细胞角蛋白片段19—2G2对鼻咽癌的辅助诊断价值

Diagnostic value of cytokeratin 19 fragment in nasopharyngeal carcinoma

目的研究细胞角蛋白（cK）片段19—2G2对鼻咽癌的临床价值。方法采用逆转录聚合酶链反应（RT．PCR）方法测定102例鼻咽癌组织细胞中CK19mRNA的基因表达；采用Westernblot验证CK19—2G2在癌组织细胞中的表达，并用免疫组织化学测定角蛋白片段CK19-2G2在癌组织细胞中的定位；采用化学发光法检测102例鼻咽癌患者、90例良性鼻咽病患者及150例健康人血清样本中的CK19—2G2的含量，同时用酶联免疫吸附（ELISA）法检测患者和健康人血清中EB-VCAIgA水平，进行统计学比较分析，研究其在鼻咽癌中的临床应用价值。结果RT—PCR扩增产物CK19mRNA在102例鼻咽癌组织中64例为阳性，Westernblot显示CK19—2G2蛋白片段60例为阳性，CK19．2G2在癌组织细胞中的定位表达20例强阳性、34例阳性、12例弱阳性，均证实CK19-2G2在鼻咽癌组织中有高表达。同时在鼻咽癌患者血清中角蛋白片段19-2G2水平高于良性鼻咽病患者及健康人。单项CK19-2G2检测鼻咽癌的灵敏度为49．0％，特异度为89．2％；EB-VCA IgA检测鼻咽癌的灵敏度为52．9％，特异度为85．4％；CK19—2G2联合EB—VCAIgA检测鼻咽癌的灵敏度可提高至73．5％，特异度保持80．0％。结论CK19—2G2在鼻咽癌组织和血清中均有高表达，CK19—2G2检测可用于鼻咽癌辅助诊断，联合CK19-2G2和EB—VCAIgA检测可明显提高诊断鼻咽癌的灵敏度，并保持较高的特异度。

Objective To explore the clinical significance of cytokeratin 19 fragments test in the diagnosis of nasopharyngeal carcinoma. Methods The study included 102 cases of nasopharyngeal carcinoma, 90 cases of nasal polyp/nasopharyngitis, and 150 healthy individuals. RT-PCR was used to detect CK19 mRNA expression and Western blot to detect CK19 fragment protein expression in tissues of nasopharyngeal carcinoma. Expression of CK19-2G2 was examined by immunohistochemistry. Chemiluminescence analysis was used to detect the serum levels of CK19-2G2, and ELISA to detect that of EB-VCA IgA. Results Among 102 cases of nasophryngeal carcinoma, 64 showed CK19 mRNA expression by RT-PCR, 60 showed CK19 protein fragments in tumor tissues by Western blot, and 66 showed expression of CK19-2G2 by immunohistochemistry in nasopharyngeal carcinoma, including strong positivity in 20 cases, moderate in 34 cases and weak in 12 cases. The sensitivity and specificity of CK19-2G2 in the diagnosis of nasopharyngeal carcinoma were 49.0% and 89. 2%, and those of EB-VCA IgA were 52. 9% and 85.4% , respectively. The combined detection of CK19-2G2 and EB-VCA IgA increased the sensitivity to 73.5% while the specificity remained at 80.0%. Conclusions High levels of CK19-2G2 fragment expressed in tissue and serum are present in patients with nasopharyngeal carcinoma. The serum level of CK19-2G2 is helpful in the diagnosis of nasopharyngeal carcinoma. Furthermore, the combination of serum CK19-2G2 and EB-VCA IgA improves the detection sensitivity.