血清学指标在非酒精性脂肪性肝病诊断中的意义

万 艳， 常剑波， 白艳霞， 李倩楠， 戴光荣

(延安大学附属医院， 陕西 延安 716000)

血清学指标在非酒精性脂肪性肝病诊断中的意义

万 艳， 常剑波， 白艳霞， 李倩楠， 戴光荣

(延安大学附属医院， 陕西 延安 716000)

近年来，脂肪性肝病发病率呈明显上升趋势，肝脏活组织检查是诊断脂肪肝的金标准，但有其不可避免的缺点。目前尚缺乏一种方便、价廉、准确、适用于临床的无创诊断方法。主要回顾了多项血清学指标在非酒精性脂肪性肝病(NAFLD)诊断中的意义，认为血清学指标中肝酶、AST与ALT比值、血清铁蛋白、血清硒、尿酸、高空腹胰岛素浓度、视黄醇结合蛋白4、细胞角蛋白18、PNPLA3基因、TM6SF2基因在NAFLD的诊断中有较大的价值，而IL-28B对NAFLD的诊断价值存在较大争议，尚需更多临床试验证实。相信在不久的将来，多项血清指标组合会成为较准确，且适用于临床的早期诊断NAFLD、肝脂肪变性程度及肝纤维化程度的无创方法。

脂肪肝； 生物学标记； 诊断； 综述

近年来，脂肪肝发病率呈明显上升趋势，已成为我国第一大非感染性慢性肝病，其中，以非酒精性脂肪性肝病(NAFLD)最多见，其疾病谱包括单纯性非酒精性脂肪肝(NAFL)、非酒精性脂肪性肝炎(NASH)及相关肝硬化和肝癌[1]。有研究表明NAFLD主要与肥胖、饮食习惯及基因有关[2]。据统计，25%的脂肪肝患者的肝脏逐渐纤维化，6%的患者最终进展为肝硬化，生命受到威胁[3]。NAFLD是可逆性疾病，尽早干预和治疗可完全恢复。因此，NAFLD患者的早期诊断是关键。虽然，肝脏活组织检查是诊断NAFLD的金标准，但肝脏穿刺为有创操作，重复性差，且存在取样误差；影像学检查价格昂贵，不便于随访；而血清学检查简便无创，对NAFLD的诊断意义备受瞩目。

1 实验室检查

1.1 肝脏酶学 肝脏酶学中血清ALT、AST、ALP、GGT等常用于普通人群肝病的筛查。一项来自英国的横断面研究[4]显示，NAFLD为体检人群肝酶异常的主要原因。我国一项研究[5]表明，肥胖成人的血清ALT水平与TG含量独立相关，可作为NAFLD程度的预测指标。Maximos等[6]研究也表明，NAFLD患者的血浆转氨酶升高主要取决于胰岛素抵抗程度和TG含量，且ALT升高者肝细胞脂肪变性程度更严重。然而，Cruz等[7]以腹部B超检查为对照，证实AST、ALT、GGT、胰岛素抵抗内稳态模型联合B超可用于肝脏脂肪变性程度的评估，且在显示脂肪变性程度方面，AST比ALT更有价值。已知GGT早已纳入脂肪肝参数系统[8]。最新一项研究[9]纳入35例NAFLD患者，通过肝活组织检查复查肝脏病变情况显示，血清AST和GGT水平升高与NAFLD活动度评分恶化高度相关。Kawamura等[10]建立了一个同时纳入AST和ALT等指标的评分系统，可准确预测NASH患者的肝纤维化分期，且预测进展期纤维化(≥3期)的受试者工作特征曲线下面积(AUC)为0.909，优于其他几种纤维化评分系统。

1.2 AST与ALT比值(AAR) 早有报道称AAR参与了肝脂肪变性指数系统[11]、肝脂评分系统[12]、肝纤维化评分系统[13]。最近，Fallatah等[14]通过评估肝纤维化用的FibroScan检查，也证实了AAR与FibroScan之间呈高度正相关。

1.3 血清铁蛋白 2011年Manousou等[15]研究认为血清铁蛋白是NASH的独立危险因素。后来，Kowdley等[16]证实当血清铁蛋白>1.5倍正常值上限(ULN)可用于诊断NASH，并可预测NAFLD相关肝纤维化。近期，马会民等[17]选取243例NAFLD患者的研究结果显示血清铁蛋白水平升高，认为其可能通过影响肝脏脂质代谢参与NAFLD进展。与此同时，冯红萍等[18]纳入250例NAFLD患者，并根据患者首诊时CT检查结果将其分为轻、中、重3组，对3组患者的血清铁蛋白值进行比较分析，结果提示血清铁蛋白在轻度脂肪性肝病时即可较早地反映肝功能损伤，比ALT、AST更灵敏，并认为血清铁蛋白可作为NAFLD病情进展程度的独立预测指标。Goh等[19]应用AST水平、血清铁蛋白水平、BMI、血小板计数、2型糖尿病和高血压等变量建立的评分系统用于预测NAFLD患者发生NASH风险的AUC为0.81。

