The liver is one of the most important organs of the body. It performs many jobs, such as those listed below.

making proteins, cholesterol, bile, heme, and other substances
regulating fats in the body
activating vitamins and drugs
detoxifying harmful chemicals

With all of these important jobs, many things can potentially go wrong if the liver is damaged. Further complicating the disease is the fact that, although the hepatitis C virus (HCV) primarily infects the liver, it can affect any organ system of the body.

One tool health care providers use to find out how HCV is affecting your body is laboratory testing. A large number of tests are available to help your health care providers find out what is happening inside your body. This section describes some of the most common laboratory tests used to diagnose and/or monitor chronic hepatitis C.

Your health care provider will consider your symptoms and disease status in deciding which tests you need and when they should be done. Therefore, you should not look at this list as tests that should be done, but rather as a list of tests that may be helpful in specific situations.

Other tests are available that are not listed here. If your health care provider orders a test you are not familiar with, ask him or her what the test is and why it is being done. If you are considering interferon-based therapy, be sure to read, "What You Need to Know Regarding Therapy" in Chapter 9, Section 2: Allopathic Medicine, Initial Treatment Options for a complete list of recommended tests before, during, and after treatment.

What is Normal?

Each testing laboratory has its own range of "normal" values for each test. A laboratory's normal range means that the majority of people in good health tested by that laboratory have values within this range. Your test results will be compared to the laboratory's normal range. If you have had the same test done before, the new result will be compared to previous results. This allows your health care provider to look for changes over time. It is important for you and your health care provider to know what laboratory is conducting your tests to ensure that appropriate comparisons are being made.

We suggest that you request copies of your laboratory test results for your own files. This can help you better understand your disease process.

Liver Enzymes and Liver Function Tests

You will probably hear your health care providers talk about liver enzymes and liver function tests (LFTs). These two broad categories of tests give your health care providers different information about what is happening in your liver.

Liver enzymes are proteins inside liver cells. When liver cells are damaged, liver enzymes are released into the blood. Therefore, liver enzyme tests indicate how much damage is occurring to your liver. Examples of liver enzymes that are frequently monitored in chronic hepatitis C include AST, ALT, GGT and alkaline phosphatase.

Although liver enzymes indicate how much damage is being done to the liver cells, they do not tell your health care provider how much repair is taking place. Unlike many other organs, the liver has a remarkable ability to repair itself. This is important when considering liver enzymes because, although there may be ongoing damage to liver cells, the liver may be able to repair this damage without a decrease in function.

What?
Alpha-fetoprotein is a substance normally found in only trace amounts in the body. High amounts may indicate the presence of a tumor.
Why Test?
People with chronic hepatitis C are at increased risk for liver cancer. Alpha-fetoprotein is a tumor marker for liver cancer, meaning an abnormally high amount may indicate the presence of a cancerous liver tumor. Elevated alpha-fetoprotein does not always indicate the presence of liver cancer. However, it is often used to screen for the disease in people with HCV.

ALT - see alanine aminotransferase

aminopyrine clearance test

What?
Aminopyrine is a chemical used to determine how well the liver is metabolizing and detoxifying substances.
Why Test?
Two of the liver's many important jobs are to metabolize drugs and detoxify foreign chemicals. The aminopyrine clearance test is used to determine how well the liver is performing these jobs. A single test does not give much useful information, but comparing a series of tests over time can show if liver function is decreasing.

ammonia

What?
Ammonia is a chemical normally found in very low levels in the blood. It comes from the normal breakdown of proteins in the body.
Why Test?
One potential complication of cirrhosis and portal hypertension is a condition called hepatic encephalopathy. See Chapter 4, Signs and Symptoms That May be Associated with Hepatitis C for an explanation of hepatic encephalopathy. Ammonia levels are high in hepatic encephalopathy and testing for ammonia can help make the diagnosis.

anti-HCV antibodies

Other Names
HCV antibodies, hepatitis C screening test, HCV-EIA
What?
After being exposed to the hepatitis C virus, the body develops several different types of antibodies to the virus. The anti-HCV test detects these antibodies.
Why Test?
The presence of HCV antibodies indicates a person has been exposed to HCV. Several different tests are available to detect HCV antibodies. Depending on the test used, there are differences in how soon HCV antibodies can be detected in the blood after exposure to the virus. If this screening test is positive, a second test called a confirmatory test may be performed so you and your health care provider will know for sure whether you have been exposed to HCV. The anti-HCV antibody test cannot tell whether you currently have the hepatitis C virus in your body. It only determines whether you have been exposed to the virus.

