萬(wàn) 艷， 常劍波， 白艷霞， 李倩楠， 戴光榮

(延安大學(xué)附屬醫(yī)院， 陜西 延安 716000)

血清學(xué)指標(biāo)在非酒精性脂肪性肝病診斷中的意義

萬(wàn) 艷， 常劍波， 白艷霞， 李倩楠， 戴光榮

(延安大學(xué)附屬醫(yī)院， 陜西 延安 716000)

近年來(lái)，脂肪性肝病發(fā)病率呈明顯上升趨勢(shì)，肝臟活組織檢查是診斷脂肪肝的金標(biāo)準(zhǔn)，但有其不可避免的缺點(diǎn)。目前尚缺乏一種方便、價(jià)廉、準(zhǔn)確、適用于臨床的無(wú)創(chuàng)診斷方法。主要回顧了多項(xiàng)血清學(xué)指標(biāo)在非酒精性脂肪性肝病(NAFLD)診斷中的意義，認(rèn)為血清學(xué)指標(biāo)中肝酶、AST與ALT比值、血清鐵蛋白、血清硒、尿酸、高空腹胰島素濃度、視黃醇結(jié)合蛋白4、細(xì)胞角蛋白18、PNPLA3基因、TM6SF2基因在NAFLD的診斷中有較大的價(jià)值，而IL-28B對(duì)NAFLD的診斷價(jià)值存在較大爭(zhēng)議，尚需更多臨床試驗(yàn)證實(shí)。相信在不久的將來(lái)，多項(xiàng)血清指標(biāo)組合會(huì)成為較準(zhǔn)確，且適用于臨床的早期診斷NAFLD、肝脂肪變性程度及肝纖維化程度的無(wú)創(chuàng)方法。

脂肪肝； 生物學(xué)標(biāo)記； 診斷； 綜述

近年來(lái)，脂肪肝發(fā)病率呈明顯上升趨勢(shì)，已成為我國(guó)第一大非感染性慢性肝病，其中，以非酒精性脂肪性肝病(NAFLD)最多見(jiàn)，其疾病譜包括單純性非酒精性脂肪肝(NAFL)、非酒精性脂肪性肝炎(NASH)及相關(guān)肝硬化和肝癌[1]。有研究表明NAFLD主要與肥胖、飲食習(xí)慣及基因有關(guān)[2]。據(jù)統(tǒng)計(jì)，25%的脂肪肝患者的肝臟逐漸纖維化，6%的患者最終進(jìn)展為肝硬化，生命受到威脅[3]。NAFLD是可逆性疾病，盡早干預(yù)和治療可完全恢復(fù)。因此，NAFLD患者的早期診斷是關(guān)鍵。雖然，肝臟活組織檢查是診斷NAFLD的金標(biāo)準(zhǔn)，但肝臟穿刺為有創(chuàng)操作，重復(fù)性差，且存在取樣誤差；影像學(xué)檢查價(jià)格昂貴，不便于隨訪；而血清學(xué)檢查簡(jiǎn)便無(wú)創(chuàng)，對(duì)NAFLD的診斷意義備受矚目。

1 實(shí)驗(yàn)室檢查

1.1 肝臟酶學(xué) 肝臟酶學(xué)中血清ALT、AST、ALP、GGT等常用于普通人群肝病的篩查。一項(xiàng)來(lái)自英國(guó)的橫斷面研究[4]顯示，NAFLD為體檢人群肝酶異常的主要原因。我國(guó)一項(xiàng)研究[5]表明，肥胖成人的血清ALT水平與TG含量獨(dú)立相關(guān)，可作為NAFLD程度的預(yù)測(cè)指標(biāo)。Maximos等[6]研究也表明，NAFLD患者的血漿轉(zhuǎn)氨酶升高主要取決于胰島素抵抗程度和TG含量，且ALT升高者肝細(xì)胞脂肪變性程度更嚴(yán)重。然而，Cruz等[7]以腹部B超檢查為對(duì)照，證實(shí)AST、ALT、GGT、胰島素抵抗內(nèi)穩(wěn)態(tài)模型聯(lián)合B超可用于肝臟脂肪變性程度的評(píng)估，且在顯示脂肪變性程度方面，AST比ALT更有價(jià)值。已知GGT早已納入脂肪肝參數(shù)系統(tǒng)[8]。最新一項(xiàng)研究[9]納入35例NAFLD患者，通過(guò)肝活組織檢查復(fù)查肝臟病變情況顯示，血清AST和GGT水平升高與NAFLD活動(dòng)度評(píng)分惡化高度相關(guān)。Kawamura等[10]建立了一個(gè)同時(shí)納入AST和ALT等指標(biāo)的評(píng)分系統(tǒng)，可準(zhǔn)確預(yù)測(cè)NASH患者的肝纖維化分期，且預(yù)測(cè)進(jìn)展期纖維化(≥3期)的受試者工作特征曲線下面積(AUC)為0.909，優(yōu)于其他幾種纖維化評(píng)分系統(tǒng)。

