH workshop emphasized a need for research to identify effective interventions for reducing indoor exposures and improving asthma outcomes. A number of innovative measures were described, though evidence supporting their use was lacking. A recent systematic review described various interventions for which evidence is available. The greatest challenge for this approach is the same as that for the medical approach to treatment: nonadherence. Given evidence for effective interventions, control of environmental exposures should lead to improved asthma outcomes. Methods to improve adherence need to be identified.

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.

Seasonality in airborne bacterial, fungal, and (1→3)-β-D-glucan concentrations in two indoor laboratory animal rooms

AIMS

The purpose of this study was to assess the temporal changes in the concentrations of bioaerosols in a laboratory mouse room (LMR) and laboratory rabbit room (LRR), and to determine environmental factors associated with the culturable bacteria, fungi and (1→3)-β-D-glucan concentrations.

METHOD

The concentrations of culturable airborne bacteria, fungi and (1→3)-β-D-glucan in the LMR and LRR were sampled once a month from March 2011 to February 2012. A single-stage viable cascade impactor was used to sample bacteria and fungi, while a two-stage cyclone bioaerosol sampler was used to collect airborne (1→3)-β-D-glucan.

RESULTS

The culturable bacterial concentrations in the LMR showed a gradual increase during the summer. The culturable fungal concentrations showed similar seasonal patterns of change in the LMR and LRR with a noticeable increase during the summer. The (1→3)-β-D-glucan concentrations were highest during the warmer spring and summer months. Relative humidity (RH) was the environmental factor most associated with the concentrations of culturable bacteria and fungi. The overall airborne microbe concentrations were significantly higher in the LRR than in the LMR.

CONCLUSIONS

Airborne microbe concentrations in the LMR and LRR varied greatly depending on season, and these changes were affected by environmental factors.

Anaphylaxis in laboratory workers because of rodent handling: two case reports

Introduction:

Occupational allergy to rodents among laboratory animal workers is common. Most patients generally experience allergic symptoms after the first few years of work. Associated symptoms are usually mild, such as rhinoconjunctivits, urticaria, and asthma. Anaphylaxis, although rare, could be severe and life threatening.

Methods:

We have described in this study two cases of laboratory workers that developed skin and respiratory reactions following laboratory rat and mouse bites, consistent with anaphylaxis.

Results:

Skin testing was found positive for rat epithelium in the patient with anaphylaxis due to rat bite. Elevated levels of specific IgE antibodies against rat and mouse epitheliums were also detected in both the patients.

Conclusion:

These cases illustrate a severe hypersensitivity reaction that could potentially occur in occupational workers that are in close contact with rodents. Reduction of allergen exposure, regular screening, and job modification could be beneficial for affected individuals. Health care workers should be made aware that anaphylaxis could be a serious consequence of laboratory animal bites, particularly in those already sensitized.

The impact of allergic rhinitis on the management of asthma in a working population

Background

Currently, little data is available about the management of asthma in the working population. The aim of this study was to describe asthma control and severity among workers according to current or previous allergic rhinitis comorbidity.

Methods

A network of occupational physicians participated in this pilot study on a voluntary basis. They included a random sample of salaried workers during their systematic occupational medical check-up. All subjects completed a self-administered questionnaire based on the European Community Respiratory Health Survey screening questionnaire, and if they reported any respiratory symptoms including allergic rhinitis, the physician filled in a medical questionnaire. Current asthma control and severity were evaluated according to 2006 Global Initiative for Asthma guidelines.

Results

A total of 110 occupational physicians from two French regions participated. Out of the 6906 employees screened, 3102 identified respiratory symptoms and completed the medical questionnaire and performed spirometry. Overall, 374 were identified as current asthmatics, including 271 (72.5 %) with allergic rhinitis. Among current asthmatics with current allergic rhinitis (n = 95), 68.8 % had partially controlled asthma or uncontrolled asthma, including 51.6 % who received insufficient anti-asthmatic treatment. Partly or no control asthma was not associated with current rhinitis (OR = 1.4; 95 % CI: 0.8-2.7). Current asthmatics with current or previous allergic rhinitis had a significantly lower risk of emergency department visits than current asthmatics without allergic rhinitis (respectively 11.6, 17.1 and 29.1 %; P = 0.002).

