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Laboratory studies initially may not contribute to the diagnosis. The rheumatoid factor assay is initially negative in
many patients--and in up to 30%,the assay is never positive. The ESR may or may not be elevated at presentation,the elevation
may not occur for weeks and even months. Elevated ESR may be found in other,certain diseases.
Erythrocyte sedimentation rate -ESR (sed rate)--The most often used measurement of inflammation is the E.S.R. This
test is based on how quickly red blood cells settle out on the bottom of a test tube. In inflammatory conditions of any type
(arthritis included), red blood cells settle out more quickly.
The "sed rate" is a useful test and most physicians use it. A normal rate is about 20 millimeters per hour or less,but
in some forms of arthritis it may as high as 80 millimeters per hour.
A high sedimentation rate can confirm suspicions of inflammation, but,like many other tests,the results may be elevated
in conditions other then arthritis,and sometimes in normal people. Many physicians use it to follow disease course,but to
the question,"Is the patient getting better or worse". A few questions and a quick exam may be better at times.
The CRP (C-reactive protein) is a blood test that is starting to be used more often now. It can be automated so it's
cheaper to perform,and it's less likely to be fooled by non-inflammatory conditions than the sed rate.
Rheumatoid Factor--This test determines whether RF is present in the blood. Rheumatoid Factor is an antibody found in
the blood of most people who have RA. RF may be found in many other diseases beside RA,and sometimes in normal healthy
people .
Eighty % of patients with RA have an increased level of the RF in their blood. The RF is elevated in most patients with
RA. An elevated RF is consistent with,but does not prove that RA is present. However,a negative RF,particularily early on
in the disease does not exclude RA.
Most patients with moderate or severe RA develop a positive RF within the first 6 months to 1 year of contacting the
disease. Some patients with a family history of RA will test positive all their lives.
The more positive the test,the greater likelihood of RA being present. However,most doctors have seen patients with strongly
positive tests and no other evidence of arthritis. Unfortunately,early on in the disease and in patients with the mild form
of the disease,the RF is often very low,or even negative.
Urinalysis-- In this test,a urine sample is studied for protein,red blood cells,white blood cells,or casts. These abnormalities
indicate kidney diseases which may be seen in several rheumatic diseases such as lupus or vasculitis (RA) Some DMARDs can
also cause abnormal findings on urinalysis. Gold therapy requires this test to be conducted regularly.
Complete blood count (CBC)--This test determines the number of white blood cells,red blood cells,and platelets present
in a sample of blood. Some drugs used to treat arthritis are associated with a low white blood count (leukopenia),low red
blood count (anemia),or low platelet count (thrombocytopenia). when doctor's prescribe medications that affect the CBC,they
periodically check the patient's blood.
Since red blood cells carry oxygen from the lungs to the body,white blood are one of the body's main means of dealing
with infection,and platelets are very important in blood clotting,problems with any one of them may cause real trouble.
Anemia (a low red blood cell count ) is common in inflammatory arthritis. Usually this reflects the fact that the bone
marrow,which is where blood cells are made,just isn't able to keep up production when inflammation is present,even if it has
all the ingrediants,including enough iron. But anemia can be due to arthritis medicine,particuarly NSAIDs such as ASA,which
may cause bleeding from the stomach or duodenal ulcer,and a resulting low red blood cell count.
Low white blood cell counts and low number of platelets may occur, separately or together,in some kinds of arthritis.
Unfortunately, similar problems may be caused by some of the drugs used to treat the disease, so the sitution can be confusing
at times.
White blood cell count (WBC)--This test determines the number of white blood cells present in a sample of blood. The
number may increase as a result of infection or decrease in respose to certain medications or with certain diseases such as
lupus.
Low number of white blood cells increase a person's risk of infection. The white cell count is usually normal in patients
with RA,but can be mildly elevted secondary to inflammation similarily,the platelet count is usually normal,but thrombocytosis
occurs in response to inflammation
X-rays and other imaging procedures--to see what the joint looks like the doctor may order x-rays or other imaging devices.
