Standardized allergen extracts for allergen immunotherapy.

Nineteen U.S. allergen extracts were standardized by the U.S. Food and Drug Administration (FDA) between 1987 and 1998, including of two house-dust mites, short ragweed, cat hair and cat pelt, seven temperate and one southern grass, and six Hymenoptera venom preparations. Relevant literature was reviewed. For each allergen, a "representative" extract was established; the potency of each representative extract was determined by measurement of the total protein content (Hymenoptera venom), radial diffusion measurement of the dominant allergen (short ragweed and cat), or, if there was no dominant allergen, then by quantitative skin testing by using the ID50EAL (intradermal dilution for 50 mm sum of erythema determines the bioequivalent allergy units) method. In vitro tests were developed to allow the manufacturer to demonstrate that each lot of its extract was statistically identical, within defined limits, to the FDA reference extract. These tests included radial immunodiffusion, competitive enzyme-linked immunosorbent assay, and isoelectric focusing. The standardized extracts offer the advantage of consistent potency from lot to lot for each manufacturer and also from manufacturer to manufacturer, and assure the presence of recognized significant allergens within the extract. Therefore, standardized extracts offer improved safety and efficacy over their nonstandardized predecessors.

Detecção do vírus da imunodeficiência felina em gatos domésticos (Felis catus) pela técnica de reação em cadeia da polimerase / Detection of feline immunodeficiency virus in domestic cats (Felis catus) by polymerase chain reaction technique

O objetivo deste trabalho foi detectar a presença de DNA do Vírus da Imunodeficiência Felina (FIV) em gatos domesticos (Feliz catus) assintomáticos. Foi realizada a tecnica de reação em cadeia da polimerase (PCR) em 50 animais. Para tal, foram coletadas amostras de sangue, por venopunção da jugular, de forma asséptica para armazenamento de 1-2 mL de sangue total. Os animais que participaram do estudo fizeram parte do projeto de castração "Vida digna" da Universidade Federal Rural da Amazônia. E a escolha dos animais foi realizada de maneira aleatória, sem distinção por sexo ou idade, resultando em 29 foram fêmeas e 21 machos. Para o diagnóstico, foi realizada a extração do DNA, em seguida as amostras foram testadas em duas reações de PCR utilizando- se dois conjuntos de primers do Gene gag de FIV. Achou-se uma prevalência de 2% (1/50), confirmando assim a presença do vírus na cidade de Belém. Assim, evidenciando a importância de testar os felinos mesmo sendo assintomáticos. Desta forma, faz-se necessário a realização de trabalhos futuros que amplie o número amostral dos animais testados para assim elucidar o perfil epidemiológico da doença na região de Belém do Pará, considerando a relevância clínica desta infecção e a correta conduta médica veterinária para evitar novas infecções.

The objective of this work was to detect the presence of Feline Immunodeficiency Virus (FIV) proviral DNA in asymptomatic domestic cats (Feliz catus). The polymerase chain reaction technique was performed from 50 animals. For this, blood samples were collected by jugular venipuncture, aseptically for storage of 1-2 mL of whole blood. The animals that participated in the study were part of the castration project "Vida digna" at the Universidade Federal Rural da Amazônia. And the choice of animals was performed randomly, without distinction by sex or age, resulting in 29 females and 21 males. For diagnosis, DNA extraction was performed, then the samples were tested in two PCR reactions using two sets of FIV gag gene primers. A prevalence of 2% (1/50) was observed, thus confirming the presence of the virus in the city of Belém. Thus, highlighting the importance of testing the felines even if they are asymptomatic. Therefore, it is necessary to carry out future work that expands the sample number of animals tested in order to elucidate the epidemiological profile of the disease in the region of Belém do Pará, considering the clinical relevance of this infection and the correct veterinary medical conduct to avoid new infections.

