Kanerva L, Estlander T, Jolanki R
Section of Dermatology, Institute of Occupational Health, Helsinki, Finland.
Acta Derm Venereol. 1988;68(2):116-22.
A long-lasting allergic patch test is a "normal" allergic patch test that remains positive for weeks or months. An immunohistochemical study of immunocompetent cells in the skin in this rare type of patch tests was performed. Most inflammatory cells were T11 positive T-lymphocytes. The majority of these cells were of the helper/inducer phenotype (T4+), but a relative increase of T8+ cells as compared to the initial (1-2d) stages of allergic patch tests was observed. T6+ Langerhans' cells (LCs) were normal or increased in number in the epidermis, while very few dendritic cells displayed Ial antigen in the epidermis, indicating loss of Ial-staining of LCs. High to very high numbers of T6+ cells were found in the dermis. An inflammatory reaction of hair follicles with moderate numbers of T6+ cells in the peribulbar infiltrate was observed indicating that hair follicles might act as shunt pathways for allergens. A defect in down regulation of the contact hypersensitivity reaction and/or a constant antigen stimulation could be responsible for the long-lasting allergic patch tests.
长期过敏斑贴试验是一种“正常”的过敏斑贴试验，其阳性结果可持续数周或数月。针对这种罕见类型斑贴试验中皮肤免疫活性细胞进行了一项免疫组织化学研究。大多数炎症细胞是T11阳性T淋巴细胞。这些细胞大多数为辅助/诱导表型（T4 +），但与过敏斑贴试验初始（1 - 2天）阶段相比，观察到T8 +细胞相对增加。表皮中T6 +朗格汉斯细胞（LCs）数量正常或增加，而表皮中极少树突状细胞显示Ial抗原，表明LCs的Ial染色缺失。真皮中发现大量至高数量的T6 +细胞。观察到毛囊有炎症反应，毛囊周围浸润中有中等数量的T6 +细胞，这表明毛囊可能作为变应原的分流途径。接触性超敏反应下调缺陷和/或持续的抗原刺激可能是长期过敏斑贴试验的原因。
