Is Liver Biopsy the Gold Standard?Mamta K. Jain, MD, MPH

What are the indications for a liver biopsy?

• Diagnosis of liver disease• Assess severity of liver disease• Assess response to treatment

Hepatitis B• Initial trials used pre-treatment and post-treatment biopsy to

assess response to nucleoside therapy• Knodell index grades histological activity from 0-22

– Periportal bridging necrosis (0-10)– Focal necrosis (0-4)– Portal inflammation (0-4)– Fibrosis (0-4)

• Treatment response based on 2 point decrease in necroinflammatory activity– composed of the first three parameters– measured (0-18)

Lai et al. New Engl J Med 1998;339:61-8

Hepatitis C

• Clinical trials have used viral response as primary endpoint

• Liver biopsies pre- and post- treatment were done for– Confirmation of chronic hepatitis, r/o other

causes, identify cirrhosis (staging)– Change in histological activity

• Knodell HAI• METAVIR

McHutchison et al. New Engl J Med 1998;339:1485-92Poynard et al. Lancet 1998;352:1426-32

Relationship Between Liver disease Stage and Fibrosis

• Fibrosis– excess collagen– Collagen proportion of liver fibrosis correlates with hepatic

venous pressure gradient (HVPG)– Increasing fibrosis has prognostic value– Histological assessment of fibrosis is by trichrome or

reticulin stains but does not correlate with quantitative amount of hepatic collagen

• Fibrosis is part of histologic staging of disease severity

Germani et al. Histopathology 2010; 57:773-784

Relationship Between Liver Disease Stage and Fibrosis

• Staging describes features that depend on architectural changes, not just degree of fibrosis

• Histopathologic assignment of liver disease stage is a different process from measurement of liver fibrosis

• Both measurements are complementary but are imperfectly correlated

Germani et al. Histopathology 2010; 57:773-784

Size of Liver Biopsy

• Smaller biopsy is associated with greater sampling error– Error reduced by increasing sample size and

number of biopsies performed– Study found 25 mm biopsy had error rate of 25%– Optimal size 40 mm

• But only 16% of samples are >20 mm

Bedossa et al. Hepatology 2003;38:1449-1457

Sampling Error

• Studies have shown 10-30% of cirrhosis was understaged by percutaneous liver biopsy

• Study of biopsy of the left and right lobe of the liver found discrepancy in 50% of the samples

– Inaccurate by 1 stage– Underestimation of inflammation

Maharaj et al. Lancet 1986; 1:523-25Poniachik et al. Gastrointest endosc 1996; 43:568-571Regev et al. Am J Gastroenterol 2002; 97:2614-2618.

Intra-observer Variability

• Intra-observer variability seen in up to 10% of samples and was 1 stage or 1 grade.

• Use of scoring system has made staging more consistent

Regev et al. Am J Gastroenterol 2002; 97:2614-2618.

Complications

• HALT-C reported complications of liver biopsy in HCV patients with advanced liver disease– 1.1 % serious adverse events– 0.6% due to bleeding (most common)

• More common if platelet <60,000• INR>1.3

Seeff et al. Clin Gastroentrol Hepatol 2010; 8:877--83.

Pro and Cons for Liver BiopsyPros• Steatosis assessment and

quantification• Fibrosis assessment and

architectural distortion• Iron level measurement• Diagnose other pathology

– Using special stains– other liver disease (viral

hepatitis + NAFLD, EtOH, etc)

Cons• Invasive• Risk of complications 1-5%

– Mortality .01% to 0.1%

• Limitations– Sampling error– Intra-observer variability

What are the alternatives?• Radiology

– CT– MRI– US– Hepatic elastography

• Serum markers of fibrosis– Indirect– Direct

Pros and Cons for RadiologyPros• Non-invasive• US with Doppler can be

used to support diagnosis of cirrhosis

• Accuracy 82-88%

Cons• Insufficient resolution to

detect earlier stages of fibrosis

Aube et al. J Hepatol 1999; 30:472-478Gaiani et al. J Hepatol 1997;27:979-985

Hepatic Elastography• Emerging technology to stage hepatic fibrosis• Elastography technique measures liver stiffness of

hepatic tissue (FibroScan; Echosens, Paris, France)• Ultrasound wave that produces elastic shear

– velocity of the shear wave is related to tissue stiffness– more rigid, the faster the wave travels

• Increased rigidity is marker of progressive fibrosis

Sandrin et al. Ultrasound Med Biol 2003;29:1705-1713.

Liver Fibrosis Measurement of Stiffness in Patients with HCV

• Pt distribution for METAVIR fibrosis stage, activity grade, and steatosis

• AUROC curve

Ziol et al. Hepatology 2005; 41:48-54.

0.79-0.810.91-0.95

0.97-0.99

http://www.google.com/imgres?imgurl=http://www.medgadget.com/archives/img/978546fib1.jpg&imgrefurl=http://medgadget.com/archives/2007/01/fibroscan.html&h=329&w=468&sz=40&tbnid=JNXkqwRFOYX8vM:&tbnh=90&tbnw=128&prev=/search?q=fibroscan+picture&tbm=isch&tbo=u&zoom=1&q=fibroscan+picture&hl=en&usg=__rblHIlGmbK5qFuwdPmzYveZaoFM=&sa=X&ei=E3ugTbSTNobG0QHU87iTBQ&ved=0CBkQ9QEwAA

Liver Stiffness and HVPG• HVPG– predictor of survival and

decompensation in cirrhotic patients• Liver stiffness measurement (LSM) predicted

severe portal hypertension in HCV patients• AUROC curves for prediction of HVPG

– >10mmHg was 0.99– >12mmHg was 0.92– LSM Cut-off values 13.6kPa sensitivity 97%– LSM Cut-off values 17.6kPa sensitivity 94%

Vizzutti et al. Hepatology 2007; 45:1290-97.

