Practice of FibroMax for steatosis and non-alcoholic steatohepatitisUp one level
FibroTest, SteatoTest and AshTest are non-invasive diagnostic tools for steatosis and non-alcoholic steatohepatitis (diabetes, overweight, hypertriglyceridemia, hypercholesterolemia, hypertension).
This article offers a review of steatosis and non-alcoholic steatohepatitis, their lesions and then the use of these diagnostic tests on a day-to-day basis.
Steatosis and non-alcoholic steatohepatitis - A brief reminder
Short history of the liver and metabolic diseases
At the beginning of the 1960's, liver toxicity from excessive alcohol consumption was detected, and since the 1980's and 1990's, the increasing role of viral hepatitis B and C in worldwide mortality has been described. Since 1990, the frequency of metabolic steatosis and the cirrhogenous risk of non-alcoholic steatohepatitis (NASH) in the subjects with metabolic factors (diabetes, overweight, hypertriglyceridemia, hypercholesterolemia, hypertension) were identified. Metabolic steatosis is now the most common cause of anomalies of the standard hepatic workup (transaminases and GGT).
Natural history of the disease
It is estimated that about 25% of the world population has hepatic steatosis related to the presence of at least one metabolic syndrome factor: diabetes, overweight, hypertriglyceridemia, hypercholesterolemia, hypertension. A small portion of these steatoses cases (less than 10%) may be complicated by necrosis and inflammation (NASH), fibrosis with risk of progression to cirrhosis and liver cancer.
Metabolic hepatic lesions
Hepatic fibrosis is a process of scarring through fibrous tissue deposit which results in the destruction of the parenchyma, with the ultimate progressive stage being cirrhosis.
The METAVIR score, initially developed to assess the stages of fibrosis in subjects with chronic viral hepatitis C and B, can also be used in patients with metabolic disease. The F1 stage must be defined as a perisinusoidal fibrosis without septum since contrary to the viral hepatitises, fibrosis does not begin in the portal area but in the centrilobular region.
The METAVIR score assesses the fibrosis in metabolic liver disease according to a 5-stage classification:
- F0 : no fibrosis
- F1 : perisinusoidal finbrosis without septa
- F2 : portal and periportal fibrosis with rare septum
- F3 : portal and periportal fibrosis with many septum
- F4 : cirrhosis
Hepatic steatosis is an accumulation of triglycerides in the hepatocytes.
The steatosis score is determined through the percentage of hepatocytes with cytoplasmic steatosis. It varies from 0 to 100%.
Necroinflammatory activity: non-alcoholic steatohepatitis (NASH)
The activity (or grade) estimates the significance of lesions of lobular inflammation, ballooning and necrosis.
The steatohepatitis score [or acute alcoholic hepatitis (NASH)] assesses the activity according to a consensual 3-grade diagnostic classification from a score combining steatosis, necrosis and inflammation (Kleiner NAS score):
- NAS 0-2 : no activity (no NASH)
- NAS 3-4 : possible activity (NASH possible)
- NAS 5-8 : certain activity (NASH certain)
The 3 BioPredictive tests for these 3 lesions
FibroTest measures the hepatic fibrosis stage with a blood test.
FibroTest was evaluated in relation to liver biopsy in 267 patients with nonalcoholic metabolic liver disease and has been used in over 350,000 patients (2008).
FibroTest retains the same diagnostic value independent of sex or transaminases.
FibroTest has the same diagnostic value for the intermediate stages and the extreme stages.
The use of FibroTest was validated for the diagnosis of fibrosis.
The French National Authority for Health (HAS) has not recommended the use of FibroTest as a first-line assessment tool for fibrosis with metabolic liver diseases, as with hepatitis C; the reevaluation however according to the latest positive published results is scheduled in 2009.
Interpretation of the FibroTest results
The FibroTest result is provided as a score of 0 to 1, proportional to the severity of the fibrosis, with a conversion to the METAVIR system (from F0 to F4). To facilitate the visual interpretation, the result must be accompanied by a colored graph with three classes of severity:
- Green (minimal or absent)
- Orange (moderate)
- Red (significant)
The conversion of FibroTest into stages according to the three most used histological classifications (METAVIR, Knodell and Ishak) is proposed in the following grid:
Using the same blood test, NashTest measures the degree of necroinflammatory activity of metabolic origin.
NashTest combines the FibroTest-ActiTest markers with AST, total cholesterol, triglycerides, fasting glucose, weight and height.
NashTest was validated in relation to liver biopsy in 267 subjects.
Interpretation of the NashTest results
The NashTest result is provided as a score in 3 classes: No NASH, possible NASH and certain NASH.
To facilitate the visual interpretation, the result must be accompanied by a colored graph with three classes of severity:
- Green: no NASH
- Orange: possible NASH
- Red: NASH certain
Fibromax (FibroTest + SteatoTest + NashTest) instructions for use
The use of our non-invasive tests is very simple: the physician writes a FibroMax prescription(available on the website).
The patient goes to a nearby laboratory for the ten-parameters blood test. FibroMax combines ten serum markers with the age, sex, height and weight of the patient:
- Apolipoprotein A1
- Gamma-glutamyl transpeptidase (GGT)
- Total bilirubin
- Total Cholesterol
- Blood sugar (fasting)
A prototype prescription is available on the website(download the prescription).