Conclusions

Most current asthmatics both with and without allergic rhinitis had uncontrolled asthma, with inappropriate treatment. Future intervention strategies need to be developed for effective control and prevention of asthma in the workplace.

In vitro evaluation of digestive and endolysosomal enzymes to cleave CML-modified Ara h 1 peptides

Ara h 1 is a major peanut allergen. Processing-induced modifications may modulate the allergenic potency of Ara h 1. Carboxymethyl lysine (CML) modifications are a commonly described nonenzymatic modification on food proteins. In the current study, we tested the ability of digestive and endolysosomal proteases to cleave CML-modified and unmodified Ara h 1 peptides. Mass spectrometric analyses of the digested peptides demonstrate that carboxymethylation of lysine residues renders these peptides refractory to trypsin digestion. We did not detect observable differences in the simulated gastric fluid or endolysosomal digestion between the parental and CML-modified peptides. One of the tested peptides contains a lysine residue previously shown to be CML modified laying in a previously mapped linear IgE epitope, but we did not observe a difference in IgE binding between the modified and parental peptides. Our findings suggest a molecular mechanism for the increased resistance of peanut allergens modified by thermal processing, such as Ara h 1, to digestion in intestinal fluid after heating and could help explain how food processing-induced modifications may lead to more potent food allergens by acting to protect intact IgE epitopes from digestion by proteases targeting lysine residues.

Improved single pellet grasping using automated ad libitum full-time training robot

The single pellet grasping (SPG) task is a skilled forelimb motor task commonly used to evaluate reaching and grasp kinematics and recovery of forelimb function in rodent models of CNS injuries and diseases. To train rats in the SPG task, the animals are usually food restricted then placed in an SPG task enclosure and presented food pellets on a platform located beyond a slit located at the front of the task enclosure for 10-30 min, normally every weekday for several weeks. When the SPG task is applied in studies involving various experimental groups, training quickly becomes labor intensive, and can yield results with significant day-to-day variability. Furthermore, training is frequently done during the animals' light-cycle, which for nocturnal rodents such as mice and rats could affect performance. Here we describe an automated pellet presentation (APP) robotic system to train and test rats in the SPG task that reduces some of the procedural weaknesses of manual training. We found that APP trained rats performed significantly more trials per 24 h period, and had higher success rates with less daily and weekly variability than manually trained rats. Moreover, the results show that success rates are positively correlated with the number of dark-cycle trials, suggesting that dark-cycle training has a positive effect on success rates. These results demonstrate that automated training is an effective method for evaluating and training skilled reaching performance of rats, opening up the possibility for new approaches to investigating the role of motor systems in enabling skilled forelimb use and new approaches to investigating rehabilitation following CNS injury.

Animal allergens and their presence in the environment

Exposure to animal allergens is a major risk factor for sensitization and allergic diseases. Besides mites and cockroaches, the most important animal allergens are derived from mammals. Cat and dog allergies affect the general population; whereas, allergies to rodents or cattle is an occupational problem. Exposure to animal allergens is not limited to direct contact to animals. Based on their aerodynamic properties, mammalian allergens easily become airborne, attach to clothing and hair, and can be spread from one environment to another. For example, the major cat allergen Fel d 1 was frequently found in homes without pets and in public buildings, including schools, day-care centers, and hospitals. Allergen concentrations in a particular environment showed high variability depending on numerous factors. Assessment of allergen exposure levels is a stepwise process that involves dust collection, allergen quantification, and data analysis. Whereas a number of different dust sampling strategies are used, ELISA assays have prevailed in the last years as the standard technique for quantification of allergen concentrations. This review focuses on allergens arising from domestic, farm, and laboratory animals and describes the ubiquity of mammalian allergens in the human environment. It includes an overview of exposure assessment studies carried out in different indoor settings (homes, schools, workplaces) using numerous sampling and analytical methods and summarizes significant factors influencing exposure levels. However, methodological differences among studies have contributed to the variability of the findings and make comparisons between studies difficult. Therefore, a general standardization of methods is needed and recommended.