1.4 血清硒 硒是人类必不可少的微量元素，主要来自空气、食物和水。一些动物研究[20-22]表明硒暴露能引起血清肝酶水平增加及Kupffer细胞激活，其肝组织胰岛素抵抗和甘油三酯浓度均高于对照组。随后，Stranges等[23]进行流行病学研究发现，高硒暴露可能导致代谢异常，包括血脂异常、2型糖尿病或胰岛素抵抗。最近，在中国上海，一项纳入8550例研究对象的横断面研究[24]显示血浆硒水平与NAFLD患病率呈正相关，且血浆硒水平升高者的低密度脂蛋白胆固醇、空腹血糖、糖化血红蛋白、ALT、AST和GGT水平均较健康人群升高(P值均< 0.05)。由此可见，硒暴露可能会导致NAFLD发生的风险增加。

1.5 尿酸 尿酸是嘌呤在肝脏代谢的最终产物，其生成和排泄决定了血清尿酸的水平。目前有关尿酸在NAFLD中的发生机制的主要假说是“二次打击学说“，大量研究显示高血清尿酸与NAFLD的发生与发展密切相关。Sirota等[25]也认为尿酸浓度升高是NAFLD的独立危险因素，且NAFLD损伤严重程度随尿酸的增高而加重。Yuan等[26]证实了血清尿酸水平每升高1 mg/dl，导致 NAFLD的风险增加21%。李韶丰等[27]指出控制尿酸有望成为NAFLD综合治疗手段之一，早期对高尿酸血症合并NAFLD患者综合干预至关重要。一项82 608例成人参与的研究[28]表明，血清尿酸和ALT水平呈显著正相关，具有量效关系。1.6 空腹胰岛素浓度 大量研究证实胰岛素抵抗及2型糖尿病可促进NAFLD的发展，空腹胰岛素浓度已参与肝脂评分系统[12]。但是，在发展成2型糖尿病之前，葡萄糖代谢和NAFLD患者肝组织病变之间的关系并不为众所周知。Masuda等[29]纳入103例NAFLD患者研究在糖尿病前期，葡萄糖代谢与肝纤维化是否有相关性，结果证实纤维化3期组的女性数量、年龄、AAR、空腹胰岛素浓度、糖化血红蛋白、透明质酸和Ⅳ型胶原蛋白7s比纤维化0～2期组明显更高，认为在NAFLD发展至2型糖尿病之前，高空腹胰岛素浓度是预测肝纤维化严重程度的关键。

2 生物化学标志物

2.1 视黄醇结合蛋白(retinol-binding protein，RBP)4 RBP-4是视黄醇类结合蛋白家族中的一员，主要由肝脏分泌，脂肪组织也少量分泌，主要与维生素A的储存、代谢和转运有关。研究认为RBP-4与代谢综合征、胰岛素抵抗、2型糖尿病、慢性肝病、慢性肾病、心脑血管疾病均有关，而这些大多为NAFLD的高危因素，故认为RBP-4与NAFLD发病有关。早在2006年，Graham等[30]证实了血清RBP-4水平与胰岛素抵抗程度呈正相关。我国孙立山等[31]也认为血清RBP-4是NAFLD发病相关的独立危险因素。后来，Chang等[32]研究认为RBP-4可作为腹部肥胖的一个标志物，且随着肝脏脂肪含量的增加，BMI、腰围、腰臀比、TG、ALT、AST、GGT也逐渐升高，高密度脂蛋白逐渐下降；而总胆固醇、低密度脂蛋白、ALP无显著变化。Liu等[33]通过动物实验证实RBP-4 mRNA在NAFLD模型中异常升高，与肝TG积累呈正相关，并认为可能与线粒体含量减少和线粒体脂肪酸β-oxidation受损有关。

