Johnson Mahlon D
Dept. of Pathology, Division of Neuropathology, University of Rochester School of Medicine, United States.
Neurosci Lett. 2021 Feb 16;746:135649. doi: 10.1016/j.neulet.2021.135649. Epub 2021 Jan 20.
Recent studies suggest the leptomeninges may have a lymphatic drainage system connecting the subarachnoid space with dorsal cervical lymph nodes. The distribution and histologic features of any dural "lymphatics" has not been established or extensively studied.
Duras from 113 patients were evaluated including 96 formalin-fixed dural samples (mean age 62 years) collected from 2010 to 2015. An additional 17 samples were collected from Alzheimer's disease (AD) patients (mean age 81) autopsied between 1995 and 1997. Two, 2 cm length coronal sections were taken from mid-convexity dura, parallel to the middle meningeal artery, 3-5 cm below and perpendicular to the superior sagittal sinus (SSS). Sections of twenty-two cases were also taken of the SSS and peri-SSS dura. To screen for possible lymphatics, 52 dural and 22 SSS samples from these cases were evaluated with CD31 and podoplanin (D240) immunohistochemistry.
Numerous unlined microscopic channels were found in 101 of 113 (89 %). In non-AD duras, 86 of 92 (93 %) had numerous channels. Duras with AD had significantly less channels i.e. 15 of 21(71 %, P = 0.048). None of the channels had lymphocytes, or neutrophils in their lumena. In the superior sagittal sinus, 9 of 9 non-AD and 12/13 AD SSS duras had fluid channels. Congo red stains revealed no amyloid-like material in the AD duras. Immunohistochemically, CD31 was not found in fluid channels but was in endothelium in 36 of 36 non-AD duras and in most blood vessels including 16 of 16 AD patients. Seven of 36 (19 %) with non-AD and 1 of 16 (6%) with AD had podoplanin in thin walled vessels suggestive of lymphatics but none showed staining in fluid channels.
Unlined fluid channels are present in the dura but not clearly lymphatic.
近期研究表明，软脑膜可能存在一个将蛛网膜下腔与颈背淋巴结相连的淋巴引流系统。硬脑膜“淋巴管”的分布及组织学特征尚未明确，也未得到广泛研究。
对113例患者的硬脑膜进行评估，包括2010年至2015年收集的96份福尔马林固定的硬脑膜样本（平均年龄62岁）。另外17份样本取自1995年至1997年进行尸检的阿尔茨海默病（AD）患者（平均年龄81岁）。从硬脑膜中凸部平行于脑膜中动脉、在矢状窦上方3 - 5厘米处且垂直于上矢状窦（SSS）取两个2厘米长的冠状切片。对22例患者的上矢状窦及上矢状窦周围硬脑膜也进行切片。为筛查可能的淋巴管，对这些病例中的52份硬脑膜样本和22份上矢状窦样本进行CD31和足板蛋白（D240）免疫组织化学评估。
113例中有101例（89%）发现大量无内衬的微小通道。在非AD硬脑膜中，92例中有86例（93%）有大量通道。AD患者的硬脑膜通道明显较少，即21例中有15例（71%，P = 0.048）。所有通道管腔内均无淋巴细胞或中性粒细胞。在上矢状窦中，9例非AD和12/13例AD患者的上矢状窦硬脑膜中有液体通道。刚果红染色显示AD硬脑膜中无淀粉样物质。免疫组织化学检测显示，液体通道中未发现CD31，但36例非AD硬脑膜中的内皮细胞以及包括16例AD患者在内的大多数血管中有CD31。36例非AD患者中有7例（19%）、16例AD患者中有1例（6%）在薄壁血管中有足板蛋白，提示可能为淋巴管，但液体通道均未显示染色。
硬脑膜中存在无内衬的液体通道，但并非明确的淋巴管。
