甲胎蛋白异质体的检测及临床应用

甲胎蛋白（alpha fatoprotein，AFP）是早期肝细胞癌（HCC）诊断的良好指标，但是部分良性肝病也有AFP升高，30％～40％的肝细胞癌AFP正常，这样导致部分肝病无法判断良恶性。研究发现，AFP存在糖链有差别的异质体，并利用它与不同植物凝集素的亲和进行分类，有小扁豆凝集素（lens culinaris lectin，LCA）型和刀豆素A（concanavalin A，ConA）型等。据AFP和LCA亲和的强弱程度分为AFP—L1、AFP-L2、AFP-L3，AFP—L1是LCA非结合型，     

微量离心柱法与亲和交叉免疫电泳法检测甲胎蛋白异质体的研究

目的 比较微量离心柱法和亲和交叉免疫电泳自显影法两种方法 检测甲胎蛋白异质体(AFP-L3)对甲胎蛋白阳性的良恶性肝病鉴别诊断价值.方法 采用微量离心柱法和亲和交叉免疫电泳自显影法分别分析102例原发性肝癌、41例慢肝及肝硬化血清中的AFP-L3比率,比较2种方法 检测AFP-L3%对良恶性肝病鉴别诊断价值.结果 微量离心柱法和亲和电泳法对102例原发性肝癌AFP-L3%的敏感性分别是79.4%、91.2%.对41例慢肝、肝硬化AFP-L3%的特异性分别为70.7%、29.3%.亲和电泳法、微量离心柱法两种方法 检测肝癌的符合率分别为76.9%、73.4%,在ROC曲线下的面积AUC分别为0.791、0.758.4例AFP低值的原发性肝癌,采用亲和电泳方法 检测均为阴性,而采用微量离心柱方法 检测均为阳性.结论 微量离心柱法检测AFP-L3不仅操作简便、省时,而且比传统亲和电泳方法 更适合于AFP阳性良恶性肝病的鉴别诊断.     

甲胎蛋白异质体L3预警原发性肝癌的研究

目的 探讨甲胎蛋白异质体(AFP-L3)的检测在预警原发性肝癌中的作用.方法 对100例AFP升高肝病患者血清,应用甲胎异质体微量离心柱分离并洗脱获得AFP-L3,再同时检测原始血清中的AFP以及AFP-L3含量,计算AFP-L3在AFP中的比例,对AFP-L3异常升高者、正常者进行跟踪,结合6个月后临床诊断结果 ,分析AFP-L3升高在鉴别良性肝脏病变与预警肝癌中的作用.结果 肝癌、疑似肝癌患者与良性肝病患者中的AFP-L3阳性率差异有统计学意义(分别为81.80%、73.68%、11.80%,P＜0.05).未确诊肝癌(疑似HCC、肝病)的患者中,AFP-L3阳性的21例中有12例在6个月内被诊断为HCC,而且有6例是通过B超、CT等影像学手段被早期确诊的单发性小肝癌.AFP-L3阴性的62例标本中,6个月内有3例发生肝癌,AFP-L3阳性发生肝癌的危险率增加了11.9倍.结论 AFP-L3与AFP值无相关性,可以作为一个独立肝细胞癌诊断因子.AFP-L3的测定对于AFP升高时良、恶性肝病的鉴别及肝癌的早期预警诊断具有重要意义.     

甲胎蛋白异质体L3对低浓度甲胎蛋白肝癌诊断的临床意义

目的探讨在低浓度甲胎蛋白（AFP）肝病患者中,甲胎蛋白异质体L3（AFP-L3）的百分含量（AFP—L3％）对肝癌的早期诊断和疗效评估的临床意义。方法收集245例血清低AFP含量（5～40ng／m1）的肝病患者样本（其中肝硬化患者100例、肝癌患者145例）,检测AFP—L3％,并对其中100例肝硬化患者和20例肝癌术后患者分别进行3个月和12个月的随访。结果以AFP—L3％≥10％作为阳性判断标准,100例肝硬化患者中阳性为23例,经3个月随访后其中8例诊断为肝癌;145份肝癌患者血清AFP-L3％阳性率为46．2％（67／145）。低浓度AFP肝癌组的AFP—L3％水平显著高于低AFP肝硬化组（t=7．318,P=0．001〈0．01）;20例肝癌患者术后有5例AFP．L3％仍为阳性,其在12个月内的生存率为0,而术后AFP—L3％阴性患者生存概率为15／15。结论AFP—L3％在低浓度AFP肝病患者中对肝癌的早期诊断和术后疗效评估都具有一定的临床意义。     

