Purpose: 

The purpose of this study was to evaluate the expression of cytokeratin (K) 13 on the corneal surface and to validate its application in the diagnosis of limbal stem cell deficiency (LSCD).

Methods: 

This prospective comparative study included 26 corneal impression cytology (IC) specimens from patients diagnosed with LSCD. Twenty-three IC specimens from normal donors served as controls. K12 and K13 expression were detected on the IC specimens by immunohistochemistry study. The number of K12⁺ or K13⁺ cells in all areas of the IC was quantified using ImageJ software.

Results: 

The epithelial cells harvested from IC specimens from control corneas were all K12⁺. In eyes with LSCD, K13⁺ and K12⁺/K13⁺ cells accounted for 93.8% and 2.6%, respectively, in the cornea. In eyes with sectoral LSCD, the median number of K13⁺ cells in the clinically affected area was higher than that in the unaffected area (810.0 vs. 115.0 cells/mm²; P < 0.001). No significant correlation was found between the LSCD severity and the number of K12⁺ cells (r = −0.284, P = 0.16) or K13⁺ cells (r = −0.011, P = 0.95). The presence of at least 16 K13⁺ cells/mm² was suggestive of LSCD.

Conclusions: 

Identification of K13⁺ cells on IC specimens provides a simple and reliable method to detect conjunctival epithelial cells on the cornea. K13 is a marker for diagnosing LSCD and localizing the involved area in sectoral LSCD.

中文翻译：

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细胞角蛋白 13 是诊断角膜缘干细胞缺陷的新生物标志物

目的： 

本研究的目的是评估角膜表面细胞角蛋白（K）13的表达并验证其在角膜缘干细胞缺陷（LSCD）诊断中的应用。

方法： 

这项前瞻性比较研究包括 26 份来自诊断患有 LSCD 的患者的角膜印迹细胞学 (IC) 标本。来自正常捐献者的 23 份 IC 标本作为对照。通过免疫组织化学研究检测IC标本上K12和K13的表达。使用 ImageJ 软件对 IC 所有区域中K12 ⁺或 K13 ⁺细胞的数量进行定量。

结果： 

从对照角膜的 IC 标本中收获的上皮细胞均为 K12 ⁺。在患有LSCD的眼睛中，角膜中K13 ⁺和K12 ⁺ /K13 ⁺细胞分别占93.8%和2.6%。^{在患有扇形性LSCD的眼睛中，临床受影响区域的K13 +}细胞中位数高于未受影响区域（810.0 vs. 115.0 个细胞/mm ²；P < 0.001）。^{LSCD 严重程度与 K12 +}细胞（r = -0.284，P = 0.16）或 K13 ⁺细胞（r = -0.011，P = 0.95）数量之间未发现显着相关性。至少 16 K13 ⁺细胞/mm ²的存在提示 LSCD。

结论： 

IC 标本上K13 ⁺细胞的鉴定提供了一种简单可靠的方法来检测角膜上的结膜上皮细胞。K13是诊断LSCD和定位部门性LSCD受累区域的标志物。