Arthritis

Arthritis is an autoimmune disease frequently characterized by swollen and painful joints. Uncontrolled arthritis can lead to joint damage and deformities. Arthritis may be caused by inflammation of the tissue lining the joints. This inflammation causes redness, heat, pain, and swelling. Drug treatment targets the overactive immune system, whereas physical therapy can be used to strengthen muscles and improve mobility.

Types

The two most common types of arthritis are osteoarthritis and rheumatoid arthritis. When the latter occurs in children, the condition is called juvenile rheumatoid arthritis.

Osteoarthritis is the most common form of arthritis. It is associated with advancing age and most often affects the fingers, knees, and hips. Sometimes osteoarthritis is caused by joint injury that had occurred years earlier. For example, knee injuries inflicted while playing a sport could cause osteoarthritis in the knee later in life.

Rheumatoid arthritis happens when the body’s own defense system doesn’t work properly. It affects joints and bones (often of the hands and feet), and may also affect internal organs and systems.

Another common type of arthritis, gout, is caused by accumulation of crystals in the joints. It usually affects the big toe, but many other joints can be affected.

Some other types of arthritis include the following:

• septic arthritis in which joints swell in response to a bacterial infection
• ankylosing spondylitis which primarily affects the spine and could lead to complete fusion of the vertebrae
• Still disease, a form of juvenile rheumatoid arthritis characterized by fevers and rash

Arthritis can occur with many other conditions. These are called secondary forms because they are a complication of another disease. Some forms of secondary arthritis include the following:

• Systemic lupus erythematosus, also called lupus, is a disease in which the body’s defense system can harm the joints, heart, skin, kidneys, and other organs.
• Psoriatic arthritis occurs when the immune system attacks the skin and results in scaly skin (psoriasis)
• Vasculitis in its many forms (e.g., Henoch-Schönlein purpura) is a form of arthritis characterized by inflammation of the blood v vessels
• Reactive arthritis occurs in response to an infection in another part of the body.
• Inflammatory bowel disease, which includes Crohn disease and ulcerative colitis, affects the intestines and causes diarrhea.^[1]

Signs and Symptoms

Most types of arthritis cause pain and swelling in the joints. The joints may also feel hot to the touch and appear red. Some other common symptoms of arthritis include the following:

• nausea
• fatigue
• stiffness (especially in the morning)

Some symptoms that occur in specific forms of the disorder include the following:

• fever
• weight loss
• trouble breathing
• rash or itch
• diarrhea
• nodules or bumps in the skin

These symptoms are nonspecific, and thus occur in many different diseases.

Cause

Arthritis is an autoimmune disease. In these diseases, the immune system does not recognize the body’s own tissues as “self” and mounts an attack on the tissue it detects as foreign. This attack involves the production of antibodies and the signaling, activation, and proliferation of white blood cells. These white blood cells gather in the targeted tissue and cause inflammation. Normally this inflammation is used to protect against foreign invaders, such as bacteria or organ transplants. In arthritis the inflammation is unnecessary and produces pain and damages joints over the long-term.

In most cases, the reason for the overactive immune system of arthritis is not known. In some cases, a bacterial infection can trigger the inflammation, but why the inflammation persists when the foreign invaders have been eliminated is not known.

Diagnosis

Diagnosis depends on the type of arthritis. However, in general doctors use pain and swelling in the absence of injury as an indication that the immune system is overactive. Diagnosis is aided by the use of x-rays and blood tests. The x-rays can detect joint damage. Blood tests are used to find markers of disease. For example, people with rheumatoid arthritis can have elevated rheumatoid factor and anti-nuclear factor. These factors measure the amount of antibody in the blood that is directed against the the body’s own tissues.

Treatment

Treatment for arthritis focuses on reducing the pain and inflammation. Most treatments are designed to suppress the immune system. These drugs are called immunosuppressants or sometimes immunomodulators. Physiotherapy is often used to improve mobility and strength in osteoarthritis, rheumatoid and several other forms of arthritis that affect the joints. If the disease is not controlled, sometimes surgery is needed to replace damaged bones and joints.