Antibody prevalence of Leptospira spp. and Brucella abortus in domestic cats from Araguaína, Tocantins, North Region of Brazil / Prevalência de anticorpos para Leptospira spp. e Brucella Abortus em gatos domésticos de Araguaína, Tocantins, Região Norte do Brasil

Leptospira spp. and Brucella abortus are bacterial pathogens that can infect humans and animals. The present study aimed to detect anti-Leptospira and anti-B. abortus antibodies and verified the presence of factors associated with seropositivity in cats. One hundred and eighty serum samples were collected from domestic cats (Felis silvestris catus) from the urban area of the municipality of Araguaína-Tocantins by phlebocentesis of the cephalic and jugular veins. The samples were subjected to detection of anti-Leptospira and anti-B.abortus antibodies, respectively, by microscopic seroagglutination and buffered acidified antigen testing, followed by confirmation by the 2-mercaptoethanol test and slow seroagglutination in tubes. Data from the epidemiological questionnaire (the age, sex, origin, breed, and presence of clinical signs) were analyzed using Epi Info® software with seropositivity data found to search for associated factors using the chi-square test. In the present study, the prevalence of Leptospira spp. was 5.56% (10/180). However, no sample was reactive to B. abortus. None of the studied variables were associated with seropositivity for the pathogens evaluated. Therefore, there is contact between Leptospira spp. and the feline population of the municipality, indicating the possibility of the circulation of pathogenic serovars and that the presence of anti-Leptospira antibodies does not depend on the variables analyzed.

Leptospira spp. e Brucella abortus são patógenos bacterianos que podem infectar humanos e animais. O presente estudo teve como objetivo detectar anticorpos anti-Leptospira e anti-B.abortus e verificar a presença de fatores associados com a soropositividade em gatos. Foram coletadas 180 amostras de soro de gatos domésticos (Felis silvestris catus) da zona urbana do município de Araguaína-Tocantins por flebocentese das veias cefálica e jugular. As amostras foram submetidas à detecção de anticorpos anti-Leptospira e anti-B. abortus, respectivamente, por soroaglutinação microscópica e teste do antígeno acidificado tamponado, seguido de confirmação pelo teste de 2-mercaptoetanol e soroaglutinação lenta em tubos. Os dados do questionário epidemiológico (idade, sexo, procedência, raça e presença de sinais clínicos) foram analisados no software Epi Info® com os dados de soropositividade encontrados para pesquisa de fatores associados pelo teste do qui-quadrado. No presente estudo, a prevalência de Leptospira spp. foi de 5,56% (10/180). No entanto, nenhuma amostra foi reativa para B. abortus. Nenhuma das variáveis estudadas foi associada com a soropositividade para os patógenos avaliados. Portanto, há contato entre Leptospiraspp. e a população felina do município, indicando a possibilidade de circulação de sorovares patogênicos e que a presença de anticorpos anti-Leptospira independe das variáveis analisadas.

Toxoplasma gondii infections are associated with costly boldness toward felids in a wild host.

Toxoplasma gondii is hypothesized to manipulate the behavior of warm-blooded hosts to promote trophic transmission into the parasite's definitive feline hosts. A key prediction of this hypothesis is that T. gondii infections of non-feline hosts are associated with costly behavior toward T. gondii's definitive hosts; however, this effect has not been documented in any of the parasite's diverse wild hosts during naturally occurring interactions with felines. Here, three decades of field observations reveal that T. gondii-infected hyena cubs approach lions more closely than uninfected peers and have higher rates of lion mortality. We discuss these results in light of 1) the possibility that hyena boldness represents an extended phenotype of the parasite, and 2) alternative scenarios in which T. gondii has not undergone selection to manipulate behavior in host hyenas. Both cases remain plausible and have important ramifications for T. gondii's impacts on host behavior and fitness in the wild.

Antibody Responses in Cats Following Primary and Annual Vaccination against Feline Immunodeficiency Virus (FIV) with an Inactivated Whole-Virus Vaccine (Fel-O-Vax® FIV).