1.2 AST與ALT比值(AAR) 早有報(bào)道稱AAR參與了肝脂肪變性指數(shù)系統(tǒng)[11]、肝脂評(píng)分系統(tǒng)[12]、肝纖維化評(píng)分系統(tǒng)[13]。最近，F(xiàn)allatah等[14]通過(guò)評(píng)估肝纖維化用的FibroScan檢查，也證實(shí)了AAR與FibroScan之間呈高度正相關(guān)。

1.3 血清鐵蛋白 2011年Manousou等[15]研究認(rèn)為血清鐵蛋白是NASH的獨(dú)立危險(xiǎn)因素。后來(lái)，Kowdley等[16]證實(shí)當(dāng)血清鐵蛋白>1.5倍正常值上限(ULN)可用于診斷NASH，并可預(yù)測(cè)NAFLD相關(guān)肝纖維化。近期，馬會(huì)民等[17]選取243例NAFLD患者的研究結(jié)果顯示血清鐵蛋白水平升高，認(rèn)為其可能通過(guò)影響肝臟脂質(zhì)代謝參與NAFLD進(jìn)展。與此同時(shí)，馮紅萍等[18]納入250例NAFLD患者，并根據(jù)患者首診時(shí)CT檢查結(jié)果將其分為輕、中、重3組，對(duì)3組患者的血清鐵蛋白值進(jìn)行比較分析，結(jié)果提示血清鐵蛋白在輕度脂肪性肝病時(shí)即可較早地反映肝功能損傷，比ALT、AST更靈敏，并認(rèn)為血清鐵蛋白可作為NAFLD病情進(jìn)展程度的獨(dú)立預(yù)測(cè)指標(biāo)。Goh等[19]應(yīng)用AST水平、血清鐵蛋白水平、BMI、血小板計(jì)數(shù)、2型糖尿病和高血壓等變量建立的評(píng)分系統(tǒng)用于預(yù)測(cè)NAFLD患者發(fā)生NASH風(fēng)險(xiǎn)的AUC為0.81。

1.4 血清硒 硒是人類必不可少的微量元素，主要來(lái)自空氣、食物和水。一些動(dòng)物研究[20-22]表明硒暴露能引起血清肝酶水平增加及Kupffer細(xì)胞激活，其肝組織胰島素抵抗和甘油三酯濃度均高于對(duì)照組。隨后，Stranges等[23]進(jìn)行流行病學(xué)研究發(fā)現(xiàn)，高硒暴露可能導(dǎo)致代謝異常，包括血脂異常、2型糖尿病或胰島素抵抗。最近，在中國(guó)上海，一項(xiàng)納入8550例研究對(duì)象的橫斷面研究[24]顯示血漿硒水平與NAFLD患病率呈正相關(guān)，且血漿硒水平升高者的低密度脂蛋白膽固醇、空腹血糖、糖化血紅蛋白、ALT、AST和GGT水平均較健康人群升高(P值均< 0.05)。由此可見(jiàn)，硒暴露可能會(huì)導(dǎo)致NAFLD發(fā)生的風(fēng)險(xiǎn)增加。