anti-liver-kidney microsomal antibodies (anti-LKM)

What?
Anti-liver-kidney microsomal antibodies are a type of autoantibody. Normally, the body makes antibodies only against foreign substances such as bacteria and viruses. Autoantibodies are abnormal antibodies that act against your own cells.
Why Test?
More than half of all people with chronic hepatitis C have one or more autoantibodies in their blood. This is important to know because autoantibodies can cause additional symptoms and disease.

anti-nuclear antibodies (ANA)

What?
Anti-nuclear antibodies are a type of autoantibody. Normally, the body makes antibodies only against foreign substances such as bacteria and viruses. Autoantibodies are abnormal antibodies that act against your own cells.
Why Test?
More than half of all people with chronic hepatitis C have one or more autoantibodies in their blood. This is important to know because autoantibodies can cause additional symptoms and disease.

anti-smooth muscle antibodies (anti-SMA)

What?
Anti-smooth muscle antibodies are a type of autoantibody. Normally, the body makes antibodies only against foreign substances such as bacteria and viruses. Autoantibodies are abnormal antibodies that act against your own cells.
Why Test?
More than half of all people with chronic hepatitis C have one or more autoantibodies in their blood. This is important to know because autoantibodies can cause additional symptoms and disease.

APTT - see partial thromboplastin time

aspartate aminotransferase (AST)

Other Names
aspartate transaminase, previously called glutamate oxaloacetate transaminase (GOT or SGOT)
What?
AST is an enzyme found in liver cells. It is also found in other cells such as those of the heart and muscles. The largest amounts of AST are found in the heart and liver.
Why Test?
Testing the blood for AST is one way of telling if liver cells are dying. When liver cells die, AST is released into the blood. AST levels rise over a period of 7-12 days, and then slowly return to normal. When there is ongoing liver cell death, AST levels remain elevated. Your AST level tells your health care provider how much ongoing damage is occurring in your liver. However, an elevated AST level does not necessarily mean your liver disease is getting worse because this test cannot determine how much repair is occurring and how many new liver cells are being produced.

AST - see aspartate aminotransferase

bicarbonate (HCO3)

Other Names
total carbon dioxide
What?
Bicarbonate is a charged particle called an electrolyte. It is one of four major electrolytes in the body.
Why Test?
Electrolytes perform many important jobs in the body. Two of the most important jobs are regulating the amount of water in your body and keeping your blood pH normal. Some people with hepatitis C hold more water in their bodies than they need. This can cause abnormal bicarbonate levels. This is more likely in people with cirrhosis than in those without cirrhosis.

bile acids

What?
Bile acids are a group of chemicals produced by the breakdown of cholesterol.
Why Test?
A blood bile acid level is a sensitive indicator of liver and gall bladder function. Abnormal bile acid levels suggest abnormal functioning of the liver and/or gall bladder.

bilirubin, conjugated

Other Names
direct bilirubin
What?
Bilirubin is a yellow chemical produced during the normal breakdown of red blood cells. Bilirubin is normally processed by the liver into other substances that can be eliminated from the body. There are two forms of bilirubin in the body, conjugated (direct) bilirubin and unconjugated (indirect) bilirubin. Conjugated bilirubin is bilirubin that is attached to another chemical called glucuronic acid in a process called conjugation. Conjugation takes place inside liver cells. Conjugated bilirubin is excreted in the bile. Normally, conjugated bilirubin makes up less than 10% of the total bilirubin.
Why Test?
If the total bilirubin in the blood is high, it is important to know how much of it is conjugated because this tells your health care provider what process in the liver is not working normally. High amounts of conjugated bilirubin mean the bile flow is blocked either inside or outside the liver. Problems inside the liver such as hepatitis, fibrosis, and cirrhosis can cause increased conjugated bilirubin. Problems outside the liver such as gallstones can also cause increased conjugated bilirubin. A high level of conjugated bilirubin in the blood can also be detected in the urine.

bilirubin, total

What?
Bilirubin is a yellow chemical produced during the normal breakdown of red blood cells. Bilirubin is normally processed by the liver into other substances that can be eliminated from the body.
Why test?
Testing the blood for bilirubin is one measure of how well the liver is working. When the liver is not working normally, bilirubin can build up in the body. If bilirubin levels get very high, the skin and/or the whites of the eyes will become yellow, a condition called jaundice. However, bilirubin levels can be elevated without jaundice.