Medications

The pain and inflammation may be alleviated with over-the-counter non-steroidal anti-inflammatory drugs. These drugs, which include aspirin, ibuprofen (Advil), or celecoxib (Celebrex), are often the first step. They target an enzyme called cyclooxygenase, which synthesizes molecules that cause pain and inflammation. Several topical (on the skin) preparations are also available to help soothe sore joints. These drugs only target the symptoms of the disease and not the underlying cause.

Other drugs used for arthritis may slow the progression of the disease, and are thus called disease-modifying anti-rheumatic drugs (DMARDs). Numerous DMARDs are available:

• Gold salt injections
• methotrexate (Trexall)
• Leflunomide (Arava)
• chloroquine (Aralen)
• cyclosporine (Neoral)
• etanercept (Enbrel)
• infliximab (Remicade)
• sulfasalazine (Azulfidine)

These drugs suppress the immune response in people with arthritis. Some, like etanercept and infliximab, interfere with signaling among white blood cells, and others, like methotrexate, actually inhibit the production of white blood cells. Because these drugs suppress the immune system, the risk of infection is increased during administration.

In more serious cases of arthritis, when DMARDs are ineffective, steroids like prednisone are often used. These are often very effective but cannot be used for any extended periods of time because of serious side effects. Prednisone is converted into cortisol in the body. Cortisol is a hormone that suppresses inflammation. Some clinical trials are testing the usefulness of bone marrow transplants in people whose arthritis cannot be controlled by any other means.

Physical and occupational therapy

Many people with arthritis benefit from physical or occupational therapy. Physical therapy involves an exercise regiment designed to strengthen muscles and improve flexion. Often this therapy also reduces pain while improving the ability to perform daily activities. Occupational therapy targets day-to-day function. Occupational therapists can make devices, such as splints, to support joints during daily activities, or at night. These devices may also reduce pain.

The pain and stiffness of arthritis may also be relieved by warm showers, ice pack application to sore joints, and rest of a sore joint.

Surgery

Joint damage sometimes progresses despite intervention. In these cases, surgery may be necessary to replace the joint. Knee and hip replacements are some of the more common surgical approaches.

Living with Arthritis

Arthritis, if uncontrolled, can seriously hinder daily activities. Simple tasks, such as dressing, bathing, or even eating can become difficult. Arthritis can affect performance on the job, or even the choice of a career.

Complications

Uncontrolled inflammation, as well as the side effects of many arthritis medications, can have lifelong consequences. Inflammation cause joint damage and deformities that may require surgery. Medications can have serious side effects. Prednisone, for example, can cause osteoporosis or diabetes, and the long-term use of immunosuppressants could increase the risk of cancer.

Arthritis can also affect more than just the joints. In some cases, the chest, heart, skin and eyes become involved. Inflammation in the eyes can lead to blindness if not diagnosed and controlled early.

Risk Factors

Increasing Age and joint injury are two major risk factors for arthritis. Eye involvement is more likely to occur in he late teens and in girls rather than boys.

Clinical Trials

• Rheumatoid Arthritis (RA) Moderate to Low Disease Activity Study (CERTAIN)
• Clinically Important Changes in Rheumatoid Arthritis

Research

There remains no cure for this arthritis and the current treatments are only modestly effective at slowing the disease's progression and providing symptomatic relief. The clinical effectiveness of current treatment regimens has been limited by short half-lives of the drugs and the requirement for repeated systemic administration. Investigators have been searching for alternative treatment that may provide a cure. One of the possibilities is the use of gene transfer technology to correct the underlying imbalance.^[2]

References

1. ↑ Weigl M, Cieza A, Cantista P, Reinhardt JD, Stucki G. Determinants of disability in chronic musculoskeletal health conditions: a literature review. Eur J Phys Rehabil Med. 2008 Mar;44(1):67-79. Abstract | Full Text
2. ↑ Traister RS, Hirsch R. Gene therapy for arthritis. Mod Rheumatol. 2008;18(1):2-14. Epub 2008 Jan 5. Abstract | Full Text

External Links

Arthritis Foundation American College of Rheumatology

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