Animal allergens and their presence in the environment

Exposure to animal allergens is a major risk factor for sensitization and allergic diseases. Besides mites and cockroaches, the most important animal allergens are derived from mammals. Cat and dog allergies affect the general population; whereas, allergies to rodents or cattle is an occupational problem. Exposure to animal allergens is not limited to direct contact to animals. Based on their aerodynamic properties, mammalian allergens easily become airborne, attach to clothing and hair, and can be spread from one environment to another. For example, the major cat allergen Fel d 1 was frequently found in homes without pets and in public buildings, including schools, day-care centers, and hospitals. Allergen concentrations in a particular environment showed high variability depending on numerous factors. Assessment of allergen exposure levels is a stepwise process that involves dust collection, allergen quantification, and data analysis. Whereas a number of different dust sampling strategies are used, ELISA assays have prevailed in the last years as the standard technique for quantification of allergen concentrations. This review focuses on allergens arising from domestic, farm, and laboratory animals and describes the ubiquity of mammalian allergens in the human environment. It includes an overview of exposure assessment studies carried out in different indoor settings (homes, schools, workplaces) using numerous sampling and analytical methods and summarizes significant factors influencing exposure levels. However, methodological differences among studies have contributed to the variability of the findings and make comparisons between studies difficult. Therefore, a general standardization of methods is needed and recommended.

The characteristics, treatment and prevention of laboratory animal allergy

Laboratory animal allergy (LAA) is a pervasive problem that affects up to one-third of laboratory animal personnel. An immediate hypersensitivity reaction can be triggered by contact with antigens present in urine, hair, dander and saliva of laboratory animals. The authors provide an overview of the epidemiology, triggering mechanisms, diagnosis, treatment and risk factors of LAA. They also discuss primary and secondary prevention measures that can be taken to reduce LAA morbidity and to allow personnel suffering from LAA to safely continue to do their jobs.

Mammalian-derived respiratory allergens - implications for diagnosis and therapy of individuals allergic to furry animals

Furry animals cause respiratory allergies in a significant proportion of the population. A majority of all mammalian allergens are spread as airborne particles, and several have been detected in environments where furry animals are not normally kept. The repertoire of allergens from each source belongs to a restricted number of allergen families. Classification of allergen families is particularly important for the characterization of allergenicity and cross-reactivity of allergens. In fact, major mammalian allergens are taken from only three protein families, i.e. the secretoglobin, lipocalin and kallikrein families. In particular, the lipocalin superfamily harbours major allergens in all important mammalian allergen sources, and cross-reactivity between lipocalin allergens may explain cross-species sensitization between mammals. The identification of single allergen components is of importance to improve diagnosis and therapy of allergic patients using component-resolved diagnostics and allergen-specific immunotherapy (ASIT) respectively. Major disadvantages with crude allergen extracts for these applications emphasize the benefits of careful characterization of individual allergens. Furthermore, detailed knowledge of the characteristics of an allergen is crucial to formulate attenuated allergy vaccines, e.g. hypoallergens. The diverse repertoires of individual allergens from different mammalian species influence the diagnostic potential and clinical efficacy of ASIT to furry animals. As such, detailed knowledge of individual allergens is essential for adequate clinical evaluation. This review compiles current knowledge of the allergen families of mammalian species, and discusses how this information may be used for improved diagnosis and therapy of individuals allergic to mammals.

