Keigo Kurata

Positive reactions to common allergens in 42 atopic dogs in Japan.

Clinically important allergens for the diagnosis and treatment of atopic dermatitis vary geographically. In order to identify the most prevalent allergens in atopic dogs in Japan, 42 dogs with a clinical diagnosis of atopy were tested using both in vivo (intradermal skin test (IDST)) and in vitro (antigen-specific IgE assay) allergy tests. Allergens used for IDST included 26 allergen extracts from eight allergen groups: trees, weeds, grasses, house dust mites (HDM), molds, foods, epithelia, and arthropods. Immunodot assay was used to measure antigen-specific IgE against 24 allergens from these eight groups and against fish such as cod and sole. In the 42 dogs, the most common positive allergen reaction was to HDM on both IDST (29/42 dogs or 69%) and in vitro testing (23/42 or 54.8%). The second most frequent positive allergen reaction was to Japanese cedar pollen (21/42 or 50.0% for IDST and 7/42 or 16.7% for in vitro testing). In both tests, less than 20% of dogs had positive reactions to molds or foods. Positive reactions to cat epithelia were frequently found on IDST, but rarely found on in vitro testing. Agreement between the two tests was found in 26 instances: HDM (21 dogs), Japanese cedar pollen (five dogs) and wheat (one dog). In this study, the two most common allergens involved in atopic dermatitis in dogs in Japan were HDM and Japanese cedar pollen.

Lesional expression of thymus and activation-regulated chemokine in canine atopic dermatitis.

In this study, we investigated the mRNA expression of a chemokine, thymus and activation-regulated chemokine (TARC), and cytokines including IL-1beta, IL-4, IFN-gamma and TNF-alpha in skin samples obtained from both dogs with atopic dermatitis (AD) and healthy dogs. TARC mRNA was found to be selectively expressed in lesional skin of the dogs with AD, but not in non-lesional skin of the dogs with AD or the normal skin of the healthy dogs. The expression levels of IL-1beta, IFN-gamma and TNF-alpha in the lesional skin were also significantly higher than those in the non-lesional skin of the dogs with AD. However, IL-4 mRNA was not detected in any of the skin samples in this study. The present results suggest that TARC and inflammatory cytokines such as IL-1beta, IFN-gamma and TNF-alpha may play roles in the pathogenesis of canine AD as well as that of human AD.

IgE sensitivity and cross-reactivity to crude and purified mite allergens (Der f 1, Der f 2, Der p 1, Der p 2) in atopic dogs sensitive to Dermatophagoides mite allergens.

The present study investigates IgE-reactivity to crude and purified mite allergens by intradermal skin test (IDST), Immunodot method, and ELISA in atopic dogs sensitive to mite allergens, as well as the allergenic cross-reactivity between Dermatophgoides (D) farinae (DF) and D. pteronyssinus (DP) in dogs by IgE-ELISA inhibition. IDST and Immunodot method for crude mite allergens were performed for atopic dogs and 16 atopic dogs showed sensitivity to mite allergens. Of the 16 dogs, all dogs had anti-DF IgE and 11 had anti-DP IgE. We measured specific IgE to purified major allergens (Der f 1, Der f 2, Der p 1, Der p 2). Of the 16 atopic dogs, six had anti-Der f 1 IgE and seven had anti-Der f 2 IgE. Similarly, of the 16 dogs, six had anti-Der p 1 IgE and seven had anti-Der p 2 IgE. However, eight dogs had no specific IgE to these mite allergens. These dogs may be sensitive to other major mite allergens except Der 1 and Der 2. In the dogs that had both anti-DF and DP IgE, IgE binding to DF was greatly inhibited by DP, and reciprocal inhibition was observed. Based on these data, it appears that there is a strong cross-reactivity between DF and DP in dogs. Similarly, a cross-reactivity between DF and DP in purified allergens was also observed. IDST and Immunodot method are useful methods for the diagnosis of atopic diseases in dogs, and ELISA is a useful method for further investigation of IgE-reactivity for the allergens.

Isolation and characterization of native Cry j 3 from Japanese cedar (Cryptomeria japonica) pollen.

Background:  Japanese cedar (Cryptomeria japonica) pollinosis is the most prevalent allergy in Japan. Recently, the Japanese cedar pollen allergen Cry j 3 was cloned as a homologue of Jun a 3, which is a major allergen from mountain cedar (Juniperus ashei) pollen. However, native Cry j 3 has not been isolated and there are no reports on its allergenic activity. The aims of this study were to isolate native Cry j 3 and assess its immunoglobulin E (IgE)‐binding capacity in patients with Japanese cedar pollinosis.