产甲胎蛋白的胃癌患者血清甲胎蛋白异质体检测分析

产甲胎蛋白胃癌（AFPGC）是指患者血清和癌组织中含有大量甲胎蛋白（AFP）的胃癌。报道最多的是胃的肝样腺癌,但并非产甲胎蛋白的胃癌均为肝样腺癌,AFP是一种特异性肿瘤标志物,是在胚胎发育时期由胚肝及卵黄囊合成的一种糖蛋白,临床上广泛应用于肝细胞肝癌和卵黄囊肿瘤的诊断,近来研究发现其他内胚层肿瘤也有AFP产生,如胃癌、肠癌、胰腺癌、胆囊癌、乳腺癌,其中胃癌相对多见。     

AFP异质体检测及其临床应用价值

目的 :探讨甲胎蛋白 （AFP）异质体检测对原发性肝癌、良性肝病的临床应用价值。方法 :根据小扁豆凝集素对AFP亲和力不同 ,采用亲和免疫电泳印迹法检测AFP L3;化学发光免疫分析法检测AFP。结果 :以AFP L3≥ 15 %作为PHC的诊断标准 ,其敏感性为 91 1% ,与慢性肝病鉴别诊断的特异性为 95 .0 % ,AFP L3含量与血清AFP浓度及原发性肝癌癌灶大小无关。结论 :AFP L3结合AFP检测对原发性肝癌 ,尤其是小肝癌的早期诊断和与良性肝病的鉴别诊断具有重要的临床应用价值。     

血清中甲胎蛋白异质体L3含量与肝癌分期及大小的相关性

目的 探讨原发性肝癌患者血清中的甲胎蛋白异质体L3（AFP-L3）水平与肝癌分期和癌灶大小的相关性.方法 随机选取162例原发性肝癌（PHC）患者的血清,分别进行总甲胎蛋白（AFP）和AFP-L3的纯化和检测,并计算AFP-L3的百分含量后与患者的癌灶大小和肝癌分期进行相关性分析.结果 PHC患者血清AFP-L3百分含量与癌灶大小呈正相关（r=0.332,P=0.009）,与肝癌分期不相关（r=0.121,P=0.189）.结论 AFP-L3的测定对于判断癌灶的大小具有一定的临床意义.     

微量离心柱法分离检测甲胎蛋白异质体(AFP-L3)及其临床意义

目的探讨甲胎蛋白异质体（AFP-L3）在肝细胞癌诊断中的意义。方法应用预装有耦联小扁豆凝集素（LCA）的琼脂糖微量离心柱分离AFP-L3，采用双抗体夹心、化学发光法检测AFP和AFP-L3，并计算AFP—L3值，以AFP〉20μg／L，AFP-L3〉10％作为阳性判断标准。结果肝细胞癌患者血清中AFP、AFP-L3水平明显高于其他肝病患者，P值均〈0．001，肝癌患者以AFP、AFP-L3作为诊断指标的敏感度分别是85．1％、72．3％，特异度分别是55．4％、97．2％；8例肝病患者AFP-L3〉10％，影像诊断未发现肝癌，至少三个月以后确诊肝癌。结论甲胎蛋白异质体（AFP—L3）在肝细胞癌诊断及与良性肝病的鉴别诊断中具有重要价值。     

甲胎蛋白异质体在原发性肝癌诊断中的价值

目的探讨甲胎蛋白异质体（AFP-L3）在诊断原发性肝癌中的临床应用价值。方法收集137例甲胎蛋白阳性患者（〉10ng/mL）血清样本,采用亲和吸附法测定AFP-L3含量,计算AFP-L3占总AFP的比例（%）。结果 AFP-L3比值在肝癌组为17.63±5.78,显著高于肝硬化组（8.24±2.49）、肝炎组（7.12±2.01）和对照组（5.49±1.78）,差异具有统计学意义（P〈0.01）;AFP-L3比值诊断原发性肝癌的ROC曲线下面积分别为0.894。结论 AFP-L3比值可以作为原发性肝癌临床诊断的分子标志物,对临床具有辅助诊断和鉴别诊断价值。     