The FibroTest, SteatoTest and NashTest scores are provided together on a result sheet combining all the information. The laboratory (or the physician) connects to the BioPredictive website for calculation of the tests and prints the results sheet which is available immediately and is accompanied by an interpretation aid and precautions for use.
Precautions for use, safety
An expert system analyzes each FibroMax and its parameters in order to ensure their proper applicability. Over 95% of tests are interpretable and enable an effective diagnosis of fibrosis, steatosis and steatohepatitis. In less than 5% of cases, the expert system detects the profiles that are at risk of false positives or false negatives and clearly indicates them on the result sheet.
Applicability and safety integrated in the tests
FibroTest : 95-99%
FibroTest is applicable in 95 to 99% of cases. It has been validated for the following diseases : (available scientific publications)
- Chronic hepatitis C
- Chronic hepatitis B
- Chronic hepatitis C or B with HIV co-infection
- Alcoholic liver diseases (steatosis and steatohepatitis)
- Steatosis and non-alcoholic steatohepatitis (diabetes, overweight, hypertriglyceridemia, hypercholesterolemia, hypertension)
The test is robust and validated, including for the following specific populations:
- Subjects over the age of 65 years
- Patients with renal insufficiency and patients with renal transplanation
- Patients with chronic inflammatory disease
- General population
The tests are not applicable in only 1 to 5% of cases:
- Acute hepatitises, e.g., acute viral hepatitis A, B, C, D, E; drug-induced hepatitis
- Extrahepatic cholestasis, e.g., pancreatic cancer, gallstones
- Severe hemolysis, e.g., some cardiac valves
- Gilbert's syndrome with high unconjugated hyperbilirubinemia
- Acute inflammatory syndrome (the blood test just needs to be postponed)
These cases are detected by our safety mechanisms and are clearly indicated on the results sheet.
Only the analyses performed in pre-analytical and analytical conditions and using the automated analyzers and reagents validated by our reference center are authorized by BioPredictive.
Our systems are declared with the French Committee on Technologies and Freedom (CNIL) and guarantee the anonymity of the provided information. The BioPredictive information system implements a tracibility device on all of its processes, thus assuring its quality management.
Use of FibroMax in the management of non-alcoholic metabolic liver diseases (NAFLD).
The management of non-alcoholic metabolic liver diseases and the therapeutic decisions depend on the degree of fibrosis according to three classes of severity: green (minimal), orange (moderate) and red (significant), as well as the presence of nonalcoholic steatohepatitis.
Comparison of FibroTest and liver biopsy
Biopsy is an imperfect tool; due to sampling errors, biopsy size (5 to 30 mm) and intra- and interobservor variability, it is now agreed that biopsy presents a mean error of 30%: it is called the "imperfect Gold Standard". The "perfect Gold Standard" of the liver is utopian, it would essentially be necessary to use the entire liver to rule out any possibility of diagnostic error.
Biopsy continues to present major inconveniences: 30% of patients complain of pain, 0.6% have been noted to have severe complications and even 0.03% deaths. Its use as a first-line tool is no longer suitable, and as its repeatability is very weak, biopsy is not practical for patient monitoring.
FibroTest is a non-invasive diagnostic test (simple blood test) which is very easily reproduced and has the same relevance as a 25 mm biopsy.
There is a mean discordance of 25% observed between FibroTest and biopsy. Half of these discordances are attributable to an error of the biopsy, often too small, and the other half to FibroTest.
In conclusion, FibroTest has the same diagnostic value as a 25 mm biopsy, while being noninvasive and easily repeatable.
Key figures of FibroTest
|87,5 %||Diagnostic accuracy (percentage of true positives and true negatives compared to histology)|
|0 %||False positives within a population of 1,000 blood donors|
|0.84||Diagnostic value for advanced fibrosis, estimated by the area under the curve (AUROC)|
|0.90||Diagnostic value for cirrhosis, estimated by the area under the curve (AUROC)|
Here are several key references:
- Halfon et al, FibroTest-ActiTest as a non-invasive marker of liver ﬁbrosis. Gastroenterol Clin Biol 2008;32:22-38
- Poynard et al, Standardization of ROC curve areas for diagnostic evaluation of liver fibrosis markers based on prevalences of fibrosis stages. Clin Chem. 2007;53:1615-1622
- Poynard et al, Methodological aspects for the interpretation of liver fibrosis non-invasive biomarkers: a 2008 update. Gastroenterol Clin Biol 2008;32:8-21
- Ratziu et al, Diagnostic value of biochemical markers (FibroTest-FibroSURE) for the prediction of liver fibrosis in patients with non-alcoholic fatty liver disease BMC Gastroenterology 2006, 6:6
- Poynard et al,Diagnostic value of biochemical markers (NashTest) for the prediction of NASH in patients with non-alcoholic fatty liver disease. BMC Gastroenterol. 2006;6:34
- Poynard et al,The diagnostic value of biomarkers (SteatoTest) for the prediction of liver steatosis Comp Hepatol. 2005;4:10
- Munteanu et al, Noninvasive biomarkers for the screening of fibrosis, steatosis and steatohepatitis in patients with metabolic risk factors: FibroTest-FibroMax Experience. J Gastrointestin Liver Dis. 2008;17:187-91
The complete list of publications is available on the website : liste des publications.