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 HomeMethodsStatementsThe
Liver
Patients' Perspectives
What ARE those blood tests?
What are Liver Function
Tests?
LFTs (liver function tests) are a group of blood tests
that can help to show how well a person's liver is working. LFTs
include measurements of albumin, various liver enzymes (ALT, AST,
GGT and ALP), bilirubin, prothrombin time, cholesterol and total
protein. All of these tests can be performed at the same time.
Measuring Liver
Proteins:
Total protein testing (also called TP or serum total
protein) measures the amount of proteins in the bloodstream. Many
different things can cause abnormally high or low protein levels. A
doctor may order total protein testing to help diagnose kidney or
liver disease, blood cancer, malnutrition or abnormal body swelling.
Normal protein levels in the bloodstream range from 6.5 to 8.2 grams
per deciliter Two of the main proteins found in the bloodstream are
albumin and globulin.
Globulins are made by various liver cells and the immune
system. They help to fight off infections. Low globulin levels can
have many causes other than liver damage.
Albumin is a protein made in the liver. If the liver is
badly damaged, it can no longer produce albumin. Albumin maintains
the amount of blood in the veins and arteries. When albumin levels
become very low, fluid can leak out from the blood vessels into
nearby tissues, causing swelling in the feet and ankles. Very low
levels of albumin may be a sign of liver damage. The normal albumin
range is from 3.9 grams/ deciliter to 5.0 grams/deciliter.
Prothrombin (also called factor II) is a protein that
helps to clot blood. Prothrombin is made in the liver. A prothrombin
time test measures how much time it takes for a person's blood to
clot. The normal time needed for blood to clot is between 10 and 15
seconds. A person with an abnormally long prothrombin time may be at
risk for excessive bleeding. A longer prothrombin time can be caused
by serious liver disease or:
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A lack of vitamin K,
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Blood-thinning medicines,
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Other medications that can interfere with the test.
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Certain bleeding disorders.
Measuring Liver
Enzymes:
ALT and AST are enzymes made in the liver. They are
also known as transaminases. The liver uses these enzymes to
metabolize amino acids and to make proteins. When liver cells are
damaged or dying, ALT and AST leak into the bloodstream. Many
different things can cause liver enzymes to rise above normal
levels, including:
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Viral hepatitis
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Excessive alcohol intake/Alcoholic liver disease
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Liver inflammation from medications and certain herbs,
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Auto-immune hepatitis - a condition where a person's immune
system mistakes the liver for an invader and attacks it,
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Fatty liver- fat build -up in liver cells, called
steatohepatitis when the fatty liver is inflamed
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Inherited liver diseases
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Liver tumors
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Heart failure
ALT (also called alanine aminotransferase or SGPT) is
found in the liver only. High levels of ALT in the bloodstream mean
that there may be liver inflammation and/or damage. This test cannot
predict liver damage or disease progression. It is simply a direct
measurement of the amount of ALT in the person's bloodstream at the
time of the test. The normal range of ALT levels is between 5 IU/L
to 60 IU/L (International Units per Liter). ALT levels in people
with HCV often rise and fall over time, so additional testing such
as HCV RNA, HCV genotyping and a liver biopsy may be needed to help
determine the cause and extent of liver damage.
AST (also called aspartate aminotransferase or SGOT) is
found in other organs besides the liver. High AST levels in the
bloodstream can be a sign of liver trouble. AST testing measures the
level of AST in a person's bloodstream at a given time. The normal
range for AST levels in the bloodstream are 5 IU/L to 43 IU/L. Like
ALT levels, AST levels in people with HCV often vary over time and
can't be used to forecast disease progression or specifically
measure liver damage.
Cholestatic Liver
Enzymes:
GGT and ALP are also called cholestatic liver
enzymes. Chloestasis is a term used for partial or full blockage of
the bile ducts. Bile ducts bring bile from the liver into the
gallbladder and the intestines. Bile is a green fluid produced in
liver cells. Bile helps the body to break down fat, process
cholesterol and get rid of toxins. If the bile duct is inflamed or
damaged, GGT and ALP can get backed up and spill out from the liver
into the bloodstream.
ALP metabolizes phosphorus and brings energy to the body. GGT
brings oxygen to tissues.
