Test Summary
Enhanced Liver Fibrosis (ELF) Score
Test code: 10350
Clinical use
- Assess likelihood that nonalcoholic steatohepatitis (NASH) will progress to cirrhosis and liver-related clinical events (eg, hepatic decompensation event, Model for End-Stage Liver Disease score ≥15, liver transplantation, or death)
Clinical background
NASH is a severe form of nonalcoholic fatty liver disease (NAFLD) characterized by chronic inflammation and liver cell injury. (NASH has been renamed metabolic dysfunction–associated steatohepatitis [MASH] and NAFLD has been renamed metabolic dysfunction–associated steatotic liver disease [MASLD]1; however, this test summary will continue to use NAFLD and NASH until the new names have been extensively adopted.) NASH has an estimated prevalence of 3% to 14% in the US general population.2,3 About 40% of patients with NASH develop liver fibrosis.2 The disease course can lead to advanced fibrosis (ie, bridging [F3] fibrosis) and ultimately result in cirrhosis (ie, F4 fibrosis) and associated complications, such as hepatocellular carcinoma.2
Patients with severe disease and a high risk of poor liver-related outcomes may be considered for aggressive interventions, such as intensive lifestyle modifications, bariatric surgery, pharmacotherapy changes, and referral to clinical trials.4,5 Liver biopsy is the standard assessment used to confirm a NASH diagnosis, characterize disease severity, and help determine prognosis.4 However, this procedure is suboptimal for follow-up assessment because it is invasive and involves safety risks.6
The Enhanced Liver Fibrosis (ELF) Score is a noninvasive test that indicates whether a patient with NASH and advanced fibrosis has a higher or lower risk of disease progression to cirrhosis (for those with F3 fibrosis) or other liver-related clinical events (for those with F3 or F4 fibrosis) within 1 to 4 years.7–10 ELF is included as a secondary risk assessment in the NAFLD care pathways of the American Association for the Study of Liver Diseases (AASLD),4 American Gastroenterological Association,5 American Association of Clinical Endocrinology,11 and American Diabetes Association.12 In patients with indeterminate or high risk following a primary assessment (eg, FIB-4), ELF can be used to further stratify risk and identify those who require specialized gastroenterology or hepatology care.4,5,11,12
ELF uses an algorithm that incorporates measurements of 3 extracellular matrix components involved in the development of liver fibrosis.10 The test is intended to provide prognostic information in conjunction with other laboratory findings and clinical assessments. This test is not for use in the diagnosis of NASH or the staging of fibrosis.
Individuals suitable for testing
- Patients with advanced (F3 or F4) fibrosis due to NASH
Method
- Chemiluminescent immunoassay to measure hyaluronic acid, amino-terminal propeptide of type III procollagen, and tissue inhibitor of matrix metalloproteinase 1
- Proprietary algorithm combines biomarker measurements to generate the ELF score
Interpretive information
The ELF score indicates the risk of disease progression to cirrhosis or liver-related events based on established thresholds (Table).10
Table. Interpretation of ELF Test Results
ELF score |
Risk of disease progression10,a |
<9.80 |
Lower |
≥9.80 and <11.30 |
Midb |
≥11.30 |
Higher |
| a | Disease progression includes development of cirrhosis or liver-related events. |
| b | Mid risk is similar to the pre-test risk (likelihood of disease progression in the intended use population without considering the ELF score). |
According to AASLD guidance, based on expert opinion, an ELF score ≥7.7 during secondary risk assessment suggests the need for specialized care.4
Results should be interpreted in conjunction with the patient’s medical history, clinical presentation, and other findings.10
References
