背景:CD4+辅助性T细胞2型细胞在春季角膜结膜炎(VKC)的发病机制中起重要作用,和抗原呈递细胞是细胞活化所必需的。在这项研究中,我们的目的是调查密度,分布,通过体内共聚焦显微镜观察VKC患者的树突状细胞(DC)的形态。
方法:35例患者(平均值,包括受VKC影响的12.4±5.3年)。所有患者均接受0.1%氟米龙滴眼液和0.5%环孢素A滴眼液治疗。在治疗前和治疗后1、3和6个月,通过体内共聚焦显微镜评估每只右眼DC的密度和形态分布特征。35名年龄匹配的正常受试者(平均值,16.5±1.8年)作为对照进行了研究。
结果:VKC组与对照组的年龄差异有统计学意义(F=18.17,P<0.05)。与正常眼睛相比,在VKC患者中发现DC数量增加,球结膜的平均细胞密度为244.09±59.76个细胞/mm(2),574.53±87.34细胞/mm(2),治疗前角膜周边细胞403.32±106.59细胞/mm(2)。这些DC表现出典型的树突状。治疗后3个月,结膜处DC密度显著降低(P<0.05),在控制中接近这一点。在3个月和6个月时,角膜缘和角膜周边的DC密度也显著降低(P<0.05),但在统计学上仍高于对照组。这些DC,有小的树枝状突起或不规则形状,观察到逐渐位于上皮基底膜和基底下神经丛。
结论:体内共聚焦显微镜似乎是评估结膜和角膜DC动态变化的有价值的工具。DC在VKC中起重要作用,因此可构成VKC治疗干预的靶标。
BACKGROUND: CD4+ T helper type 2 cells play a central role in the pathogenesis of vernal keratoconjunctivitis (VKC), and antigen-presenting cells are required for the cell activation. In this study, we aimed to survey the density, distribution, and morphology of dendritic cells (DCs) in patients with VKC by in vivo confocal microscopy.
METHODS: Thirty-five patients (mean, 12.4 ± 5.3 years) affected by VKC were included. All patients were treated with 0.1% fluorometholone eye drops and 0.5% cyclosporine A eye drops. The density and morphological and distributional characteristics of DCs in each right eye were evaluated by in vivo confocal microscopy before treatment and at 1, 3, and 6 months after treatment. Thirty-five age-matched normal subjects (mean, 16.5 ± 1.8 years) were studied as controls.
RESULTS: There was significant difference in age between the VKC group and the control group (F = 18.17, P < 0.05). Compared with normal eyes, increased numbers of DCs were found in patients with VKC, with mean cell densities of 244.09 ± 59.76 cells/mm(2) at the bulbar conjunctiva, 574.53 ± 87.34 cells/mm(2) at the limbus, and 403.32 ± 106.59 cells/mm(2) at the peripheral cornea before treatment. These DCs exhibited a typical dendritic shape. At 3 months after treatment, the DC density at the conjunctiva decreased significantly (P < 0.05), approximating that in the controls. At 3 and 6 months, the DC densities at the limbus and peripheral cornea also decreased significantly (P < 0.05), but were still statistically higher than those in the controls. These DCs, with small dendritic processes or irregular shapes, were observed to gradually locate at the epithelial basal membrane and subbasal nerve plexus.
CONCLUSIONS: In vivo confocal microscopy appears to be a valuable tool in evaluating the dynamic change of DCs at the conjunctiva and cornea. DCs play an essential role in VKC and therefore may constitute a target for therapeutic intervention for VKC.