Development of diagnosis of Atopic Dermatitis by simple and high-sensitive determination method of LTE4

建立了人尿中白三烯E4(LTE4)的LC/MS/MS定量分析方法。在尿液中加入氚标记的内标物后，用EMPORE C18磁盘盒进行固相萃取。在选择性反应监测(SRM)模式下，用LC/MS/MS对重组提取物进行分析。白三烯(LTS)是花生四烯酸在5-脂氧合酶作用下产生的炎性介质。半胱氨酰白三烯(LTC4、LTD4和LTE4)是炎症介质，在炎症性疾病的发病机制中起重要作用。它们增加血管通透性，扩张皮肤血管。因此，增强LT的产生在AD的发病机制中具有潜在的作用。由于LTE4是LTC4和LTD4的稳定代谢产物，特应性皮炎(AD)是一种慢性…，因此尿液LTE4水平是体内产生半胱氨酰LT的有用指标炎症性皮肤病多见于有呼吸道过敏个人或家族史的患者。许多研究表明，IgE介导的机制在AD的发病机制中起一定作用。采用LC/MS-MS法测定AD患者和健康志愿者的尿液LTE4水平，并探讨其与血清总IgE水平的关系。我阐明了AD患者与健康志愿者相比LTE4排泄量的增加，以及AD患者尿LTE4与血清总IgE水平的显著相关性。本研究结果提示半胱氨酸LTS在AD的发病机制中起重要作用。5-脂氧合酶抑制剂和受体拮抗剂可能在AD的治疗中发挥有益的作用。此外，AD的诊断主要基于皮试和血清总IgE和特异性IgE的测量。尿液LTE4测定简便、无创，可用于AD患者血清IgE水平和病理症状的评估。此外，为了比较其与AD的关系，我建立了11-脱氢血栓素B2(11-dedro TXB2)的微量测定方法，11-脱氢血栓素B2是血栓素A2的代谢产物。较少

Liquid chromatography/tandem mass spectrometric method (LC/MS/MS) was developed for the quantitation of leukotriene E4(LTE4) in human urine. After addition of deuterium labeled internal standard to urine, these subjects were extracted by solid-phase extraction using Empore C18 disk cartridge. The reconstituted extracts were analysed by LC/MS/MS in the selected reaction monitoring (SRM) mode monitoring. Leukotrienes (LTs) are inflammatory mediators derived from arachidonic acid by the action of 5-lipoxygenase. The cysteinyl LTs (LTC4, LTD4 and LTE4) are inflammatory mediators and are known to play a part in the pathogenesis of inflammatory diseases. They increase vascular permeability and dilate skin blood vessels. Thus, a potential role for enhanced LT production in the pathogenesis of AD has been suggested. Urinary LTE4 levels are a useful index of whole-body cysteinyl LT production in vivo because LTE4 is a stable urinary metabolite of LTC4 and LTD4.Atopic dermatitis (AD) is a chroni … More c inflammatory skin disease frequently seen in patients with a personal or family history of respiratory allergy. Many observations have indicated that IgE-mediated mechanisms play a part in the pathogenesis of AD. I used LC/MS-MS to determine urinary LTE4 levels in patients with AD and healthy volunteers, and examined the relationship between urinary LTE4 and total serum IgE levels. I clarified theincreased LTE4 excretion in patients with AD compared with healthy volunteers, and a significant correlation between urinary LTE4 and total serum IgE levels in patients with AD.The present findings suggest that cysteinyl LTs play a crucial part in the pathogenesis of AD. Beneficial effects of 5-lipoxygenase inhibitors and receptor antagonists may be expected in the treatment of AD. Moreover, the diagnosis of AD is primarily based on skin tests and measurements of total IgE and specific IgE in serum. Measurement of urinary LTE4, which is simple and non-invasive, may be useful in evaluating the serum IgE level and assessing the pathological symptoms in AD.Furthermore, to compare the relation to AD with LTE4, I developed microdetermination method of 11-dehydro thromboxane B2(11-dehydro TXB2, a urinary metabolite of thromboxane A2). Less