Serum markers used in the evaluation and monitoring of chronic liver disease are indirect and direct measures of liver fibrosis. The stage of fibrosis is the most important single predictor of significant morbidity and mortality in individuals with hepatitis C and other chronic liver diseases. This document addresses serum marker tests (e.g., FibroSure^™ [also known as FibroTest or ActiTest] [Laboratory Corporation of America, Burlington, NC]; FIBROSpect II^® [Prometheus Laboratories, Inc., San Diego, CA]) used in the evaluation and monitoring of individuals with hepatitis C and other chronic liver diseases.

Investigational and Not Medically Necessary:

Serum marker tests of hepatic fibrosis, used to produce a predictive score indicating the probability of liver fibrosis, are considered investigational and not medically necessary in the diagnosis and monitoring of individuals with hepatitis C or other chronic liver disease.

While there have been many studies of individual and groups of serum markers, in different populations with liver disease, recently, there has been interest in analyzing multiple markers using proprietary algorithms to generate a score categorizing individuals corresponding to the METAVIR score, which is a commonly used scoring system designed to monitor fibrosis progression in liver biopsies. It is proposed these serum marker tests can be used as an alternative to liver biopsy in individuals with liver disease, particularly hepatitis C.

FibroSure and FIBROSpect II 

Initial research into the FibroSure algorithm involved testing an initial panel of 11 serum markers in 339 individuals with liver fibrosis who had undergone liver biopsy (Imbert-Bismut, 2001). From the original group of 11 markers, five were selected as the most informative, based on logistic regression, neural connection, and receiver operating curves. Markers included alpha-2 macroglobulin, haptoglobin, gamma globulin, apolipoprotein A1, gamma glutamyl transpeptidase and total bilirubin. Using an algorithm-derived scoring system ranging from 0–1.0, the authors reported a score of less than 0.10 was associated with a negative predictive value of 100% (i.e., absence of fibrosis, as judged by liver biopsy scores of METAVIR F2 -F4). A score greater than 0.60 was associated with a 90% positive predictive value of fibrosis (i.e., METAVIR F2 - F4). The authors concluded liver biopsy might be deferred in those with a score less than 0.10.

The next step in the development of this test was the further evaluation of the algorithm in a cross section of individuals, including those with hepatitis C participating in large clinical trials before and after the initiation of antiviral therapy. One study focused on subjects with hepatitis C who were participating in a randomized study of peginterferon and ribavirin (Poynard, 2003). From the 1,530 participants, 352 subjects with stored serum samples and liver biopsies at study entry and at 24-week follow-up were selected. The FibroSure score was calculated and then compared to the METAVIR liver biopsy score. At a cutoff point of 0.30, the FibroSure score had 90% sensitivity and 88% positive predictive value for the diagnosis of METAVIR F2-F4. The specificity was 36%, and the negative predictive value was 40%. There was a large overlap in scores for those in the METAVIR F2-F4 categories, and thus the scoring system has been primarily used to subdivide individuals with and without fibrosis (i.e., METAVIR F0-F1 vs. F2-F4). When used as a monitoring test, individuals can serve as their own baseline. Those with a sustained virological response to interferon also experienced reductions in the FibroTest or ActiTest scores.

Further studies were done to formally validate the parameters used to calculate the FibroSure scores. Acceptable levels of "intra-laboratory and intra-patient variability" were reported (Halfon, 2002; Imbert-Bismut, 2004). Poynard and colleagues (2004) also evaluated discordant results in 537 individuals who underwent liver biopsy and the FibroTest and ActiTest on the same day; with the discordance attributed to either to the limitations in the biopsy or serum markers. In this study, cutoff values were used for the individual METAVIR scores (i.e., F0-F4) and for combinations of METAVIR scores (i.e., F0-F1, F1-F2, etc.). The definition of a significant discordance between FibroTest and ActiTest and biopsy scores was a discordance of at least two stages or grades in the METAVIR system. Discordance was observed in 29% of these individuals. Risk factors for biopsy failure included the biopsy size, number of fragments, and the number of portal tracts represented in the biopsy sample. Risk factors for failure of the FibroSure scoring system were presence of hemolysis, inflammation, possible Gilbert syndrome, acute hepatitis, drugs inducing cholestasis, or an increase in transaminases. Discordance was attributable to markers in 2.4% and to the biopsy in 18% and nonattributed in 8.2% of these individuals. The authors suggest biopsy failure, frequently due to the small size of the biopsy sample, is a common problem. As noted in two reviews, the bulk of the research regarding FibroSure was conducted by researchers with an interest in the commercialization of the algorithm (Afdhal, 2003; Lichtinghagen, 2004). Rossi (2003) attempted to independently duplicate the results of FibroSure in 125 individuals with hepatitis C. Using the cutoff point of less than 0.1 to identify lack of bridging fibrosis (i.e., METAVIR stages F0-F1) and greater than 0.6 to identify fibrosis (i.e., METAVIR stages F2-F4), the negative predictive value for a score <0.1 was 89%, compared to the 100% originally reported by Imbert-Bismut, and the positive predictive value of a score greater than 0.6 was 78% compared to 90%. The reasons for the inferior results in this study are unclear, but the authors concluded the FibroSure score did not accurately predict the presence or absence of fibrosis and could not reliably be used to reduce the need for liver biopsy.