Causes of elevated ALP and GGT levels include:
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Scarring of the bile ducts (called primary biliary cirrhosis),
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Fatty liver (steatosis),
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Alcoholic liver disease,
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Liver inflammation from medications and certain herbs,
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Liver tumors,
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Gallstones or gall bladder problems.
ALP (also called alkaline phosphatase) is found in the bones,
intestines, kidneys and placenta as well as the liver. Abnormally
high ALP can have many causes other than liver damage, including:
bone disease, congestive heart failure, and hyperthyroidism. A rise
in ALP levels can indicate liver trouble if GGT levels are also
elevated. The normal range of ALP is from 30 IU/L to 115 IU/L.
GGT (gamma-glutamyltranspeptidase) is found in the liver.
Obesity, PBC, heavy drinking, fatty liver, and certain medications
or herbs that are toxic to the liver can cause GGT levels to rise
the normal range of GGT is from 5 IU/L to 80 IU/L.
Bilirubin:
Bilirubin is a yellow fluid produced in the liver when
worn-out red blood cells are broken down. Bilirubin can leak out
from the liver into the bloodstream if the liver is damaged. When
bilirubin builds up, it can cause jaundice - a yellowing of the eyes
and skin, dark urine and light colored feces. The causes of abnormal
bilirubin levels include:
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Viral hepatitis,
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Blocked bile ducts,
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Other liver diseases,
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Liver scarring (cirrhosis)
Total bilirubin testing measures the amount of bilirubin in the
bloodstream. Normal total bilirubin levels range from .20mg/dl to
1.50 (milligrams per deciliter). Direct bilirubin testing measures
bilirubin made in the liver. The normal level of direct bilirubin
range from .00 to .03 mg/dl
http://www.atdn.org/simple/liverfun.html
More Tests & Meaning
CBC with platelets and five part differential
A CBC is a complete blood count. This means that your doctor wants to
know the amounts and proportions among the various components of your
blood, explained below. The term differential refers to the fact that
each person has several different kinds of white cells and each type
performs a different function in our bodies. The differential measures
each different kind of white cell and calculates the proportion of each
as a percentage of all the cells in your blood.
White blood cell count: White blood cells are also called
leucocytes (luke-o-sites). The white blood cell count is simply the
number of white blood cells in your blood. It is often reported in
thousands. Some labs report this as numbers like 4.6, i.e., 4600 white
blood cells, while others report it as the whole number, i.e., 4600.
Among patients this is frequently called whites, as in "What were your
whites today?"
The whites and the differential are the two tools your oncologist uses
to help figure out what's happening to your body while you're being
treated and how your bone marrow is reacting.
Red blood cell count (also called erythrocyte count): Red blood
cells are also called erythrocytes (ee-ree-throw-sites). The red blood
cell count is simply the number of red blood cells in your blood. It is
also often reported in millions. Some labs report this as 5.5 while
others report it as the whole number, 550,000. Patients have also
developed their own shorthand for this and often call it "reds".
The reds reflect more about what's happening with the chemistry and
physics of your blood as you're being treated. The life of a red in your
body is usually about 120 days (4 months).
Hemoglobin: Hemoglobin is the primary component of your red
blood cells. This amount is reported as grams per deciliter (a
deciliter is 1/10th of a liter). The hemoglobin carries oxygen and
carbon dioxide around your bodies. It has one part called heme which
contains iron and the characteristic red pigment of your blood called
porphyrin (pore-fer-in). The other part is a protein called globin
formed from a number of amino acids. The oxygen easily combines with
the heme so it can get around to your body's cells. Because the oxygen
actually attaches to your hemoglobin, it is important for your doctor to
know how much hemoglobin you have.
Hematocrit: Hematocrit is a measure of the "mass" of your red
blood cells. In this test, the blood cells and plasma are separated
(that's what the word hematocrit means) and the proportion of reds in
your whole blood is reported as a percentage. This value is calculated
and, as such, is slightly less accurate than a hemoglobin count which is
measured directly.
Mean corpuscular volume: This ratio is calculated for your
doctor. The equation for the ratio is:
MCV (g/dl) = (hemoglobin (g/dl) * 100) / HCT (percent)
Mean corpuscular hemoglobin: This ratio is also calculated for your
doctor and reported in your test results. The equation for this ratio
is:
MCH ( pg/cell) = (hemoglobin (g/dl) * 10) / RBC (pg/L)
Red cell distribution width: Normal red cells are approximately round
and have some variation in their width. But, abnormal variation in
size, called anisocytosis (ann-iso-si-toe-sis), together with MCV, helps
your doctor determine what kind of anemia you may have.
