Sulphido‐leukotriene production from peripheral leukocytes and skin in clinically normal dogs and house dust mite positive atopic dogs

Abstract

Pathogenesis of canine atopy has not been completely elucidated. In humans, sulphido-leukotrienes (s-LT) play a role in atopy, and increased production of s-LT occurs in the skin and peripheral leukocytes after allergen challenge. The study population included 16 clinically normal and 13 atopic dogs. All atopic dogs had in common a positive reaction (4+) to the intradermal injection of house dust mite (allergen of reference). Blood samples and skin biopsies were collected. Sulphido-LT synthesis by peripheral leukocytes after stimulation was measured, and no statistically significant difference was found between clinically normal and atopic dogs. Sulphido-LT concentrations in skin samples from stimulated and unstimulated sites were measured, and no statistically significant difference was detected between clinically normal and atopic dogs or between lesional and nonlesional skin within the atopic group. Clinical signs of atopic dogs were graded by owners and no correlation was found between their severity and cutaneous concentrations of s-LT. In this study there was no increase in s-LT synthesis in atopic dogs.

Review: Innate immunity, lipid metabolism and nutrition in canine atopic dermatitis

“…In contrast, a study evaluating the concentration of sulfidoleukotrienes (e.g. LTC4, LTD4 and LTE4) in lesional, nonlesional and healthy canine skin failed to find any significant differences between the groups or correlation with clinical signs . At this time, there is insufficient evidence to draw any clear conclusions about the role of leukotrienes in the blood or skin of dogs with AD.…”

“…Mast cells isolated from atopic dog skin appeared to exhibit enhanced mediator release compared with those from healthy dogs, possibly due to increased local levels of stem cell factor . Canine mast cells were demonstrated to produce a variety of preformed and de novo ‐synthesized mediators, including histamine, tryptase, chymase, leukotrienes and tumour necrosis factor α (TNFα) …”

“…Initial studies in the investigation of leukotriene production in the basenji–greyhound dog model of asthma/atopic dermatitis demonstrated that aerosol allergen challenge induced the release of the ‘slow‐reacting substance of anaphylaxis’ (a mixture of the sulphido‐leukotrienes LTC4, LTD4 and LTE4) in sensitized dogs . Nonetheless, a prospective study investigating production of leukotrienes in skin and peripheral leucocytes failed to identify any significant differences between healthy and atopic dogs …”

Investigation on the effects of topical therapy with 0.1% tacrolimus ointment (Protopic®) on intradermal skin test reactivity in atopic dogs

“…The HDM was an equal mixture of Dermatophygoides farinae and D. pteronyssinus , as is routinely used in the clinic by the PI. Histamine was used as a positive control for immediate reactions, and LPS was used as a positive control for late‐phase reactions 12 . House dust and HDM were chosen as allergens of reference.…”

“…Histamine was used as a positive control for immediate reactions, and LPS was used as a positive control for late-phase reactions. 12 House dust and HDM were chosen as allergens of reference. ISTs were repeated 2 and 4 weeks after discontinuation of topical therapy in the second treatment period to determine if reactions returned to baseline by 2 or 4 weeks post treatment.…”