2.2 细胞角蛋白(cytokeratin,CK)18 CK-18与细胞凋亡相关，当细胞坏死时，血液中CK-18浓度随之升高，而NAFLD的进展与肝实质细胞脂肪变性、坏死和凋亡密切相关。Maliken等[34]研究表明血清CK-18及其裂解物的水平随着肝细胞坏死、凋亡程度增加而升高，且与肝细胞坏死水平呈正相关。Castera等[35]也表明CK-18的主要价值在于可提示NASH的存在，并能评价炎症程度及纤维化的发生。Chalasani等[36]总结了一些后续研究和荟萃分析，证实血清CK-18评估NASH的敏感度和特异度分别为78%和87%，其AUC为0.82。Kazankov等[37]联合sCD163和CK-18，认为NAFLD/NASH患者细胞凋亡可能与巨噬细胞活化有关。

NAFLD具有遗传倾向，Feldstein等[38]报道CK-18有望成为NASH患儿非侵入性诊断标志物之一。随后，李娜等[39]研究也证实了这一观点。然而，由于不同实验研究所所用的特定临界值不同，缺乏统一标准，美国肝病学会指南并未将CK-18作为临床常用的检测指标。近期，Zwolak等[40]同时检测了RBP-4和CK-18，结果认为RBP-4与肥胖的NAFLD 患者密切相关，CK-18与非肥胖的NAFLD患者密切相关。

大量研究证实，炎症反应在NAFLD的发展中起关键作用，炎性标志物有IL-6、超敏C反应蛋白(hs-CRP)、脂联素、TNFα，其中脂联素具有抗炎作用[41]，其水平下降可使NAFLD发展至NASH[42]。TNFα则通过参与氧化应激和脂质氧化介导肝脏炎症反应，从而导致肝损伤。蓝常明等[43]将98例轻、中、重度NAFLD患者和38例作为对照组的健康体检者进行血清TNFα检测，Spearman相关分析结果显示血清TNFα水平与NAFLD病情严重等级呈正相关(r=0.516，P<0.05)，且在NAFLD发展、NASH及肝纤维化中起重要作用。

3 遗传基因

3.1 PNPLA3基因 PNPLA3基因位于人类第22号染色体的长臂上，可翻译出一条包含481个氨基酸的跨膜多肽链，在脂肪组织和肝脏中高表达，其表达主要受营养状况的影响，基因的多态性影响了PNPLA3的表型，从而易引起能量代谢的紊乱。PNPLA3 rs738409 G可降低脂联素水平，已在多个国家被证明与NAFLD及脂肪变性程度密切相关[44]。最近，一项基于肝活组织病理基础的多中心研究[45]显示，PNPLA3 rs738409基因多态性可使肝脏脂肪含量增加及肝纤维化加重。同时，一项针对日本的经肝活组织检查证实为NAFLD患者的研究[46]认为，严重的肝纤维化和PNPLA3 rs738409基因多态性是NAFLD患者发生肝细胞癌的独立危险因素。由此可见，PNPLA3与NAFLD患者的肝脂肪含量、脂肪变性程度、肝纤维化，甚至肝癌的发生均有密切关系。

3.2 TM6SF2基因 TM6SF2基因位于第19号染色体上，编码一段由351个氨基酸构成的蛋白，主要在脑组织、肾脏、肝脏及小肠表达，其中在小肠组织表达最高。2014年Kozlitina等[47]首次报道了TM6SF2 rs58542926与NAFLD易感的相关性，TM6SF2 rs58542926在p.E167K位点上将谷氨基酸转换成赖氨基酸，且AST和ALT与这种改变呈高度正相关。近日，一项针对中国汉族人群关于PNPLA3 rs738409、rs2294918、NCAN rs2228603、GCKR rs780094、LYPLAL1 rs12137855和TM6SF2 rs58542926的全基因组关联研究证实了TM6SF2和PNPLA3一样，是中国NAFLD患者最重要的危险等位基因[48]。最新研究[45]认为TM6SF2 rs58542926主要与NAFLD患者肝脂肪堆积有关，与肝纤维化联系不大。

Krawczyk等[49]联合检测PNPLA3 rs738409和TM6SF2 rs58542926，结果证实在含有PNPLA3 rs738409的患者中，TM6SF2变体的存在会加重血清转氨酶升高，并进一步加重肝脏脂肪变性。

