非酒精性脂肪性肝病诊断——病理的重要性
DOI: 10.3969/j.issn.1001-5256.2023.03.002
-
摘要: 对于非酒精性脂肪性肝病的明确诊断、单纯性脂肪肝(NAFL)及非酒精性脂肪性肝炎(NASH)区分及疾病严重程度的分级评分,均需依靠肝穿刺活检组织病理学评估完成,而临床上仍多依赖于血液学及影像学检测手段。尽管目前已有大量相关研究针对非酒精性脂肪性肝病的无创纤维化评估、疾病诊断模型出现,其敏感性及特异性仍有待提高。本文拟分别从NAFL及NASH的主要病理学特征、纤维化及分级分期评分方法,NASH肝硬化的病理学诊断等方面进行论述,以期提高临床医师对于该疾病组织学诊断的重视。Abstract: Histopathological evaluation based on liver biopsy is required to make a confirmed diagnosis of nonalcoholic fatty liver disease, differentiate nonalcoholic fatty liver (NAFL) from nonalcoholic steatohepatitis (NASH), and perform the grading and scoring of disease severity, while hematological and radiological examinations are often used in clinical practice. Although there have been a large number of studies on noninvasive models for fibrosis assessment and disease diagnosis in nonalcoholic fatty liver disease, the sensitivity and specificity of such models need to be further improved. This article reviews the main pathological features of NAFL and NASH, fibrosis and grading/staging/scoring systems, and the pathological diagnosis of NASH liver cirrhosis, in order to improve the awareness of the histological diagnosis of such disease among clinicians
-
Key words:
- Non-alcoholic Fatty Liver Disease /
- Pathology /
- Diagnosis, Differential
-
表 1 CRN提出的NAFLD/NASH病理诊断分级NAS评分法
Table 1. NAS scoring of NAFLD/NASH
组织学特征 评分 诊断标准 脂肪变性(低倍镜) 0 <5% 1 5%~33% 2 34%~66% 3 >66% 肝细胞气球样变性 0 无 1 少量 2 数量较多,同时形态较为明显 小叶炎症(所有炎症病灶) 0 无 1 <2点灶坏死/20倍镜视野 2 2~4点灶坏死/20倍镜视野 3 >4点灶坏死/20倍镜视野 NAS总分 0~8 表 2 NASH CRN修改的Brunt分期系统
Table 2. Brunt scoring system after CRN modified
分期 诊断标准 0 无 1 1a 轻度,腺泡3区窦周纤维化,需Masson染色辨认 1b 中度,腺泡3区-窦周纤维化,HE染色即可辨认 1c 仅汇管区/汇管区周围纤维化 2 1期+汇管区/汇管区周围纤维化,局灶或广泛 3 桥接纤维化,局灶或广泛 4 肝硬化(+/-残余窦周纤维化) 表 3 NAFLD/NASH SAF评分
Table 3. SAF scoring system of NAFLD/NASH
病理学特征 评分 诊断标准 脂肪变性(S) 0~3 0 <5% 1 5%~33% 2 34%~66% 3 >66% 炎症评分(A) 0~4 包括肝细胞气球样变性+小叶炎症 肝细胞气球样变性 0 无 1 圆形的胞质疏松淡染的肝细胞成簇 2 圆形的胞质疏松淡染的肝细胞成簇并大于两倍正常肝细胞体积 小叶炎症(所有炎症病灶) 0 无 1 <2个点灶/20倍视野 2 >2个点灶/20倍视野 纤维化评分(F) 0~4 纤维化程度 0 无 1a 轻度,腺泡3区/窦周纤维化仅胶原染色可见 1b 中度,腺泡3区/窦周纤维化 1c 仅汇管区/汇管区周边纤维化 2 腺泡3区/窦周纤维化+汇管区纤维化 3 桥接纤维化 4 肝硬化 表 4 NASH肝硬化诊断相关定义:肝病论坛共识
Table 4. NASH cirrhosis definition: Liver forum consensus
确定 很可能 可能 a.病理表现同时具备NASH和肝硬化 a.既往病理诊断NAFL,现发展为肝硬化
有或曾有2项以上代谢综合征(包括肥胖和/或T2DM)a.隐源性肝硬化,无脂肪肝证据
有或曾有1项以上代谢综合征(包括肥胖和/或T2DM)b.既往病理诊断NASH,现发展为肝硬化有或曾有1项以上代谢综合征 b.肝硬化,目前或既往影像提示脂肪肝,无组织学证据
有或曾有2项以上代谢综合征(包括肥胖和/或T2DM)b.既往HCV清除,或既往曾有酗酒史,现有肝硬化+NASH组织学证据 c.现病理NAFL+肝硬化,并排除其他病因
有或曾有2项以上代谢综合征(包括肥胖和/或T2DM)c.隐源性肝硬化,无脂肪肝证据
有或曾有2项以上代谢综合征(包括肥胖和/或T2DM) -
