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Diseases
Introduction: (RHEUMATOID ARTHRITIS)
RA is not a generic term for just any type of arthritis.
It also is not a term applied to any form of severe arthritis. It is
a specific type of arthritis that begins in the soft tissue around
the joint known as the synovium (sin-O-vee-um). RA affects 1% of the
U.S. population, with women outnumbering men 2:1 to 4:1. While the
peak age of onset is in the 30’s to 50’s, RA can begin at any age.
It is a disease that progresses most rapidly within the first two
years of onset, and those afflicted with RA have twice the mortality
rate of individuals of the same age in the general population.
Features of RA:
The basic problem in RA is inflammation of the synovium,
causing swelling, pain, and morning stiffness, and which can lead to
irreversible joint damage and loss of function. The joints most
often affected are the wrists and the small joints of the hands,
usually the first and second row of knuckles past the wrists. Other
commonly affected joints include those in the balls of the feet, the
ankles, the knees, the elbows, and the shoulders. While neck
involvement is common, the lower back is typically spared. The
pattern of arthritis has a strong tendency to be symmetrical,
affecting the same joints on both sides of the body.
When joints become affected in RA, they don’t
simply hurt; they become progressively damaged. The inflamed
synovium, when not properly treated, can invade the bone and
cartilage surrounding the joint and result in irreversible damage
and loss of function. This may result in not only pain, but also
limited mobility, deformity, and difficulty using the impaired
joint. This process does not discriminate according to age, race or
gender; all affected with RA are at risk for complications.
While the joint disease is the most striking
manifestation of RA, the inflammation will often affect other
organs. Up to 40% of RA patients will have abnormalities in lung
function, which are often subtle and may go unnoticed. Many
patients, however, can experience serious lung damage requiring more
aggressive therapy. Roughly ¼ of patients will have dry eyes and dry
mouth known as secondary Sjögren’s syndrome (see section on
Sjögren’s), and about 20% will have inflammation that may cause
irritation of the eyes, or less commonly, vision loss. A condition
known as Felty’s syndrome causes low blood counts and frequent
enlargement of the spleen, and rheumatoid vasculitis (inflammation
of the blood vessels) may result in rash, skin ulcers, or less
commonly damage to the nerves or other organs. Both of these
conditions are infrequently encountered in RA (about 1% of
patients).
Diagnosis:
RA is predominantly diagnosed by a thorough review of a
patient’s symptoms and physical examination. While laboratory
studies help in the evaluation, no laboratory test can either
establish or rule out a diagnosis of RA. The rheumatoid factor (RF),
markers of inflammation, and a new antibody know as anti-CCP are
useful studies and are often used to predict the severity of RA in
individual patients. X-rays are also useful diagnostic tools,
particularly films of the hands and feet, and can be used to monitor
disease progression by assessing the degree of joint damage.
Treatment (see Medications section):
Therapy in RA has two goals: reducing symptoms and
preventing joint damage and disability. We have more tools available
to treat RA today than ever before, and studies have documented that
early treatment with specific medications has a long-term impact on
the course of the disease. While all therapies have potential side
effects, the consequences of not treating RA are generally much
greater. Your doctor will work carefully with you to select the
right medications for you as an individual.
Non-steroidal anti-inflammatory drugs (NSAIDs) such as ibuprofen
(Motrin) and simple analgesics such as acetaminophen (Tylenol) or
even narcotic-strength pain relievers have a role in treating RA.
These therapies, however, are limited to their effects on reducing
day-to-day symptoms and have no effect on the long-term course of
the disease. Many of these medications may be given in combination
with other RA therapies to reduce pain in inflamed joints.
Corticosteroids such as prednisone may be very effective in
rapidly reducing pain and swelling in inflamed joints, both when
given orally and injected directly into a joint. Some evidence
suggests that these medications may even slow down joint damage.
Long-term side effects, however, limit the use of corticosteroids in
RA. Generally speaking, steroids should be used for disease flares,
for brief periods of time, or in low doses to avoid these
complications (see Medications section).
Disease-modifying anti-rheumatic drugs (DMARDs) should be the
mainstay of therapy for most patients with RA. Generally speaking,
the sooner they are started after the onset of symptoms, the more
effective they are at treating the disease. Ideally, DMARDs should
be initiated within three months of disease onset to achieve an
optimal response. Because patients are individuals, your doctor will
work with you to determine which DMARD is appropriate for the
severity and stage of your disease. All of the agents listed below
fall under this category.
Anti-malarial drugs are generally among the safest of the
DMARDs but are generally utilized to treat milder RA.
Hydroxychloroquine (HCQ), marketed under the trade name Plaquenil,
takes 3 to 6 months to begin working and can be used either by
itself or in combination with other DMARDs. The only potential
complication requiring monitoring is that of damage to the retina,
the layer in the back of the eye, which can potentially impair color
vision. While this is of concern, it occurs in only one of 1,000
people taking the drug and is detectable before serious damage
occurs if monitored by your eye doctor every 6-12 months. HCQ doses
of less than 6.5 mg/kg/day generally have a very low incidence of
retinal damage.
Sulfasalazine (SSZ) was developed many decades ago to treat
RA and is also commonly used to treat Crohn’s disease, an
inflammatory intestinal disorder. SSZ takes effect in 1 to 3 months
and seems to have a modest effect on slowing down joint damage in
RA. This drug also seems to be more effective in patients who are
“seronegative” (with a negative RF). The most common side effect of
SSZ is stomach upset, which may be eliminated by using a coated
preparation of the drug. Allergic reactions are also no unusual.