3.3 IL-28B IFN家族包括Ⅰ型(IFNα、IFNβ等)、Ⅱ型(IFNγ)和Ⅲ型(IFNλs，包括IFNλ1、IFNλ2和IFNλ3，又分别称为IL-29、IL-28A和IL-28B)。IL-28B即IFNλ3，其基因的编码位于人类第19号染色体上(19q13.13)，其单核苷酸多态性可以影响基因转录及翻译，进而影响IFNλ3的合成。大量研究也证实了IL-28B与病毒性肝炎及其相关肝硬化、肝癌的发生发展、抗病毒治疗的应答反应及预后密切相关。近年来，随着NAFLD患者的增多，越来越多的研究者开始探索IL-28B与NAFLD的相关性。有研究发现IL-28B基因多态性与肝脏脂肪变性[50]、炎症反应[51]和肝纤维化[52]的严重程度有关。Petta等[53]认为在NAFLD患者中，IL-28B rs12979860 CC基因型和PNPLA3 rs738409 GG与肝损伤的严重程度相关。有研究[54]表明，在非肥胖的NAFLD患者中，携带IL-28B rs12979860 CC基因型的患者肝小叶炎性反应和F2～F4期肝纤维化患病率比携带TT/TC基因型的患者高(28/46和9/48，P<0.001)，而在肥胖的NAFLD患者中却未发现这种差异[55]，并证实IL-28B rs12979860位点与NAFLD无相关性。Hashemi等[56]针对伊朗人的一项研究认为IL-28B rs8099917位点也不是NAFLD的危险因素。李江文[57]收集190例NAFLD患者和183例正常人的血液标本，采用多重高温连接酶检测反应技术对IL-28B rs12979860、IL-28B rs8099917两位点进行基因检测，结果也证实IL-28B rs12979860、IL-28B rs8099917两位点与NAFLD无明显相关性。目前，关于IL-28B与NAFLD相关性的研究相对较少，尚需大量研究加以证实。

Severson等[44]认为遗传因素及基因多态性导致NAFLD及其最终结果，这些基因是未来提高诊断及管理水平的关键。

4 目前已存在的血清指标组合在NAFLD中的应用

诊断脂肪变性的参数系统有：脂肪变性测试系统[58]，包括6个变量(肝硬度、FibroTest指数、BMI、TC、TG和血糖)；脂肪肝参数[8]，包括4个变量(BMI、腰围、TG和GGT)；脂质积累量[59]，包括3个变量(腰围、TG及性别)；肝脂肪变性指数系统[11]，包括3个变量(AAR、BMI和2型糖尿病)；NAFLD肝脂评分系统[12]，包括5个变量(代谢综合征、2型糖尿病、空腹胰岛素水平、AST及AAR)，可预测肝脏脂肪的百分比。

用于肝纤维化评价的系统包括：NAFLD肝纤维化评分、BARD评分、NIKEI、NASH-CRN回归得分、AST与PLT比值指数、FIB-4指数、King′s评分、GUCI、Lok指数、Forns分数和肝纤维化血清学指标。Lykiardopoulos等[60]纳入158例NAFLD患者，其中38例处于肝纤维化早期阶段，以肝活组织检查结果为金标准，研究表明FIB-4(包括血小板、ALT、AST和年龄)和King′s评分(年龄、AST、血小板)诊断肝纤维化的AUC分别为0.84和0.83；并用创建的包括年龄、空腹血糖、透明质酸等指标的预测早期肝纤维化的模型(LINKI-1)和包括这些指标合并血小板计数，且用数学方法夸大其反面影响的替代模型(LINKI-2)证实，在总群中LINKI-1和LINKI-2模型的AUC高达0.91和0.89。同时有研究[61]表明，通过多项血清指标组合的无创模型虽然诊断NAFLD的效能差，但排除肝硬化的准确性>90%。

5 展望

综上所述，血清学指标中肝酶、AAR、血清铁蛋白、血清硒、尿酸、高空腹胰岛素浓度、PNPLA3、TM6SF2、RBP-4、CK-18对NAFLD的诊断价值值得肯定，而IL-28B对NAFLD的诊断价值存在较大争议，尚需更多临床试验证实。并且多项血清指标组合在评价肝脂肪变性、肝纤维化及肝硬化方面的研究还处于初期阶段，尚不能有效的对NAFLD进行全面的评估。相信通过大量的研究，更全面的血清指标组合将会问世，其诊断NAFLD的价值或许有望取代肝脏活组织病理检查。

[1] HAAS JT, FRANCQUE S, STAELS B. Pathophysiology and mechanisms of nonalcoholic fatty liver disease[J]. Annu Rev Physiol, 2016, 78(1): 181-205.

[2] NELSON JE, HANDA P, AOUIZERAT B, et al. Increased parenchymal damage and steatohepatitis in Caucasian non-alcoholic fatty liver disease patients with common IL1B and IL6 polymorphisms[J]. Aliment Pharmacol Ther, 2016, 44(11-12): 1253-1264.[3] WU XM. Detection of fatty liver disease in people undergoing physical examination and related factors: an analysis of 867 cases[J]. Jilin Med J, 2012, 33(6): 1154-1155. (in Chinese) 吴晓铭. 867例健康体检中脂肪肝检验结果与相关因素分析[J]. 吉林医学, 2012,33(6): 1154-1155.