bilirubin, unconjugated

Other Names
indirect bilirubin
What?
Bilirubin is a yellow chemical produced during the normal breakdown of red blood cells. Bilirubin is normally processed by the liver into other substances that can be eliminated from the body. There are two types of bilirubin in the body, conjugated (direct) bilirubin and unconjugated (indirect) bilirubin. Conjugated bilirubin is bilirubin that is attached to another chemical called glucuronic acid in a process called conjugation. Conjugation takes place inside liver cells. Conjugated bilirubin is excreted in the bile. Unconjugated bilirubin has not undergone the conjugation process. Normally, unconjugated bilirubin makes up over 90% of the total bilirubin.
Why Test?
If the total bilirubin in the blood is high, it is important to know how much of it is unconjugated because this tells your health care provider what process in the liver is not working normally. In hepatitis, fibrosis, and cirrhosis, high amounts of unconjugated bilirubin signify the liver is not conjugating bilirubin normally causing unconjugated bilirubin to build up in the blood.

blood urea nitrogen (BUN)

What?
BUN is a chemical produced by the liver in the process of breaking down proteins.
Why Test?
BUN is most commonly measured to check how well the kidneys are working. BUN is normally eliminated from the body in the urine. When the kidneys are not working normally, BUN increases. Some people with advanced cirrhosis and liver failure develop a condition called hepatorenal syndrome. With this syndrome, the kidneys begin to fail because the liver is failing. BUN is one test used to check for hepatorenal syndrome in people with cirrhosis and liver failure.

In the absence of kidney failure, BUN is often lower than normal in people with cirrhosis and liver failure. This is because the failing liver does not metabolize proteins normally, and as a result, lower than normal amounts of BUN are produced. Because of this, BUN is one test that can be used to see how well the liver is performing one of its many jobs in people with cirrhosis and liver failure, but no kidney failure.

branched DNA test for HCV (b-DNA)

What?
The branched DNA (b-DNA) test for HCV is used to check for the presence of the virus in the blood.
Why Test?
The b-DNA test is used to measure the amount of detectable HCV in the blood. This is called the viral load. In order for a b-DNA test to be positive, there has to be a certain amount of virus in the blood. For this reason, a negative b-DNA test is reported as "undetectable," not zero. A negative b-DNA test does not mean there is no HCV in the blood, only that there is no detectable virus. The b-DNA test for HCV is not as sensitive as the HCV PCR test, another test used to check viral load. This means the b-DNA test cannot detect as low a viral load as the HCV PCR test.

HCV viral loads fluctuate within a very broad range. These fluctuations are typical of untreated, chronic hepatitis C. HCV viral loads do not reflect liver disease status nor disease progression. Therefore, many health care providers do not monitor HCV viral load in people who are not on interferon-based therapy. However, if you are considering interferon-based therapy or are on such treatment, your HCV viral load becomes important. HCV viral load is measured before and during interferon-based therapy because viral load is used to determine response to treatment. Research has shown that those people who experience a sustained viral response to interferon-based therapy have experience an early viral response (EVR). An early viral response to interferon-based therapy is defined as either undetectable HCV-RNA or at least a 2-log drop in HCV viral load by week 12-20 of treatment (at least a 100-fold decrease in viral load).

Health care providers often discuss viral load changes using the term "logs." The term "log" refers to the mathematical notation called logarithms. Although there are many log scales, when used to discuss viral load, the scale being referred to is log₁₀ or log base 10. While this may seem complicated, the use of logs is just a short-hand way of talking about viral load changes.

a 2-log change is a 100-fold change in viral load

Examples:
1,000 copies/mL to 100,000 copies/mL is a 2-log increase in viral load
(1,000 x 100 = 100,000)
8,500,000 copies/mL to 85,000 copies/mL is a 2-log decrease in viral load
(8,500,000 ÷ 100 = 85,000)

If you have questions about a change in your viral load, talk with your health care provider. He or she can explain what your test results mean.

BUN - see blood urea nitrogen

caffeine metabolism

What?
Caffeine is the stimulating chemical in coffee, black teas, colas, chocolate, and other foods. Caffeine is processed (metabolized) by the liver.
Why Test?
Caffeine metabolism decreases as liver function decreases. Therefore, caffeine metabolism is measured as one way to evaluate liver function. The rate of caffeine metabolism is markedly decreased in people with cirrhosis. Caffeine metabolism can be evaluated by checking the fasting caffeine level in the blood, measuring the release of radiolabeled carbon dioxide in the breath after a dose of labeled caffeine is administered, or measuring the rate of elimination of caffeine from the blood after a loading dose is administered.

calcium

What?
Calcium is a charged particle called an electrolyte. It is needed for many important functions of the body including bone formation and muscle contractions.
Why Test?
People with cirrhosis can have lower than normal vitamin D levels because it is not being absorbed normally in the intestines. When the level of vitamin D is too low, the amount of calcium in the blood also drops. Many different symptoms can occur if your calcium is too low.
If cirrhosis has led to development of hepatorenal syndrome in which both the kidneys and the liver fail, the blood calcium can actually become elevated, which can cause other problems.

