The signal transducer and activator of transcription 6 (STAT-6) mediates Th2 inflammation and tissue damage in a murine model of peanut-induced food allergy

Introduction: Food allergies are inflammatory conditions mediated by Th2 and probably STAT-6 dependent immune responses. Objective and design: Here we investigated the role of Signal Transducer and Activator of Transcription 6 (STAT-6) in development of inflammation in peanut allergy. Methods: To induce food allergy, wild-type (WT) and mice deficient for STAT-6 (Stat6-/-) were sensitized with peanut proteins and challenged with peanut seeds. Results: WT animals lost weight and refused the peanut diet, in contrast to Stat6-/- mice, which had a better maintenance of body weight and more regular seeds' consumption. The augmented peanut-specific IgG, IgG1 and IgE in the allergic WT was abolished in Stat6-/- animals that also presented increased IgG2a. There was an overall reduction in the gut mediators in the absence of STAT-6, including those related to inflammatory and Th2 responses, in contrast to a rising counter regulatory and Th1 reaction in Stat-6-/- mice. These animals had IFN-γ and IL-10 similar to WT after the four-week challenge. Most interestingly, Stat-6-/- mice had no intestinal damage, in contrast to WT animals, which had inflammatory infiltrate, tissue destruction, epithelial exulceration, edema, congestion and loss of villous architecture in the small gut segments. Conclusions: STAT-6 plays an important role in the establishment of the Th2 inflammatory responses and intestinal damage in peanut allergy

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Food-specific sublingual immunotherapy is well tolerated and safe in healthy dogs: a blind, randomized, placebo-controlled study.

BACKGROUND: Food allergies are increasing in prevalence but no treatment strategies are currently available to cure dogs with food allergy. Over the past decade, experimental food allergen-specific sublingual immunotherapy (FA-SLIT) has emerged as a potential treatment for food allergies in human medicine. However, FA-SLIT has not been investigated in dogs. Therefore, the objective of this study was to prospectively evaluate the safety, tolerability and dispenser sterility of FA-SLIT in healthy dogs before testing it in food allergic dogs. Eight experimental healthy beagle dogs, never orally exposed to peanut, were randomized in two groups to receive SLIT with peanut or placebo for 4 months. Subjects were monitored daily for local and systemic adverse effects. Blood samples for complete blood count and serum biochemistry, and urine for urinalysis were collected and the dogs' body weight was recorded at day 0, 35 and 119 of the SLIT treatment. Sera for the determination of peanut-specific IgG and IgE were collected at day 0, 35, 49, 70, 91, 105 and 119. Intradermal tests were performed before (day 0) and after (day 119) the experiment. The content of each dispenser used to administer treatment or placebo was tested for sterility after usage. In order to assess the presence or absence of sensitization, dogs were challenged 6 months after the end of the study with 2000 µg of peanut extract daily for 7 to 14 days. RESULTS: All dogs completed the study. The treatment did not provoke either local or systemic side-effects. Peanut-specific IgG significantly increased in treatment group. Even though a significant increase in peanut-specific IgE was also seen, intradermal tests were negative in all dogs before and after the experiment, and the challenge test did not trigger any adverse reactions in the treated dogs, which shows the protocol did not cause sensitization to peanut, but nevertheless primed the immune system as indicated by the humoral immune response. All dispenser solutions were sterile. CONCLUSIONS: Our results demonstrate that the used peanut-SLIT protocol is well tolerated and safe in healthy dogs. Further studies should evaluate tolerability, safety and efficacy in dogs with food allergy.

Putative peanut allergy-induced urticaria in a dog.

A 9-year-old, spayed male schnauzer dog was presented with vomiting, diarrhea, generalized erythema, pruritic urticaria and conjunctival hyperemia after ingestion of peanut. The history, clinical signs, and histopathology of the lesions were compatible with a hypersensitivity reaction. The clinical signs resolved rapidly after treatment with prednisolone and antihistamine. This is the first report of urticaria caused by peanut ingestion in a dog.

Urticaire putative induite par une allergie aux arachides chez un chien. Un chien mâle Schnauzer stérilisé âgé de 9 ans est présenté avec des vomissements, de la diarrhée, un érythème généralisé, de l'urticaire pruritique et une hyperémie conjonctivale après l'ingestion d'arachides. L'anamnèse, les signes cliniques et l'histopathologie des lésions sont compatibles avec une réaction d'hypersensibilité. Les signes cliniques se sont résorbés rapidement après le traitement avec de la prednisolone et des antihistaminiques. Il s'agit du premier rapport d'urticaire causé par l'ingestion d'arachides chez un chien.(Traduit par Isabelle Vallières).