What is Autoimmune Disease?

Autoimmune disease is an immune system disorder that mistakes self tissues for non-self and mounts an inappropriate attack.

 

Causes, incidence, and risk factors of an autoimmune disorder

The immune system protects the body from potentially harmful substances (antigens) such as microorganisms, toxins, cancer cells, and foreign blood or tissues from another person or species. Antigens are destroyed by the immune response, which includes production of antibodies (molecules that attach to the antigen and make it more susceptible to destruction) and sensitized lymphocytes (specialized white blood cells that recognize and destroy particular antigens).

An immune system disorder occurs when the immune response is inappropriate, excessive, or lacking. An autoimmune disorder develops when the immune system destroys normal body tissues. This is caused by a hypersensitivity reaction similar to allergies, where the immune system reacts to a substance that it normally would ignore. In allergies, the immune system reacts to an external substance that would normally be harmless. With autoimmune disorders, the immune system reacts to normal self body tissues.

Normally, the immune system is capable of differentiating self from non-self tissue. Some immune system cells (lymphocytes) become sensitized against self; tissue cells, but these faulty lymphocytes are usually controlled (suppressed) by other lymphocytes. Autoimmune disorders occur when the normal control process is disrupted. They may also occur if normal body tissue is altered so that it is no longer recognized as self. The mechanisms that cause disrupted control or tissue changes are not known. One theory holds that various microorganisms and drugs may trigger some of these changes, particularly in people with a genetic predisposition to an autoimmune disorder.

Autoimmune disorders result in destruction of one or more types of body tissues, abnormal growth of an organ, or changes in organ function. The disorder may affect only one organ or tissue type or may affect multiple organs and tissues. Organs and tissues commonly affected by autoimmune disorders include blood components such as red blood cells, blood vessels, connective tissues, endocrine glands such as the thyroid or pancreas, muscles, joints, and skin.

 

Types of Autoimmune Disorders:

1. Multiple Sclerosis

The body’s immune system attacks the central nervous system and keeps the nerves from telling the body to do things like walk, talk, or write. Multiple Sclerosis is often called simply "M-S". Some people with MS will need to use a wheel chair to get around. Click here for more info on MS.

 

2. Insulin-Dependent Diabetes Mellitus (Type 1 or "Juvenile Diabetes")

The body’s immune system attacks the insulin-making cells in the pancreas (a body organ) and destroys them. Without enough insulin, the body cannot control how much sugar is in the blood. Someone with Insulin dependent diabetes needs daily shots of insulin to live.

 

3. Rheumatoid Arthritis:

The body’s immune system attacks the tissues around the joints in the body. This disease makes the tissues swell up, and can cause pain and stiffness. It also can hurt the heart, lungs, and eyes.

4. Dermatomyositis

5. Fibromyalgia:

The body’s immune system attacks the muscles, tendons, and ligaments, causing pain and tiredness. 

6. Lupus:

   The body’s immune system attacks the joints, skin, kidneys, heart, lungs, blood vessels, and brain. Sometimes it is very hard to tell if you have lupus. Common signs are a bright rash of the face, pain in the joints, unexplained fever; chest pain when you breathe; and unusual loss of hair.

7. Asthma

8. Chronic Fatigue Syndrome

9. Allergies to drugs and food

10. Addison's disease

11. Inflammatory Bowel Disease

12. Reiter's Syndrome

13. Grave’s Disease and Hashimoto’s Thyroiditis:

    The body’s immune system attacks the thyroid gland. The thyroid gland controls how the body uses energy. These diseases can make people lose or gain weight, sweat more, become more sensitive to heat changes, as well and change a woman’s menstrual flow.

 

Symptoms of Autoimmune Disorders

Symptoms of autoimmune disease vary widely depending on the type of disease. A group of very nonspecific symptoms often accompany autoimmune diseases especially of the collagen vascular type and include:

• fatigue

• dizziness

• malaise (nonspecific feeling of not being well)

• fever, low-grade temperature elevations

• destruction of an organ or tissue resulting in decreased functioning of an organ or tissue (for example, the islet cells of the pancreas are destroyed in diabetes)

• increase in size of an organ or tissue (for example, thyroid enlargement in Grave's disease)

Note: Symptoms vary with the specific disorder and the organ or tissue affected.

 

Genetic factors

There are more than 80 autoimmune diseases that affect different parts of the human body. About 75% of autoimmune diseases are found in women. A woman is more likely to get an autoimmune disease if other family members have autoimmune diseases. Certain diseases such as psoriasis can occur among several members of the same family, suggesting that a specific gene or set of genes predisposes a family member to psoriasis.   In addition, individual family members with autoimmune diseases may inherit and share a set of abnormal genes, although they may develop different autoimmune diseases.

These diseases are often chronic, requiring lifelong care and monitoring, even when the person may look or feel well. Currently few autoimmune diseases can be cured or made to "disappear" with treatment. However, many people with these diseases can live normal lives when they receive appropriate medical care. Scientists are searching for ways to prevent and treat these diseases by studying the immune system factors, the role of genetics, and the possible role of infectious agents.

 

Treatment

The goals of treatment are to reduce symptoms and control the autoimmune process while maintaining the ability to fight disease. The treatment of these diseases is principally based in the use of immunosuppressant drugs, such as glucocorticoids, calcineurin inhibitors, and antiproliferatives-antimetabolites. However, these pharmacological therapies can reduce the immune function as a whole, have various cytotoxic effects, and therefore can suppress the immune system in a non specific way, exposing the patient to the risk of infections and cancer. In addition, Calcineurin and glucocorticoids cannot be used in diabetes patients. Side effects of medications used to suppress the immune system can be severe, which include fast/irregular/pounding heartbeat, stomach pain, blood in the stools, mental/mood changes, severe headache, easy bruising or bleeding, leg pain or swelling, numbness or tingling of the hands or feet, unsteadiness, unexplained muscle weakness, seizures, vision changes, extreme fatigue, chest pain, joint pain, butterfly-shaped rash on the nose and cheeks.  You may also have a slightly increased risk of developing a certain type of cancer (lymphoma), tuberculosis infection.

The latest therapeutic advances in immuno-suppression are the anti CD3 monoclonal antibodies; the anti IL-2 receptor monoclonal antibodies and the anti-TNFa monoclonal antibodies. Despite the fact that these treatments exhibit marked immunosuppressing effects, anaphylaxis reactions, opportunistic infections (Tuberculosis) and neoplasm’s, fever, urticaria, hypotension, dyspnea are associated with these medicines, representing  a serious problem in the application of said compositions and pharmaceutical products. In injectable applications, one out of three patient can present itching, swelling, and pain.

 

Emerging Therapies

Recent breakthroughs in the transcription and translation of a variety of mediators have led to increased interest in therapeutic approaches directed at the level of gene transcription (e.g. COX2, iNOS, IL1beta, TNFalpha, ICAM, etc.).  One of the most important mediators is NF-kappaB which plays a key role in the regulated expression of a large number of pro-inflammatory mediators including cytokines such as IL-6 and IL-8, cell adhesion molecules, such as ICAM and VCAM, and inducible nitric oxide synthase (iNOS). These Proinflammatory mediators are known to play a role in inflammation and in the case of iNOS, may lead to organ destruction in some inflammatory and autoimmune diseases.  Click here for more information on NFkB