Objective: To analyze the clinical histopathologic characteristics of lacrimal glands and possible mechanisms of lacrimal gland prolapse in blepharochalasis (BC). Methods: A case-controlled study of 23 consecutive patients with prolapse of lacrimal glands in BC was performed. All samples were obtained during surgery from the Department of Ophthalmology, Beijing Tongren Hospital, Capital Medical University between January 2009 and December 2016. The lacrimal tissue included prolapsed lacrimal glands (30 samples) and controls from the donors in the eye bank of Beijing Tongren Hospital, Capital Medical University (8 samples). Hematoxylin-eosin staining, special staining, immunohistochemistry and colloidal gold-labeled pre-embedded indirect immunogold electron microscopy (Gold-IIEM) were performed to analyze the histopathologic characteristics of the samples. The nonparametric Wilcoxon signed-ranks test was carried out for statistical analysis. Results: Among the 23 patients with lacrimal gland prolapse in BC, there were 3 males and 20 females. The mean age of morbidity was 11 years old (7-16 years). In the 8 normal control cases, 3 males and 5 females were included. The mean age was 15 years (10-20 years). In the 30 prolapsed lacrimal gland samples, hematoxylin-eosin staining showed enlargement of glandular lumina accompanied by inflammatory infiltrates of interstitial tissue in 2 samples. Marked loosening of collagen fibers of the obtainable lacrimal fascia was observed. The results on immunohistochemical staining demonstrated an increased level of immunocytes in the 30 prolapsed lacrimal gland samples, including IgA (+++, ++, +, -; 12, 11, 4, 3 vs. 0, 0, 1, 7; Z=-3.892), CD3(+)T cells (+++, ++, +, -; 2, 19, 7, 2 vs. 0, 0, 1, 7; Z=-4.168), matrix metalloproteinase (MMP)-3 (+++, ++, +, -; 0, 0, 11, 19 vs. 0, 0, 0, 8; Z=-2.005) and MMP-9 (+++, ++, +, -; 14, 14, 0, 2 vs. 0, 0, 0, 8; Z=-4.552) (all P<0.05). IgG, IgM, CD20 and C1-inhibitor were either absent or expressed at background level in the 30 prolapsed lacrimal gland samples (all P>0.05). Gold-IIEM showed zymogon granules in lacrimal glands were out of shape. MMP-3 and MMP-9 colloidal gold particles existed on the zymogon granules, and MMP-3 colloidal gold particles also existed on the surface of lacrimal gland epithelial cells. Conclusions: The histopathological changes in the lacrimal glands of lacrimal gland prolapse with BC include inflammatory infiltration, elastic fiber degeneration, marked loosening of the supporting fascia tissue, and an increased level of immunocytes, including IgA, CD3(+)T cells, MMP-3 and MMP-9. The results suggest that lacrimal gland prolapse with BC may result in the immuno-pathogenetic mechanisms with the involvement of cell-mediated immune responses. (Chin J Ophthalmol, 2020, 56: 205-210).
目的： 分析眼睑松弛症并发泪腺脱垂者泪腺组织的组织病理学特征及泪腺脱垂的可能机制。 方法： 病例对照研究。收集2009年1月至2016年12月就诊于首都医科大学附属北京同仁医院眼整形科手术治疗的眼睑松弛症并发泪腺脱垂患者23例（30只眼）的30份泪腺组织标本，并与首都医科大学附属北京同仁医院眼库的8份正常泪腺组织（对照）标本进行对比。分别行HE染色、Verhoeff-Van-Gieson染色、相关抗原及抗体免疫组织化学染色，对比观察患者与对照泪腺标本的组织学变化及相关抗原及抗体表达的差异。应用胶体金标记的免疫电镜技术在超微结构下观察基质金属蛋白酶（MMP）-3和MMP-9的表达及分布。采用非参数秩和检验进行统计学分析。 结果： 眼睑松弛症并发泪腺脱垂患者中男性3例，女性20例，平均发病年龄11岁（7~16岁）；对照泪腺组织来自3例男性，5例女性；平均年龄15岁（10~20岁）。眼睑松弛症并发泪腺脱垂患者30份泪腺组织标本中，仅2份标本HE染色表现为明显腺腔扩张，间质中脂肪细胞浸润及淋巴细胞、嗜酸细胞增多，其余标本与对照正常泪腺组织标本无明显差别或仅有轻度慢性炎性反应；30份标本Verhoeff-Van-Gieson染色均显示包被泪腺的筋膜组织结构破坏，胶原纤维变性，并伴有炎症细胞浸润。免疫组织化学染色显示，眼睑松弛症并发泪腺脱垂患者泪腺组织中IgA表达为+++、++、+、-的标本分别为12、11、4、3份，对照标本中分别为0、0、1、7份；白细胞分化抗原CD3表达为+++、++、+、-分别为2、19、7、2份，对照标本中分别为0、0、1、7份；MMP-3表达为+++、++、+、-分别为0、0、11、19份，对照标本均为阴性；MMP-9表达为+++、++、+、-分别为14、14、0、2份，对照标本均为阴性；眼睑松弛症并发泪腺脱垂患者泪腺组织中IgA、CD3、MMP-3和MMP-9的表达均高于对照，差异均有统计学意义（Z=-3.892，-4.168，-2.005，-4.552；均P<0.05）；而IgG、IgM、CD20、补体C1抑制物的表达强度与对照比较，差异均无统计学意义（均P>0.05）。免疫电镜技术显示，与对照标本相比，泪腺脱垂者泪腺腺泡细胞内的酶原颗粒形状失去规则的圆形或椭圆形，酶原颗粒表面有MMP-3及MMP-9表达，腺泡细胞膜上有MMP-3表达。 结论： 眼睑松驰症并发泪腺脱垂者泪腺组织的组织病理学改变表现为免疫炎性反应、胶原纤维变性、筋膜组织松解断裂以及IgA、CD3(+)T淋巴细胞、MMP-3和MMP-9阳性表达，眼睑松驰症并发泪腺脱垂的发病机制可能为细胞介导的免疫应答。（中华眼科杂志，2020，56：205-210）.
Keywords: Eyelid diseases; Inflammation; Lacrimal apparatus; Microscopy, immunoelectron; Prolapse.