甲胎蛋白异质体与甲胎蛋白比值在肝癌诊断中的意义

Significance of ratio for α-fetoprotein-L3 and α-fetoprotein in diagnosis of hepatocellular carcinoma

目的对甲胎蛋白异质体(AFP-L3)与甲胎蛋白(AFP)比值在肝脏良恶性疾病鉴别诊断中的性能及意义进行探讨。方法采用微量离心柱法对146例肝病患者(肝癌76例,良性肝病70例)血清分离AFP-L3,采用电化学发光法检测AFP及AFP-L3水平,计算AFP-L3在AFP比例(AFP-L3%)。结果两组中AFP、AFP-L3%水平差异有统计学意义(P<0.01)。AFP及AFP-L3%受试者工作特征(ROC)曲线下面积分别为0.819、0.907。根据二者ROC曲线,得出鉴别肝脏疾病临界值(cut-off)AFP=400μg/L(敏感度63.1%、特异度81.4%、阳性预测值76.7%、阳性似然比3.16);AFP-L3%=13%(敏感度94.7%、特异度88.6%、阳性预测值90.0%、阳性似然比8.29)。当AFP<100μg/L及AFP>500μg/L时,良恶性肝病检出率差异有统计学意义,当AFP在100～500μg/L之间时,良恶性肝病检出率差异无统计学意义。结论 AFP-L3%指标对肝脏疾病诊断性能优于AFP。特别当AFP水平在100～500μg/L之间时,肝脏良恶性疾病难以区分。同时测定AFP、AFP-L3,计算其比值,可以提高肝脏良恶性疾病鉴别诊断性能。

Objective To explore the significance and characters using ratio of α-fetoprotein isoform（AFP-L3） and α-fetoprotein in differentiating benign and malignant hepatocellular carcinoma.Methods Serum samples were collected from 146 patients,76 diagnosed with hepatcellular carcinoma and 70 with benign liver diseases.AFP-L3 was isolated by using microspincolumn coupled with lens culinaris agglutinin.The levels of AFP and AFP-L3 were detected by electrochemiluminesent method.The ratio of AFP-L3 and total AFP（AFP-L3%） was calculated.Results The levels of AFP and AFP-L3% between two groups had statistic significance（P0.01）.The area under the receiver operating characteristic（ROC） curve of AFP and AFP-L3 were 0.819,0.907,respectively.According to the two curves,the cut-off value for differentiating liver disease was AFP=400 μg/L（sensitivity,specificity,positive predictive value and positive likelihood ratio were 63.1%,81.4%,76.7%,3.16%,respectively）;AFP-L3=13%（sensitivity,specificity,positive predictive value and positive likelihood ratio were 94.7%,88.6%,90.0%,8.29,respectively）.When the levels of AFP were 100 μg/L and 500 μg/L,the checking out ratios for benign and malignant liver disease had significant difference.When the level of AFP was between 100-500 μg/L,the ratios had no significant difference.Conclusion The diagnostic characters of AFP-L3% were superior to AFP in differentiating benign and malignant liver disease.Specially,when the level of AFP is between 100-500 μg/L,it is difficult to differentiate benign and malignant liver disease.Simultaneous detection on the levels of AFP and AFP-L3 and calculation on the ratio of AFP-L3% and AFP can increase diagnostic characters.