Environmental assessment and exposure reduction of cockroaches: a practice parameter

This parameter was developed by the Joint Task Force on Practice Parameters, representing the American Academy of Allergy, Asthma & Immunology (AAAAI); the American College of Allergy, Asthma & Immunology (ACAAI); and the Joint Council of Allergy, Asthma & Immunology. The AAAAI and the ACAAI have jointly accepted responsibility for establishing "Environmental assessment and remediation: a practice parameter." This is a complete and comprehensive document at the current time. The medical environment is a changing environment, and not all recommendations will be appropriate for all patients. Because this document incorporated the efforts of many participants, no single person, including those who served on the Joint Task Force, is authorized to provide an official AAAAI or ACAAI interpretation of these practice parameters. Any request for information about or an interpretation of these practice parameters by the AAAAI or ACAAI should be directed to the Executive Offices of the AAAAI, the ACAAI, and the Joint Council of Allergy, Asthma & Immunology. These parameters are not designed for use by pharmaceutical companies in drug promotion. The findings and conclusions in this manuscript are those of the authors and do not necessarily represent the official position of the Centers for Disease Control and Prevention (CDC).

Association between pet ownership and the sensitization to pet allergens in adults with various allergic diseases

Purpose

As pet ownership increases, sensitization to animal allergens due to domestic exposure is a concern. Sensitization to animal allergens may occur from indirect exposure, as well as direct ownership of animals. However, there have been conflicting results regarding the association between pet ownership and sensitization to animal allergens in adults.

Methods

In total, 401 patients with various allergic diseases were enrolled in this study. We performed skin prick tests with 55 common inhalant and food allergens, including dog, cat, and rabbit allergens. A mean wheal diameter of 3 mm or greater was considered a positive reaction. The exposure modality to each animal allergen was investigated using a questionnaire and included present ownership, past ownership, occupational exposure, occasional exposure, contact with pet owner, and no contact. Present ownership, past ownership, occupational, and occasional exposure were regarded as direct exposure.

Results

The sensitization rate for animal allergens was 20.4% for dog, 15.0% for cat, and 9.0% for rabbit. Direct exposure to dogs (72.0%) was significantly higher than that of other animals (18.4% for cats and 16.7% for rabbits), whereas 'no contact' with cats (78.3%) and rabbits (83.3%) was significantly higher than with dogs (26.8%; P<0.0001). Independent risk factors for sensitization to animal allergens were sensitization to Dermatophagoides pteronyssinus (OR=2.4, P=0.052), Dermatophagoides farinae (OR=5.1, P<0.001), cat (OR=4.4, P<0.0001), and direct exposure to dogs (OR=1.5, P=0.029) for dog, and sensitization to dog (OR=4.4, P<0.0001) and rabbit (OR=2.6, P=0.036) for cats. Finally, for rabbits, the independent risk factor was sensitization to Alternaria (OR=6.0, P<0.002).

Conclusions

These results suggest that direct exposure to dogs contributes to the sensitization to dog allergens in patients with allergic diseases, whereas indirect exposure to cats and rabbits may induce sensitization to each animal's allergen.

Laboratory animals and respiratory allergies: the prevalence of allergies among laboratory animal workers and the need for prophylaxis

OBJECTIVE

Subjects exposed to laboratory animals are at a heightened risk of developing respiratory and allergic diseases. These diseases can be prevented by simple measures such as the use of personal protective equipment. We report here the primary findings of the Laboratory Animals and Respiratory Allergies Study regarding the prevalence of allergic diseases among laboratory animal workers, the routine use of preventive measures in laboratories and animal facilities, and the need for prevention programs.

METHODS

Animal handlers and non-animal handlers from 2 Brazilian universities (University of São Paulo and State University of Campinas) answered specific questionnaires to assess work conditions and symptoms. These subjects also underwent spirometry, a bronchial challenge test with mannitol, and skin prick tests for 11 common allergens and 5 occupational allergens (rat, mouse, guinea pig, hamster, and rabbit).

