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Various Theories for Autoimmunity

Discussion in 'Other Health News and Research' started by sandralee, Nov 1, 2011.

  1. sandralee


    Sydney, Australia
    Here is a clear and simple explanation of autoimmunity, and the various theories behind its cause.

    An autoimmune disease is different in that the immune system is attacking self - parts of you. Its an immune system gone awry.

    Theres no organ or bodily system excluded from potential attack. Your finest weapon can become your greatest enemy. Like any other part of the body, defects can arise in the immune system.

    Autoimmunity can be caused by defects in almost any part of the immune process. In most European countries and the USA, it is realistic to say that at least 5% of the population (1 in 20) will suffer from a self-destructive autoimmune disease during their lifetime. Dr. John Morrow. Dr. David Isenberg Friendly Fire: Explaining Autoimmune Disease

    Some examples of overactive or autoimmune dysfunction are:
    Lupus (considered a classic autoimmune disease)
    Multiple Sclerosis
    Autoimmune Hepatitus

    For an autoimmune disease list as compiled by the American Autoimmune Related Disease Association (63) click here

    Where Do Autoimmune Diseases Come From?
    According to Drs. Isenberg and Morrow the onset of an autoimmune disease would require a combination of several factors going wrong at the same time.

    Cited as possibilities are: genetic predisposition, hormonal influences, enzyme abnormalities, stress, diet, ultraviolet light and micro-organisms like bacteria and viruses.

    These types of factors influence immune system health and status. They also state, Autoimmune diseases can result from several different defects, combinations of defects, in the immune system

    It might be worthy to note that in spite of the fact that there are over 60 autoimmune related diseases recognized with over 60 different symptoms, the reason they all exist is due to immune system malfunction. That is the deep, core issue.

    [See Immune Stressors] See also Immune products

    Potential Immune Mechanisms of Autoimmune Disease
    Researchers dont appear to have come to any definite conclusions regarding the mechanisms of immune dysfunction behind autoimmune diseases. This is not surprising since the immune system itself is a new frontier of study.

    The following are some examples of credible possibilities put forth by a variety of researchers. Its an intricate area and experts dont necessarily agree. There may also be some overlapping. Some theories are more widely held than others.

    T Suppressor Cells
    The function of T suppressor cells in the immune system is to stop the immune response; the foe is destroyed! T suppressor cells can damp down an immune response at the appropriate time.

    It is a widely held belief that the seemingly unregulated autoantibody production in autoimmune disease is a result of inadequate T suppressor cell function. T suppressor cells also are thought to be responsible for distinguishing between self and foreign tissue and thus prevent autoimmunity.

    Decreased numbers and activity of T suppressor cells in patients with virtually all types of autoimmune disorders have been reported. Drs. Isenberg and Morrow, Friendly Fire

    T Helper Cells
    The Helper T cell is the quarterback of the immune system. Theyre the organizers of immune activity; aiding, abetting and directing virtually every facet of the immune system.

    Almost everything your immune system can do is dependent on the T Helper cell. It directs the activity through the secretion of protein molecules called cytokines.

    Interleukin 2 and Gamma Interferon are examples of cytokines. Cytokines are information molecules and are produced by other cells as well.

    T Helper cells produce Th1 and Th2 cytokine profiles, among others, based upon the cytokine environment (information/cytokines from other cells). Th1 cytokines are great for promoting a defense against a viral or bacterial attack.

    Th2 cytokines organize defenses against parasites and mucosal infections but will shut down the activity of Th1 in the process. Some researchers believe that some viruses, bacteria and mycoplasma make proteins that mimic a cytokine that effectively turns on the Th2 cytokines thereby turning off the Th1 cytokines actually needed to promote killing them.

    This leaves the immune system, or part of it, in a state not fully functional for the task at hand.

    Dr. Lauren Sompayrac states that by secreting the appropriate set of cytokines, Th cells can help produce an immune response that is appropriate to a given invader so that the punishment fits the crime.

    Infection & Autoimmune
    There are intimate links between infectious agents (viruses, bacteria, etc) and autoimmunity. Drs. Isenberg and Morrow

    A similar perspective on infection is offered by Dr. Lauren Sompayrac, For years physicians have noticed that autoimmune diseases frequently follow bacterial or viral infections, and immunologists believe that microbial attack may be one of the key environmental factors that trigger autoimmune disease. Dr.Lauren Sompayrac, How the Immune System Works

    The immune system is constantly being challenged by infection. Events can arise from infections if the immune system does not eliminate the invading organism quickly and efficiently.

    Most researchers believe infection to be a trigger but also believe other conditions must be present. This is obvious since everyone who gets an infection does not get an autoimmune disease.

