Auto-Immune Aspects of Arachnoiditis
WHAT ARE AUTOIMMUNE DISORDERS?
In autoimmune diseases, the body is basically fighting against itself. Antibodies, which are part of the body’s defense mechanism against invading viruses and bacteria, are formed against body tissue. Autoimmune diseases are characterized by the presence of antibodies and T-cells against "self" components, called autoantibodies and auto-reactive T-cells.
There are 2 main theories as to why this might be happening:
1. The molecular mimicry theory. Some invading organisms, in particular certain types of viruses, may mimic the genetic make-up of the body’s cells. The body mounts a normal immune response to these antigens by creating antibodies. The immune cells however, find it difficult to distinguish between the foreign cells and those of the body that they closely resemble. After the infection has been dealt with, the T cells, continue to stimulate production of antibodies, which now attack the body’s own cells.
2. The "hidden antigen theory". T cells are “programmed” in early life in the thymus, to recognize antigens that it needs to attack. In other words, it learns to distinguish between “self” and “non-self”. However, some antigens may remain “hidden” so that there is no recognition of them. If there is no exposure to these antigens, then there will not be an autoimmune response, but if the antigen does get exposed, because of infection or trauma, it could cause an autoimmune response.
A third theory suggests that the control systems which normally suppress autoimmune attack by our T cells somehow fail to do their jobs.
There is evidence that some people have a genetic predisposition to developing autoimmune disease. This may be measurable in some types of disease such as rheumatoid arthritis, lupus and ankylosing spondylitis, as a specific HLA (MHC) type.
MacDonald ([i]) noted that 18% of the general population carry a factor in the blood (Histamine Release Factor HRF) which causes a strong, sustained autoimmune reaction. If this group of patients could be identified, it might help to tell us who is at greater risk of developing autoimmune disease.
One of the known triggers for autoimmune disease is chemical insult e.g. drugs.
Autoimmune diseases are either “organ specific” (affecting one organ) or “non-organ specific” (i.e. affecting several organs).
Of the organ specific types (which include thyroiditis, diabetes etc): various neurological conditions have an autoimmune component.
These include Guillain–Barre Syndrome, Myasthenia gravis, Multiple sclerosis, and several types of immune neuropathies such as Chronic Inflammatory Demyelinating Polyneuropathy. Some of these disorders are similar to arachnoiditis in certain aspects. Also, there are a number of arachnoiditis patients who have a dual diagnosis of arachnoiditis and MS.
Of the non-organ specific types (e.g. lupus) there are often neurological aspects, including neuropathy.
There is a third group of autoimmune disorders: Multiple autoimmune syndromes.
These are when there are 3 or more co-existing discrete autoimmune disorders, and there are also “overlap” syndromes in which the features of one disease overlap with another concomitant disease.
Many autoimmune diseases involve vasculitis (inflammation of blood vessels) as a cause for the tissue damage, including central nervous system. Indeed, vasculitic neuropathy is a recognized feature of conditions such as Wegener’s Granulomatosis. There are features in arachnoiditis that are suggestive of a vasculitic process, including, in particular, the skin rashes that may be vasculitic.
AUTOIMMUNE ASPECTS OF ARACHNOIDITIS
Whilst there have been individual doctors who suspect an autoimmune component to arachnoiditis, there has been little specific research into this. The following ideas are like pieces of a jigsaw and may be difficult to put together to form a picture, as many of the pieces of the puzzle remain missing. I am merely attempting to note the following as pointers towards possible future areas for research.
Arachnoiditis is chronic inflammation of the arachnoid layer of the meninges, resulting in formation of scar tissue that causes nerve roots to adhere to each other and the dural layer.
Usually this is limited by the fibrinolytic process, which breaks down excess scar tissue, but in arachnoiditis the scar tissue continues to form.
Authors such as Jayson have suggested that there may be a defect in the fibrinolytic pathway.
Dr. Frank Mayfield felt that there might be an immune response that is responsible for the degree of reaction, especially to chemical insult.
Frank and his colleagues cultured arachnoidal cells in vitro and demonstrated their immune capabilities. ([ii])
There seems, from anecdotal evidence, to be a significant proportion of arachnoiditis patients who have autoimune problems. In some cases, the autoimmune features were present before the event that triggered arachnoiditis (e.g. surgery or myelogram) which suggests an underlying predisposition. In many other cases, the autoimmune disorders were diagnosed after onset of arachnoiditis, pointing to an autoimmune reaction, probably to chemical insult such as myelographic dye. ( similar in essence to the neuropathy caused by adulterated rapeseed oil).
It may therefore be that arachnoiditis involves a non-organ specific autoimmune response, or that it is part of a multiple autoimmune syndrome.
Marinac ([iii]) noted that there appears to be an association between the occurrence of hypersensitivity-type reactions in drug and chemical induced meningitis (an acute reaction) and underlying collagen vascular disease (known to be autoimmune).