Platelet count: This is a simple count of the number of
platelets in your blood. The result is reported in thousands by most
laboratories, for example, 140, or, in other laboratories as the actual
number, for example, 140,000. Platelets are critical to clotting and
preventing bleeding.
Mean platelet volume: This measures the size of your platelets.
It is reported in femtoliters. Its values, with other information, help
your doctor evaluate low platelet counts.
Differential: Each of the various kinds of white blood cells
performs several different functions. They include:
a.. Neutrophils: Combat infections, among other functions
b.. Eosinophils: Work on allergic disorders and parasitic
infestations among other functions
c.. Basophils: Work on parasitic infections among other functions
d.. Lymphocytes: Combat bacterial infections, such as strep, and
viral infections, such as measles and chickenpox, among other functions
e.. Monocytes: Work on severe infections, among other functions (one
of our reviewers refers to this as the PacMan of blood cells)
Each of these components is reported in two ways, as a percentage of the
total number of whites and as the total number of that particular
component reported in thousands, for example, 4.6 or 4600.
Blood chemistry tests
A group of these tests are usually performed together, primarily for
cost-savings. For the cost of two or three of the individual tests, it
is possible to perform many tests in an automated system. The
combination of tests is usually called a chemistry panel, chem panel, or
comprehensive metabolic panel. The various blood chemistry tests listed
here are ones from the panel as well as some others that are often
checked for certain patients.
CO2 content: Determining your CO2 level gives your oncologist an
idea about whether your blood is acidic or alkaline. As with several of
the tests in this list, this gives your doctor an idea about whether
your treatment might be affecting your kidneys. Severe vomiting and
severe diarrhea can also affect your CO2 levels. Finally, because some
chemotherapy regimens also include diuretics, this can be used to see
whether those are affecting you adversely.
Electrolytes
These are tests to be certain that cells in various parts of your body
have the chemicals needed to operate properly. Except for calcium and
phosphorus which are reported as milligrams per deciliter, electrolytes
are reported in micromols per liter. The amount of nearly all these
will decline whenever you become dehydrated, such as through sweating,
vomiting, and diarrhea. When one or more of these becomes abnormally
low, you are likely to develop serious physical problems so part of your
treatment, especially during chemotherapy, will include replacing these
chemicals.
Calcium: Most of your calcium is stored in your bones and
teeth. But, for your muscles to flex, and for your heart to beat (it
is, after all, a muscle flexing), your body needs what is called ionized
calcium, that is, calcium in a specific form which is NOT part of your
bones and teeth. If the level in your blood is abnormally low, your
body will draw calcium from your bones and teeth, which can result in
other problems. If your calcium is too high, your oncologist will
institute specific therapies. See the discussion of phosphorus below as
well.
Chloride: This helps your cells operate properly. In between
your cells is an area called the extracellular spaces. Molecules that
need to move into and out of your cells depend on a process called
osmosis, which governs the movement of molecules through permeable
membranes, including the walls of your body's cells. Chloride in the
extracellular spaces helps osmosis work properly.
Phosphorus: Phosphorus is required together with calcium for
your bones. However, some of it is found in other parts of your body as
well. It is required so that new bone can be formed. It is also
required to metabolize both glucose (the simple sugar found in your
blood) as well as lipids (fats). As part of its role in metabolism, it
also helps move energy around your body. There must be a balance
between calcium and phosphorus in your body. When one increases, the
other is decreased by excreting it through your kidneys. So, if you
have excess calcium, you may have abnormally low phosphorus and vice
versa.
Potassium: Potassium is the principal electrolyte in
intracellular fluid, that is, fluid inside your cells. Even if you
don't eat any potassium-containing foods (bananas and dark, green leafy
vegies for example), your body still excretes potassium. It's quite
likely that, if you're unable to eat for a period of time, your body
will have a low potassium level and you might require a pill or other
medication. Potassium is very important for conducting nerve impulses,
for muscle functioning (again, especially the heart), and in the osmosis
process mentioned in the discussion of chlorine. A low potassium level
can be determined also by looking at an electrocardiogram which will
show a U-wave in the absence of the proper amount of potassium. Too high
a level of potassium can be fatal.