Although the antibody response induced by primary vaccination with Fel-O-Vax® FIV (three doses, 2-4 weeks apart) is well described, the antibody response induced by annual vaccination with Fel-O-Vax® FIV (single dose every 12 months after primary vaccination) and how it compares to the primary antibody response has not been studied. Residual blood samples from a primary FIV vaccination study (n = 11), and blood samples from cats given an annual FIV vaccination (n = 10), were utilized. Samples from all 21 cats were tested with a commercially available PCR assay (FIV RealPCRTM), an anti-p24 microsphere immunoassay (MIA), an anti-FIV transmembrane (TM; gp40) peptide ELISA, and a range of commercially available point-of-care (PoC) FIV antibody kits. PCR testing confirmed all 21 cats to be FIV-uninfected for the duration of this study. Results from MIA and ELISA testing showed that both vaccination regimes induced significant antibody responses against p24 and gp40, and both anti-p24 and anti-gp40 antibodies were variably present 12 months after FIV vaccination. The magnitude of the antibody response against both p24 and gp40 was significantly higher in the primary FIV vaccination group than in the annual FIV vaccination group. The differences in prime versus recall post-vaccinal antibody levels correlated with FIV PoC kit performance. Two FIV PoC kits that detect antibodies against gp40, namely Witness® and Anigen Rapid®, showed 100% specificity in cats recently administered an annual FIV vaccination, demonstrating that they can be used to accurately distinguish vaccination and infection in annually vaccinated cats. A third FIV PoC kit, SNAP® Combo, had 0% specificity in annually FIV-vaccinated cats, and should not be used in any cat with a possible history of FIV vaccination. This study outlines the antibody response to inactivated Fel-O-Vax® FIV whole-virus vaccine, and demonstrates how best to diagnose FIV infection in jurisdictions where FIV vaccination is practiced.

Kisspeptin/Kiss1r system and angiogenic and immunological mediators at the maternal-fetal interface of domestic cats.

The Kisspeptin/Kiss1r system is a key regulator of reproduction by stimulating gonadotrophin-releasing hormone and luteinizing hormone release, and in vitro studies have shown that Kisspeptin can modulate angiogenesis and immune function, factors that are also essential for reproduction However, there are no studies on the expression of Kisspeptin/Kiss1r at the maternal-fetal interface in domestic cats and its relationship with angiogenic and immunological mediators. Thus, our objective was to evaluate the spatiotemporal expression profile of Kisspeptin/Kiss1r and angiogenic and immunological mediators in the uterus and placenta of domestic cats during pregnancy. Uterus and placenta samples were collected from cats in mid pregnancy (N = 6) and late pregnancy (N = 6), in addition to uterus from non-pregnant cats in diestrus (N = 7), to evaluate protein and gene expression of kisspeptin (Kiss1), kisspeptin receptor (Kiss1r), vascular endothelial growth factor (VEGF), tyrosine kinase receptor (Flk-1), placental growth factor (PLGF), interferon gamma (INFγ), migration inhibiting factor (MIF), tumor necrosis factor (TNFα), interleukins (IL6 and IL10) by immunohistochemistry and quantitative polymerase chain reaction. Pregnancy increased the uterine expression of Kiss1 and Kiss1r, especially at the late pregnancy, in addition to upregulating INFy, MIF, Vegf, Il10, and Tnf and downregulating Plgf. Higher placental expression of Kiss1r and Plgf mRNA occurred at the late pregnancy, while the expression of Kiss1, VEGF, Flk-1, INFy, TNFα, Il6, and IL10 was higher in the mid of pregnancy. A positive correlation between Kiss1 and Tnf was observed in the placenta, while Kiss1r had a negative correlation with Infγ, Il6, and Il10. The findings reveal that Kisspeptin/Kiss1r and angiogenic and immunological mediators at the maternal-fetal interface of pregnant cat have a gene correlation and are modulated by the gestational age. These data suggest possible functional links of Kisspeptin in placental angiogenesis and immunology.

Array-based measurements of aero-allergen-specific IgE correlate with skin-prick test reactivity in asthma regardless of specific IgG4 or total IgE measurements.