Serious problems, such as a drop in the white blood cells or acute
damage to the liver, are unusual and typically occur early in the
course of therapy, if at all. Blood tests to monitor for these
complications will generally pick up any problems before they become
severe.
Methotrexate (MTX) is perhaps the most popular and most
commonly prescribed DMARD among rheumatologists, and for good
reason. MTX slows joint damage, improves symptoms and physical
functioning in RA patients, and has an onset of action of 1 to 3
months after starting the medication. It is taken once weekly in the
form of pills or injections, with injections being associated with
better availability of the medication and often less side effects.
Nausea, mouth sores, thinning of the hair, lowering of blood counts,
susceptibility to infection, and liver damage are among the more
common side effects and can be reduced by taking folic acid or
folinic acid (Leucovorin) supplementation. Rarely, acute lung injury
may occur that can resemble pneumonia. Despite these potential side
effects, problems with MTX can generally be detected with regular
lab monitoring every 1 to 2 months. Most importantly, patients with
RA taking MTX have a mortality rate that is only 40% of the
mortality rate of RA patients not taking the drug. This finding
seems to indicate that for most patients, the trade-off between
benefit and side effects is very good.
Leflunomide (LEF), marketed under the trade name Arava, is a
relatively new drug used to treat RA. It is taken orally once daily
and begins to take effect in 1 to 3 months. The efficacy of LEF is
similar to that of MTX, and it does seem to slow down the
development of joint damage. LEF can result in nausea, diarrhea,
hair loss, and liver damage, but the incidence of lowered blood
counts and infection are lower than with MTX.
TNF antagonists are perhaps the most exciting class of
medications to be recently introduced for the treatment of RA.
Currently, there are 3 available medications in this class:
etanercept (Enbrel), infliximab (Remicade), and adalimumab (Humira).
Enbrel is given as a once weekly injection, Remicade is given as an
intravenous infusion every 4-8 weeks, and Humira is administered as
an injection every 2 weeks. Each of these medications inhibits a
substance known as tumor necrosis factor (TNF) in one way or
another. TNF is known to play a key role in inflammation in
inflammation and joint damage in RA, and for this reason these
medications are highly effective in controlling both the symptoms of
the disease and the joint damage. In fact, some studies suggest that
these medications actually halt joint damage in RA patients.
Each of the TNF antagonists may begin working within a few
weeks of starting therapy. While individual patients may respond
more favorably to one agent over another, all of these drugs seem to
have similar efficacy. Disadvantages of these therapies include
cost, inconvenience of injections or infusions, injection site or
infusion reactions, and suppression of the immune system.
Respiratory infections occur in increased frequency in patients
treated with TNF antagonists, and those exposed to tuberculosis may
experience reactivation of their disease. For this reason, a TB skin
test is recommended prior to starting therapy. Patients with
multiple sclerosis or severe congestive heart failure may experience
worsening of their disease and therefore should not take these
medications. Thus far, cancer rates have not been clearly shown to
be increased in RA patients taking TNF antagonists versus other RA
patients, but the data is somewhat confusing. Recently, the press
has publicized an increased rate of a cancer known as lymphoma in
patients taking these medications, but this was compared to the
normal population. Because RA patients as a whole have an increased
risk of lymphoma, it is not clear if the medications themselves or
the disease accounts for this increased rate.
On the whole, we have found these medications to be well
worth the cost and the potential side effects and have seen them
virtually eliminate signs of active disease in patients resistant to
many of our standard therapies. Currently, we are using TNF
antagonists mostly in patients who have inadequately responded to
MTX or other therapies. Most often, these drugs are added to MTX and
may be more effective when used in this manner but may also be used
alone. Use of TNF antagonists earlier in the course of the disease
is being investigated and may be recommended for certain patients in
the future.
Miscellaneous drugs that are less commonly used to treat RA
but which may be useful in certain individuals include minocycline,
azathioprine (Imuran), injectable gold, D-penicillamine, and
anakinra (Kineret).
Minocycline is an antibiotic that is also used to treat acne
and other skin diseases. Like HCQ, minocycline is usually used to
treat milder RA, but one study showed that if started within one
year of disease onset and continued for one year, up to 40% of
patients went into remission. Other than nausea, dizziness, and sun
sensitivity in some individuals, minocycline is usually very well
tolerated.
Imuran is a medication that suppresses the immune system and
may be effective at reducing the inflammation in the joints of RA
patients as well as in other organ systems, such as the lungs.
Increased infection rates, lowered blood counts, and liver damage
are potential side effects.
Injectable gold is given once weekly in the doctor’s office
and must be monitored closely, including blood and urine tests with
each visit to screen for low blood counts and protein in the urine.
Rashes, damage to the liver, and lung damage are also potential side
effects. While effective in treating RA, the inconvenience,
toxicity, and delayed onset of action (4 to 6 months) have made gold
a less popular choice among rheumatologists and patients.
D-penicillamine, a drug also used to bind toxic levels of
heavy metals in the body, has a therapeutic effect in RA. The
toxicity of this agent, however (blood cells, kidneys, liver,
secondary autoimmune diseases), has led to less frequent use in
treating RA patients.
Kineret is a newly introduced injectable drug given once
daily and inhibits a substance know as interleukin-1 (IL-1). While
effective in a subset of RA patients, responses to therapy are
generally less dramatic that those seen with TNF antagonists. A
somewhat increased infection rate and injection site reactions are
the most commonly observed side effects.
"Information reproduced with the permission of the American College
of Rheumatology. www.rheumatology.org"
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