[4] ARMSTRONG MJ, HOULIHAN DD, BENTHAM L, et al. Presence and severity of non-alcoholic fatty liver disease in a large prospective primary care cohort [J]. J Hepatol, 2012, 56(1): 234-240.

[5] CHEN Z, HAN CK, PAN LL, et al. Serum alanine aminotransferase independently correlates with intrahepatic triglyceride contents in obese subjects[J]. Dig Dis Sci, 2014, 59(10): 2470-2476.

[6] MAXIMOS M, BRIL F, SANCHEZ PP, et al. The role of liver fat and insulin resistance as determinants of plasma aminotransferase elevation in nonalcoholic fatty liver disease[J]. Hepatology, 2015, 61(1): 153-160.

[7] CRUZ MA, CRUZ JF, MACENA LB, et al. Association of the nonalcoholic hepatic steatosis and its degrees with the values of liver enzymes and homeostasis model assessment-insulin resistance index [J].Gastroenterology Res, 2015, 8(5): 260-264.

[8] BEDOGNI G, BELLENTANI S, MIGLIOLI L, et al. The fatty liver index: a simple and accurate predictor of hepatic steatosis in the generalpopulation[J]. BMC Gastroenterol, 2006， 6(2): 33-38.

[9] CHAN W K, IDA N H, CHEAH P L, et al. Progression of liver disease in non-alcoholic fatty liver disease: a prospective clinicopathological follow-up study[J]. J Dige Dis, 2014, 15(10): 545-552.

[10] KAWAMURA Y, IKEDA K, ARASE Y, et al. New discriminant score to predict the fibrotic stage of non-alcoholic steatohepatitis in Japan[J]. Hepatol Int, 2015, 9(2): 269-277.

[11] LEE JH, KIM D, KIM HJ, et al. Hepatic steatosis index: a simple screening tool reflecting nonalcoholic fatty liver disease[J]. Dig Liver Dis, 2010, 42(7): 503-508.

[12] KOTRONEN A, PELTONEN M, HAKKARAINEN A, et al. Prediction of non-alcoholic fatty liver disease and liver fat using metabolic and genetic factors[J]. Gastroenterology， 2009, 137(3): 865-872.

[13] RUFFILLO G, FASSIO E, ALVAREZ E, et al. Comparison of NAFLD fibrosis score and BARD score in predicting fibrosis in nonalcoholic fatty liver disease[J]. J Hepatol, 2011, 54(1): 160-163.

[14] FALLATAH HI, AKBAR HO, FALLATAH AM, et al. Fibroscan compared to FIB-4, APRI, and AST/ALT ratio for assessment of liver fibrosis in saudi patients with nonalcoholic fatty liver disease[J]. Hepat Monm, 2016, 16(7): e38346.

[15] MANOUSOU P, KALAMBOKIS G, GRILLO F, et al. Serum ferritin is a discriminant marker for both fibrosis and inflammation in histologically proven non-alcoholic fatty liver disease patients[J]. Liver Int, 2011, 31(5): 730-739.

[16] KOWDLEY KV, BELT P, WILSON LA, et al. Serum ferritin is an independent predictor of histologic severity and advanced fibrosis in patients with nonalcoholic fatty liver disease[J]. Hepatology, 2012, 55(1): 77-85.

[17] MA HM, BAI PP, ZHANG LZ, et al. Change in serum ferritin level and its significance in patients with non-alcoholic fatty liver disease[J]. Shandong Med J, 2016, 52(29): 42-44. (in Chinese) 马会民, 白萍萍, 张连仲, 等. 非酒精性脂肪肝患者血清铁蛋白水平变化及意义[J]. 山东医药, 2016, 52(29): 42-44.

[18] FENG HP, REN YL. Signiifcance of serum ferritin in patients with non-alcoholic fatty liver disease[J/CD]. Chin J Liver Dis：Electronic Edition, 2016, 8(2): 113-115. (in Chinese) 冯红萍, 任艳玲. 非酒精性脂肪性肝病患者血清铁蛋白检测的意义[J/CD]. 中国肝脏病杂志: 电子版, 2016, 8(2): 113-115.

[19] GOH GB, ISSA D, LOPEZ R, et al. The development of a non-invasive model to predict the presence of non-alcoholic steatohepatitis in patients with non-alcoholic fatty liver disease[J]. J Gastroenterol Hepatol, 2016, 31(5): 995-1000.