Skin prick testing (SPT) and measurement of serum allergen-specific IgE (sIgE) are used to investigate asthma and other allergic conditions. Measurement of serum total IgE (tIgE) and allergen-specific IgG4 (sIgG4) may also be useful. The aim was to ascertain the correlation between these serological parameters and SPT. Sera from 60 suspected asthmatic patients and 18 healthy controls were assayed for sIgE and sIgG4 reactivity against a panel of 70 SPT allergen preparations, and for tIgE. The patients were also assessed by skin prick tests for reactivity to cat, dog, house dust mite and grass allergens. Over 50% of the patients had tIgE levels above the 75th percentile of the controls. 58% of patients and 39% of controls showed sIgE reactivity to ≥1 allergen. The mean number of allergens detected by sIgE was 3.1 in suspected asthma patients and 0.9 in controls. 58% of patients and 50% of controls showed sIgG4 reactivity to ≥1 allergen. The mean number of allergens detected by sIgG4 was 2.5 in patients and 1.7 in controls. For the patients, a strong correlation was observed between clinical SPT reactivity and serum sIgE levels to cat, dog, house dust mite (HDM) and grass allergens. SPT correlations using sIgE/sIgG4 or sIgE/tIgE ratios were not markedly higher. The measurement of serum sIgE by microarray using SPT allergen preparations showed good correlation with clinical SPT reactivity to cat, dog, HDM and grass allergens. This concordance was not improved by measuring tIgE or sIgG4.

Immunogenicity of a new allergoid from Felis domesticus

BACKGROUND: The chemical modification of allergens with glutaraldehyde improves safety while maintaining clinical efficacy, which permits the administration of higher doses of immunotherapy, reducing the risk of adverse reactions. The aim of this study is to evaluate the immunogenic capacity of a new cat dander polymer by immunizing mice and quantifying immunoglobulins in serum, in comparison with the non-modified allergen. METHODS: The study consists of the immunization of three mice groups with the polymerized and the native extract, together with a negative control group. The immunoglobulin levels in serum have been measured by indirect ELISA. By means of the non-parametric Mann-Whitney U test, it was determined if there were significant differences in the values of specific antibodies between groups. RESULTS: The group immunized with the allergoid showed significantly higher specific IgG and IgG1 values to dander allergens and specific IgG to the major allergen Fel d 1, while there were no significant changes in IgG2a and IgE values. These results could be due to a higher immunization dose. The vaccine formulation was based on the optimal defined dose for clinical efficacy of allergen immunotherapy. CONCLUSIONS: This preclinical study carried out with the present assay has established that the allergoid of cat dander extract, as designed for its optimal use in allergen immunotherapy, produces a higher specific IgG than the native extract, in addition to showing significantly higher specific IgG1 levels, evidencing a greater effectiveness in immunization

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Effects of educational efforts in tribal homes and schools to reduce asthma triggers, symptoms and missed school days.

Native American asthma prevalence has been estimated higher than for the U.S. population average, and uncontrolled asthma results in absence from schools. This study analyzed effects of targeted education campaigns in both homes and schools on reducing asthma triggers and symptoms among 119 children with asthma, who were recruited from Cherokee and Nez Perce communities. The education campaigns were developed in collaboration with the researchers and the tribes, tailoring strategies to reduce asthma triggers adapted to tribal lifestyles. There was a special emphasis in identification of Traditional Ecological Knowledge (TEK) aspects, which were woven into the study plan and implementation. Some 62 study homes were investigated and the parents received targeted education at the beginning of the study, whereas the remaining control homes received the same education at the end of the study. In Cherokee homes, allergen levels were significantly increased in both control and study groups throughout the study. In Nez Perce homes, dog and cockroach allergen levels decreased significantly in the study homes. The parents reported asthma control test (ACT) scores of the children were significantly improved in both study and control groups, whereas respiratory illness days were reduced in the study group. In schools, allergen levels, particularly cat, dog and cockroach allergens, increased throughout the year in both study and control schools. However, high contact surface cleaning effectiveness based on adenosine tri phosphate (ATP) readings was improved in the study schools. It was also found that high contact surface cleaning effectiveness may have effects on students' absence rates tracked by schools. In conclusion, the results indicate partial improvements in parent reported health symptoms, although the improvements could not be definitively attributed to reduction of any specific exposure in the home environment. In the school environment, effective cleaning throughout the flu season could result in decreased absence rates.

Survey of Dirofilaria immitis antigen and antibodies to Leishmania infantum and Toxoplasma gondii in cats from Madeira Island, Portugal.