    Molecular Mimicry
    Another favored theory is that B cell and T cell receptors in the immune system recognize things that are similar as opposed to things identical. If a receptor is activated in the normal way by an invader, and self immune stimulators are present (in the same locality) at the same time, the immune system may react to both.

    Another way of putting it is that some microorganisms trick the immune system into attacking self because of a superficial resemblance. Since the immune system has layers of tolerance or self protection, other break-downs in these systems are also required.

    Immunologists believe that the majority of autoimmune diseases result when the layers of tolerance inducing mechanisms fail to eliminate self-reactive cells in genetically normal individuals. Dr. Lauren Sompayrac

    Infection Slightly Different Perspective
    The possibility that at least some such diseases [autoimmune] are due to cryptic microorganisms continues to intrigue many immunologists. If even tiny traces of invading microbes remain lodged in human tissues after an infection, they argue, immune-based disease could ensue.

    Although the microorganisms would be present in amounts too low to be detected by even the most sensitive clinical tests, they would still be detected by the immune system.

    In such amounts, even the most virulent microbes would themselves be unlikely to cause disease, but the attempts of the immune system to ferret them out and destroy them could cause extensive damage to apparently normal human tissues. Dr. William Clark, At War Within

    Antigenic Mimickry
    What if part of an invading microorganism (bacteria, virus, etc.) actually contains a protein identical to some human protein? There is some evidence that this might happen in a few cases. Many researchers contend this is highly unlikely.

    Reference: Friendly Fire: Explaining Autoimmune Disease by Dr. David Isenberg and Dr. John Morrow; At War Within by Dr. William R. Clark; Dr. Paul Cheney; How the Immune System Works by Lauren Sompayrac

    Mechanisms Change
    Through the integrity of the immune system we remain separate from our environment. This inner image of self-ness or uniqueness somehow carries through to each defensive cell as it works to eliminate cancer cells that arise daily or virus particles as they penetrate from the outside world.

    The mechanisms by which this image of self is transmitted and carried out are still largely unknown. We do know that the mechanisms exist and, more important, that they are subject to change.

    Macrophages, for example, do not merely mope about hoping to bump against a bacterium or other source of food. They migrate from distant corners of the body, zero in on targets that they know are alien, and then destroy them. Dr. Jesse Stoff, The Prostate Miracle

    An Important Question
    One important question: Is an autoimmune disease preceded by deficient immune function?

    That information, clearly stated, doesnt seem available from a scientific source. It would seem logical, however, that a functional immune system would be able to fight off invaders without becoming self attacking especially since genetics are not thought to be the major part of the problem.

    Note on genetics: Genetics can contribute to susceptibility (in relationship to MHC molecule expression).

    However, to repeat, Although some autoimmune disorders result from genetic defects, immunologists believe that the majority of autoimmune diseases result when the layers of tolerance inducing mechanisms fail to eliminate self-reactive cells in genetically normal individuals. Dr. Lauren Sompayrac

    Genetic inheritance is not the central determinant for autoimmune diseases for most people.

    Conventional Approach
    The main choice of treatment for autoimmune disease appears to be corticosteroids like prednisone. There are others. These drugs are anti-inflammatory and extremely immune suppressive. There are significant side effects.

    Who Gets Autoimmune Diseases?
    Individually, autoimmune diseases arent very common, with the exception of thyroid disease, diabetes, and systemic lupus erythematosus. However, taken as a whole, they represent the fourth largest cause of disability among women in the United States. Why focus on women?

    For reasons not fully understood, about 75% of autoimmune diseases on average occur in women. Hormones are thought to play a role as symptoms can improve or change depending on hormone activity.

    Hormone Imbalance & The Immune System
    Autoimmune Disease & Female Hormones: Progesterone/Estrogen

    Symptoms Vary Widely
    Symptoms vary widely from one type of autoimmune disease to another, but also vary within the same autoimmune disease. Individual diseases range from the benign to the severe.

    [Reference: American Autoimmune Related Diseases Association]

    All the best,

    taniaaust1 likes this.
  2. alex3619

    alex3619 Senior Member

    Logan, Queensland, Australia
    Hi, while a lot of the suspected automimmune issues arising from bacteria and viruses are thought to be molecular mimicry, where the pathogen has evolved to chemically resemble something in the body so if you fight it you fight yourself, a lot of it is just basic biology. We have man of the same chemicals in our body as bacteria. If we have bacterial fragments entering our body, which includes LPS as previously studied, then we might attack them. Since we have many of the same or similar chemicals, this could lead to an immune attack on our own bodies. This includes cardiolipin which in various forms is a common phospholipid in bacteria. Bye, Alex

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