CBC - see complete blood count

chloride (Cl)

What?
Chloride is a charged particle called an electrolyte. It is one of the four major electrolytes in the body.
Why Test?
Electrolytes perform many important jobs in the body. Two of the most important jobs are regulating the amount of water in your body and keeping your blood pH normal. Some people with hepatitis C hold more water in their bodies than they need. This can cause abnormal chloride levels. This is more likely in people with cirrhosis than in those without cirrhosis.

cholesterol

What?
Cholesterol is a lipid or fat that is both absorbed from the food we eat and manufactured by the liver. Normally, most of the circulating blood cholesterol comes from the liver, not from what we eat.
Why Test?
The liver is responsible for both production and breakdown of cholesterol. The liver breaks down cholesterol and excretes it into the bile. Blockage of bile flow either inside or outside the liver increases the amount of cholesterol in the blood. The more obstructed the bile flow, the higher the amount of cholesterol in the blood. Cirrhosis can block bile flow in the liver, and gallstones can block bile flow outside of the liver. Both of these situations can occur with chronic hepatitis C infection.

complete blood count (CBC)

What?
A CBC is a group of tests indicating the concentration and characteristics of cells circulating in the blood. A CBC typically includes the following tests: RBC count, WBC count, hemoglobin, hematocrit, and platelet count. Other tests may also be included.
Why Test?
See individual tests for an explanation of the role of each test in chronic hepatitis C.

conjugated bilirubin - see bilirubin, conjugated

coproporphyrin

What?
Coproporphyrin is a substance produced in the liver and bone marrow during the process of making a chemical called heme. Heme is the chemical that binds oxygen to red blood cells.
Why Test?
Since the liver is one of two sites for heme production, liver cell damage can interfere with the production of heme. When heme production is abnormal, the substances used to make heme build up in the blood. Coproporphyrin is used to determine how well the liver is performing its job of making heme.

creatinine

What?
Creatinine is a waste product of muscle cell metabolism. Creatinine is excreted by the kidneys in the urine.
Why Test?
Creatinine is most commonly measured to check how well the kidneys are working. When the kidneys are not working normally, blood creatinine increases. Some people with advanced liver cirrhosis and liver failure develop a condition called hepatorenal syndrome. With this syndrome, the kidneys begin to fail because the liver is failing. Creatinine is one test used to check for hepatorenal syndrome in people with cirrhosis and liver failure.

cryoglobulins

What?
Cryoglobulins are immunoglobulins that are joined together.
Why Test?
Some people with hepatitis C develop cryoglobulins in their blood, a condition called cryoglobulinemia. It is important to know if someone has cryoglobulinemia because it can cause kidney damage.

direct bilirubin - see bilirubin, conjugated

enzyme immunoassay (EIA)

What?
EIA is a common testing method used to screen for anti-HCV antibodies in the blood.
Why Test?
EIA is a rapid, economical method of screening for the presence of anti-HCV antibodies. A RIBA test is often used to confirm a positive EIA test for anti-HCV antibodies. For additional information about the significance of a positive test result, see anti-HCV antibodies.

ferritin

What?
Ferritin is a protein found in the liver, spleen, and intestine. It binds iron.
Why Test?
Ferritin is measured to check for iron overload in the body. High amounts of ferritin in the blood signify an overabundance of iron in the body. This is important because iron overload is often seen with chronic hepatitis C. This condition must be treated because iron overload worsens the damage done to the liver by the hepatitis C virus.

fibrinogen

What?
Fibrinogen is a protein produced by the liver. It is an important part of the body's ability to form blood clots in response to bleeding.
Why Test?
A cirrhotic, failing liver may be unable to produce normal amounts of fibrinogen. Measuring fibrinogen is one way of telling how severely the liver is failing. Testing the amount of fibrinogen in the blood is also important because, if the level gets very low, a person may not be able to form a blood clot if he or she begins to bleed for any reason.