1.5 尿酸 尿酸是嘌呤在肝臟代謝的最終產(chǎn)物，其生成和排泄決定了血清尿酸的水平。目前有關(guān)尿酸在NAFLD中的發(fā)生機(jī)制的主要假說(shuō)是“二次打擊學(xué)說(shuō)“，大量研究顯示高血清尿酸與NAFLD的發(fā)生與發(fā)展密切相關(guān)。Sirota等[25]也認(rèn)為尿酸濃度升高是NAFLD的獨(dú)立危險(xiǎn)因素，且NAFLD損傷嚴(yán)重程度隨尿酸的增高而加重。Yuan等[26]證實(shí)了血清尿酸水平每升高1 mg/dl，導(dǎo)致 NAFLD的風(fēng)險(xiǎn)增加21%。李韶豐等[27]指出控制尿酸有望成為NAFLD綜合治療手段之一，早期對(duì)高尿酸血癥合并NAFLD患者綜合干預(yù)至關(guān)重要。一項(xiàng)82 608例成人參與的研究[28]表明，血清尿酸和ALT水平呈顯著正相關(guān)，具有量效關(guān)系。1.6 空腹胰島素濃度 大量研究證實(shí)胰島素抵抗及2型糖尿病可促進(jìn)NAFLD的發(fā)展，空腹胰島素濃度已參與肝脂評(píng)分系統(tǒng)[12]。但是，在發(fā)展成2型糖尿病之前，葡萄糖代謝和NAFLD患者肝組織病變之間的關(guān)系并不為眾所周知。Masuda等[29]納入103例NAFLD患者研究在糖尿病前期，葡萄糖代謝與肝纖維化是否有相關(guān)性，結(jié)果證實(shí)纖維化3期組的女性數(shù)量、年齡、AAR、空腹胰島素濃度、糖化血紅蛋白、透明質(zhì)酸和Ⅳ型膠原蛋白7s比纖維化0～2期組明顯更高，認(rèn)為在NAFLD發(fā)展至2型糖尿病之前，高空腹胰島素濃度是預(yù)測(cè)肝纖維化嚴(yán)重程度的關(guān)鍵。

2 生物化學(xué)標(biāo)志物

2.1 視黃醇結(jié)合蛋白(retinol-binding protein，RBP)4 RBP-4是視黃醇類結(jié)合蛋白家族中的一員，主要由肝臟分泌，脂肪組織也少量分泌，主要與維生素A的儲(chǔ)存、代謝和轉(zhuǎn)運(yùn)有關(guān)。研究認(rèn)為RBP-4與代謝綜合征、胰島素抵抗、2型糖尿病、慢性肝病、慢性腎病、心腦血管疾病均有關(guān)，而這些大多為NAFLD的高危因素，故認(rèn)為RBP-4與NAFLD發(fā)病有關(guān)。早在2006年，Graham等[30]證實(shí)了血清RBP-4水平與胰島素抵抗程度呈正相關(guān)。我國(guó)孫立山等[31]也認(rèn)為血清RBP-4是NAFLD發(fā)病相關(guān)的獨(dú)立危險(xiǎn)因素。后來(lái)，Chang等[32]研究認(rèn)為RBP-4可作為腹部肥胖的一個(gè)標(biāo)志物，且隨著肝臟脂肪含量的增加，BMI、腰圍、腰臀比、TG、ALT、AST、GGT也逐漸升高，高密度脂蛋白逐漸下降；而總膽固醇、低密度脂蛋白、ALP無(wú)顯著變化。Liu等[33]通過(guò)動(dòng)物實(shí)驗(yàn)證實(shí)RBP-4 mRNA在NAFLD模型中異常升高，與肝TG積累呈正相關(guān)，并認(rèn)為可能與線粒體含量減少和線粒體脂肪酸β-oxidation受損有關(guān)。

2.2 細(xì)胞角蛋白(cytokeratin,CK)18 CK-18與細(xì)胞凋亡相關(guān)，當(dāng)細(xì)胞壞死時(shí)，血液中CK-18濃度隨之升高，而NAFLD的進(jìn)展與肝實(shí)質(zhì)細(xì)胞脂肪變性、壞死和凋亡密切相關(guān)。Maliken等[34]研究表明血清CK-18及其裂解物的水平隨著肝細(xì)胞壞死、凋亡程度增加而升高，且與肝細(xì)胞壞死水平呈正相關(guān)。Castera等[35]也表明CK-18的主要價(jià)值在于可提示NASH的存在，并能評(píng)價(jià)炎癥程度及纖維化的發(fā)生。Chalasani等[36]總結(jié)了一些后續(xù)研究和薈萃分析，證實(shí)血清CK-18評(píng)估NASH的敏感度和特異度分別為78%和87%，其AUC為0.82。Kazankov等[37]聯(lián)合sCD163和CK-18，認(rèn)為NAFLD/NASH患者細(xì)胞凋亡可能與巨噬細(xì)胞活化有關(guān)。