ELISA法检测甲胎蛋白异质体用于肝癌诊断的探讨

目的应用ELISA检测甲胎蛋白异质体(AFP-L3),并探讨AFP-L3浓度在HCC组与良性肝病组诊断与鉴别诊断的价值。方法用ELISA法检测137例AFP阳性的肝病患者血清AFP-L3浓度,用ROC曲线分析AFP-L3。结果 92例HCC患者AFP-L3浓度为109.04±62.51ng/mL,明显高于45例良性肝病组(25.96±49.43ng/mL)P0.001。HCC的ROC曲线面积为0.819,以AFP-L3浓度37.89ng/mL为临界值,分析HCC患者与良性肝病患者AFP-L3浓度异常的敏感性为83.7%,特异性为88.9%,诊断正确率为85.4%。结论用ELISA法检测AFP-L3浓度对HCC诊断与良性肝病鉴别诊断有较高的临床价值,操作简便,费用低廉。     

Intrahepatic bile duct adenoma in a patient with chronic hepatitis B accompanied by elevation of alpha-fetoprotein

A 51-year-old male patient with chronic hepatitis B was referred to our hospital due to a 1-cm liver nodule on ultrasonography. Alpha-fetoprotein (AFP) was slightly elevated. The nodule showed prolonged enhancement on dynamic liver magnetic resonance imaging and appeared as a hyperintensity on both diffusion-weighted and T2-weighted imaging. The nodule was followed up because it was small and typical findings of hepatocellular carcinoma (HCC) were not observed in the dynamic imaging investigations. However, liver contrast-enhanced ultrasonography performed 1 month later showed enhancement during the arterial phase and definite washout during the delayed phase. Also, AFP had increased to over 200 ng/mL even though AST and ALT were decreased after administering an antiviral agent. He was presumptively diagnosed as HCC and underwent liver segmentectomy. Microscopy findings of the specimen indicated bile duct adenoma. After resection, the follow-up AFP had decreased to within the normal range. This patient represents a case of bile duct adenoma with AFP elevation mimicking HCC on contrast-enhanced ultrasonography.     

离心柱法检测甲胎异质体在预测TACE术后疗效的研究

目的 探讨微量离心柱法检测甲胎蛋白异质体在原发性肝癌患者行肝动脉化疗栓塞术疗效预测的作用.方法 收集28例行TACE术治疗的肝癌患者,通过测定TACE治疗前后AFP和AFP-L3水平,比较血清AFP-L3％变化与TACE术疗效之间的关系.结果 28例行TACE治疗的肝癌患者,11例AFP-L3％下降组中有8例患者疗效好,17例AFP-L3％未下降组中只有5例患者疗效好,差异有统计学意义(x2=4.858,P＜0.05).结论 微量离心柱法检测AFP-L3对于TACE疗效的判断具有重要的临床应用价值.     

亲和电泳酶免疫法快速测定AFP异质体

目的 建立AFP异质体快速检测新方法,以促进其在临床上的普及,方法。方法 采用亲和电泳结合单合隆双抗体夹心酶免疫分析法。结果 本法可在6h内得同结果,灵敏度为1ng/mL,高、中、低浓度AFP样本的结合型AFP（AFP－h),平均CV为5.57%。临床应用表明,总AFP主其异质体（AFP－h）诊断原发性肝癌（PHC）的敏感性分别为73.5%和90.2%,特异性分别为63.5%和89.3%;准确度分别为84.6%和94.3%。结论 本法简便快速、使过去亲和交叉免疫电泳自显影法的70h缩短为6h,而且灵敏度高,重复性好;AFP-h百分比与AFP含量无关;AFP－h诊断PHC的敏感性、特异性和准确度均优于AFP,并具有排除转移性肝癌和肝血管瘤的功能。     

微量离心柱法检测AFP-L3的临床应用研究

目的 探讨微量离心柱法检测甲胎蛋白异质体在肝癌预警及良恶性肝病鉴别诊断中的临床价值.方法 应用装有耦联小扁豆凝集素（LCA）的微量离心柱分离300例肝病患者的AFP-L3,采用化学发光法检测AFP及AFP-L3,计算AFP-L3占总AFP的比率（判断标准以AFP-L3≥10%者为阳性）.结果 AFP-L3在肝细胞癌患者组中的阳性率是95%,在慢性肝病患者组的阳性率是64%,两组患者AFP-L3阳性率差异有统计学意义（x2=134.72,P＜0.01）;AFP-L3阳性的慢性肝病患者与阴性患者肝癌发生率差异有统计学意义（x2=80.158,P＜0.01）;AFP-L3的百分比与AFP浓度不相关（r=0.046,P＞0.05）.结论 微量离心柱法检测甲胎蛋白异质体（AFP-L3）在肝细胞癌诊断、预警及与良恶性肝病的鉴别诊断中具有重要价值.     