FIBROSpect™

What?
FIBROSpect™ is a proprietary set of blood tests used together to differentiate no/mild liver fibrosis from severe fibrosis.
Why Test?
Liver biopsy remains the most certain method of determining the presence and degree of liver fibrosis. However, some people are hesitant to have a liver biopsy because it is an invasive test and has an associated risk of rare but serious complications. While FIBROSpect™ is not a substitute for liver biopsy, it can possibly provide some useful information for people who cannot or do not wish to have a liver biopsy.

Fibrosure™

Other Names
FibroTest-ActiTest, HCV Fibrosure
What?
Fibrosure™ is a proprietary set of blood tests used together to differentiate no/mild liver fibrosis from severe fibrosis.
Why Test?
Liver biopsy remains the most certain method of determining the presence and degree of liver fibrosis. However, some people are hesitant to have a liver biopsy because it is an invasive test and has an associated risk of rare but serious complications. While Fibrosure™ is not a substitute for liver biopsy, it can possibly provide some useful information for people who cannot or do not wish to have a liver biopsy.

gamma-glutamyl transferase (GGT)

Other Names
GGTP, glutamyl peptide
What?
GGT is an enzyme found in all cells of the body except muscle cells.
Why Test?
GGT is elevated in all forms of liver disease. It is highest when bile flow is blocked either inside or outside the liver.

genotyping

What?
There are many different strains of the hepatitis C virus. A genotyping test tells what strain of the virus a person has.
Why Test?
Genotyping is currently used to determine the required length and potential response to interferon-based therapy. There are currently over 70 known strains of HCV. Researchers have discovered that certain strains are more likely to respond to treatment than others are. Future studies will hopefully discover why this occurs. This may allow researchers to develop more effective treatments for HCV.

GGT - see gamma-glutamyl transferase

GGTP - see gamma-glutamyl transferase

glucose

What?
Glucose is another name for blood sugar.
Why Test?
People with chronic hepatitis C can have blood sugar abnormalities, either too high or too low. A glucose test is done to see if your blood sugar level is abnormal.

glutathione

What?
Glutathione is an amino acid found throughout the body.
Why Test?
Glutathione protects cells from a type of injury called oxidative damage. Scientists believe oxidative damage is one of the key ways HCV damages liver cells. This damage is done by agents called free radicals. Glutathione prevents free radicals from causing damage to cells. Measuring the amount of glutathione in the blood is one way your health care providers can tell how capable your liver is of preventing and/or repairing liver damage.

HCV polymerase chain reaction (HCV PCR)

Other Names
PCR, RT-PCR, reverse transcription polymerase chain reaction
What?
HCV PCR checks for the presence of HCV in the blood. The test detects the genetic material of the virus (HCV RNA).
Why Test?
There are two types of HCV PCR tests. The first is a qualitative test. A qualitative HCV PCR test does not measure the amount of virus in the blood, but rather determines if there is detectable virus in the blood. The second type of test is called a quantitative test. It is used to measure the amount of detectable HCV in the blood. The amount of detectable virus is called the viral load.

A certain amount of virus must be present in the blood to be detected using PCR. For this reason, a negative PCR test is reported as "undetectable," not zero. A negative PCR test does not mean there is no HCV in the blood, only that there is no detectable virus.

HCV viral loads fluctuate within a very broad range. These fluctuations are typical of untreated, chronic hepatitis C. HCV viral loads do not reflect liver disease status nor disease progression. Therefore, many health care providers do not monitor HCV viral load in people who are not on interferon-based therapy. However, if you are considering interferon-based therapy or are on such treatment, your HCV viral load becomes important. HCV viral load is measured before and during interferon-based therapy because viral load is used to determine response to treatment. Research has shown that those people who experience a sustained viral response to interferon-based therapy have experience an early viral response (EVR). An early viral response to interferon-based therapy is defined as either undetectable HCV-RNA or at least a 2-log drop in HCV viral load by week 12-20 of treatment (at least a 100-fold decrease in viral load).

Health care providers often discuss viral load changes using the term "logs." The term "log" refers to the mathematical notation called logarithms. Although there are many log scales, when used to discuss viral load, the scale being referred to is log₁₀ or log base 10. While this may seem complicated, the use of logs is just a short-hand way of talking about viral load changes.

a 2-log change is a 100-fold change in viral load

Examples:
1,000 copies/mL to 100,000 copies/mL is a 2-log increase in viral load
(1,000 x 100 = 100,000)
8,500,000 copies/mL to 85,000 copies/mL is a 2-log decrease in viral load
(8,500,000 ÷ 100 = 85,000)

If you have questions about a change in your viral load, talk with your health care provider. He or she can explain what your test results mean.

