Diagnostic Tests
The following are tests that can be beneficial in diagnosing
lupus. No one test will be able to give you a diagnosis of
lupus on its own. A combination of tests and symptoms will
lead to a diagnosis.
Blood tests
These tests are just some of the tests that could lead to a diagnosis of lupus, or another
autoimmune disease:
ANA (anti-nuclear antibody) - this test is used often in a first round of testing when
there is a suspicion of an autoimmune disease because a positive result can be very
helpful in leading to a diagnosis. In most cases, a positive ANA test indicates that your
immune system has launched a misdirected attack on your own tissue — in other
words, an autoimmune reaction. But some people have positive ANA tests even
when they're healthy.
The ranges for an ANA test vary between labs but generally a result of 1:80 is
considered a low positive result. The way these tests work is that the number
doubles with each dilution. The results is the number is took to completely
dilute the antibody in your blood. For example if you had a result of 1:80 vs a
result of 1:2560, it took five more dilutions to get the result of 1:2560. This means
that there were more anti-nuclear antibodies present in the blood. This is much
more indicative of the presence of a disease.
Anti-ENA panel - An ENA Profile is useful in the evaluation of a patients
specific antinuclear antibodies. This profile can yield important diagnostic and
prognostic information in patients with systemic rheumatic disease. The profile
consists of qualitative assays for antibodies against SSA, SSB, Sm, RNP, Jo-1,
Scl-70 and total histones.
Having a positive result on any of these tests means that there is some form
of disease activity as these are not antibodies found in a healthy individual. The
different antibodies tested for can be indicative of many different diseases.
Here is a list of the different antibodies this test is looking at and what they might
indicate:
Anti-RNP: Present in Mixed Connective Tissue Disease, Lupus, and Scleroderma
Anti-SM: Typically only present in Lupus.
Anti-Ro: Seen mostly in Sjogrens patients, but also seen in Lupus and Scleroderma
Anti-La: Seen mostly in Sjogrens patients, but also seen in Lupus and Scleroderma.
Not commonly seen without Anti-Ro as well.
Anti-Scl-70: Only present in Scleroderma
Anti-Jo-1: Only seen in Polymyositis.
Ant-dsDNA - This test helps to lead specifically to a lupus diagnosis when there
are other positive tests as well indicating lupus. The presence or absence of this
antibody can not alone determine if you have lupus.
LDH (lactate dehydrogenase) - It is an enzyme involved in the breakdown of lactic acid. Anything which causes cellular
damage, including heart attacks, and liver disease.
CPK (Creatine phosphokinase) - When the total CPK level is very high, it usually
means there has been injury or stress to the heart, the brain, or muscle tissue. For
example, when a muscle is damaged, CPK leaks into the bloodstream. Determining
which specific form of CPK is high helps doctors determine which tissue has been damaged.
CRP (C-Reactive Protein) - C-reactive protein (CRP) is a non-specific test. It is used
by a doctor to detect inflammation if there is a high suspicion of tissue injury or infection
somewhere in the body, but the test cannot tell where the inflammation is or what condition
is causing it. CRP is not diagnostic of any condition, but it can be used together with signs
and symptoms and other tests to evaluate an individual for an acute or chronic inflammatory condition.
CBC With Differential - A complete blood count (CBC) gives important information
about the kinds and numbers of cells in the blood, especially red blood cells, white,
blood cells, and platelets. A CBC helps your doctor check any symptoms, such as
weakness, fatigue, or bruising, you may have. A CBC also helps him or her diagnose
conditions, such as anemia, infection, and many other disorders.
Comprehensive Metabolic Panel - The Comprehensive Metabolic Panel (CMP) is
a frequently ordered panel of tests that gives your doctor important information about
the current status of your kidneys, liver, and electrolyte and acid/base balance as well
as of your blood sugar and blood proteins. Abnormal results, and especially
combinations of abnormal results, can indicate a problem that needs to be addressed.
The CMP is typically a group of 14 specific tests that have been approved, named, and
assigned a CPT code (a Current Procedural Terminology number) as a panel by
Medicare, although labs may adjust the number of tests up or down. Since the
majority of insurance companies also use these names and CPT codes in their
claim processing, this grouping of tests has become standardized throughout the
United States.
SED Rate - The erythrocyte sedimentation rate (ESR) is an easy, inexpensive,
nonspecific test that has been used for many years to help detect conditions associated
with acute and chronic inflammation, including infections, cancers, and autoimmune
diseases. ESR is said to be nonspecific because increased results do not tell the
doctor exactly where the inflammation is in the body or what is causing it, and also
because it can be affected by other conditions besides inflammation. For this reason,
the ESR is typically used in conjunction with other tests.
Differential - The white blood cell differential is often used as part of a complete blood
count (CBC) as a general health check. It may be used to help diagnose the cause of a
high or low white blood cell (WBC) count, as determined with a CBC. It may also be used
to help diagnose and/or monitor other diseases and conditions that affect one or more
different types of WBCs.
Anti-Phospholipid Profile - Depending on the patient’s clinical findings, a physician
may order one or more types and classes of these tests to help detect the presence of
antiphospholipid antibodies and to help diagnose antiphospholipid syndrome (APS).
Cardiolipin antibodies (IgG, IgM, and sometimes IgA) are frequently ordered as they
are the most common antiphospholipids. If a patient has a prolonged PTT test, further
lupus anticoagulant testing is usually indicated. Anti-beta2 glycoprotein I and
anti-phosphatidylserine testing may be ordered along with the other antiphospholipid
antibodies to detect their presence and to provide the doctor with additional information.
lupus. No one test will be able to give you a diagnosis of
lupus on its own. A combination of tests and symptoms will
lead to a diagnosis.
