Simon Dagmar, Simon Hans-Uwe
Department of Dermatology, University of Bern, Bern, Switzerland.
J Allergy Clin Immunol. 2007 Jun;119(6):1291-300; quiz 1301-2. doi: 10.1016/j.jaci.2007.02.010. Epub 2007 Apr 2.
Eosinophilic inflammatory responses occur in association with multiple disorders. Although the initial cause and the affected organs vary among the different eosinophilic disorders, there are only 2 major pathways that mediate eosinophilia: (1) cytokine-mediated increased differentiation and survival of eosinophils (extrinsic eosinophilic disorders), and (2) mutation-mediated clonal expansion of eosinophils (intrinsic eosinophilic disorders). Independent from the original trigger, the most common cause of eosinophilia is the increased generation of IL-5-producing T cells. In some cases, tumor cells are the source of eosinophil hematopoietins. The intrinsic eosinophilic disorders are characterized by mutations in pluripotent or multipotent hematopoietic stem cells leading to chronic myeloid leukemias with eosinophils as part of the clone. Here, we propose a new classification of eosinophilic disorders on the basis of these obvious pathogenic differences between the 2 groups of patients. We then discuss many known eosinophilic disorders, which can be further subdivided by differences in T-cell activation mechanisms, origin of the cytokine-producing tumor cell, or potency of the mutated stem cell. Interestingly, many subgroups of patients originally thought to have the idiopathic hypereosinophilic syndrome can be integrated in this classification.
嗜酸性粒细胞炎症反应与多种疾病相关。尽管不同嗜酸性粒细胞疾病的初始病因和受累器官各不相同，但介导嗜酸性粒细胞增多的主要途径只有两条：（1）细胞因子介导的嗜酸性粒细胞分化增加和存活时间延长（外在性嗜酸性粒细胞疾病），以及（2）突变介导的嗜酸性粒细胞克隆性扩增（内在性嗜酸性粒细胞疾病）。嗜酸性粒细胞增多最常见的原因是产生白细胞介素-5的T细胞生成增加，与最初的触发因素无关。在某些情况下，肿瘤细胞是嗜酸性粒细胞造血因子的来源。内在性嗜酸性粒细胞疾病的特征是多能或多潜能造血干细胞发生突变，导致慢性髓系白血病，嗜酸性粒细胞作为克隆的一部分。在此，我们基于这两组患者之间明显的致病差异，提出了一种嗜酸性粒细胞疾病的新分类方法。然后我们讨论了许多已知的嗜酸性粒细胞疾病，这些疾病可根据T细胞激活机制、产生细胞因子的肿瘤细胞来源或突变干细胞的潜能差异进一步细分。有趣的是，许多最初被认为患有特发性高嗜酸性粒细胞综合征的患者亚组可以纳入这一分类。