HCV transcription mediation amplification (HCV TMA)

What?
HCV TMA is used to measure the amount of detectable HCV in the blood.
Why Test?
The TMA test for HCV is used to measure the amount of detectable HCV in the blood. The amount of detectable virus is called the viral load.

A certain amount of virus must be present in the blood to be detected using TMA. For this reason, a negative TMA test is reported as "undetectable," not zero. A negative TMA test does not mean there is no HCV in the blood, only that there is no detectable virus.

HCV viral loads fluctuate within a very broad range. These fluctuations are typical of untreated, chronic hepatitis C. HCV viral loads do not reflect liver disease status nor disease progression. Therefore, many health care providers do not monitor HCV viral load in people who are not on interferon-based therapy. However, if you are considering interferon-based therapy or are on such treatment, your HCV viral load becomes important. HCV viral load is measured before and during interferon-based therapy because viral load is used to determine response to treatment. Research has shown that those people who experience a sustained viral response to interferon-based therapy have experience an early viral response (EVR). An early viral response to interferon-based therapy is defined as either undetectable HCV-RNA or at least a 2-log drop in HCV viral load by week 12-20 of treatment (at least a 100-fold decrease in viral load).

Health care providers often discuss viral load changes using the term "logs." The term "log" refers to the mathematical notation called logarithms. Although there are many log scales, when used to discuss viral load, the scale being referred to is log₁₀ or log base 10. While this may seem complicated, the use of logs is just a short-hand way of talking about viral load changes.

a 2-log change is a 100-fold change in viral load

Examples:
1,000 copies/mL to 100,000 copies/mL is a 2-log increase in viral load
(1,000 x 100 = 100,000)
8,500,000 copies/mL to 85,000 copies/mL is a 2-log decrease in viral load
(8,500,000 ÷ 100 = 85,000)

If you have questions about a change in your viral load, talk with your health care provider. He or she can explain what your test results mean.

hematocrit (HCT)

What?
A hematocrit test measures the percentage of the blood made up by red blood cells.
Why Test?
Liver disease can lead to a shortage of red blood cells, a condition called anemia. The hematocrit is used to test for anemia.

hemoglobin (HGB)

What?
Hemoglobin is the protein inside red blood cells that carries oxygen.
Why Test?
Liver disease can lead to a shortage of hemoglobin. The hemoglobin test is used to check if there is enough hemoglobin in the blood.

immunoglobulins (Igs)

What?
Immunoglobulins are a group of proteins that act as antibodies in the body.
Why Test?
When the Igs are tested in the laboratory, the different proteins of the group are separated and each is measured. The test shows how much of each type of protein is present. Different patterns may point to different problems in the liver. For example, one pattern may indicate liver cell damage, while a different pattern indicates that cirrhosis has developed.

indirect bilirubin - see bilirubin, unconjugated

iron (Fe)

What?
Iron is a metal found in red blood cells. It helps red blood cells carry oxygen to all the cells of the body.
Why Test?
The liver is one of the main places in the body where iron is stored. When liver cells are damaged, iron is released into the blood. Therefore, the amount of iron in the blood is one way to check how much damage is being done to liver cells by HCV. Iron overload worsens the damage done to the liver by HCV.

lactate dehydrogenase (LDH)

What?
LDH is an enzyme found in many cells of the body. It is highly concentrated in red blood cells, liver, heart, and muscle cells.
Why Test?
Elevated LDH is one indicator of liver cell damage. However, since it is found in many other cell types, it is usually tested only in combination with other liver enzymes.

LIPA assay - see genotyping

liver biopsy

What?
A liver biopsy is a surgical procedure to remove two or three tiny pieces of the liver using a long needle that is inserted into the liver through the skin of the abdomen. The samples are stained and looked at under a microscope.
Why Test?
A liver biopsy is the only way to be certain what is happening in the liver as a result of hepatitis C infection. The three main things that will be looked for are inflammation (the presence of inflammatory cells in the liver), fibrosis (scar tissue that forms when liver cells are destroyed by the virus), and cirrhosis (widespread damage to the liver resulting in abnormal liver structure and function).