[1] LOOMBA R, ADAMS LA. The 20% rule of NASH progression: The natural history of advanced fibrosis and cirrhosis caused by NASH[J]. Hepatology, 2019, 70(6): 1885-1888. DOI: 10.1002/hep.30946. [2] SAXENA R. Practical hepatic pathology, a diagnostic approach[M]. 2nd edition. Philadelphia, PA: Elsevier, 2017. [3] BRIL F, BARB D, PORTILLO-SANCHEZ P, et al. Metabolic and histological implications of intrahepatic triglyceride content in nonalcoholic fatty liver disease[J]. Hepatology, 2017, 65(4): 1132-1144. DOI: 10.1002/hep.28985. [4] POUWELS S, SAKRAN N, GRAHAM Y, et al. Non-alcoholic fatty liver disease (NAFLD): a review of pathophysiology, clinical management and effects of weight loss[J]. BMC Endocr Disord, 2022, 22(1): 63. DOI: 10.1186/s12902-022-00980-1. [5] BRUNT EM, KLEINER DE, CARPENTER DH, et al. NAFLD: Reporting histologic findings in clinical practice[J]. Hepatology, 2021, 73(5): 2028-2038. DOI: 10.1002/hep.31599. [6] BRUNT EM. Pathology of fatty liver disease[J]. Mod Pathol, 2007, 20 (Suppl 1): S40-S48. [7] FELDSTEIN AE, WIECKOWSKA A, LOPEZ AR, et al. Cytokeratin-18 fragment levels as noninvasive biomarkers for nonalcoholic steatohepatitis: a multicenter validation study[J]. Hepatology, 2009, 50(4): 1072-1078. DOI: 10.1002/hep.23050. [8] DUAN Y, PAN X, LUO J, et al. Association of inflammatory cytokines with non-alcoholic fatty liver disease[J]. Front Immunol, 2022, 13: 880298. DOI: 10.3389/fimmu.2022.880298. [9] SANYAL AJ, HARRISON SA, RATZIU V, et al. The natural history of advanced fibrosis due to nonalcoholic steatohepatitis: data from the simtuzumab trials[J]. Hepatology, 2019, 70(6): 1913-1927. DOI: 10.1002/hep.30664. [10] BRUNT EM. Grading and staging the histopathological lesions of chronic hepatitis: the Knodell histology activity index and beyond[J]. Hepatology, 2000, 31(1): 241-246. DOI: 10.1002/hep.510310136. [11] LUO J, LIU LW, LIU JM, et al. Comparative study of clinicopathological features, and risk factors of advanced fibrosis between genders with non-alcoholic fatty liver disease[J]. Chin J Hepatol, 2021, 29(4): 356-361. DOI: 10.3760/cma.j.cn501113-20200203-00027.罗娟, 刘立伟, 刘纪民, 等. 非酒精性脂肪性肝病临床和病理特点及进展期纤维化危险因素性别差异的对比研究[J]. 中华肝脏病杂志, 2021, 29(4): 356-361. DOI: 10.3760/cma.j.cn501113-20200203-00027. [12] ANGULO P, KLEINER DE, DAM-LARSEN S, et al. Liver fibrosis, but no other histologic features, is associated with long-term outcomes of patients with nonalcoholic fatty liver disease[J]. Gastroenterology, 2015, 149(2): 389-397. e10. DOI: 10.1053/j.gastro.2015.04.043. [13] TIAN AP, YANG YF. A comparative analysis of pathological grading and staging systems for chronic hepatitis[J]. J Clin Hepatol, 2018, 34(11): 2271-2277. DOI: 10.3969/j.issn.1001-5256.2018.11.002.田爱平, 杨永峰. 慢性肝炎病理学分级分期评分系统比较[J]. 