RESULTS

Four hundred fifty-five animal handlers (32±10 years old [mean±SD], 209 men) and 387 non-animal handlers (33±11 years old, 121 men) were evaluated. Sensitization to occupational allergens was higher among animal handlers (16%) than non-animal handlers (3%, p<0.01). Accessibility to personal protective equipment was measured at 85% (median, considering 73 workplaces of the animal handler group). Nineteen percent of the animal handlers indicated that they wear a respirator at all times while handling animals or working in the animal room, and only 25% of the animal handlers had received an orientation about animal-induced allergies, asthma, or rhinitis.

CONCLUSION

In conclusion, our data indicate that preventive programs are necessary. We suggest providing individual advice to workers associated with institutional programs to promote a safer work environment.

Occupational exposure to laboratory animals causing a severe exacerbation of atopic eczema

A 24-year-old man with a long history of severe atopic eczema presented with a marked exacerbation requiring hospital admission. It emerged that his occupation as an animal house technician required him to work closely with laboratory animals, particularly mice and rats. Radioallergosorbent tests to mice allergens were markedly elevated. Avoidance of animal work, in conjunction with medical treatment, resulted in a marked improvement of his eczema.

Occupational mouse allergen exposure among non-mouse handlers

This study assessed mouse allergen exposure across a range of jobs, including non-mouse handling jobs, at a mouse facility. Baseline data from 220 new employees enrolled in the Jackson Laboratory (JAXCohort) were analyzed. The baseline assessment included a questionnaire, allergy skin testing, and spirometry. Exposure assessments consisted of collection of two full-shift breathing zone air samples during a 1-week period. Air samples were analyzed for mouse allergen content, and the mean concentration of the two shifts represented mouse allergen exposure for that employee. The mean age of the 220 participants was 33 years. Ten percent reported current asthma and 56% were atopic. Thirty-eight percent were animal caretakers, 20% scientists, 20% administrative/support personnel, 10% materials/supplies handlers, and 9% laboratory technicians. Sixty percent of the population handled mice. Eighty-two percent of study participants had detectable breathing zone mouse allergen, and breathing zone mouse allergen concentrations were 1.02 ng/m³ (0.13-6.91) (median [interquartile range (IQR)]. Although mouse handlers had significantly higher concentrations of breathing zone mouse allergen than non-handlers (median [IQR]: 4.13 ng/m³ [0.69-12.12] and 0.21 ng/m³ [below detection (BD)-0.63], respectively; p < 0.001), 66% of non-handlers had detectable breathing zone mouse allergen. Mouse allergen concentrations among administrative/support personnel and materials/supplies handlers, jobs that generally do not entail handling mice, were median [IQR]: 0.23 ng/m³ [BD-0.59] and 0.63 ng/m³ [BD-18.91], respectively. Seventy-one percent of administrative/support personnel, and 68% of materials/supplies handlers had detectable breathing zone mouse allergen. As many as half of non-mouse handlers may have levels of exposure that are similar to levels observed among mouse handlers.

Prevention of occupational asthma

Prevention of occupational asthma related to a work-sensitizing agent ideally would be achieved by avoidance of exposures that cause immunologic sensitization and subsequent asthma. There are a few examples in which a sensitizing agent has been removed from a work process and others in which exposure has been significantly changed or reduced with associated reduced rates of sensitization and disease. Additional measures include containment, use of robots, ventilation measures, exposure monitoring, and use of respiratory protective devices. Secondary prevention includes medical surveillance, which may involve periodic respiratory questionnaires, spirometry, and immunologic tests aiming to detect sensitization or disease early to allow intervention and improve outcomes. Education measures for workers to understand the meaning of work-related respiratory symptoms and appropriate workplace safety measures have not been formally evaluated but may also be expected to enhance protective measures and lead to earlier diagnosis. Tertiary prevention includes medical management and workers' compensation.

Hypersensitivity reactions to mAbs: 105 desensitizations in 23 patients, from evaluation to treatment

BACKGROUND

Rapid desensitization, a procedure for graded drug administration, allows for the safe readministration of a medication after certain types of hypersensitivity reactions (HSRs) and is indicated in cases in which there are no reasonable therapeutic alternatives. The use of rapid desensitization for HSRs to mAbs has not been validated.