More recent studies have attempted to validate the FibroSure test. Ratzui and colleagues (2006) conducted a study to determine the diagnostic validity of the FibroTest in nonalcoholic liver disease. For advanced fibrosis, FibroTest had a sensitivity of 77% for advanced fibrosis, and a specificity of 98%. One of the researchers has a commercial interest in the algorithm. Halfon and colleagues (2006) compared liver biopsy results with the FibroTest in individuals with chronic hepatitis C. In 18% of those tested, there were at least two stages of discordance between the serum test and liver biopsy. Poynard and collegues (2007) studied the diagnostic value of FibroTest in chronic liver disease by performing meta analyses of both published studies and individual data. Based upon study results, the authors concluded the FibroTest could be used as an alternative to biopsy in those with chronic hepatitis C and B, alcoholic liver disease, and non alcoholic fatty liver disease. Of note, the primary author of this study has a capital interest in the company marketing FibroTest. Shaheen and colleagues (2007) compared FibroTest and another technique (FibroScan) to biopsy in individuals with hepatitis C related fibrosis. For significant fibrosis, FibroTest had a sensitivity of 47% and a specificity of 90%. There was lesser accuracy for earlier stages of fibrosis. The authors noted these tests are not ready to replace liver biopsy and additional studies should be conducted.

Although FibroSure test is reported to be widely disseminated and accepted in France, a literature search of English language publications did not identify any clinical article in which the HCV FibroSure was actively used in the management of an individual's medical care. It is not clear whether the HCV FibroSure could be used in lieu of an initial liver biopsy, or whether it could be used as an interval test in individuals receiving therapy to determine whether an additional liver biopsy was necessary.

In contrast to the FibroSure test, there are minimal published data regarding FIBROSpect II. Patel and colleagues (2004) investigated the use of these serum markers in an initial training set of 294 individuals with hepatitis C and further validated the resulting algorithm in a validated set of 402 individuals. The algorithm was designed to distinguish between no/mild fibrosis (F0-F1) and moderate to severe fibrosis (F2-F4). With the prevalence of F2-F4 disease of 52% and a cutoff value of 0.36; the positive and negative predictive values were 74.3% and 75.8%, respectively. No studies were identified in the published literature in which results of the FIBROSpect II test were actively used in the management of the individual's medical care. Zaman and colleagues (2007) prospectively studied FIBROSpect II by obtaining serum from 108 consecutive individuals with hepatitis C seen at a single center hepatology clinic at the time of liver biopsy. The performance of FIBROSpect II was assessed by comparing the serum results with the liver biopsy. The sensitivity and specificity of FIBROSpect II were 71.8%, and 73.9%, respectively. In a more recent study, Patel and colleagues (2008) prospectively compared the FIBROSpect II against pathology assessments and a quantitative measure of fibrosis. Liver biopsy specimens and serum were obtained from 252 individuals with chronic hepatitis C from three centers. Biopsy specimens were scored at each center and quantification of fibrosis was performed by digitized morphometry. Serum tests were blinded to clinical or histologic evaluation. The sensitivity and specificity of FIBROSpect II were determined to be 83.5% and 66.7%, respectively, with an accuracy of 80.2%. The authors noted: "Assessing the diagnostic utility of biomarkers is limited by variability in methods to quantify fibrosis and poor interobserver agreement for histologic staging."