Sodium: Sodium is the principal electrolyte in our blood. The
other electrolytes are there but not as prominant. Like potassium and
chlorine, it is important in cell osmosis. It is also important in the
transmission of nerve impulses. A number of compounds work at keeping
the level of sodium in our bodies at an appropriate level and, even if
we become dehydrated for some reason, it is quite difficult to reduce
the amount of sodium circulating in our blood without fundamental,
underlying health problems.
Glucose and related tests
Glucose: Glucose is a simple sugar. For anything you eat to be
used by your body for energy, it needs to be converted to glucose. Not
only are "big" sugars such as sucrose (found in granular sugar) or
fructose (found in soft drinks and other "sugary" treats) converted to a
simpler form, but lipids (fats) and complex carbohydrates (such as
grains) are also converted to glucose. The big sugars convert to
glucose most quickly and lipids convert most slowly to glucose. Complex
carbohydrates convert to glucose at an intermediate rate. Glucose is
reported in milligrams per deciliter. Elevated glucose levels, as in
diabetes, can interfere with proper metabolism of your chemotherapy
drugs and can otherwise interfere in your life.
Glycosylated hemoglobin: Glycosylated (gli-cos-i-lated)
hemoglobin is a measure of your long-term control of blood glucose
levels. This test is primarily used for monitoring diabetics. As reds
circulate, they combine some of the glucose in your blood with
hemoglobin to form a special form of hemoglobin called glycohemoglobin.
The amount of this as a percentage of your total hemoglobin is reported
in your test results. If good control of blood glucose levels does not
occur, this test will indicate the situation to your doctor.
Metabolic products
Metabolic products are "waste products" of your cells. They need to be
removed from your body. Your blood is one way that these are removed
from your cells and the areas around them and moved to your body's
garbage dumps for processing. The three metabolic tests listed below
are reported in milligrams per deciliter.
Bilirubin, total: Bilirubin (billy-ru-bin) is a result of the breakdown
of red blood cells which are then handled by your liver. If your reds
are undergoing their normal process and your liver is fine, your
bilirubin level will be within the normal limits. But, if your reds are
damaged somehow or if your liver is inflammed, obstructed, or otherwise
damaged, the amount of bilirubin is likely to go up because your blood
will be hauling the damaged reds off to the liver for processing.
Blood urea nitrogen: This is sometimes also reported simply as urea
nitrogen or as BUN. It describes how your kidneys are functioning. This
test is less sensitive than the test for creatinine, but taken together,
the two tests can help your doctor understand whether your chemotherapy,
other treatment, or other disease is having a negative effect on your
kidneys.
Creatinine: Creatinine (cree-ah-tuh-neen) is a measure of how your
body metabolizes energy. It is produced at a steady rate and depends on
the amount of muscle in your body. Larger people will produce more than
smaller people. If the amount of muscle in your body changes, the
amount of creatinine will change. Creatinine is normally excreted
through your kidneys, so this also gives an indication of how well your
kidneys are functioning.
Protein tests
The two major protein tests, albumin and total protein are reported in
grams per deciliter. Proteins are responsible for many functions in
our bodies, including transporting certain molecules to the parts of our
bodies where they're needed, regulating certain enzymes that govern our
bodies' functions, and as immunologic agents.
Albumin: The levels of albumin are another clue that your oncologist
uses to see how your treatment is affecting your body. For example,
when you have IVs, become dehydrated, or have decreases in your liver or
kidney functions, the amount of albumin circulating in your blood will
change.
Total protein: The total amount of protein in your blood will change
when you become dehydrated or when your blood becomes hemoconcentrated
due to fluid loss for some reason. This is also an indicator of a
number of different problems with various organs of your body. So, this
test is used together with other tests to monitor your progress.
Enzyme tests
These enzyme tests are reported in units per liter. The various enzymes
are present in a variety of situations in your body. Each one is a
measure of how well (or poorly) a particular organ or group of organs is
functioning.