IgE reactivity to vaccine components in dogs that developed immediate-type allergic reactions after vaccination.

Abstract Allergic reactions after vaccination are considered as an important practical problem in dogs; however, their immunological mechanism has not been well understood. The present study was designed to investigate the relationship between IgE reactivity to the vaccines and immediate-type allergic reactions after vaccination in dogs. Sera from 10 dogs that developed immediate-type allergic reactions such as circulatory collapse, cyanosis, dyspnea, facial edema, and vomiting within 1h after vaccination with non-rabies monovalent or combined vaccines and sera from 50 dogs that did not develop allergic reactions after vaccination were collected. Serum IgE reactivity to the injected vaccines was measured by fluorometric ELISA using a mouse monoclonal anti-dog IgE antibody. Then, IgE reactivity to fetal calf serum (FCS) and stabilizer proteins (gelatin, casein, and peptone) included in the vaccines was measured in sera that had high levels of IgE to the vaccines. Levels of serum specific IgE to the vaccines in dogs with immediate-type allergic reactions (59–4173 fluorescence units [FU], mean±S.D.: 992.5±1181.9 FU) were significantly higher than those in control dogs (38–192 FU, 92.4±43.3 FU) (P <0.001). Of the eight dogs that developed immediate-type allergic reactions and had high levels of serum specific IgE to the vaccines, seven had specific IgE directed to FCS. The IgE reactivity to the vaccines in sera from these dogs was almost completely inhibited by FCS. The other one dog had serum IgE directed to gelatin and casein included in the vaccine as stabilizers. The results obtained in this study suggest that immediate-type allergic reactions after vaccination in dogs were induced by type I hypersensitivity mediated by IgE directed to vaccine components. In addition, FCS, gelatin, and casein included in vaccines could be the causative allergens that induced immediate-type allergic reactions after vaccination in dogs.

IgE-reactivity to major Japanese cedar (Cryptomeria japonica) pollen allergens (Cry j 1 and Cry j 2) by ELISA in dogs with atopic dermatitis

The present study investigated IgE-reactivity to two major Japanese cedar (Cryptomeria japonica, C. japonica) pollen allergens (Cry j 1 and Cry j 2) in dogs with atopic dermatitis by use of a fluorometric ELISA. The serum samples from 27 dogs that showed IgE-sensitivity to crude C. japonica pollen allergen by ELISA were tested for specific IgE to the two major allergens. All 27 dogs had anti-Cry j 1 IgE, and 10 (37%) had anti-Cry j 2 IgE. Inhibition of binding of dog specific IgE to crude C. japonica pollen allergen was carried out by addition of Cry j 1. When serum samples containing anti-Cry j 1 IgE but no anti-Cry j 2 IgE were incubated with Cry j 1, specific IgE binding to crude C. japonica pollen allergen was almost abolished. These findings suggest that Cry j 1 is a major allergen in dogs.

Increase of CC chemokine receptor 4-positive cells in the peripheral CD4+ cells in dogs with atopic dermatitis or experimentally sensitized to Japanese cedar pollen

Background Since dogs frequently develop allergic diseases, similar to those in humans, dogs represent a possible animal model for allergy in humans. In human atopic dermatitis (AD), CC chemokine receptor 4 (CCR4) has been shown to play an important role in the development of allergic inflammation of AD; however, the association between allergic reaction and CCR4 is not well understood in dogs.

Induction of Th1 immune responses to Japanese cedar pollen allergen (Cry j 1) in mice immunized with Cry j 1 conjugated with CpG oligodeoxynucleotide.

We determined whether a major Japanese cedar pollen allergen (Cry j 1) conjugated with CpG oligodeoxynucleotide would enhance allergen-specific Th1 responses in mice. Cry j 1 conjugated with CpG (Cry j 1-CpG) induced IL-12 in the spleen cells of naïve mice. Cry j 1-CpG immunization of BALB/c mice suppressed anti-Cry j 1 IgE response and enhanced anti-Cry j 1 IgG(2a) to subsequent Cry j 1 and alum adjuvant injection. CD4(+)T cells isolated from the spleens in mice immunized with Cry j 1-CpG produced higher IFN-γ levels than did CD4(+)T cells obtained from mice as negative controls. Our results suggested that Cry j 1-CpG immunization can induce Cry j 1-specific Th1 immune responses, thereby inhibiting IgE response to the pollen allergen.