- Rinella ME, Lazarus JV, Ratziu V, et al. A multisociety Delphi consensus statement on new fatty liver disease nomenclature. Hepatology. 2023;78(6):1966-1986. doi:10.1097/hep.0000000000000520
- Povsic M, Wong OY, Perry R, et al. A structured literature review of the epidemiology and disease burden of non-alcoholic steatohepatitis (NASH). Adv Ther. 2019;36(7):1574-1594. doi:10.1007/s12325-019-00960-3
- Harrison SA, Gawrieh S, Roberts K, et al. Prospective evaluation of the prevalence of non-alcoholic fatty liver disease and steatohepatitis in a large middle-aged US cohort. J Hepatol. 2021;75(2):284-291. doi:10.1016/j.jhep.2021.02.034
- Rinella ME, Neuschwander-Tetri BA, Siddiqui MS, et al. AASLD Practice Guidance on the clinical assessment and management of nonalcoholic fatty liver disease. Hepatology. 2023;77(5):1797-1835. doi:10.1097/hep.0000000000000323
- Long MT, Noureddin M, Lim JK. AGA Clinical Practice update: diagnosis and management of nonalcoholic fatty liver disease in lean individuals: expert review. Gastroenterology. 2022;163(3):764-774.e1. doi:10.1053/j.gastro.2022.06.023
- Tapper EB, Lok AS. Use of liver imaging and biopsy in clinical practice. N Engl J Med. 2017;377(8):756-768. doi:10.1056/nejmra1610570
- Sanyal AJ, Harrison SA, Ratziu V, et al. The natural history of advanced fibrosis due to nonalcoholic steatohepatitis: data from the simtuzumab trials. Hepatology. 2019;70(6):1913-1927. doi:10.1002/hep.30664
- Are VS, Vuppalanchi R, Vilar-Gomez E, et al. Enhanced Liver Fibrosis score can be used to predict liver-related events in patients with nonalcoholic steatohepatitis and compensated cirrhosis. Clin Gastroenterol Hepatol. 2021;19(6):1292-1293.e3. doi:10.1016/j.cgh.2020.06.070
- Younossi ZM, Anstee QM, Wong VWS, et al. The association of histologic and noninvasive tests with adverse clinical and patient-reported outcomes in patients with advanced fibrosis due to nonalcoholic steatohepatitis. Gastroenterology. 2021;160(5):1608-1619.e13. doi:10.1053/j.gastro.2020.12.003
- Enhanced Liver Fibrosis (ELF™). Package insert. Siemens Healthcare Diagnostics Inc; 2022. Accessed March 21, 2024. https://content.doclib.siemens-healthineers.com/rest/v1/view?document-id=879118
- Cusi K, Isaacs S, Barb D, et al. American Association of Clinical Endocrinology clinical practice guideline for the diagnosis and management of nonalcoholic fatty liver disease in primary care and endocrinology clinical settings: co-sponsored by the American Association for the Study of Liver Diseases (AASLD). Endocr Pract. 2022;28(5):528-562. doi:10.1016/j.eprac.2022.03.010
- American Diabetes Association Professional Practice Committee. 4. Comprehensive medical evaluation and assessment of comorbidities: standards of care in diabetes—2024. Diabetes Care. 2024;47(Suppl 1):S52-S76. doi:10.2337/dc24-s004
Content reviewed 04/2024
10350 - Enhanced Liver Fibrosis (ELF) Score
The ELF score is not for use in the diagnosis of NASH, the staging of fibrosis, the serial monitoring of disease progression, or the monitoring of effects of therapeutic products.
The ELF score is derived from an algorithm that combines measurements of PIIINP, TIMP-1, and HA. PIIINP is a marker of early fibrogenesis and inflammation, TIMP-1 is the circulating inhibitor of MMP enzymes that can enhance fibrogenesis, and HA is a glycosaminoglycan that is produced by hepatic stellate cells. Together, these assays measure qualitative and quantitative changes in the extracellular matrix (ECM). The ECM refers to a set of macromolecules that comprise the extracellular scaffolding of the liver. Some ECM markers reflect fibrogenesis and others reflect fibrosis regression, allowing for a dynamic evaluation of ECM activity.
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Reference ranges are provided as general guidance only. To interpret test results use the reference range in the laboratory report.
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