Increased urinary leukotriene E₄ excretion in patients with atopic dermatitis

Background: Synthesis of cysteinyl leukotrienes (LTs) is known to play a part in the pathogenesis of inflammatory diseases. Objectives: To define the involvement of cysteinyl LTs in atopic dermatitis (AD). Methods Synthesis of cysteinyl LTs was assessed in patients with AD and healthy volunteers by measuring urinary LTE₄, a useful index of systemic cysteinyl LT synthesis, using liquid chromatography/tandem mass spectrometry. Results: Mean ± SD urinary LTE₄ levels in patients with AD (125 ± 69 pg mg^-1 creatinine, n = 20) were significantly higher (P < 0.01) than in healthy volunteers (60 ± 19 pg mg^-1 creatinine, n = 17). A significant correlation between urinary LTE₄ and total serum IgE levels in patients with AD was observed (r = 0.643, P < 0.05). Conclusions: Our findings demonstrate an enhanced synthesis of cysteinyl LTs in patients with AD and suggest that cysteinyl LTs are involved in the pathophysiology of AD.