BACKGROUND: Dirofilaria immitis, Leishmania infantum and Toxoplasma gondii are zoonotic parasites which can affect domestic cats. Considering the lack of published data from the local feline population, this study aimed to assess infection with or exposure to these pathogens in cats from Madeira Island, Portugal. METHODS: One hundred and forty-one domestic cats (77 males and 64 females; median age: 2 years) were sampled at a veterinary medical centre in Funchal, from September 2018 to January 2019. Serum samples were tested for D. immitis antigen, with an enzyme-linked immunosorbent assay kit, and for antibodies to Leishmania spp. or to T. gondii, with the direct agglutination test and the modified agglutination test, respectively. RESULTS: Five cats (3.5%; 95% confidence interval, CI: 1.2-8.1) were positive to D. immitis; no cats were seropositive to Leishmania spp. (0%; 95% CI: 0-2.6%); and 43 cats (30.5%; 95% CI: 23.0-38.8%) were seropositive to T. gondii. Prevalence of the D. immitis antigen was significantly different between cats that received ectoparasiticides and those which did not (0 vs 12.2%; P = 0.009). Prevalence of antibodies to T. gondii was significantly different between juvenile and adult cats (12.8 vs 38.0%; P = 0.007). There were two cats concurrently positive to D. immitis and T. gondii, but no statistical association between these two dependent variables was found (P = 0.641). CONCLUSIONS: To our knowledge, this is the first report of the presence of parasites D. immitis and T. gondii in the feline population of Madeira Island. Knowledge on the epidemiological situation of these and other zoonotic pathogens should raise awareness, both at the veterinary medical and public health levels, and contribute to promoting prevention and control.

IL-33 is associated with allergy in children sensitized to the cat

BACKGROUND: Several studies suggest that early-life exposure to animal allergens constitutes a relevant risk factor for the development of allergic sensitization. OBJECTIVES: The aim of the present study was to determine the role of interleukin-33 in children sensitive to cat allergen with allergic rhinitis and/or asthma. METHODS: The study included 51 children aged 5-18 years, both sexes, allergic to cats. Sensitization to cat allergen was confirmed by skin prick tests or specific IgE. Children were evaluated for the presence of bronchial asthma, atopic dermatitis, allergic rhinitis. A questionnaire evaluating the occurrence of allergic symptoms in children after contact with the cat and dog was performed. Mothers completed a questionnaire regarding cat exposure: during pregnancy and having a cat at home. A blood sample was taken from all children to measure the level of IL-33 in the serum. RESULTS: Keeping a cat in the home, once in the past, or having a cat in the home during the mother's pregnancy, revealed a statistically significant relationship with IL-33 levels in the studied patients. Also, daily contact with a cat during pregnancy affected the level of IL-33. Higher levels of IL-33 were shown in people with hypersensitivity to cat and pollen allergens and cat and other animals. In patients with bronchial asthma higher levels of IL-33 were found than in patients without bronchial asthma. CONCLUSIONS: Increased serum levels of IL-33 is related with keeping cats during pregnancy and in early childhood and can be associated with the development of asthma in children

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Nasal allergen challenge and environmental exposure chamber challenge: A randomized trial comparing clinical and biological responses to cat allergen.

BACKGROUND: The direct-instillation nasal allergen challenge (NAC) and the environmental exposure chamber (EEC) are 2 methods of conducting controlled allergen provocations. The clinical and biological comparability of these methods has not been thoroughly investigated. OBJECTIVE: We sought to compare clinical and immunologic responses to cat allergen in NAC versus EEC. METHODS: Twenty-four participants were randomized to receive either NAC followed by a 2-day challenge in an EEC or a 2-day challenge in an EEC followed by NAC. Challenges were separated by 28-day washout periods. We measured total nasal symptom scores, peak nasal inspiratory flow, nasal (0-8 hours) and serum cytokines, serum antibodies, peripheral blood antigen-specific T lymphocytes, and gene expression in nasal scrapings. The primary outcome was the total nasal symptom score area under the curve for the first 3 hours after allergen exposure in NAC or after initiation of exposure in EEC. RESULTS: Both challenges increased IL-5 and IL-13 in nasal fluids and serum and resulted in altered nasal cell expression of gene modules related to mucosal biology and transcriptional regulation. Changes in gene modules, more so than cytokine measurements, showed significant associations with total nasal symptom score and peak nasal inspiratory flow. Overall, EEC exposure generated larger responses and more early terminations compared with NAC. Although the 2 challenges did not correlate in symptom magnitude or temporality, striking correlations were observed in cytokine levels. CONCLUSIONS: Although clinical outcomes of NAC and EEC were temporally different and nonequivalent in magnitude, immunologic responses were similar. Selection of a particular allergen challenge method should depend on considerations of study objectives and cost.