Blood tests
These tests are just some of the tests that could lead to a diagnosis of lupus, or another
autoimmune disease:
ANA (anti-nuclear antibody) - this test is used often in a first round of testing when
there is a suspicion of an autoimmune disease because a positive result can be very
helpful in leading to a diagnosis. In most cases, a positive ANA test indicates that your
immune system has launched a misdirected attack on your own tissue — in other
words, an autoimmune reaction. But some people have positive ANA tests even
when they're healthy.
The ranges for an ANA test vary between labs but generally a result of 1:80 is
considered a low positive result. The way these tests work is that the number
doubles with each dilution. The results is the number is took to completely
dilute the antibody in your blood. For example if you had a result of 1:80 vs a
result of 1:2560, it took five more dilutions to get the result of 1:2560. This means
that there were more anti-nuclear antibodies present in the blood. This is much
more indicative of the presence of a disease.
Anti-ENA panel - An ENA Profile is useful in the evaluation of a patients
specific antinuclear antibodies. This profile can yield important diagnostic and
prognostic information in patients with systemic rheumatic disease. The profile
consists of qualitative assays for antibodies against SSA, SSB, Sm, RNP, Jo-1,
Scl-70 and total histones.
Having a positive result on any of these tests means that there is some form
of disease activity as these are not antibodies found in a healthy individual. The
different antibodies tested for can be indicative of many different diseases.
Here is a list of the different antibodies this test is looking at and what they might
indicate:
Anti-RNP: Present in Mixed Connective Tissue Disease, Lupus, and Scleroderma
Anti-SM: Typically only present in Lupus.
Anti-Ro: Seen mostly in Sjogrens patients, but also seen in Lupus and Scleroderma
Anti-La: Seen mostly in Sjogrens patients, but also seen in Lupus and Scleroderma.
Not commonly seen without Anti-Ro as well.
Anti-Scl-70: Only present in Scleroderma
Anti-Jo-1: Only seen in Polymyositis.
Ant-dsDNA - This test helps to lead specifically to a lupus diagnosis when there
are other positive tests as well indicating lupus. The presence or absence of this
antibody can not alone determine if you have lupus.
LDH (lactate dehydrogenase) - It is an enzyme involved in the breakdown of lactic acid. Anything which causes cellular
damage, including heart attacks, and liver disease.
CPK (Creatine phosphokinase) - When the total CPK level is very high, it usually
means there has been injury or stress to the heart, the brain, or muscle tissue. For
example, when a muscle is damaged, CPK leaks into the bloodstream. Determining
which specific form of CPK is high helps doctors determine which tissue has been damaged.
CRP (C-Reactive Protein) - C-reactive protein (CRP) is a non-specific test. It is used
by a doctor to detect inflammation if there is a high suspicion of tissue injury or infection
somewhere in the body, but the test cannot tell where the inflammation is or what condition
is causing it. CRP is not diagnostic of any condition, but it can be used together with signs
and symptoms and other tests to evaluate an individual for an acute or chronic inflammatory condition.
CBC With Differential - A complete blood count (CBC) gives important information
about the kinds and numbers of cells in the blood, especially red blood cells, white,
blood cells, and platelets. A CBC helps your doctor check any symptoms, such as
weakness, fatigue, or bruising, you may have. A CBC also helps him or her diagnose
conditions, such as anemia, infection, and many other disorders.
Comprehensive Metabolic Panel - The Comprehensive Metabolic Panel (CMP) is
a frequently ordered panel of tests that gives your doctor important information about
the current status of your kidneys, liver, and electrolyte and acid/base balance as well
as of your blood sugar and blood proteins. Abnormal results, and especially
combinations of abnormal results, can indicate a problem that needs to be addressed.
The CMP is typically a group of 14 specific tests that have been approved, named, and
assigned a CPT code (a Current Procedural Terminology number) as a panel by
Medicare, although labs may adjust the number of tests up or down. Since the
majority of insurance companies also use these names and CPT codes in their
claim processing, this grouping of tests has become standardized throughout the
United States.
SED Rate - The erythrocyte sedimentation rate (ESR) is an easy, inexpensive,
nonspecific test that has been used for many years to help detect conditions associated
with acute and chronic inflammation, including infections, cancers, and autoimmune
diseases. ESR is said to be nonspecific because increased results do not tell the
doctor exactly where the inflammation is in the body or what is causing it, and also
because it can be affected by other conditions besides inflammation. For this reason,
the ESR is typically used in conjunction with other tests.
Differential - The white blood cell differential is often used as part of a complete blood
count (CBC) as a general health check. It may be used to help diagnose the cause of a
high or low white blood cell (WBC) count, as determined with a CBC. It may also be used
to help diagnose and/or monitor other diseases and conditions that affect one or more
different types of WBCs.
Anti-Phospholipid Profile - Depending on the patient’s clinical findings, a physician
may order one or more types and classes of these tests to help detect the presence of
antiphospholipid antibodies and to help diagnose antiphospholipid syndrome (APS).
Cardiolipin antibodies (IgG, IgM, and sometimes IgA) are frequently ordered as they
are the most common antiphospholipids. If a patient has a prolonged PTT test, further
lupus anticoagulant testing is usually indicated. Anti-beta2 glycoprotein I and
anti-phosphatidylserine testing may be ordered along with the other antiphospholipid
antibodies to detect their presence and to provide the doctor with additional information.