5'-nucleotidase (5'NT)

Other Names
5'-ribonucleotide phosphohydrolase (NTP)
What?
5'NT is an enzyme found in many tissues throughout the body including the liver.
Why Test?
5'NT is increased 2-6 times the normal amount when bile flow is blocked either inside or outside the liver. Hepatitis, fibrosis, and cirrhosis can block bile flow inside the liver. Gallstones can block bile flow outside the liver.

partial thromboplastin time (PTT)

Other Names
activated partial thromboplastin time, APTT
What?
A partial thromboplastin time is a test to see how quickly blood is able to form a clot.
Why Test?
The liver produces many of the proteins needed for clot formation. People with cirrhosis and liver failure may not be able to produce normal amounts of these proteins. The PTT is one indicator of the liver's ability to make proteins. It is also important to know if someone cannot form blood clots normally because he or she may not be able to stop bleeding should bleeding begin for any reason.

PCR - see HCV polymerase chain reaction

platelet count

What?
Platelets are small pieces of cells circulating in the blood. Platelets help form blood clots to halt bleeding.
Why Test?
Liver disease can cause a shortage of platelets. The platelet count is used to test for such a shortage, which can lead to easy bruising and uncontrollable bleeding.

polymerase chain reaction - see HCV polymerase chain reaction

porphyrins

What?
Porphyrins are a group of substances produced in the liver and bone marrow during the process of making a chemical called heme. Heme is the chemical that binds oxygen to red blood cells.
Why?
Since the liver is one of two sites for heme production, liver cell damage can interfere with the production of heme. When heme production is abnormal, the substances used to make heme build up in the blood. Testing for porphyrins is done to check how well the liver is performing its job of making heme.

potassium (K)

What?
Potassium is a charged particle called an electrolyte. It is one of the four major electrolytes in the body.
Why Test?
Electrolytes perform many important jobs in the body. Two of the most important jobs are regulating the amount of water in your body and keeping your blood pH normal. Some people with hepatitis C hold more water in their bodies than they need. This can cause abnormal potassium levels. This is more likely in people with cirrhosis than in those without cirrhosis.

prealbumin - see transthyretin

prothrombin time (PT)

What?
Prothrombin time (PT) is a test to see how quickly the blood is able to form a clot.
Why Test?
The liver produces many of the proteins needed for clot formation. People with cirrhosis and liver failure may not be able to produce normal amounts of these proteins. The PT is one indicator of the liver's ability to make proteins. It is also important to know if someone is not able to form blood clots normally because he or she may not be able to stop bleeding should bleeding begin for any reason.

PT - see prothrombin time

PTT - see partial thromboplastin time

RBC - see red blood cell count

recombinant immunoblot assay (RIBA)

What?
RIBA is a sensitive testing method used to detect the presence of anti-HCV antibodies in the blood.
Why Test?
The RIBA test is most often used to confirm a positive result on an EIA (enzyme immunoassay) screening test for anti-HCV antibodies. There are currently three generations of RIBA tests for HCV denoted RIBA-1, RIBA-2, and RIBA-3. For additional information about the significance of a positive test result, see anti-HCV antibodies.

red blood cell count (RBC)

What?
Red blood cells carry oxygen from the air we breathe to all of the organs and tissues of the body.
Why Test?
Liver disease can lead to a shortage of red blood cells, a condition called anemia. The red blood cell count is used to test for anemia.

retinol - see vitamin A

rheumatoid factor (RF)

What?
Rheumatoid factor is a type of autoantibody. Normally, the body makes antibodies against foreign substances such as bacteria and viruses. Autoantibodies are abnormal antibodies that act against your own cells.
Why Test?
More than half of all people with chronic hepatitis C have one or more autoantibodies in their blood. This is important to know because autoantibodies can cause additional symptoms and disease.

RIBA - see recombinant immunoblot assay

sodium

What?
Sodium is a charged particle called an electrolyte. It is one of four major electrolytes in the body.
Why Test?
Electrolytes perform many important jobs in the body. Two of the most important jobs are regulating the amount of water in your body and keeping your blood pH normal. Some people with hepatitis C hold more water in their bodies than they need. This can cause abnormal sodium levels. This is more likely in people with cirrhosis than in those without cirrhosis.

T3 - see triiodothyronine

T4 - see thyroxin

thyroid stimulating hormone (TSH)

Other Names
thyrotropin
What?
Thyroid stimulating hormone (TSH) is produced by the pituitary gland. It acts on the thyroid gland to cause it to produce the two thyroid hormones.
Why Test?
Some people with hepatitis C develop thyroid problems because of autoantibodies. Measuring the TSH along with the levels of the thyroid hormones in the blood tells your health care provider if the thyroid gland is working normally.

thyroxin (T4)

What?
Thyroxin is one of two hormones produced by the thyroid gland.
Why Test?
Some people with hepatitis C develop thyroid problems because of autoantibodies. Measuring the thyroxin in the blood is one way to test whether the thyroid gland is working normally.