Other nonivasive imaging devices such as computed tomography (CT or CAT),magnetic resonance imaging (MRI),and arthrograpy
(joint x-ray) show the whole joint.
The doctor may use a arthroscope (a small,flexible tube that transmits a image, of the inside of a joint, to a monitor
to examine damage to a joint). The arthroscope is inserted into the affected joint through a very small incision in the skin.
This procedure called arthroscopy allows the doctor to see inside the joint. Doctors also use arthroscopy to perform surgery
for some types of joint injury.
Creatine--This blood test is commonly ordered in patients who have rheumatic diseases to moniter for underlying kidney
disease.
Complement--this test measures the level of complement,a group of proteins in the blood. complement helps destroy foreign
substances such as germs that enter the body. A low level of blood complement is usually found in people who have lupus.
Hematocrit (PCV packed cell volume) This test and the test for hemoglobin (a substance in the red blood cell that carries
oxygen through the body) measure the number of red blood cells present in a sample of blood. A decrease in the number of red
blood cells (anemia) is common in people with inflammatory arthritis.
Arthrocentesis--Arthrocentesis or joint aspiration is done to obtain a sample of synovial fluid. The doctor injects a
local anesthetic,inserts a thin,hollow needle into the joint and removes the synovial fluid into a syringe. The test provides
important diagnostic information.
Antinuclear antibody (ANA)--This test checks blood levels of antibodies that are often present in people who have
connective tissue diseases or other autoimmune disorders such as lupus. Since the antibodies react with material in the cell's
(control center),they are referred to as antinuclear antibodies.
There are also tests for individual types of ANA's that may be more specific in people with certain autoimmune disorders.
ANA's are sometimes found in healthy people. Therefore having ANA's in the blood does not necessarily mean that a person has
a disease.
It is more helpful in determining if inflammatory disease is present or not. However, the antiinuclear
antibody test is often positive without any underlying disease present.
Complete bone count test ( approximately 250 bones in the body)procedure is not taught at the family physician
level in medical school training. The rheumatoligist training provides this test but a complete bone count is not often
done,and the time factor may be involved. The complete test may take over an hour.
Synovial Fluid Assessment--If the joints are very swollen,the physician may take a small amount of fluid from the swollen
joint for testing . Normal synovial fluid is clear,thick,and oily,which helps to lubricate the joints.
In RA (not OA),the fluid becomes cloudy because it is infiltrated with cells,usually white blood cells and debris. These
cells break down the oily substance (hyaluronic acid) and make it very watery. By looking at the fluid the physician
can tell if it is normal or the presence of inflammation. In the laboratory the presence of inflammation can be determined.
Chemistry is normal in RA,with the exception of a slight decrease in albumin,and increase in protein,reflecting the chronic
inflammatory process. Renal and liver function should be checked prior to therapy.
Diagnosing rheumatic diseases can be difficult because some symptoms and signs are common to many different diseases.
A general practisioner or family doctor may be able to evaluate a patient or refer him or her to a rheumatoligist
The doctor will review the patient's medical history,conduct a physical examination and obtain laboratory tests and x-rays
or other imaging tests. The doctor may need to see the patient more than once to make a accurate diagnosis. In patients with
any evidence of ongoing disease activity,a plain film of the most severly affected joints can be very helpful. Documentation
of progressive joint destruction would permit earlier intervention with aggressive therapy.
There are two common tests used to monitor the progress of inflammatory arthritis. A hemoglobin test measures your red
blood cell count: During a flare of inflammatory activity,normal hemoglobin levels drop. This "low blood" differs from the
anemia of "iron poor blood",since it can occur even if you're storing adequate amounts of iron.
How successfully your DMARD therapy is at reducing inflammation determines whether your hemoglobin returns to normal
levels. The other test is called a sedimentation (or "sed") rate: It measures certain proteins in the blood that indicate
inflammatory activity. The lower the score the better.