OBJECTIVE

We sought to describe our experience with rapid desensitization to mAbs, including rituximab, infliximab, and trastuzumab.

METHODS

One hundred five rapid desensitizations were performed in 23 patients with a standardized 12-step, 6-hour protocol. Our approach to patient evaluation before desensitization is described. The severity, characteristics, and timing of both initial HSRs and HSRs during desensitization were determined by means of retrospective review of medical records. After a reaction during desensitization, patient-specific protocol modifications were made before each subsequent desensitization.

RESULTS

104 of 105 desensitizations undertaken were successfully completed. We observed HSRs during 29% of desensitizations, including 27 mild reactions, 1 moderate reaction, and 2 severe reactions. Overall, reactions during desensitization were markedly less severe than initial HSRs, but reactions did recur in a minority of successive desensitizations.

CONCLUSIONS

Rapid desensitization is a promising method for the delivery of monoclonal therapeutics after an HSR, but the possibility of a reaction remains with each desensitization.

Role of mouse allergens in allergic disease

Mouse allergen has long been recognized as an important cause of occupational allergy and asthma, but only recently has it been implicated in asthma and allergic diseases in community settings. Recent studies have established that mouse allergen is detectable in most US homes, with strikingly high levels in some inner cities. Inner city homes in major northeastern and midwestern US urban centers have levels as much as 100-fold higher than those found in other geographic regions. In addition, about 25% of inner city children with asthma have evidence of IgE sensitization to mouse. Several studies have shown that the combination of sensitization and exposure to higher levels of mouse allergen is associated with substantial asthma morbidity, including hospitalizations. Integrated pest management is efficacious in reducing mouse allergen levels and is recommended for sensitized patients with asthma. However, its impact on clinical outcomes has not yet been proven.

["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.

A survey for rhinitis in an automotive ring manufacturing plant

We report findings regarding otolaryngologist-confirmed rhinitis, current exposure to MWF aerosols, fungi, and endotoxins for workers in a plant manufacturing automobile piston rings. Questionnaire data showed that 61.5% of 187 workers exhibited rhinitis-related symptoms. Rhinitis was confirmed in 99 of 115 workers whom were medically examined. Otolaryngologist-confirmed rhinitis was present in 10 of 19 grinding workers (52.6%), 67 of 142 production workers (47.2%), and 22 of 26 quality control (QC) workers (84.6%). These rates are much higher than the rates of rhinitis-related symptoms in automobile plants and other occupational settings and quite high even allowing for the common occurrence of rhinitis in the general population. We found that rhinitis could develop even in workers exposed to less than 0.5mg/m(3) MWF aerosol. The average exposure to fungi exceeded 10 x 10(3) CFU/m(3), a level higher than that reported for other automobile plants. Although we were unable to identify significant risk factors for rhinitis using only the physician-confirmed rhinitis cases, this study concludes that exposure to MWF aerosol, which would include microbes and metals, could contribute to a high occurrence of rhinitis in grinding and production workers. Forty-nine workers (63.6%) of 77 rhinitis patients in grinding and production operations were determined to handle synthetic MWF directly. For QC workers, for whom the prevalence of physician-confirmed rhinitis was highest, exposure to a low level of MWF aerosol, including specific microbe species we couldn't identify, bright light, dry air, and certain work characteristics during inspection are possible risk factors for development of rhinitis. Further studies including identification of fungi species should be conducted so a firm conclusion can be made regarding the development of rhinitis in QC manufacturing plant workers.

Serial exhaled nitric oxide measurements in the assessment of laboratory animal allergy

BACKGROUND

Laboratory animal allergy (LAA) may cause eosinophilic airway inflammation, for which exhaled nitric oxide (FE(NO)) measurements are sensitive and specific. Our objective was to assess whether serial FE(NO) measurements might detect exposure-related inflammation in laboratory animal workers. METHODS. Fifty laboratory animal workers participated. Measurements of FE(NO) and spirometry were obtained at baseline (Friday) and twice-daily following a weekend with no animal contact.