[20] HASEGAWA T, TANIGUCHI S, MIHARA M, et al. Toxicity and chemical form of selenium in the liver of mice orally administered selenocystine for 90 days[J]. Arch Toxicol, 1994, 68(2): 91-95.

[21] KOODZIEJCZYK L, PUT A, GRZELA P, et al. Liver morphology and histochemistry in rats resulting from ingestion of sodium selenite and sodium fluoride[J]. Fluoride, 2000, 33: 6-16.

[22] MUELLER AS, KLOMANN SD, WOLF NM, et al. Redox regulation of protein tyrosine phosphatase 1B by manipulation of dietary selenium affects the triglyceride concentration in rat liver [J]. J Nutr, 2008, 138(12): 2328-2336.

[23] STRANGES S, NAVAS-ACIEN A, RAYMAN MP, et al. Selenium status and cardiometabolic health: state of the evidence[J]. Nutr Metab Cardiovasc Dis, 2010, 20(10): 754-760.

[24] YANG Z, YAN C, LIU G, et al. Plasma selenium levels and nonalcoholic fatty liver disease in Chinese adults: a cross-sectional analysis[J]. Sci Rep, 2016, 6: 37288.

[25] SIROTA J C, MCFANN K, TARGHER G, et al. Elevated serum uric acid levels are associated with non-alcoholic fatty liver disease independently of metabolic syndrome features in the United States: liver ultrasound data from the National Health and Nutrition Examination Survey [J]. Metabolism, 2013, 62(3): 215-216.

[26] YUAN H, YU C, LI X, et al. Serum uric acid levels and risk of metabolic syndrome: a dose-response meta-analysis of prospective studies[J]. J Clin Endocrinol Metab, 2015, 100(11): 4198-4207.

[27] LI SF, LIAO XH, YE JZ, et al. Role of uric acid in the development and progression of nonalcoholic fatty liver disease[J]. J Clin Hepatol, 2016, 32(9): 1814-1818. (in Chinese) 李韶丰, 廖献花, 叶俊钊, 等. 尿酸在非酒精性脂肪性肝病发生发展中的作用[J]. 临床肝胆病杂志, 2016, 32(9): 1814-1818.

[28] ZELBERSAGI S, BENASSULI O, RABINOWICH L, et al. The association between serum levels of uric-acid and alanine aminotransferase in a population-based cohort[J]. Liver Int, 2015, 35(11): s750-s751.

[29] MASUDA K, NOGUCHI S, ONO M, et al. High fasting insulin concentrations may be a pivotal predictor for the severity of hepatic fibrosis beyond the glycemic status in nonalcoholic fatty liver disease patients before development of diabetes mellitus[J]. Hepatol Res, 2016. [Epub ahead of print]

[30] GRAHAM TE, YANG Q, BLUHER M, et al. Retinol-binding protein 4 and insulin resistance in lean, obese, and diabetic subjects[J]. N Engl J Med, 2006, 354(24): 2552-2563.

[31] SUN LS, FAN LY, WANG N, et al. The correlation between serum RBP-4 and nonalcoholic fatty liver disease[J]. Lab Med, 2011, 26(9): 602-605. (in Chinese) 孙立山, 范列英, 王暖, 等. 血清视黄醇结合蛋白4和非酒精性脂肪性肝病的相关性[J]. 检验医学, 2011, 26(9): 602-605.

[32] CHANG X, YAN H, BIAN H, et al. Serum retinol binding protein 4 is associated with visceral fat in human with nonalcoholic fatty liver disease without known diabetes: a cross-sectional study [J]. Lipids Health Dis, 2015, 14: 28.

[33] LIU Y, MU D, CHEN H, et al. Retinol-binding protein 4 induces hepatic mitochondrial dysfunction and promotes hepatic steatosis[J].J Clin Endocrinol Metab, 2016,101(11): 4338-4348.

[34] MALIKEN BD, NELSON JE, KLINTWORTH HM, et al. Hepatic reticuloendothelial system cell iron deposition is associated with increased apoptosis in nonalcoholic fatty liver disease[J]. Hepatology, 2013, 57(5): 1806-1813.

[35] CASTERA L, VILGRAIN V, ANGULO P. Noninvasive evaluation of NAFLD[J]. Nat Rev Gastroenterol Hepatol, 2013, 10(11): 666-675.

[36] CHALASANI N, YOUNOSSI Z, LAVINE JE, et al. The diagnosis and management of non-alcoholic fatty liver disease: practice guideline by the American Gastroenterological Association, American Association for the Study of Liver Diseases, and American College of Gastroenterology[J]. Gastroenterology, 2012, 142(7): 15921-609.