临床肝胆病杂志, 2018, 34(11): 2271-2277. DOI: 10.3969/j.issn.1001-5256.2018.11.002. [14] KLEINER DE, BRUNT EM, van NATTA M, et al. Design and validation of a histological scoring system for nonalcoholic fatty liver disease[J]. Hepatology, 2005, 41(6): 1313-1321. DOI: 10.1002/hep.20701. [15] BEDOSSA P, POITOU C, VEYRIE N, et al. Histopathological algorithm and scoring system for evaluation of liver lesions in morbidly obese patients[J]. Hepatology, 2012, 56(5): 1751-1759. DOI: 10.1002/hep.25889. [16] ALKHOURI N, de VITO R, ALISI A, et al. Development and validation of a new histological score for pediatric non-alcoholic fatty liver disease[J]. J Hepatol, 2012, 57(6): 1312-1318. DOI: 10.1016/j.jhep.2012.07.027. [17] CLEVELAND E, BANDY A, VANWAGNER LB. Diagnostic challenges of nonalcoholic fatty liver disease/nonalcoholic steatohepatitis[J]. Clin Liver Dis (Hoboken), 2018, 11(4): 98-104. DOI: 10.1002/cld.716. [18] LONGERICH T, SCHIRMACHER P. Determining the reliability of liver biopsies in NASH clinical studies[J]. Nat Rev Gastroenterol Hepatol, 2020, 17(11): 653-654. DOI: 10.1038/s41575-020-00363-8. [19] CASTERA L, FRIEDRICH-RUST M, LOOMBA R. Noninvasive assessment of liver disease in patients with nonalcoholic fatty liver disease[J]. Gastroenterology, 2019, 156(5): 1264-1281. e4. DOI: 10.1053/j.gastro.2018.12.036. [20] KWOK R, TSE YK, WONG GL, et al. Systematic review with meta-analysis: non-invasive assessment of non-alcoholic fatty liver disease-the role of transient elastography and plasma cytokeratin-18 fragments[J]. Aliment Pharmacol Ther, 2014, 39(3): 254-269. DOI: 10.1111/apt.12569. [21] MIDDLETON MS, HEBA ER, HOOKER CA, et al. Agreement between magnetic resonance imaging proton density fat fraction measurements and pathologist-assigned steatosis grades of liver biopsies from adults with nonalcoholic steatohepatitis[J]. Gastroenterology, 2017, 153(3): 753-761. DOI: 10.1053/j.gastro.2017.06.005. [22] TAOULI B, SERFATY L. Magnetic resonance imaging/elastography is superior to transient elastography for detection of liver fibrosis and fat in nonalcoholic fatty liver disease[J]. Gastroenterology, 2016, 150(3): 553-556. DOI: 10.1053/j.gastro.2016.01.017. [23] WILDMAN-TOBRINER B, MIDDLETON MM, MOYLAN CA, et al. Association between magnetic resonance imaging-proton density fat fraction and liver histology features in patients with nonalcoholic fatty liver disease or nonalcoholic steatohepatitis[J]. Gastroenterology, 2018, 155(5): 1428-1435. e2. DOI: 10.1053/j.gastro.2018.07.018. [24] NOUREDDIN M, TRUONG E, GORNBEIN JA, et al. MRI-based (MAST) score accurately identifies patients with NASH and significant fibrosis[J]. J Hepatol, 2022, 76(4): 781-787. DOI: 10.1016/j.jhep.2021.11.012. [25] RINELLA ME, TACKE F, SANYAL AJ, et al. Report on the AASLD/EASL joint workshop on clinical trial endpoints in NAFLD[J]. J Hepatol, 2019, 71(4): 823-833. DOI: 10.1016/j.jhep.2019.04.019.