Alkaline phosphatase: Alkaline phosphatase (alka-leen fos-fuh-taze) is
found primarily in the bone and liver and somewhat in the kidney and
colon. It is a measure of liver and bone disease and, thus, in some
sense is also a tumor marker. If you have new bone that's just forming,
(osteoblasts are the cells that do this), this measure will change.
ALT (SGPT): This stands for alanine transaminase (al-a-neen
trans-am-in-ase), which is an enzyme present in the liver, with lesser
concentrations in the heart, muscle, and kidneys. It is used primarily
to diagnose liver disease of various kinds.
AST (SGOT): This stands for aspartate transaminase (ass-par-tate
trans-am-in-ase) which is an enzyme present in areas of your body that
are metabolizing glucose rapidly. When cells are injured or die, AST is
released into the blood stream. Because it measures the presence of
damaged cells, it gives your oncologist a clue as to how your treatment
is progressing and how it's affecting various parts of your body.
Aspartate transaminase is present in your liver, muscles, and lungs,
among other organs.
LD: LD is short for lactic acid dehydrogenase (dee-hyd-rog-en-ase). It
is an enzyme within your cells that is present especially in the
kidneys, liver, brain, lung, heart, reds, and skeletal muscles. It is
useful in monitoring the status of the organs in which it is
particularly present. It is reported in units per liter.
Lipoprotein tests
Lipoproteins are proteins related to fat in your body.
Cholesterol: This test is the most commonly used indicator of your risk
for atherosclerosis and related heart disease. You're likely to have
this test on a regular basis, if you had a high value at initial
testing. if you're trying to lower your cholesterol by diet, or if
you're on a cholesterol-lowering medication. It is reported in
milligrams per deciliter.
Triglycerides: This test measures your body's ability to metabolize
fats. It, like cholesterol, is a measure of risk for atherosclerosis
and related heart disease; but, because triglyceride levels are
independent of cholesterol level, doctors often want to know both values
to make a better evaluation of risk. Because this test is very sensitive
to diet, it is always measured on a fasting basis, i.e., you cannot have
had anything to eat or drink (except water) for twelve hours before your
blood is drawn for this test.
Lipoprotein electrophoresis: Often determined at the same time as a
triglyceride test, this test measures the amounts of the various kinds
of lipoproteins in your blood. Two types are most frequently reported:
a.. High-density lipoprotein (also known as HDL or alpha) is popularly
known as the "good" lipoprotein
b.. Low-density lipoprotein (also known as LDL or beta) is popularly
known as the "bad" lipoprotein
Tumor markers:
CEA (carcinoembryonic antigen): This tumor marker is found in about 60
percent of human all breast cancer tumors. The marker is reported in
nanograms per milliliter. It is also found in a large percentage of
colorectal cancers. It is used as a monitor to follow the effects of
chemotherapy and/or surgery. It is NOT a screening test, i.e., it is
NOT used to determine whether or not you have cancer..
CA 27.29: This is a relatively new test which replaces the CA15-3 test
that many of us have had.
HER-2/neu : This is a genetic mutation in which a protein called HER-2
(also called erb-B/2) in cells is "overexpressed". "Overexpressed"
means that instead of the "usual" number of copies, the person has
literally hundreds of copies. The test for HER-2 overexpression is not
commonly found in normal lab tests. However, in order to be treated
using Herceptin, you will need to have your HER-2/neu level tested based
on your original tumor blocks. At this point in time, the laboratories
which were involved in the Phase III trial of Herceptin are the ones
with lots of experience in this arena. Your her-2/neu value reports you
as being an "over-expressor" or not being an over-expressor.
Over-expression means that the area of your DNA where this sequence
appears has multiple copies, not just a few extra but many, many copies
of the sequence of DNA information referred to as her-2/neu. The latest
test for HER-2/neu overexpression is called a FISH test (fluorescence in
situ hybridization test) which is a DNA probe assay. It is only
approved for use in women with primary breast cancer (not metastatic
disease) who are node-negative. Approximately 30 percent of patients
with breast cancer will be HER-2/neu overexpressors. Something more
than 60 percent of patients with inflammatory breast cancer (IBC) will
be overexpressors.
Infrequently seen measurement terms
fL = femtoliters (1/1000th of a microliter)
pg = picograms (per cell) for MCH
mml = micromol (1/1000th of a mol -- remember the mol without an "e"
from high school chemistry?)
http://www.yana.org/aboutbld.htm
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