[37] KAZANKOV K, BARRERA F, M∅LLER HJ, et al. The macrophage activation marker sCD163 is associated with morphological disease stages in patients with non-alcoholic fatty liver disease [J]. Liver Int, 2016, 36(10): 1549-1557.

[38] FELDSTEIN AE, ALKHOURI N, DE VR, et al. Serum cytokeratin-18 fragment levels are useful biomarkers for nonalcoholic steatohepatitis in children[J]. Am J Gastroenterol, 2013, 108(9): 1526-1531.

[39] LI N, ZHOU MJ, CHEN N. Expression and significance of serum TNF-α and CK-18 levels in children with non-alcoholic steatohepatitis[J]. Chin Gen Pract, 2014, 17(15): 1723-1727.(in Chinese) 李娜, 周明锦, 陈楠. 非酒精性脂肪性肝炎患儿血清肿瘤坏死因子α与细胞角质蛋白18的表达及意义研究[J]. 中国全科医学, 2014, 17(15): 1723-1727.

[40] ZWOLAK A, SZUSTER-CIESIELSKA A, DANILUK J, et al. Chemerin, retinol binding protein-4, cytokeratin-18 and transgelin-2 presence in sera of patients with non-alcoholic liver fatty disease [J]. Ann Hepatol, 2016, 15(6): 862-869.

[41] KADOWAKI T, YAMAUCHI T. Adiponectin and adiponectin receptors.[J]. Endocrine Reviews, 2005, 26(3): 439-451.[42] POLYZOS SA, TOULIS KA, GOULIS DG, et al. Serum total adiponectin in nonalcoholic fatty liver disease: a systematic review and meta-analysis[J]. Metabolism, 2011, 60(3): 313-326.

[43] LAN CM. Measurements of tumor necrosis factor-α and interleukin-6 and their significance in patients with varying degrees of non-alcoholic fatty liver disease[J]. Mod Digest Interv, 2016, 21(1): 85-87. (in Chinese) 蓝常明. 不同程度非酒精性脂肪肝患者肿瘤坏死因子-α、白介素-6的检测及意义[J]. 现代消化及介入诊疗, 2016, 21(1): 85-87.

[44] SEVERSON TJ, BESUR S, BONKOVSKY HL. Genetic factors that affect nonalcoholic fatty liver disease: a systematic clinical review.[J]. World J Gastroenterol, 2016, 22(29): 6742-6756.

[45] KRAWCZYK M, RAU M, SCHATTENBERG JM, et al. Combined effects of the TM6SF2 rs58542926, PNPLA3 rs738409 and MBOAT7 rs641738 variants on NAFLD severity: multicentre biopsy-based study[J]. J Lipid Res, 2017, 58(1): 247-255.

[46] SEKO Y, SUMIDA Y, TANAKA S, et al. Development of hepatocellular carcinoma in Japanese patients with biopsy-proven non-alcoholic fatty liver disease: association between PNPLA3 genotype and hepatocarcinogenesis/fibrosis progression[J]. Hepatol Res, 2016. [Epub ahead of print][47] KOZLITINA J, SMAGRIS E, STENDER S, et al. Exome-wide association study identifies a TM6SF2 variant that confers susceptibility to nonalcoholic fatty liver disease[J]. Nat Genet， 2014， 46(4): 352-356.

[48] WANG X, LIU Z, WANG K, et al. Additive effects of the risk alleles of PNPLA3 and TM6SF2 on non-alcoholic fatty liver disease (NAFLD) in a Chinese population[J]. Front Genet, 2016, 7: 140.

[49] KRAWCZYK M, RAU M, SCHATTENBERG J, et al. Combined effects of the prosteatotic TM6SF2 and PNPLA3 variants on severity of NALFD: multicentre biopsy-based study in German patients[J]. Z Gastroenterol, 2015, 53(12): 1391-1602.

[50] CAI T, DUFOUR JF, MUELLHAUPT B, et al. Viral genotype-specifi c role of PNPLA3, PPARG, MTTP, and IL28B in hepatitis C virus-associated steatosis[J]. J Hepatol, 2011, 55(3): 529-535.

[51] ABE H, OCHI H, MAEKAWA T, et al. Common variation of IL28 affects gamma-GTP levels and inflammation of the liver in chronically infected hepatitis C virus patients[J]. J Hepatol, 2010, 53(3): 439-443.

[52] MARABITA F, AGHEMO A, de NICOLA S, et al. Genetic variation in the interleukin-28B gene is not associated with fibrosis progression in patients with chronic hepatitis C and known date of infection[J]. Hepatology, 2011, 54(4): 1127-1134.