X-rays provide a baseline. After one or two years,the physician can obtain another x-ray to see whether the disease has
continued to progress radiographically. This can occur independently of clinical manifestations,even patients whose symptoms
have responded well to therapy may continue to show radiographic progression. If erosions or joint space narrowing had already
been present,it would help to predict the disease course and to determine the therapeutic strategy (one of the many aids in
therapy).
It is vital for people to give the doctor a complete medical history. Answers to the following questions will help the
doctor make a accurate diagnosis:
Is the pain in one or more joints?
When does the pain occur?
How long does the pain last?
When did you first notice the pain?
What were you doing when you first noticed the pain?
Does activity make the pain better or worse?
Have you had any illnesses or accidents that may account for the pain?
Is there a family history of any arthritis or rheumatic disease?
What medicine(s) are you taking?
It may be helpful for people to keep a daily journal to describe the pain. Patients may write down what the affected
joint looks like,how it feels,how long the pain lasts,and what they were doing when the pain started.
The doctor will examine all of the patient's joints for redness, warmth, deformity, ease of movement,and tenderness.
Because some forms forms of arthritis like lupus,and RA may affect other organs,a complete physical examination including
the heart, lungs , abdomen,nervous system,and eyes, ears, and throat may be necessary. The doctor may order some laboratory
tests to help confirm a diagnosis. Samples of blood,urine,or synovial fluid (fluid foud in the joints) may be necessary for
the tests.
Acute phase reactants (white blood cell count,platelets,ESR,and C-reactive protein) may not be always elevated in patients
with active arthritis,especially in an elderly patient. A sometimes-useful strategy is to obtain and analyze synovial fluid,which
should show features of disease activity.
Usually,the patients who are prone to joint destruction are rheumatoid factor positive,but not all patients. Only in
about 70 to 80 % of individuals with RA is the blood test,the rheumatoid factor,actually positive. In 30 % or so of patients,
that blood test is negative--seronegative rheumatoid arthritis. i.e., an individual who has rheumatoid arthritis,but the blood
test is negative. They have a sophisticated testing in research for a positive test,but not of a type that can be picked up on
the commercially available rheumatoid tests done in most labs.
The diagnosis of rheumatoid arthritis is what physicians call a clinical diagnosis. It's based on the history and what
the physician sees. There's a certain distribution and type of arthritic changes they like to see. There are things they like
to see on x-ray as well as on exam.
Treatments for arthritis include rest and relaxation,exercise,proper diet, medication,and instruction about the use of
joints,and to conserve energy. Other treatments may include the use of pain relief methods ,and assistive devices (if necessary).
The doctor may delay using medications until a definite diagnosis is made, because medications can hide important symptoms
(such as fever and swelling) and thereby interfere with diagnosis. Patients taking any medication,either prescription or over
the counter should always follow the doctors instructions. The doctor should be immediately notified if the medication is
making the symptoms worse or causing any problems such as a upset stomach,nausea,or headache. The doctor may be able to change
the doseage or medicine to reduce these side effects.
Unfortunately "bone-count" is not a regular program taught to doctors at the medical training level,therefore many physicians
are not properly trained in this procedure. Another factor is the time factor,a complete "bone count" may involve 1 hour of
testing (the bone count involves manually feeling each bone joints for inflammation). This important fact was written
by a medical school graduate--now an writer about medical conditions such as rheumatoid arthritis)
Basline laboratory evaluations should include complete blood cell count (CBC),platelet count,chemistry profile,RF measurement,and
measurement of ESR or CRP. Evaluation of renal and hepatic function is necessary since many antirheumatic agents have renal
or heotic toxicity,and may be contraindicated if these organs are impaired. As explained elsewhere and repeated,initial x-rays
(radiographs) of the hands/feet should be obtained since structural damage cannot be deducted by physical examination alone.
Arresting and preventing structural damage is a primary goal of therapy,and repeat radiographic studies of sentinel or
major involved joints may be needed periodically. Rheumatoid arthritis can attack any joint in the body,and tends to do so
in a symmetric pattern (left and right side).
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