The Major Cat Allergen Fel d 1 Binds Steroid and Fatty Acid Semiochemicals: A Combined In Silico and In Vitro Study.

The major cat allergen Fel d 1 is a tetrameric glycoprotein of the secretoglobin superfamily. Structural aspects and allergenic properties of this protein have been investigated, but its physiological function remains unclear. Fel d 1 is assumed to bind lipids and steroids like the mouse androgen-binding protein, which is involved in chemical communication, either as a semiochemical carrier or a semiochemical itself. This study focused on the binding activity of a recombinant model of Fel d 1 (rFel d 1) towards semiochemical analogs, i.e., fatty acids and steroids, using both in silico calculations and fluorescence measurements. In silico analyses were first adopted to model the interactions of potential ligands, which were then tested in binding assays using the fluorescent reporter N-phenyl-1-naphthylamine. Good ligands were fatty acids, such as the lauric, oleic, linoleic, and myristic fatty acids, as well as steroids like androstenone, pregnenolone, and progesterone, that were predicted by in silico molecular models to bind into the central and surface cavities of rFel d 1, respectively. The lowest dissociation constants were shown by lauric acid (2.6 µM) and androstenone (2.4 µM). The specific affinity of rFel d 1 to semiochemicals supports a function of the protein in cat's chemical communication, and highlights a putative role of secretoglobins in protein semiochemistry.

Effects of arginine and ornithine supplementation to a high-protein diet on selected cellular immune variables in adult cats.

BACKGROUND: Dietary protein and amino acid intake and composition can modulate immune function. OBJECTIVES: To evaluate the effects of high-protein intake and arginine and ornithine supplementation on feline immune cells. ANIMALS: Ten healthy cats. METHODS: Experimental study. Cats received a high-protein basal diet as a single daily meal. A crossover design was applied with treatments being basal diet (w/o); basal diet with arginine supplementation (+50, 75, 100% compared to the arginine provision by the basal diet; Arg 1-3); and basal diet with ornithine supplementation (+100, 150, 200% compared to the arginine provision by the basal diet; Orn 1-3). Blood samples were collected at the end of each 11-day treatment period. RESULTS: Mitogen-stimulated proliferative activity of blood leukocytes revealed a quadratic effect for the dietary supplementation of arginine (P = .02) and ornithine (P = .03) (means for ConA-stimulation: w/o = 6.96; Arg 1 = 9.31; Arg 2 = 11.4; Arg 3 = 8.04; Orn 1 = 15.4; Orn 2 = 9.43; Orn 3 = 9.28; pooled SEM: 0.96). The number (% gated) of phagocytic granulocytes linearly decreased with increasing dietary concentrations of arginine (P = .05) and ornithine (P = .03) (means: w/o = 95.5; Arg 1 = 93.0; Arg 2 = 92.5; Arg 3 = 92.6; Orn 1 = 92.6; Orn 2 = 92.6; Orn 3 = 91.5; pooled SEM = 0.44). CONCLUSIONS AND CLINICAL IMPORTANCE: This study could demonstrate immunomodulating properties of dietary arginine and ornithine in cats.

Topology and expressed repertoire of the Felis catus T cell receptor loci.