NAFLD具有遺傳傾向，F(xiàn)eldstein等[38]報(bào)道CK-18有望成為NASH患兒非侵入性診斷標(biāo)志物之一。隨后，李娜等[39]研究也證實(shí)了這一觀點(diǎn)。然而，由于不同實(shí)驗(yàn)研究所所用的特定臨界值不同，缺乏統(tǒng)一標(biāo)準(zhǔn)，美國(guó)肝病學(xué)會(huì)指南并未將CK-18作為臨床常用的檢測(cè)指標(biāo)。近期，Zwolak等[40]同時(shí)檢測(cè)了RBP-4和CK-18，結(jié)果認(rèn)為RBP-4與肥胖的NAFLD 患者密切相關(guān)，CK-18與非肥胖的NAFLD患者密切相關(guān)。

大量研究證實(shí)，炎癥反應(yīng)在NAFLD的發(fā)展中起關(guān)鍵作用，炎性標(biāo)志物有IL-6、超敏C反應(yīng)蛋白(hs-CRP)、脂聯(lián)素、TNFα，其中脂聯(lián)素具有抗炎作用[41]，其水平下降可使NAFLD發(fā)展至NASH[42]。TNFα則通過(guò)參與氧化應(yīng)激和脂質(zhì)氧化介導(dǎo)肝臟炎癥反應(yīng)，從而導(dǎo)致肝損傷。藍(lán)常明等[43]將98例輕、中、重度NAFLD患者和38例作為對(duì)照組的健康體檢者進(jìn)行血清TNFα檢測(cè)，Spearman相關(guān)分析結(jié)果顯示血清TNFα水平與NAFLD病情嚴(yán)重等級(jí)呈正相關(guān)(r=0.516，P<0.05)，且在NAFLD發(fā)展、NASH及肝纖維化中起重要作用。

3 遺傳基因

3.1 PNPLA3基因 PNPLA3基因位于人類第22號(hào)染色體的長(zhǎng)臂上，可翻譯出一條包含481個(gè)氨基酸的跨膜多肽鏈，在脂肪組織和肝臟中高表達(dá)，其表達(dá)主要受營(yíng)養(yǎng)狀況的影響，基因的多態(tài)性影響了PNPLA3的表型，從而易引起能量代謝的紊亂。PNPLA3 rs738409 G可降低脂聯(lián)素水平，已在多個(gè)國(guó)家被證明與NAFLD及脂肪變性程度密切相關(guān)[44]。最近，一項(xiàng)基于肝活組織病理基礎(chǔ)的多中心研究[45]顯示，PNPLA3 rs738409基因多態(tài)性可使肝臟脂肪含量增加及肝纖維化加重。同時(shí)，一項(xiàng)針對(duì)日本的經(jīng)肝活組織檢查證實(shí)為NAFLD患者的研究[46]認(rèn)為，嚴(yán)重的肝纖維化和PNPLA3 rs738409基因多態(tài)性是NAFLD患者發(fā)生肝細(xì)胞癌的獨(dú)立危險(xiǎn)因素。由此可見(jiàn)，PNPLA3與NAFLD患者的肝脂肪含量、脂肪變性程度、肝纖維化，甚至肝癌的發(fā)生均有密切關(guān)系。

3.2 TM6SF2基因 TM6SF2基因位于第19號(hào)染色體上，編碼一段由351個(gè)氨基酸構(gòu)成的蛋白，主要在腦組織、腎臟、肝臟及小腸表達(dá)，其中在小腸組織表達(dá)最高。2014年Kozlitina等[47]首次報(bào)道了TM6SF2 rs58542926與NAFLD易感的相關(guān)性，TM6SF2 rs58542926在p.E167K位點(diǎn)上將谷氨基酸轉(zhuǎn)換成賴氨基酸，且AST和ALT與這種改變呈高度正相關(guān)。近日，一項(xiàng)針對(duì)中國(guó)漢族人群關(guān)于PNPLA3 rs738409、rs2294918、NCAN rs2228603、GCKR rs780094、LYPLAL1 rs12137855和TM6SF2 rs58542926的全基因組關(guān)聯(lián)研究證實(shí)了TM6SF2和PNPLA3一樣，是中國(guó)NAFLD患者最重要的危險(xiǎn)等位基因[48]。最新研究[45]認(rèn)為T(mén)M6SF2 rs58542926主要與NAFLD患者肝脂肪堆積有關(guān)，與肝纖維化聯(lián)系不大。