In a similar way, it is may be that arachnoiditis represents a chronic hypersensitivity and it may also be related to underlying collagen vascular diseases.
Chemically Induced Immune System Disorder (CIISD) was described by the National Foundation For the Chemically Hypersensitive as a complex multisystem condition, resulting from toxic exposure which causes development of abnormal activated immune system and thence development of autoantibodies.
Arachnoiditis may well be an example of CIISD. ( see below)
THE LINK BETWEEN ARACHNOIDITIS AND OTHER AUTOIMMUNE DISORDERS
It has been seen in conditions such as Rheumatoid Arthritis that there may be anti-plasminogen antibodies (plasminogen is part of the fibrinolytic pathway).
It may therefore be possible that arachnoiditis involves an autoimmune process that affects fibrinolysis.
A recent paper([iv]) suggests that there is a similar process of inflammation to that seen in serous membranes such as the peritoneum, with “a negligible inflammatory cellular exudate and a prominent fibrinous exudate”. It is worth noting that the condition retroperitoneal fibrosis may be seen in association with rheumatoid arthritis.
There are also other autoimmune diseases such as scleroderma, in which fibrosis is a feature. By studying these conditions, we may be able to increase our understanding of arachnoiditis.
It is worth noting that a number of arachnoiditis patients develop multiple drug allergies. This is also a feature of autoimmune diseases such as lupus.
Another interesting point is that there is a link emerging between viral infections such as mononucleosis (Epstein Barr virus) and autoimmune disorders such as Sjogren’s disease, Systemic Lupus and MS. A number of arachnoiditis patients, either with or without diagnosed autoimmune disease, have also had preceding viral infection, maybe even some years prior to onset of arachnoiditis. It is now being postulated that these viruses may act as a trigger for underlying genetic predisposition to autoimmune disease, possibly through their ability to modify the host cell DNA, or by molecular mimicry.
FEATURES SUGGESTIVE OF AUTOIMMUNITY
Symptoms in arachnoiditis may undergo a fluctuating course, which in many patients seems to reflect periods of “flare-up” interspersed with relative remission.
During the flare-ups there may be low-grade fever, raised white cell count and/or ESR (SED).
There may also be lymph gland enlargement, joint pains and generalised malaise.
Another feature commonly found in arachnoiditis patients is skin rash, the origin of which may remain unidentified.
Symptoms of dry eyes and mouth may be related to side effects of medication, or they could be like those seen in Sjogren’s syndrome, (some patients have this diagnosis).
Multiple drug allergies are seen in some patients.
A common occurrence is the dual diagnosis of arachnoiditis and fibromyalgia (FMS). The features of FMS are undoubtedly common in arachnoiditis patients but I feel that they are part of the arachnoiditis syndrome, rather than a separate disease process.
Chemically Induced Immune System Disorder (see above) manifests itself in a broad manner:
Skin: sores, rashes etc.
Eyes: redness, burning, blurred vision
Ears: dizziness, balance problems, tinnitus
Nose: congested, nosebleeds
Throat: dry, hoarse voice
Chest: pain, shortness of breath etc.
Gastrointestinal: nausea, vomiting, cramps, diarrhoea
Menstrual: irregular periods
Urinary: blood in urine
Musculoskeletal: muscle and joint pain
Nervous system: fatigue, headaches, memory lapses, depression, etc.
There is also what is known as the “spreading phenomenon” which means that sufferers tend to become allergic to a variety of substances, the commonest of which are: petroleum products, phenol, pesticides, detergent enzymes, synthetic fragrances and flavours.
This picture is very similar to that seen in arachnoiditis.
WHY LOOK AT AUTOIMMUNITY?
Firstly, by identifying an autoimmune component in some cases, we will gain a better understanding of the disease process. It may also help to explain some of the symptoms that arachnoiditis patients experience, which are so far unexplained, such as the frequent skin rashes and the intermittent low grade fevers with a “flare-up” pattern similar to that seen in autoimmune diseases such as rheumatoid arthritis and lupus. This may mean that doctors accept the many and varied symptoms that they currently ascribe all too frequently to “psychosomatic” causes.
Secondly, the field of autoimmune disease is one in which there is extensive research. We may be able to work towards some kind of treatment based on the disease process, rather than treating the symptoms palliatively, which is the present situation.
Now when I first saw the title of the article I did not think of something like lupus as an auto-immune defeciency. Actually I would not have thought an auto-immune deficiency as being responsible or even a part of having arachnoiditis but it does make sense after reading the piece.
Of course now mind is going a million miles an hour wondering which if any deficiencies would be a factor in my arachnoiditis. Diabetes is a concern on my mothers side of the family and is a likely factor in the death of her parents.
Here is some more information on the other conditions mentioned in the reading if you are interested in knowing more about them.
Chronic Inflammatory Demyelinating Polyneuropathy
Guillain-Barre Syndrome
Myasthenia gravis
Multiple sclerosis
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