BACKGROUND: The domestic cat (Felis catus) is an important companion animal and is used as a large animal model for human disease. However, the comprehensive study of adaptive immunity in this species is hampered by the lack of data on lymphocyte antigen receptor genes and usage. The objectives of this study were to annotate the feline T cell receptor (TR) loci and to characterize the expressed repertoire in lymphoid organs of normal cats using high-throughput sequencing. RESULTS: The Felis catus TRG locus contains 30 genes: 12 TRGV, 12 TRGJ and 6 TRGC, the TRB locus contains 48 genes: 33 TRBV, 2 TRBD, 11 TRBJ, 2 TRBC, the TRD locus contains 19 genes: 11 TRDV, 2 TRDD, 5 TRDJ, 1 TRDC, and the TRA locus contains 127 genes: 62 TRAV, 64 TRAJ, 1 TRAC. Functional feline V genes form monophyletic clades with their orthologs, and clustering of multimember subgroups frequently occurs in V genes located at the 5' end of TR loci. Recombination signal (RS) sequences of the heptamer and nonamer of functional V and J genes are highly conserved. Analysis of the TRG expressed repertoire showed preferential intra-cassette over inter-cassette rearrangements and dominant usage of the TRGV2-1 and TRGJ1-2 genes. The usage of TRBV genes showed minor bias but TRBJ genes of the second J-C-cluster were more commonly rearranged than TRBJ genes of the first cluster. The TRA/TRD V genes almost exclusively rearranged to J genes within their locus. The TRAV/TRAJ gene usage was relatively balanced while the TRD repertoire was dominated by TRDJ3. CONCLUSIONS: This is the first description of all TR loci in the cat. The genomic organization of feline TR loci was similar to that of previously described jawed vertebrates (gnathostomata) and is compatible with the birth-and-death model of evolution. The large-scale characterization of feline TR genes provides comprehensive baseline data on immune repertoires in healthy cats and will facilitate the development of improved reagents for the diagnosis of lymphoproliferative diseases in cats. In addition, these data might benefit studies using cats as a large animal model for human disease.

Asthma prevalence, but not allergic rhinitis nor atopic dermatitis, is associated to exposure to dogs in adolescents.

BACKGROUND: Exposure to pets can be a predisposing factor in the development of certain diseases, including allergic diseases. OBJECTIVE: We analyzed the role that exposure to indoor dogs and cats plays in the prevalence of allergic diseases. METHODS: We examined the cross-sectional data of 1056 women and 936 men aged 15 to 18 years; these individuals were selected through stratified and cluster random sampling. We asked all participants about their exposure to indoor dogs and cats during the year that preceded our study. The prevalence of allergic diseases was determined through core questions taken from The International Study of Asthma and Allergies in Childhood questionnaire. RESULTS: The prevalence was 12.7% (95% CI: 11.3%-14.2%) for asthma, 9.0% (95% CI: 7.8%-10.4%) for allergic rhinitis, and 5.2% (95% CI: 4.3%-6.2%) for atopic dermatitis. The multivariate analyses showed that exposure to indoor dogs, but not indoor cats, was associated with asthma prevalence (aOR 1.37; 95% CI: 1.03-1.83), as was male sex (aOR=1.42; 95% CI: 1.08-1.86), a personal history of allergic rhinitis (aOR=3.24; 95% CI: 2.25-4.66), and a maternal history of asthma (aOR=3.06; 95% CI: 1.89-4.98). The population attributable risk for exposure to indoor dogs was 18%. Notably, neither allergic rhinitis nor atopic dermatitis was found to be associated with dog or cat exposure (p> 0.05). CONCLUSION: Exposure to dogs in late adolescence is a factor associated with asthma, although its contribution to the development of asthma should be investigated in new studies.

Cat Allergy as a Source Intensification of Atopic Dermatitis in Adult Patients.

Atopic dermatitis (AD) is characterized by exacerbations and remissions of eczematous skin, underlain by impaired skin barrier and aberrant Th2-type and Th-22 cytokine production. A number of allergens, in particular contact with fur animals, may aggravate the disease. This study seeks to define the influence of having a regular contact with a pet cat at home on the severity of symptoms and signs of AD. We addressed the issue using the SCORing Atopic Dermatitis (SCORAD) and visual analog (VAS) scores to assess the intensity of pruritus and by measuring the blood content of specific IgE and IL-4, IL-13, and IL-22 cytokines. The study group consisted of 47 adult patients suffering from AD since childhood, 18 of whom declared having regular contact with a cat and the remaining 29 who denied it. There also was a control group consisted of 16 healthy volunteers with no AD signs. The SCORAD and VAS scores were significantly higher in patients in contact with a cat than in those without it (median SCORAD 61.0 vs. 50.4 and VAS 9.0 vs. 4.0 points, respectively). The sIgE of a majority of patients (94.4%) in contact with a cat was in Class V-VI, compared with just a few patients (3.4%) with no such contact, having sIgE in the same classes (p < 0.001). Significant correlations were revealed between SCORAD and VAS scores and the class level of serum sIgE value. In addition, IL-22 was a single elevated cytokine, only in the patients in contact with a cat, and it correlated with pruritus severity. The results of the study underline the need to beware of the cat fur allergen, and they stress forethought and caution in acquiring and keeping a pet cat by patients suffering from AD.