Krawczyk等[49]聯(lián)合檢測(cè)PNPLA3 rs738409和TM6SF2 rs58542926，結(jié)果證實(shí)在含有PNPLA3 rs738409的患者中，TM6SF2變體的存在會(huì)加重血清轉(zhuǎn)氨酶升高，并進(jìn)一步加重肝臟脂肪變性。

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，又分別稱為IL-29、IL-28A和IL-28B)。IL-28B即IFNλ3，其基因的編碼位于人類第19號(hào)染色體上(19q13.13)，其單核苷酸多態(tài)性可以影響基因轉(zhuǎn)錄及翻譯，進(jìn)而影響IFNλ3的合成。大量研究也證實(shí)了IL-28B與病毒性肝炎及其相關(guān)肝硬化、肝癌的發(fā)生發(fā)展、抗病毒治療的應(yīng)答反應(yīng)及預(yù)后密切相關(guān)。近年來(lái)，隨著NAFLD患者的增多，越來(lái)越多的研究者開(kāi)始探索IL-28B與NAFLD的相關(guān)性。有研究發(fā)現(xiàn)IL-28B基因多態(tài)性與肝臟脂肪變性[50]、炎癥反應(yīng)[51]和肝纖維化[52]的嚴(yán)重程度有關(guān)。Petta等[53]認(rèn)為在NAFLD患者中，IL-28B rs12979860 CC基因型和PNPLA3 rs738409 GG與肝損傷的嚴(yán)重程度相關(guān)。有研究[54]表明，在非肥胖的NAFLD患者中，攜帶IL-28B rs12979860 CC基因型的患者肝小葉炎性反應(yīng)和F2～F4期肝纖維化患病率比攜帶TT/TC基因型的患者高(28/46和9/48，P<0.001)，而在肥胖的NAFLD患者中卻未發(fā)現(xiàn)這種差異[55]，并證實(shí)IL-28B rs12979860位點(diǎn)與NAFLD無(wú)相關(guān)性。Hashemi等[56]針對(duì)伊朗人的一項(xiàng)研究認(rèn)為IL-28B rs8099917位點(diǎn)也不是NAFLD的危險(xiǎn)因素。李江文[57]收集190例NAFLD患者和183例正常人的血液標(biāo)本，采用多重高溫連接酶檢測(cè)反應(yīng)技術(shù)對(duì)IL-28B rs12979860、IL-28B rs8099917兩位點(diǎn)進(jìn)行基因檢測(cè)，結(jié)果也證實(shí)IL-28B rs12979860、IL-28B rs8099917兩位點(diǎn)與NAFLD無(wú)明顯相關(guān)性。目前，關(guān)于IL-28B與NAFLD相關(guān)性的研究相對(duì)較少，尚需大量研究加以證實(shí)。

Severson等[44]認(rèn)為遺傳因素及基因多態(tài)性導(dǎo)致NAFLD及其最終結(jié)果，這些基因是未來(lái)提高診斷及管理水平的關(guān)鍵。

4 目前已存在的血清指標(biāo)組合在NAFLD中的應(yīng)用

診斷脂肪變性的參數(shù)系統(tǒng)有：脂肪變性測(cè)試系統(tǒng)[58]，包括6個(gè)變量(肝硬度、FibroTest指數(shù)、BMI、TC、TG和血糖)；脂肪肝參數(shù)[8]，包括4個(gè)變量(BMI、腰圍、TG和GGT)；脂質(zhì)積累量[59]，包括3個(gè)變量(腰圍、TG及性別)；肝脂肪變性指數(shù)系統(tǒng)[11]，包括3個(gè)變量(AAR、BMI和2型糖尿病)；NAFLD肝脂評(píng)分系統(tǒng)[12]，包括5個(gè)變量(代謝綜合征、2型糖尿病、空腹胰島素水平、AST及AAR)，可預(yù)測(cè)肝臟脂肪的百分比。