Other Scoring Systems 

Other serum marker scoring systems have been developed. For example the APRI scoring system (aspartate aminotransferase [AST] to platelet ratio) requires only the serum level of AST and the number of platelets, and uses a simple non-proprietary formula that can be calculated at the bedside to produce a score for the prediction of fibrosis (Wai, 2003). Using an optimized cutoff value derived from a training set and validation set of subjects with hepatitis C, the authors reported the negative predictive value for fibrosis was 86% and the positive predictive value was 88%. Rosenberg and colleagues (2004) developed a scoring system based an algorithm combining hyaluronic acid, amino terminal propeptide of type III collagen, and TIMP-1. The algorithm was developed in a test set of 400 individuals with a wide variety of chronic liver diseases and then validated in another 521 subjects. The algorithm was designed to discriminate between no or mild fibrosis and moderate to severe fibrosis. The negative predictive value for fibrosis was 92%.

Specialty Societies 

In a technical review on the management of hepatitis C, the American Gastroenterology Association (2006) states:

"Neither clinical nor laboratory markers, individually or in combination, predict accurately the degree of necroinflammatory activity or the level of fibrosis in the liver. Therefore, despite sampling error, liver biopsy remains the gold standard for determining histologic grade and stage." The American Association for the Study of Liver Disease's (2009) updated practice guideline on the diagnosis, management, and treatment of hepatitis C includes a recommendation which indicates current noninvasive tests should not replace the liver biopsy in routine clinical practice.

Conclusion 

There is no evidence indicating that changes in serum marker values over time correlates with changes in liver fibrosis. Published studies have emphasized 'static' time points rather than changes over time. Currently, evidence based data do not support the use of these markers; however, continued study and progress to establish their need may lead to the possibility they may ultimately find a place in predicting prognosis or risk of complications.

The hepatitis C virus (HCV) causes liver inflammation and can lead to severe liver damage, cirrhosis and hepatocellular carcinoma (HCC). According to the American Gastroenterology Association, in the United States, HCV infection is responsible for approximately 40% of all chronic liver disease, results in estimated 8,000–10,000 deaths annually, and is the most frequent indication for liver transplantation. Approximately 4 million persons have been infected and 3 million have chronic HCV infection. HCV is spread primarily by contact with blood and blood products. However, many individuals become infected with HCV without any known exposure to blood or to drug use. It is estimated that 70% of all HCV-infected individuals will eventually develop chronic liver disease and at least 20 percent will develop cirrhosis, a process that takes 10 to 20 years. After 20 to 40 years, a smaller percentage of individuals with chronic liver disease develop HCC. The population identified as high-risk for developing HCC includes males, people with a history of substance abuse; those diagnosed with cirrhosis, individuals over age 40, and those infected for 20 to 40 years.

Antiviral therapy is the recommended treatment for individuals with a reactive enzyme immunoassay for antibody to HCV, the presence of HCV RNA, and compensated liver disease. Liver biopsy is typically recommended prior to the initiation of antiviral therapy, and repeat biopsies may be performed to monitor fibrosis progression. Liver biopsies are analyzed according to a histologic scoring system; the most commonly used one is the METAVIR scoring system, which scores fibrosis from F0-F4. A METAVIR score of F2 to F4 indicates significant fibrosis, while a score of F3 and F4 signifies advanced fibrosis. Biopsies can also be evaluated according to the degree of inflammation presented, referred to as the grade or activity level. For example, the METAVIR system includes scores for necroinflammatory activity ranging from A0 to A3 (A0= no activity, A1 = minimal activity, A2 = moderate activity, A3 = severe activity). However, several limitations to liver biopsy are noted, including its invasive nature, small sample size, and subjective grading system. Regarding small sample size, liver fibrosis can be patchy and thus missed on a biopsy sample, which includes only 1:50,000 of the liver tissue.

A noninvasive alternative to liver biopsy would be particularly helpful, both as an initial assessment and then as a monitoring tool to assess response to therapy. A variety of laboratory tests have been proposed as an alternative to liver biopsy. Laboratory tests can be broadly categorized into indirect and direct markers of liver fibrosis. Indirect markers include liver function tests such as ALT (alanine aminotransferase), AST (aspartate aminotransferase), the ALT/AST ratio (also referred to as the AAR), platelet count and prothrombin index. In recent years there has been growing understanding of the underlying pathophysiology of fibrosis, leading to direct measurement of the factors involved. For example, the central event in the pathophysiology of fibrosis is activation of the hepatic stellate cell. Normally, the stellate cells are quiescent, but are activated in the setting of liver injury, producing a variety of extracellular matrix (ECM) proteins. In normal livers, the rate of ECM production equals its degradation, but in the setting of fibrosis, production exceeds degradation. Metalloproteinases are involved in intracellular degradation of ECM, and a profibrogenic state exists when there is either a down regulation of metalloproteinases or an increase in tissue inhibitors of metalloproteinases (TIMP). Both metalloproteinases and TIMP can be measured in the serum, which directly reflect fibrotic activity. Other direct measures of ECM deposition include hyaluronic acid or alpha-2 macroglobulin.