Systemic reactions to subcutaneous immunotherapy: Effects of dosing and aeroallergen content.

BACKGROUND: Systemic reactions are a known risk of subcutaneous immunotherapy (SCIT) for aeroallergens. OBJECTIVE: To identify the dose of SCIT that results in the most systemic reactions to SCIT (SCITSRs) and other risk factors for SCITSRs. METHODS: We performed a retrospective review of all SCIT encounters from 2013 to 2017 at a multisite allergy/immunology practice. SCITSRs were identified from the electronic health record through immunotherapy encounters in which epinephrine was administered. Collected data included patient demographics, the dose of immunotherapy at the time of the SCITSR, the presence or absence of asthma, and aeroallergen content. The control group was generated randomly from the same cohort during the same period. RESULTS: There were 86,949 SCIT visits, with 81 SCITSRs (0.9 per 1000 injections). A total of 77.8% of reactions occurred at a dose of 1:1 0.1 mL and above. The presence of cat (81.5% vs 63.0%, P = .01), dog (67.9% vs 37.0%, P < .001), and grass extracts (85.2% vs 67.5%, P = .01) were associated with SCITSRs. Asthma was not significantly associated with SCITSRs. The presence of dust mites, trees, weeds, and molds was not associated with SCITSRs. There were no months or seasons where SCITSRs were more likely to occur. Individuals who experienced SCITSRs had a mean (SD) higher number of included aeroallergenic groups compared with controls (5.86 [1.88] vs 5.00 [1.92], P < .001). CONCLUSION: Risk factors for SCITSRs in a multisite allergy/immunology practice included administration of the highest immunotherapy doses; inclusion of cat, dog, and grass extracts; and the number of aeroallergenic groups included in the extract. This information helps further characterize risk for patients receiving SCIT.

Anti-Fel d1 immunoglobulin Y antibody-containing egg ingredient lowers allergen levels in cat saliva.

OBJECTIVES: Fel d1 is the major cat allergen, causing IgE reactions in up to 90% of cat-allergic adults. Fel d1 secreted in saliva is spread to the haircoat during grooming. Current management includes attempts to reduce or eliminate exposure to Fel d1. A novel approach to reducing immunologically active Fel d1 (aFel d1) exposure, which involves binding the Fel d1 with an anti-Fel d1-specific polyclonal egg IgY antibody (sIgY), was evaluated. The hypothesis was that saliva from cats fed diets containing this sIgY would show a significant reduction in aFel d1. METHODS: Two trials in cats were completed. In trial 1, saliva was collected 0, 1, 3 and 5 h post-feeding during a 2 week baseline and subsequent 6 week treatment period. Trial 2 included a control and treatment group, and saliva was collected once daily. Trial 2 cats were fed the control diet during a 1 week baseline period, and then fed either control or sIgY diet during the 4 week treatment period. Fel d1-specific ELISA was used to measure salivary aFel d1. Data were analysed using repeated-measures ANOVA and a linear mixed-model analysis. RESULTS: Salivary aFel d1 decreased post-treatment in both trials. There were no differences in aFel d1 based on time of collection relative to feeding in trial 1. In trial 2, 82% of treatment group cats showed a decrease in aFel d1 of at least 20% from baseline vs just 38% of control cats. Only one (9%) treatment cat showed an increase in aFel d1 vs 63% of control cats. CONCLUSIONS AND RELEVANCE: Feeding sIgY significantly reduced aFel d1 in the saliva of cats within 3 weeks. Although additional research is needed, these findings show promise for an alternative approach to the management of allergies to cats.