Immobilized metal affinity beads for ferritin adsorption

A new metal–chelate adsorbent utilizing N-methacryloyl-(L)-cysteine methyl ester (MAC) was prepared as a metal-chelating ligand. MAC was synthesized by using methacryloyl chloride and L-cysteine methyl ester dihydrochloride. Spherical beads with an average diameter of 150–200 μm were produced by suspension polymerization of 2-hydroxyethyl methacrylate (HEMA) and MAC carried out in an aqueous dispersion medium. Then, Fe³⁺ ions were chelated directly on the beads. Properties such as specific surface area, specific pore volume and ligand occupation were determined. The specific surface area of the beads was found to be 18.9 m²/g. The total pore volume was 2.8 ml/g and represented a porosity over 52%. The average pore size of the poly(HEMA-MAC) beads was 620 nm. Fe³⁺ -chelated beads were used in the adsorption of ferritin from aqueous solutions. Ferritin adsorption increased with increasing ferritin concentration. The maximum ferritin adsorption capacity of the Fe³⁺ -chelated poly(HEMA-MAC) beads (Fe³⁺ loading 0.81 mmol/g) was found to be 3.7 mg/g at pH 4.0 in acetate buffer. The non-specific ferritin adsorption on the poly(HEMA-MAC) beads were 0.4 mg/g. Adsorption behavior of ferritin could be modelled using both the Langmuir and Freundlich isotherms. Adsorption capacity decreased with increasing ionic strength of the binding buffer. Ferritin molecules could be adsorbed and desorbed five times with these adsorbents without noticeable loss in their ferritin adsorption capacity.     

Lens culinaris agglutinin-reactive alpha-fetoprotein, an alternative variant to alpha-fetoprotein in prenatal screening for Down's syndrome.

BACKGROUND: Three serum tests, alpha-fetoprotein (AFP), human chorionic gonadotrophin and unconjugated oestriol, are now widely used for screening for Down's syndrome. Lens culinaris agglutinin-reactive alpha-fetoprotein (AFP-L3) is a variant of alpha-fetoprotein with alpha1-->6 fucose appended to the reducing terminal N-acetylglucosamine. It is the most prominent AFP detected in the serum of patients with hepatocellular carcinoma. METHODS: We investigated microheterogeneities of the carbohydrate chain on AFP in fetal liver tissues, amniotic fluids and maternal sera obtained from pregnancies with Down's syndrome using lectin affinity electrophoresis with four lectins. The percentages of AFP-L3 in maternal sera from 22 Down's syndrome and 227 unaffected pregnancies were determined. RESULTS: Unlike the case with AFP concentration, the percentage of AFP-L3 in maternal serum and amniotic fluid was similar, and apparently not influenced by membrane permeability. Knowing the percentage of AFP-L3 in maternal serum was effective for discriminating between Down's syndrome-affected pregnancies and unaffected pregnancies. The percentage of AFP-L3 in maternal serum identified 55% of Down's syndrome cases with a 5% false-positive rate. CONCLUSIONS: AFP-L3 should be an effective replacement for AFP in prenatal Down's syndrome screening.     

Flexible porous discs by radiation polymerization method for enzyme immunoassay of alpha-fetoprotein

New porous discs for enzyme immunoassay of alpha-fetoprotein (AFP) have been prepared by radiation polymerization of various monomers at low temperature. The activity (optical density) of immobilized anti-AFP disc varied with irradiation temperature, anti-AFP concentration, and the hydrophilicity of monomer, in which copolymerization of hydrophilic 2-hydroxyethyl methacrylate and hydrophobic monomers at low temperature below 0 degrees C gave a high activity. The immobilized anti-AFP disc was flexible and had a porous structure. The immobilized anti-AFP discs in dry state are convenient for storage. The minimum serum volume in the assay was 5 microliter. A good correlation (r = 0.98) was noted between AFP concentrations measured by ratio immunoassay and enzyme immunoassay with immobilized anti-AFP disc. The mean recovery of AFP (16-80 ng) added to serum was 95-110%.