RESULTS

Eleven of 50 subjects had work-related symptoms, and 2 of 11 had positive serology for LAA. Baseline FE(NO) was high (> 150 ppb) in the two seropositive subjects and increased progressively during the working week in one subject, confirming exposure-driven airway inflammation. In seronegative subjects, mean FE(NO) levels were 19.8 (standard deviation [SD], 20.1) and 21.7 (SD, 20.8) in the symptomatic and nonsymptomatic groups, respectively, with no significant changes in FE(NO) over time.

CONCLUSION

Serial FE(NO) measurements may provide complementary information in the assessment of possible occupational sensitisation. The sensitivity and specificity of this approach to diagnosing occupational asthma requires further evaluation.

Anaphylaxis after mouse bite

Allergic sensitivity to laboratory animals is an occupational risk for all workers in contact with small animals. In rare cases, life-threatening reactions can occur. We describe a laboratory worker who after six years contact with mice developed an anaphylactic reaction after a mouse bite. Testing revealed positive reactions to all components of the mouse. The greatest risk for development of allergy is in the first three years and is usually an immediate hypersensitivity to inhalant allergens.

Rodent allergen in Los Angeles inner city homes of children with asthma

Recent studies have examined the presence of mouse allergen in inner city children with asthma. Researchers have found high levels of rodent allergen in homes sampled in the northeast and midwest United States, but there has been considerable variation between cities, and there have been few studies conducted in western states. We evaluated the frequency of rodent sightings and detectable mouse allergen and the housing conditions associated with these outcomes in inner city homes in Los Angeles. Two hundred and two families of school children, ages 6-16 living in inner city neighborhoods, participated in the study. Families were predominantly Latino (94%), and Spanish speaking (92%). At study entry, parents completed a home assessment questionnaire, and staff conducted a home evaluation and collected kitchen dust, which was analyzed for the presence of mouse allergen. Fifty-one percent of homes had detectable allergen in kitchen dust. All 33 families who reported the presence of rodents had detectable allergen in the home and were also more likely to have increased levels of allergen compared to those who did not report rodents. Unwashed dishes or food crumbs, lack of a working vacuum, and a caretaker report of a smoker in the home were all significantly associated with a greater risk of rodent sightings or detectable allergen (P<0.05). Detached homes were significantly more likely to have detectable allergen. The prevalence of allergen is common enough that it may have public health implications for asthmatic children, and detectable allergen was not routinely identified based on rodent sightings. Many of the predictors of rodent allergen are amenable to low-cost interventions that can be integrated with other measures to reduce exposure to indoor allergens.

Controlling occupational allergies in the workplace

OBJECTIVES

In recent years, the prevalence of work-related asthma has increased. Therefore, more attention needs to be paid to occupational allergens and their avoidance and control in workplaces. However, risk assessment of occupational allergen exposure is difficult because the relationship between exposure concentration, sensitization, and symptoms has not been fully established. This paper introduces a systematic and comprehensive approach to assessing and managing allergen risks at workplaces.

MATERIALS AND METHODS

This approach relies on the cooperation and active communication during the whole process between management, employees, and health care personnel, with the assistance of experts when needed. In addition to gathering background information, including allergic symptoms, through questionnaires addressed to the management and employees, hazard identification is also processed in the workplace through observations and measurements. The methods generally recommended to reduce allergen exposure are compared with those used in the workplace. The process is to be carefully planned and documented to allow later follow-up and re-evaluation.

RESULTS

The multi-faceted approach encompasses several risk assessment techniques, and reveals the prevalence of work-related allergic symptoms. The process effectively focuses on the potential means for controlling allergen exposure.

CONCLUSION

Based on this approach, the synopsis on the critical points that require implementation of effective control measures can be presented.