用于肝纖維化評(píng)價(jià)的系統(tǒng)包括：NAFLD肝纖維化評(píng)分、BARD評(píng)分、NIKEI、NASH-CRN回歸得分、AST與PLT比值指數(shù)、FIB-4指數(shù)、King′s評(píng)分、GUCI、Lok指數(shù)、Forns分?jǐn)?shù)和肝纖維化血清學(xué)指標(biāo)。Lykiardopoulos等[60]納入158例NAFLD患者，其中38例處于肝纖維化早期階段，以肝活組織檢查結(jié)果為金標(biāo)準(zhǔn)，研究表明FIB-4(包括血小板、ALT、AST和年齡)和King′s評(píng)分(年齡、AST、血小板)診斷肝纖維化的AUC分別為0.84和0.83；并用創(chuàng)建的包括年齡、空腹血糖、透明質(zhì)酸等指標(biāo)的預(yù)測(cè)早期肝纖維化的模型(LINKI-1)和包括這些指標(biāo)合并血小板計(jì)數(shù)，且用數(shù)學(xué)方法夸大其反面影響的替代模型(LINKI-2)證實(shí)，在總?cè)褐蠰INKI-1和LINKI-2模型的AUC高達(dá)0.91和0.89。同時(shí)有研究[61]表明，通過(guò)多項(xiàng)血清指標(biāo)組合的無(wú)創(chuàng)模型雖然診斷NAFLD的效能差，但排除肝硬化的準(zhǔn)確性>90%。

5 展望

綜上所述，血清學(xué)指標(biāo)中肝酶、AAR、血清鐵蛋白、血清硒、尿酸、高空腹胰島素濃度、PNPLA3、TM6SF2、RBP-4、CK-18對(duì)NAFLD的診斷價(jià)值值得肯定，而IL-28B對(duì)NAFLD的診斷價(jià)值存在較大爭(zhēng)議，尚需更多臨床試驗(yàn)證實(shí)。并且多項(xiàng)血清指標(biāo)組合在評(píng)價(jià)肝脂肪變性、肝纖維化及肝硬化方面的研究還處于初期階段，尚不能有效的對(duì)NAFLD進(jìn)行全面的評(píng)估。相信通過(guò)大量的研究，更全面的血清指標(biāo)組合將會(huì)問(wèn)世，其診斷NAFLD的價(jià)值或許有望取代肝臟活組織病理檢查。

[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) 吳曉銘. 867例健康體檢中脂肪肝檢驗(yàn)結(jié)果與相關(guān)因素分析[J]. 吉林醫(yī)學(xué), 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) 馬會(huì)民, 白萍萍, 張連仲, 等. 非酒精性脂肪肝患者血清鐵蛋白水平變化及意義[J]. 山東醫(yī)藥, 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) 馮紅萍, 任艷玲. 非酒精性脂肪性肝病患者血清鐵蛋白檢測(cè)的意義[J/CD]. 中國(guó)肝臟病雜志: 電子版, 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) 李韶豐, 廖獻(xiàn)花, 葉俊釗, 等. 尿酸在非酒精性脂肪性肝病發(fā)生發(fā)展中的作用[J]. 臨床肝膽病雜志, 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) 孫立山, 范列英, 王暖, 等. 血清視黃醇結(jié)合蛋白4和非酒精性脂肪性肝病的相關(guān)性[J]. 檢驗(yàn)醫(yī)學(xué), 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, 周明錦, 陳楠. 非酒精性脂肪性肝炎患兒血清腫瘤壞死因子α與細(xì)胞角質(zhì)蛋白18的表達(dá)及意義研究[J]. 中國(guó)全科醫(yī)學(xué), 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) 藍(lán)常明. 不同程度非酒精性脂肪肝患者腫瘤壞死因子-α、白介素-6的檢測(cè)及意義[J]. 現(xiàn)代消化及介入診療, 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多態(tài)性與NAFLD的相關(guān)性研究[D]. 大連： 大連醫(yī)科大學(xué), 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, HAGSTR?M 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現(xiàn)狀與展望[J]. 臨床肝膽病雜志, 2015, 31(7): 999-1001.

引證本文：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) 萬(wàn)艷， 常劍波， 白艷霞， 等. 血清學(xué)指標(biāo)在非酒精性脂肪性肝病診斷中的意義[J]. 臨床肝膽病雜志, 2017, 33(5): 963-968.

(本文編輯：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。

萬(wàn)艷(1990-)，女，主要從事慢性肝病的診療研究。

戴光榮，電子信箱：daiguangrong6810@sina.cn。

R575.5

A

1001-5256(2017)05-0963-06