Pro and Cons for FibroScanPros• Non-invasive• Able to assess a much larger

proportion of the liver• Serial measurements to

evaluate fibrosis progression

Cons• Poor performance in mild to

moderate disease• Cannot be used in

– Patients with ascites– Morbid obesity (BMI>40)

• Cost• Cannot distinguish between

stage 0-II or III-IV

Serum Markers of Fibrosis

• Ideal biomarker– Liver specific– Independent of metabolic alterations– Detect fibrosis regardless of cause – Sensitive enough to distinguish between fibrosis

stages– Reflective of dynamic changes

Friedman. J Hepatol. 2003; 38 (Suppl 1); S38-S53.

Indirect Markers of Fibrosis

• FibroTest/FibroSure– Alpha-2 globulin– Alpha-2 macroglobulin– Gamma globulin– Apoliprotein A1– Gamma-glutamyl

transferase (GGT)– Total bilirubin

• ActiTest– Fibrotest +ALT

• Forns index• APRI• Fib-4• AST/ALT ratio• AST/ALT with plts

Afdhal and Shiffman 2006 www.CCO hepatitis.

FibroTest

• Classifies fibrosis into 1 of 3 categories– Mild (METAVIR F0-F1)– Significant (METAVIR F2-F4)– Indeterminate

• HCV– Detect F2 or higher stage

• 75% sensitivity• 85% specificity• Accuracy 46%

Imbert-Bismut Lancet. 2001;357:1069-1075.

ActiTest

• FibroTest + ALT– Reflects necro-inflammation and fibrosis– Better at identifying more advanced fibrosis

associated with histological inflammation– Meta-analysis of HCV patients found both

FibroTest and ActiTest reliable alternatives for liver biopsy.

Poynard et al. Comp Hepatol 2004;3:8.Halfon et al. Am J Gastroenterol. 2006;101:547-555

Forns Test• Uses 4 common clinical measurements

– Patient age– Cholesterol level– Platelet count– Gamma-glutamyl transpeptidase

• Studies HCV patients to – 96% NPV in mild fibrosis– 66% PPV in F2-F4

• Able to accurately exclude mild fibrosis• Inferior to FibroTest

Forns et al. Hepatology. 2003; 34 (4 pt 1): 986-992.Thabut et al. Hepatology. 2003:37:1220-1221

APRI• Uses clinical variables

– ALT and platelet count– NPV

• Significant fibrosis 86% • Cirrhosis 98%

– PPV• Significant fibrosis 88%• Cirrhosis 57%

– Able to exclude cirrhosis

Wai et al. Hepatology. 2003; 38: 518-526.

Fib-4 Index• Uses clinical variables

– Platelets– ALT– AST– Age

• <1.45 NPV 94.7% to exclude severe fibrosis (F3-F4) with sensitivity 74.3%

• >3.25 PPV significant fibrosis 82% with specificity of 98%• Fib-4 <1.45 or >3.25 (62% of all cases) was highly correlated

to FibroTest in 92% and 76%

Vallet-Pichard et al. Hepatology. 2007; 46: 32-36.

Indirect MethodsPros• Non-invasive• Less expensive• Useful in HCV for determining

significant fibrosis (METAVIR stage F2-F4) when HCV treatment is recommended

• May be most useful in fibrosis that is unevenly distributed

Cons• Not sensitive enough to

distinguish between stages• Degree of fibrosis does not

linearly correlate with biopsy stage

• May be better to evaluate for inflammation (i.e., FibroTest)

Direct Markers• Measure qualitative and quantitative

changes in extracellular matrix markers

• Markers matrix deposition– Procollagen type I carboxy-

terminal peptide– Procollagen type III amino-

terminal peptide– Tissue inhibitor of

metalloproteinase– Transforming growth factor-beta– Collagen type IV

• Markers of matrix removal– Procollagen Type IV C peptide– Procollagen Type IV N peptide– Matrix metalloproteinase

• Other markers– Hyaluronic acid– YkL-40

• Combination biomarker assay– FibroSpect– ELF– SHASTA

None of these markers are liver specific and are influenced by metabolism

Afdhal and Shiffman 2006 www.CCO hepatitis.

Is Liver Biopsy a Gold Standard?

• Perhaps it depends on why biopsy is being done• Yes, if it is :

– To diagnose a disease (excluding viral hepatitis)– To exclude other concomitant disease– To measure iron stores– To quantify steatosis– To get special stains for diagnosis– To stage liver disease if fibrosis is evenly distributed

Is Liver Biopsy a Gold Standard?

• No, if it is:– To determine cirrhosis– To evaluate for significant fibrosis– To determine stage if fibrosis is unevenly distributed– To follow longitudinally

Future• Hepatitis C

– With new DAA with high SVR rates, perhaps a liver biopsy is not needed?Biopsy is not typically performed in genotype 2 and 3 if patient willing to be treated

– If liver biopsy and elastography are not equivalent, then what impact does this have on patient characterization in clinical trials?Clinical trials are using FibroScan in Europe instead of liver biopsy

– Non-invasive tests need to be validated as predictors of poor outcomes and not just on correlation to liver biopsy stage

• Hepatitis B– Will we still need biopsy to determine disease activity to assess for

treatment?May not need biopsy in HIV/HBV who were started on ART with Truvada (treatment based on viral load and not on biopsy)

Conclusions

• Liver biopsy still plays an important role in– Diagnosis of some types of liver disease– Quantification of steatosis– Measurement of iron stores– To distinguish between earlier stages of disease

• Fibrosis can be determined by other means such as elastography or other non-invasive tests