[53] PETTA S, GRIMAUDO S, CAMMC, et al. IL28B and PNPLA3 polymorphisms affect histological liver damage in patients with non-alcoholic fatty liver disease [J]. J Hepatol, 2012, 56(6): 1356-1362.

[54] PETTA S, CRAXI A. Reply to: “IL28B rs12979860 is not associated with histologic features of NAFLD in a cohort of Caucasian North American patients”[J]. J Hepatol,2013, 58(2): 403-404.

[55] GARRETT ME, ABDELMALEK MF, ASHLEY-KOCH A, et al. IL28B rs12979860 is not associated with histologic features of NAFLD in a cohort of Caucasian North American patients[J]. J Hepatol, 2013, 58(2): 402-403.

[56] HASHEMI M, MOAZENI-ROODI A, BAHARI A, et al. A tetra-primer amplification refractory mutation system-polymerase chain reaction for the detection of rs8099917 IL28B genotype[J]. Nucleosides Nucleotides Nucleic Acids, 2012, 31(1): 55-60.

[57] LI JW. Association between polymorphisms of rs12979860 and rs8099917 in IL28B gene and non-alcoholic fatty liver disease[D]. Dalian： Dalian Med Univ, 2015. (in Chinese) 李江文. IL28B 基因 rs12979860、rs8099917多态性与NAFLD的相关性研究[D]. 大连： 大连医科大学, 2015.

[58] POYNARD T, RATZIU V, NAVEAU S, et al. The diagnostic value of bio-markers( SteatoTest) for the prediction of liver steatosis[J]. CompHepatol, 2005, 4(23): 10-17.

[59] BEDOGNI G, KAHN HS, BELLENTANI S, et al. A simple index of lipidoveraccumulation is a good marker of liver steatosis[J]. BMC Gas-troenterol, 2010, 10(25) : 98-104.

[60] LYKIARDOPOULOS B, HAGSTRÖM H, FREDRIKSON M, et al. Development of serum marker models to increase diagnostic accuracy of advanced fibrosis in nonalcoholic fatty liver disease: the new LINKI algorithm compared with established algorithms[J].PLoS One, 2016, 11(12): e0167776.

[61] FAN JG. Research advances in non-alcoholic fatty liver disease: a review of current status and prospect[J]. J Clin Hepatol, 2015, 31(7): 999-1001. (in Chinese) 范建高. 非酒精性脂肪性肝病的研究现状与展望[J]. 临床肝胆病杂志, 2015, 31(7): 999-1001.

引证本文：WAN Y, CHANG JB, BAI YX, et al. Significance of serological markers in diagnosis of nonalcoholic fatty liver disease[J]. J Clin Hepatol, 2017, 33(5): 963-968. (in Chinese) 万艳， 常剑波， 白艳霞， 等. 血清学指标在非酒精性脂肪性肝病诊断中的意义[J]. 临床肝胆病杂志, 2017, 33(5): 963-968.

(本文编辑：朱 晶)

Significance of serological markers in diagnosis of nonalcoholic fatty liver disease

WANYan,CHANGJianbo,BAIYanxia,etal.

(Yan′anUniversityAffiliatedHospital,Yan′an，Shaanxi716000,China)

In recent years, the incidence rate of fatty liver tends to increase markedly, and liver biopsy is the gold standard for the diagnosis of fatty liver, but it has some inevitable shortcomings. At present, there lacks a convenient, cheap, and accurate noninvasive diagnostic method for clinical practice. This article reviews the significance of various serological markers in the diagnosis of nonalcoholic fatty liver disease (NAFLD) and points out that liver enzyme, aspartate aminotransferase/alanine aminotransferase ratio, serum ferritin, serum selenium, uric acid, high fasting insulin level, retinol-binding protein-4, cytokeratin-18, PNPLA3 gene, and TM6SF2 gene have great significance in the diagnosis of NAFLD. There are still controversies over the value of interleukin-28B in the diagnosis of NAFLD, and more clinical trials are needed. We believe that in the near future, a combination of various serum markers may become an accurate noninvasive method for the diagnosis of NAFLD and the assessment of the degree of liver fatty degeneration and fibrosis.

fatty liver； biological markers； diagnosis； review

10.3969/j.issn.1001-5256.2017.05.037

2016-11-24；

2016-12-29。

万艳(1990-)，女，主要从事慢性肝病的诊疗研究。

戴光荣，电子信箱：daiguangrong6810@sina.cn。

R575.5

A

1001-5256(2017)05-0963-06