TIBC - see total iron binding capacity

TMA - see HCV transcription mediation amplification

total bilirubin - see bilirubin, total

total iron binding capacity (TIBC)

What?
The total iron binding capacity (TIBC) is a measurement of how much iron the blood is able to capture.
Why Test?
TIBC is one test used to check the amount of iron in the body. The more iron there is in the body, the lower the TIBC. An abnormally low TIBC means there is too much iron in the body. This is important because iron overload is often seen with chronic hepatitis C. This condition must be treated because iron overload worsens the damage done to the liver by HCV.

total protein (TP)

What?
Total protein is a measurement of all proteins in the blood.
Why Test?
The liver produces many of the proteins found in the blood. Measuring the total protein in the blood is one way of testing how well the liver is performing its job of producing proteins.

transthyretin

Other Names
prealbumin
What?
Transthyretin is a small protein made by the liver. It is used to make the larger protein called albumin.
Why Test?
Transthyretin is a sensitive indicator of how well the liver is able to produce proteins. The lower the transthyretin level in the blood, the poorer the liver is performing its job of making proteins.

triiodothyronine (T3)

What?
Triiodothyronine is one of two hormones produced by the thyroid gland.
Why Test?
Some people with hepatitis C develop thyroid problems because of autoantibodies. Measuring the triiodothyronine in the blood is one way to test whether the thyroid gland is working normally.

TSH - see thyroid stimulating hormone

unconjugated bilirubin - see bilirubin, unconjugated

viral load - see HCV polymerase chain reaction and branched DNA test for HCV

vitamin A

Other Names
retinol, retinoic acid
What?
Vitamin A is a fat-soluble vitamin.
Why Test?
Absorption of vitamin A from the intestines requires bile. If bile is not being made and secreted in normal amounts, the body is not able to absorb as much vitamin A as it needs. In extreme cases, this can result in night blindness, dry skin, and brittle hair and nails.

vitamin D

Other Names
ergocalciferol, cholecalciferol
What?
Vitamin D is a fat-soluble vitamin.
Why Test?
Absorption of vitamin D from the intestines requires bile. If bile is not being made and secreted in normal amounts, the body is not able to absorb as much vitamin D as it needs. Further, liver cells convert absorbed vitamin D into its active form. In cirrhosis and liver failure, the liver may not perform this job normally. In extreme cases, vitamin D deficiency can result in softening of the bones and bone pain.

vitamin E

Other Names
alpha-tocopherol
What?
Vitamin E is a fat-soluble vitamin.
Why Test?
Absorption of vitamin E from the intestines requires bile. If bile is not being made and secreted in normal amounts, the body is not able to absorb as much vitamin E as it needs. In extreme cases, vitamin E deficiency can cause a shortage of red blood cells and muscle loss.

vitamin K

Other Names
phylloquinone, antihemorrhagic factor
What?
Vitamin K is a fat-soluble vitamin.
Why Test?
Absorption of vitamin K from the intestines requires bile. If bile is not being made and secreted in normal amounts, the body is not able to absorb as much vitamin K as it needs. Vitamin K is required for the production of proteins needed for blood clotting. Vitamin K deficiency can lead to easy bruising and bleeding problems.

WBC - see white blood cell count

white blood cell count

Other Names
WBC count
What?
White blood cells protect your body against infections. They are part of the body's immune system. There are several different kinds of white blood cells including neutrophils, lymphocytes, and macrophages.
Why Test?
An elevated white blood cell count often accompanies acute infection. Changes in your white blood cell count can indicate a change in your hepatitis C disease status.

Summary

Laboratory tests and procedures give a great deal of useful information to your health care providers. They can provide information about how well the liver is performing its many jobs, and how much damage HCV is doing to your liver. In deciding what tests you need, your health care provider considers several factors, such as:

How have you been feeling?
Are you having any new signs or symptoms?
What treatments or medicines are you taking?
Where are you in your treatment plan?

Since the answers to these questions are different for each person and may differ from one clinic visit to the next, there is no one group of laboratory tests that are considered standard for people living with hepatitis C.

If you have questions about why you need a certain test or what the results mean, ask one of your health care providers. Understanding your laboratory tests can help you understand how your body is responding to HCV and the management plan you have chosen.