Test Details
Methodology
AST and ALT: kinetic
Platelet Count: automated cell counter
ELF Reflex if performed: The ELF™ test consists of three fully automated, two-site sandwich immunoassays using direct chemiluminometric technology. The component assays use two monoclonal mouse antibodies: The first antibody is an acridinium ester-labeled antibody. The second antibody is a biotin-labeled antibody. The solid phase contains streptavidin-coated paramagnetic particles. The ELF™ score is derived from an algorithm that combines PIIINP, TIMP-1, and HA. ELF™ is a trademark of Siemens Healthcare Diagnostics.
Result Turnaround Time
3 - 6 days
Turnaround time is defined as the usual number of days from the date of pickup of a specimen for testing to when the result is released to the ordering provider. In some cases, additional time should be allowed for additional confirmatory or additional reflex tests. Testing schedules may vary.
Test Includes
Alanine aminotransferase (ALT/SGPT); aspartate aminotransferase (AST/SGOT); FIB-4 Index (by calculation); platelet count. If FIB-4 Index is >1.29, testing will reflex to Enhanced Liver Fibrosis (ELF™), performed at an additional charge.
Use
According to the 2022 American Association of Clinical Endocrinology clinical practice guidelines, patients considered at high risk for Nonalcoholic Fatty Liver Disease (NAFLD), now known as metabolic dysfunction-associated steatotic liver disease (MASLD), should be screened for NAFLD and advanced fibrosis using the following blood-based tests:
• To assess the risk of NAFLD with liver fibrosis, use liver fibrosis prediction calculations. The preferred noninvasive initial test is the FIB-4.
• Consider persons belonging to the “high risk” group who have an indeterminate or high FIB-4 score for further workup with an ELF test.
The FIB-4 index is reported to be a simple, accurate, non-invasive and readily available laboratory test index that can help in the evaluation of patients with NAFLD for the presence of liver fibrosis, indication for liver biopsy, and other liver-related complications.
The Enhanced Liver Fibrosis (ELF™) blood test is a simple, accurate, non-invasive test that provides a simple, unitless numeric score that is generated via an algorithm for use in advanced liver fibrosis. It is indicated as a prognostic marker in conjunction with other laboratory findings and clinical assessments in patients with advanced fibrosis (F3 or F4) due to non-alcoholic steatohepatitis (NASH) to assess the likelihood of progression to cirrhosis and liver-related clinical events. Because ELF™ uses a blood sample rather than a biopsy, it can be used routinely for the same patient over time.
Limitations
Clumping may cause false low platelet count. Platelet satellitism around neutrophils will cause a pseudothrombocytopenia. RBC or WBC fragments including fragmented fragile leukemic cells and neutrophil pseudoplatelets may cause falsely elevated counts.
References
Specimen Requirements
Specimen
Serum and whole blood
Volume
Serum: 2 mL divided into two tubes, 1 mL for initial testing and 1 mL for possible reflex
Whole blood: tube filled to capacity
Minimum Volume
Serum: 1.5 mL divided into two tubes, 0.75 mL for initial testing and 0.75 mL for possible reflex
Whole blood: tube filled to capacity
Container
Gel-barrier tube or red-top tube and lavender-top (EDTA) tube
Collection Instructions
Serum: Separate from cells within 45 minutes of collection.
Whole blood: Invert EDTA tube immediately 8 to 10 times once tube is filled at the time of collection.
Stability Requirements
Temperature | Period |
|---|---|
Room temperature | Serum: 1 day; Whole blood: 1 day |
Refrigerated | Serum: 3 days; Whole blood: 3 days |
Frozen | Unstable |
Freeze/thaw cycles | Unstable |
Storage Instructions
Serum sample for initial testing and whole blood can be stored at room temperature. Serum sample for possible reflex can be stored refrigerated a 2°C to 8°C for 72 hours.
Causes for Rejection
Serum: Gross hemolysis; improper labeling
Whole blood: Hemolysis; clotted specimen; tube not filled with minimum volume; improper labeling; transfer tubes with whole blood; specimen diluted or contaminated with IV fluid; specimen received with plasma removed; specimen collected in any anticoagulant other than EDTA
LOINC® Map
| Order Code | Order Code Name | Order Loinc | Result Code | Result Code Name | UofM | Result LOINC |
|---|---|---|---|---|---|---|
| 402175 | FIB-4 w/Reflex to ELF | 001123 | AST (SGOT) | IU/L | 1920-8 | |
| 402175 | FIB-4 w/Reflex to ELF | 001545 | ALT (SGPT) | IU/L | 1742-6 | |
| 402175 | FIB-4 w/Reflex to ELF | 015172 | Platelets | x10E3/uL | 777-3 | |
| 402175 | FIB-4 w/Reflex to ELF | 011582 | FIB-4 Index | 98488-0 | ||
| Order Code | 402175 | |||||
| Order Code Name | FIB-4 w/Reflex to ELF | |||||
| Order Loinc | ||||||
| Result Code | 001123 | |||||
| Result Code Name | AST (SGOT) | |||||
| UofM | IU/L | |||||
| Result LOINC | 1920-8 | |||||
| Order Code | 402175 | |||||
| Order Code Name | FIB-4 w/Reflex to ELF | |||||
| Order Loinc | ||||||
| Result Code | 001545 | |||||
| Result Code Name | ALT (SGPT) | |||||
| UofM | IU/L | |||||
| Result LOINC | 1742-6 | |||||
| Order Code | 402175 | |||||
| Order Code Name | FIB-4 w/Reflex to ELF | |||||
| Order Loinc | ||||||
| Result Code | 015172 | |||||
| Result Code Name | Platelets | |||||
| UofM | x10E3/uL | |||||
| Result LOINC | 777-3 | |||||
| Order Code | 402175 | |||||
| Order Code Name | FIB-4 w/Reflex to ELF | |||||
| Order Loinc | ||||||
| Result Code | 011582 | |||||
| Result Code Name | FIB-4 Index | |||||
| UofM | ||||||
| Result LOINC | 98488-0 |
| Order Code | Order Name | Result Code | Result Name | UofM | Result LOINC | |
|---|---|---|---|---|---|---|
| Reflex 1 | 550659 | Enhanced Liver Fibrosis (ELF) | 550661 | ELF(TM) Score | 48795-9 | |
| Reflex 1 | ||||||
| Order Code | 550659 | |||||
| Order Name | Enhanced Liver Fibrosis (ELF) | |||||
| Result Code | 550661 | |||||
| Result Name | ELF(TM) Score | |||||
| UofM | ||||||
| Result LOINC | 48795-9 | |||||