Cuéllar Adriana, García Elizabeth, Rodríguez Adriana, Halpert Evelyne, Gómez Alberto
Departmento de Microbiología, Facultad de Ciencias, Pontificia Universidad Javeriana, Bogotá, Colombia.
Arch Dermatol. 2007 Nov;143(11):1415-9. doi: 10.1001/archderm.143.11.1415.
Papular urticaria is a chronic allergic disease caused by fleabite. The presence of eosinophils, predominance of CD4-positive T cells in lesions, and IgE response suggest a Th2 immune response to flea proteins in patients with papular urticaria caused by fleabite (PUFB). Although PUFB is defined as an allergic reaction, the immunological mechanisms and the role of dendritic cells (DCs) have not been established.
Flea body extract did not induce the maturation of monocyte-derived DCs in 10 patients with PUFB and in 10 healthy children. Simultaneous exposure of DCs to flea extract and lipopolysaccharide induced increased expression of CD83 (P < .01), CD86 (P < .01), and HLA-DR (P < .05), which was statistically significantly greater in patients' cells. Dendritic cells from patients stimulated with lipopolysaccharide secreted less interleukin 6 (IL-6) and IL-10 than DCs from control subjects.
Results of this study indicate that the involvement of DCs in an immune response produced in the disease is mediated through the altered expression of membrane molecules. This may be related to constitutive impairment in the production of regulatory cytokines such as IL-6 and IL-10 in these patients.
丘疹性荨麻疹是一种由跳蚤叮咬引起的慢性过敏性疾病。嗜酸性粒细胞的存在、病变中CD4阳性T细胞的优势以及IgE反应表明，在由跳蚤叮咬引起的丘疹性荨麻疹（PUFB）患者中，对跳蚤蛋白存在Th2免疫反应。尽管PUFB被定义为一种过敏反应，但其免疫机制以及树突状细胞（DCs）的作用尚未明确。
在10例PUFB患者和10名健康儿童中，跳蚤体提取物未诱导单核细胞来源的DCs成熟。DCs同时暴露于跳蚤提取物和脂多糖可诱导CD83（P <.01）、CD86（P <.01）和HLA - DR（P <.05）表达增加，患者细胞中的增加在统计学上更显著。脂多糖刺激的患者来源的树突状细胞分泌的白细胞介素6（IL - 6）和IL - 10比对照组受试者的DCs少。
本研究结果表明，DCs参与该疾病产生的免疫反应是通过膜分子表达的改变介导的。这可能与这些患者中调节性细胞因子如IL - 6和IL - 10产生的固有损伤有关。
