Cell Mediated Protection::The Autoimmune Puzzle


Disease::diseases    Cells::system    Immune::which    Symptoms::presence    Types::other    Foreign::blood

Cell Mediated Protection Few types of large cells are present in our body namely macrophages, neutrophils, and dendritic cells, mast cells, eosinophils, basophils, and natural killer cells. These cells are programmed to kill foreign body as and when they come into contact with one. The common mechanism of killing involves engulfing, sucking the foreign body and then killing it with the help of various enzymes. The phagocytes form the base of what is the Innate Immunity and are present at birth. Other forms of innate immunity include surface barriers such as the presence of killer enzymes in saliva. Antibody-Based Protection

Our body may already have antibodies against the known pathogens. When these pathogens enter the bloodstream, antibodies can eliminate them through three different ways. First, the antibody may completely cover the foreign particle. Second, the antibody can act as a watchdog, and activate other cells that kill the foreign body. Third, the antibody may attach to the foreign body, which allows other guard cells to engulf the pathogen. This type of immune system is referred to as an Adaptive Immunity. The word adaptive indicates the ability of the body to develop new antibody when it comes into contact with a new disease pathogen.

Adaptive or antibody-based protection process is most susceptible to the development of autoimmune diseases. Many complexities are still unsolved as to why body mistakenly learns to attack its cells. Autoimmune diseases variety is mind-boggling. Research suggests over 80 types that vary from each other based on the body part they attack, whereas some have a system wide impact.

While individual diseases by itself are rare, collectively, if all autoimmune diseases are combined, they affect roughly 5-8% of the human population. Several variations are also seen between ethnic races. For instance, Type 1 diabetes is more commonly seen in the white or Caucasian race, whereas Lupus is seen more in the African-American and Hispanic race. In terms of gender, autoimmune diseases are also more prevalent in women than men. Estimates suggest that nearly 80% of individuals with the autoimmune disease are women. Cause of Autoimmune Diseases

Autoimmune diseases are known to be polygenic i.e. persons who acquire an autoimmune disease have a family of genes that have some mutation or defect. However, every person who has such genes may not have the disease. However, heredity alone accounts for only 30% risk of getting the disease, with the remaining 70% risk attributed to environmental factors such as hormones, diet, drugs, toxins exposure, and infections.

Hormones, especially sex-related hormones such as estrogen and androgen are known to amplify the immune response. Women either produce more of these naturally or have a higher synthetic intake in the form of birth control pills.

Components in our diets may also contribute to the development of autoimmunity. The presence of pesticides albeit within safe limits may still trigger. In some individuals, gluten may trigger an autoimmune response. Excess intake of Iodine through Iodized products is believed to increase the autoimmune disease related to Thyroid gland. The presence of heavy metals such as mercury, silver or gold is found to induce an autoantibody response in laboratory tests.

Viral and bacterial infections are also known to trigger autoimmunity. Several different mechanisms as to how infections can trigger the disease are cited in medical research and laboratory tests in animals prove some. Autoimmune Damage Mechanism

Antibody assisted damage includes the presence of autoantibody which binds to healthy cells and induces a response by other immune cells, resulting in lysis of the healthy cell. Alternatively, they can also bind to a healthy cell surface and alter its functioning. Presence of specific autoantibody is a good predictor of a particular disease type.

When there is an overabundance of specific immune cell types called T-helper cells, it signifies that immune system is in a hyperactive mode. These cells secrete certain chemicals called Cytokines that invite the macrophages to arrive and destroy even healthy cells.

Another mechanism that can cause autoimmunity is when the regulatory cells which prevent body’s immune system from going into a hyper-drive become ineffective. Due to this mechanism, sometimes the absence of an autoantibody is not enough to rule out a particular autoimmune disease. The Autoimmune Disease Challenge

Autoimmune diseases are often very challenging to diagnose even for the most experienced physicians. When a particular autoantibody is present, it does not always imply that the person has a disease, but it is a good indication of his or her susceptibility to a disease.

When autoimmunity is caused by ineffective regulatory cells, it is hard to diagnose an autoimmune disease. In such cases, physicians rely on the symptoms that differentiate a disease from others. However, symptoms too sometimes overlap or take much longer to manifest in a form that makes the disease type clear to the physician.

Another challenge with autoimmune diseases is that different diseases impact various parts of a human body. Therefore, if one has multiple sclerosis, a neurologist would need to be involved. Likewise, if someone has Rheumatoid Arthritis, a rheumatologist must be involved. Multiple opinions may sometime be necessary to analyze the disease symptoms and get closer to diagnosing the disease. Major Disease Types and Impact Area

There are over eighty different autoimmune diseases, and they can be categorized into 2 general types:

   Localized (organ specific) – mainly one particular part of the body affected
   Systemic – multiple regions of the body affected

A person may suffer from multiple different types of autoimmune diseases, causing an overlap of symptoms.

The Autoimmune Puzzle sections
Intro   Cell Mediated Protection    Types of localized (organ specific) autoimmune diseases:    Systemic autoimmune diseases:    Diagnosis of autoimmune diseases:    References:   

Cell Mediated Protection
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