Enhanced Liver Fibrosis (ELF™)
Alternate Name: ELF Atellica
SAL Code:
1300
CPT:
81517
Loinc:
88055-9
Turn Around Time:
3 days
Setup:
Mon-Sun
Methodology:
The reagents that comprise Atellica IM ELF are Atellica IM HA, Atellica IM PIIINP, and Atellica IM TIMP-1. These reagents are based on 2-site sandwich assay methodology and direct chemiluminescent technology, and are run on fully automated Atellica IM Analyzers.
Atellica IM HA reagents use hyaluronic acid binding protein (HABP) for both capture and detection of HA. The Lite Reagent contains HABP conjugated with acridinium ester, and the Ancillary Well Reagent contains HABP conjugated with fluorescein isothiocyanate (FITC). The Solid Phase contains an anti-FITC mouse monoclonal antibody covalently bound to paramagnetic particles.
Atellica IM PIIINP reagents use 2 mouse monoclonal antibodies (MAb). The antibody in the Lite Reagent is an acridinium-ester-labeled anti-PIIINP antibody. The antibody in the Ancillary Well Reagent is a biotin-labeled anti-PIIINP antibody. The Solid Phase contains streptavidin-coated paramagnetic particles.
Atellica IM TIMP-1 reagents use 2 mouse monoclonal antibodies (MAb) that bind to TIMP-1 in the Lite Reagent: an anti-TIMP-1 F(ab)2 antibody labeled with acridinium ester and an FITC-labeled anti-TIMP-1 antibody. The Solid Phase contains an anti-FITC mouse monoclonal antibody covalently bound to paramagnetic particles.
A direct relationship exists between the amount of HA, PIIINP, and TIMP-1 present in the patient sample and the amount of relative light units (RLUs) detected by the system.
For Atellica IM Analyzer systems, the ELF score is calculated using the following equation:
ELF score = 2.278 + 0.851 ln(CHA) + 0.751 ln(CPIIINP) + 0.394 ln(CTIMP-1)
Concentrations (C) of each of the constituents are in ng/mL.
Specimen Requirements:
Primary Tube:
SST
Primary Substance:
Serum
Temperature
Period
Stable Fridge:
365 days at <= -20 C
Clinical Info:
Atellica® IM Enhanced Liver Fibrosis (ELF™) is for in vitro diagnostic use in the determination of an ELF score based on the combined quantitative measurements of hyaluronic acid, amino-terminal propeptide of type III procollagen, and tissue inhibitor of matrix metalloproteinase 1 in human serum using the Atellica® IM Analyzer.
Atellica IM ELF 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.
Test Limitations:
- Measurements of HA, PIIINP and TIMP-1 must be obtained within 8 hours of one another for the ELF score to be valid.
- Atellica IM ELF is limited to the detection of HA, PIIINP, and TIMP-1 in human serum.
- Only use results obtained on the Atellica IM Analyzer to calculate ELF scores.
- Do not use hemolyzed samples.
- Do not use in patients taking biotin supplements.
- Do not use samples that contain fluorescein. Samples with fluorescein may cause falsely depressed results. Evidence suggests that patients undergoing retinal fluorescein angiography can retain amounts of fluorescein in the body for up to 72 hours posttreatment. In cases of patients with renal insufficiency, including many diabetics, retention could be longer.
- Patient samples may contain heterophilic antibodies that could react in immunoassays and cause falsely elevated or depressed results. This assay is designed to minimize interference from heterophilic antibodies. Additional information may be required for diagnosis.
- An ELF score < 9.80 is associated with a lower prognostic risk, but disease progression is still possible for patients with ELF measurements below this threshold.
- An ELF score = 11.30 is associated with a higher prognostic risk, but disease progression may not occur in patients with ELF measurements above this threshold.
- The reagents for HA, PIIINP, and TIMP-1 have only been clinically validated in terms of their combined contribution to the ELF score. Clinical decisions should not be based on individual measurements of HA, PIIINP, or TIMP-1.
- Atellica IM ELF is not for use in the diagnosis of NASH or for the staging of fibrosis.
- Atellica IM ELF is not for use in the serial monitoring of disease progression or for the monitoring of effects of therapeutic products.
- Test results are intended to be used in conjunction with other clinical and diagnostic findings, consistent with professional standards of practice, including information obtained by alternative methods, and clinical evaluation as appropriate.
- Always interpret results in conjunction with the patient's medical history, clinical presentation, and other findings.
Test Information:
Components:
| Component Name | CPT | Loinc |
| Enhanced Liver Fibrosis Score ™ (ELF) | - |