FibroSure uses a combination of 6 serum biochemical indirect markers of liver function plus age and gender in a patented algorithm to generate a measure of fibrosis and necroinflammatory activity in the liver corresponding to the METAVIR scoring system for stage (i.e., fibrosis) and grade (i.e., necroinflammatory activity). The biochemical markers include the readily available measurements of alpha-2 macroglobulin, haptoglobin, gamma glutamyl transpeptidase (GGT), ALT, and apolipoprotein A1. The test was originally developed in France and in the United States is now offered by LabCorp.

FIBROSpect II uses a combination of 3 markers that directly measure fibrogenesis of the liver, analyzed with a patented algorithm. The markers include hyaluronic acid, TIMP-1 and alpha-2 macroglobulin. FibroSpect II is offered by Prometheus Laboratories.

Algorithm: A process or set of rules by which a calculation or process can be carried out usually referring to calculations that will be done by a computer.

Biopsy: A procedure that involves obtaining a tissue specimen for microscopic analysis to establish a precise diagnosis.

Fibrosis: The development of excess fibrous connective tissue in an organ.

Serum: The clear, straw-colored, liquid portion of blood plasma that does not contain fibrinogen or blood cells and remains fluid after clotting.

The following codes for treatments and procedures applicable to this document are included below for informational purposes.  Inclusion or exclusion of a procedure, diagnosis or device code(s) does not constitute or imply member coverage or provider reimbursement policy.  Please refer to the member's contract benefits in effect at the time of service to determine coverage or non-coverage of these services as it applies to an individual member.

When Services are Investigational and Not Medically Necessary:
When the code describes a procedure indicated in the Position Statement section as investigational and not medically necessary.

Future ICD-10 coding (effective 10/01/2013)
A draft of ICD-10 Coding related to this document, as it might look today, is available for reference and comments at: Appendix 1: Future ICD-10 coding

Peer Reviewed Publications:

1. Afdhal NH, Nunes D. Evaluation of liver fibrosis: a concise review. Am J Gastroenterol. 2004; 99(6):1160-1174.
2. Callewaert N, Van Vleirberghe H, Van Heckle A., et al. Noninvasive diagnosis of liver cirrhosis using DNA sequence-based total serum protein glycomics. Nat Med. 2004; 10(4):429-434.
3. Colletta C, Smirne C, Fabris C, et al. Value of two noninvasive methods to detect progression of fibrosis among HCV carriers with normal aminotransferases. Hepatology. 2005; 42(4):838-845.
4. Crockett SD, Kaltenbach T, Keeffe EB. Do we still need a liver biopsy?  Are the serum fibrosis tests ready for prime time? Clin Liver Dis. 2006; 10(3):513-534.
5. Halfon P, Bourliere M, Deydier R, et al. Independent prospective multicenter validation of biochemical markers (Fibrotest –Actitest) for the prediction of liver fibrosis and activity in patients with chronic hepatitis C: The Fibropaca Study. Am J Gastroenterol 2006; 101(3):547-555.
6. Halfon P, Imbert-Bismut F, Messous D, et al. A prospective assessment of the interlaboratory variability of biochemical markers of fibrosis (FibroTest) and activity test (ActiTest) in patients with chronic liver disease. Comp Hepatol. 2002; 1(1):3.
7. Imbert-Bismut F, Messous D, Thibaut V, et al. Intra-laboratory analytical variability of biochemical markers of fibrosis (Fibrotest) and activity (Actitest) and reference ranges in healthy blood donors. Clin Chem Lab Med. 2004; 42(3):323-333.
8. Imbert-Bismut F, Ratziu V, Pieroni L, et al. Biochemical markers of liver fibrosis in patients with hepatitis C virus infection: a prospective study. Lancet. 2001; 357(9262):1069-1075.
9. Kelleher TB, Afdhal N. Noninvasive assessment of liver fibrosis. Clin Liver Dis. 2005; 9(4):667-683.
10. Kelleher TB, Mehta SH, Bhaskar R, et al. Prediction of hepatic fibrosis in HIV/HCV co-infected patients using serum fibrosis markers: the SHASTA index. J Hepatol. 2005; 43(1):78-84.
11. Lackner C, Struber G, Liegl B, et al. Comparison and validation of simple noninvasive tests for prediction of fibrosis in chronic hepatitis C. Hepatology. 2005; 41(6):1376-1382.
12. Lichtinghagen R, Bahr MJ. Noninvasive diagnosis of fibrosis in chronic liver disease. Expert Rev Mol Diagn. 2004; 4(5):715-726.
13. Patel K, Gordon SC, Jacobson I, et al. Evaluation of a panel of non-invasive serum markers to differentiate mild from moderate-to-advanced liver fibrosis in chronic hepatitis C patients. J Hepatol. 2004; 41(6):935-942.
14. Patel K, Nelson DR, Rockey DC, et al. Correlation of FIBROSpect II with histologic and morphometric evaluation of liver fibrosis in chronic hepatitis C. Clin Gastroenterol Hepatol. 2008; 6(2):242-247.
15. Poynard T, McHutchison J, Manns M, et al. Biochemical surrogate markers of liver fibrosis and activity in a randomized trial of peginterferon alfa-2b and ribavirin. Hepatology. 2003; 38(2):481-492.
16. Poynard T, Morra R, Halfon P, et al.Meta-analyses of FibroTest diagnostic value in chronic liver disease. BMC Gastroenterol. 2007; 7:40.
17. Poynard T, Munteanu M, Imbert-Bismut F, et al. Prospective analysis of discordant results between biochemical markers and biopsy in patients with chronic hepatitis C. Clin Chem. 2004; 50(8):1344-1355.
18. Ratziu V, Massard J, Charlotte F, et al. Diagnostic value of biochemical markers (FibroTest-FibroSURE) for the prediction of liver fibrosis in patients with non-alcoholic fatty liver disease. BMC Gastroenterol. 2006; 14(6):6.
19. Rockey DC, Bissell DM. Noninvasive measures of liver fibrosis. Hepatology. 2006; 43(2 Suppl 1):S113-120.
20. Rosenberg WM, Voelker M, Thiel R, et al. Serum markers detect the presence of liver fibrosis: a cohort study. Gastroenterology. 2004; 127(6):1704-1713.
21. Rossi E, Adams L, Prins A, et al. Validation of the FibroTest biochemical markers score in assessing liver fibrosis in hepatitis C patients. Clin Chem 2003; 49(3):450-454.
22. Shaheen AA, Wan AF, Myers RP. FibroTest and FibroScan for the prediction of hepatitis C-related fibrosis: a systematic review of diagnostic test accuracy. Am J Gastroenterol. 2007; 102(11):2589-2600.
23. Wai CT, Greenson JK, Fontana RJ, et al. A simple noninvasive index can predict both significant fibrosis and cirrhosis in patients with chronic hepatitis C. Hepatology. 2003; 38(2):518-526.
24. Zaman A, Rosen HR, Ingram K, et al. Assessment of FIBROSpect II to detect hepatic fibrosis in chronic hepatitis C patients. Am J Med. 2007; 120(3):280.e9-14.

Government Agency, Medical Society, and Other Authoritative Publications:

1. Dienstag JL, McHutchison JG. American Gastroenterological Association medical position statement on the management of hepatitis C. Gastroenterology. 2006a; 130(1):225-230.
2. Dienstag DL, McHutchison JG. American Gastroenterological Association technical review on the management of hepatitis C. Gastroenterology 2006b; 120(1):231-264.
3. Ghany MG, Strader DB, Thomas DL, Seeff LB; American Association for the Study of Liver Diseases. Diagnosis, management, and treatment of hepatitis C: an update. Hepatology. 2009; 49(4):1335-1374.
4. National Institute of Health (NIH). Management of hepatitis C. 2002. Rockville, MD NIH, August 26, 2002.
5. Strader DB, Wright T, Thomas DL, Seeff LB; American Association for the Study of Liver Diseases.  Diagnosis, management, and treatment of hepatitis C. Hepatology. 2004; 39(4):1147-1171.

1. The National Institute of Diabetes and Digestive and Kidney Diseases of the National Institutes of Health. Chronic Hepatitis C: Current Disease Management. NIH Publication: 07-4230. January, 2010. Available at: http://digestive.niddk.nih.gov/ddiseases/pubs/chronichepc/index.htm. Accessed on December 15, 2010.

ActiTest
FIBROSpect
FIBROSpect II
FibroSure
FibroTest
FSII
FT
HCV FibroSURE^™
Liver Fibrosis, Serum Markers for
Serum Markers, Liver Fibrosis 

The use of specific product names is illustrative only.  It is not intended to be a recommendation of one product over another, and is not intended to represent a complete listing of all products available.