Abou Rahal J, Kurban M, Kibbi A-G, Abbas O
Dermatology Department, American University of Beirut Medical Center, Beirut, Lebanon.
J Eur Acad Dermatol Venereol. 2016 Jan;30(1):119-23. doi: 10.1111/jdv.12932. Epub 2014 Dec 29.
Type I interferon (IFN) signature has been implicated in alopecia areata (AA). However, type I IFN source has never been documented. Plasmacytoid dendritic cells (PDCs) are generally known to be the main source and most potent producers of local type I IFNs. Their role in AA pathogenesis has never been investigated.
Investigate PDC role in AA.
Nineteen AA cases were retrieved from our database and were immunohistochemically tested for PDC occurrence and activity using anti-BDCA-2 and anti-MxA antibodies respectively. Comparison to 10 trichotillomania and 7 androgenetic alopecia (AGA) cases was also done.
Plasmacytoid dendritic cells were present in all AA cases in a peri-bulbar location and, as indirectly assessed by MxA expression, were in an active state producing type I IFNs. All trichotillomania cases showed the presence of PDCs, though significantly less abundant and in a different distribution (mainly superficial perivascular) than that in AA. PDC presence and MxA expression were absent in AGA.
Plasmacytoid dendritic cells constitute a central component of the peribulbar infiltrate in AA suggesting a significant role in AA pathogenesis. Additionally, PDC distribution could help in microscopically differentiating AA from trichotillomania or AGA.
I型干扰素（IFN）特征与斑秃（AA）有关。然而，I型干扰素的来源从未被记录过。浆细胞样树突状细胞（PDC）通常被认为是局部I型干扰素的主要来源和最有效的产生者。它们在斑秃发病机制中的作用从未被研究过。
研究浆细胞样树突状细胞在斑秃中的作用。
从我们的数据库中检索出19例斑秃病例，分别使用抗BDCA-2和抗MxA抗体进行免疫组织化学检测，以确定浆细胞样树突状细胞的存在和活性。还与10例拔毛癖和7例雄激素性脱发（AGA）病例进行了比较。
在所有斑秃病例中，浆细胞样树突状细胞存在于毛囊球周围，并且，通过MxA表达间接评估，它们处于产生I型干扰素的活跃状态。所有拔毛癖病例均显示有浆细胞样树突状细胞存在，但其数量明显较少，分布与斑秃不同（主要在浅表血管周围）。雄激素性脱发病例中不存在浆细胞样树突状细胞及其MxA表达。
浆细胞样树突状细胞是斑秃毛囊球周围浸润的核心组成部分，提示其在斑秃发病机制中起重要作用。此外，浆细胞样树突状细胞的分布有助于在显微镜下鉴别斑秃与拔毛癖或雄激素性脱发。
