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What is Guillain-Barre and Causes of Guillain-Barre Syndrome | ||
| By Staff Writer | ||
| June 8th, 2010 | ||
Guillain-Barre syndrome (GBS) obtained its name from the neurologists who first described this symptom, Georges Guillain, Jean-Alexandre Barre and Andre Strohl. Guillain-Barre syndrome is an acute flaccid paralysis syndrome. This is a rare disorder. Generalized muscle weakness is the main clinical feature of this disease. Usually symptoms begin in the lower limbs and move up, also called ascending paralysis. Therefore the initial symptoms may include weakness or tingling sensation in the legs, this sensation spreading up to the arms and the body. In severe cases paralysis may ensue and when the disease affects respiration and heart function, it can be life threatening.
How is it caused? Guillain-Barre syndrome, is one such disease in which the body's own immune system attacks nervous system antigens. When our body's immune system attacks its own tissues, cells or molecules the condition is called autoimmunity. There are two major paths for the immune system to recognize a target molecule. One of them is through specialized proteins called antibodies. Antibodies bind to antigens to neutralize the function of the antigen or to destroy it. Antibodies may also bind to cellular antigens and kill the cells. The other route of immune recognition is through specialized cells called T lymphocytes. T lymphocytes are a subset of white blood cells, or lymphocytes. The T cells may have specificity to specific antigens on the cells leading to cellular destruction. The immune system is designed to protect against invasive pathogens, however this system sometimes misunderstand the body's own tissues resulting in autoimmune diseases. A combination of appropriate genetic and environmental factors have been suggested to play important roles in the initiation of an autoimmune disease. The environmental factors include viral and bacterial infections. One mechanism by which viral and bacterial infections may cause autoimmunity is by a process called molecular mimicry. When a bacteria or virus invade the body, the body develops an immune response specific to the invading pathogen. For example, it may make an antibody that can bind on to an antigen on the surface of the pathogen. Suppose this antigen is somewhat similar to another antigen on an important cell on the body itself! Then ideally the same antibody can recognize the body's own antigen and begin the process of destruction. A similar situation can be envisaged with the lymphocytes also (Raju and Hampe, International Reviews in Immunology, 2008;27:79). The result would be that the antibody that was developed to kill the pathogen would now recognize this self antigen and begin to destroy the cells that carry this antigen in the body. It is reported that gangliosides ( on the outer core of the bacterium Campylobacter jejuni may mimic human gangiosides (this is a an important liposaccharide), which means that an immune response to this bacterial antigen may elicit immune response to the ganglioside molecules on the nerve cells. It is reported that this is one of the possible scenarios, or at least a possible mechanism for in Guillain-Barre and Miller Fisher (discussed later) syndromes (Salloway et al. Infect. Immun.1996; 64: 2945; Prendergast and Moran, J. Endotoxin. Res.,2000; 6: 341–359). According to CDC (CDC website) infection with the bacterium Campylobacter jejuni is one of most common risk factors for Guillain-Barré. Molecular mimicry has been postulated in other autoimmune diseases such as multiple sclerosis (a central nervous system autoimmune disease), myasthenia gravis and autoimmune myocarditis. It may be noted, that infections causing autoimmunity remains an argument and credible evidences associating the two together are not proved beyond controversies. Well, if infections have a possibility to cause autoimmunity, it might be suggested that immunizations (vaccination) can also cause autoimmunity. According to CDC (CDC website, Sep 2009) people can develop Guillain-Barré after having the flu or other infections (such as cytomegalovirus and Epstein Barr virus). On very rare occasions, they may develop GBS in the days or weeks following receiving a vaccination. Guillain Barre is not a contagious disease. What is the relationship between vaccination and Guillain-Barre Syndrome? The previous section elaborates on the causes for Guillain-Barré syndrome and how infections and vaccination can cause Guillain-Barré syndrome. However, one may ask if it is well established that vaccination can cause Guillain-Barré syndrome? Evidences suggest that Guillain-Barré syndrome is immunological in origin and nerve cell antigens are recognized by the immune system. It is therefore concluded that destruction of nerve cells by the immune system causes Guillain-Barré syndrome. As symptoms are developed some times during or after infections and some times following vaccinations, infections and rarely vaccinations are attributed to be the disease pathogenesis. One of the major findings was during the 1976 outbreak of swine Flu, when there was a national campaign to vaccinate people against swine flu. An increased risk to Guillain Barre Syndrome (GBS) was observed in the group that was vaccinated, compared to those who were not vaccinated. It is noteworthy that only 1 additional case of GBS occurred per 100,000 people vaccinated (reference: CDC). In one of the recent reviews of the available literature, it was observed that the causal relationship between vaccination and Guillain-Barré syndrome is not clear, when the most association found was following the vaccination for swine flu (influenza) in 1976-1977 (Haber et al, Drug Safety 2009; 32:309). They also suggested that older vaccine formulations such as rabies vaccine cultured in mammalian brain tissues have been found to have an increased risk, but not the newer ones developed using chicken embryo cells. The issue still remains unresolved. The CDC states that they "expect the 2009 H1N1 vaccine to have a similar safety profile as seasonal flu vaccines, which have very good safety track records. The seasonal flu vaccine has not been consistently associated with GBS." What is the treatment for Guillain-Barre Syndrome? According to CDC, an estimated 3,000 to 6,000 people develop Guillain Barre syndrome each year in the United States. The treatment for GBS varies depending on the symptoms. In severe cases hospitalization is required and continued monitoring of the patient may be very important. This is because the patient may have to be placed on respirator, heart monitor or other instruments to help maintain the organ and body functions. Plasmapheresis or intravenous immunoglobulin treatments may be used. Plasmapheresis is a technique by which the watery (liquid) portion of the blood, the plasma, is selectively removed from the blood and the rest of the blood, that constitutes mainly the blood cells, is administered back into the patient. This is carried out by taking the whole blood out, performing the separation of the plasma and administering back the rest of the blood components by the aid of a machine. Intravenous immunoglobulin or IVIG drug is purified human immunoglobulin. The mechanism by which IVIG function in GBS or other diseases is not clear. Miller Fisher Syndrome Miller Fisher syndrome is another rare variant of Guillain-Barre syndrome. One of the differences from Guillain-Barre syndrome is that Miller Fisher syndrome may be characterized by descending paralysis. When Guillain-Barre syndrome starts from the legs and move up, Miller Fisher syndrome begins with symptoms related to eye muscles, these symptoms may move down. Miller-Fisher syndrome is characterized by paralysis of the eye muscles (ophthalmoplagia), abnormal muscle coordination (ataxia), and absence of the tendon reflexes (areflexia). The cause of this syndrome is also not clear as is the case with Guillain-Barre syndrome, though like in Guillain-Barre syndrome infections are suspected to be an underlying factor. Antibodies to the GQ1b (ganglioside) epitope is often tested, as serum from many patients with Miller Fisher syndrome contains antibodies to this neuronal ganglioside (a gangliside a ceramide oligosaccharide, which means that it is a complex molecule with lipids and sugars). Third, fourth and sixth cranial nerves contain good amounts of this ganglioside (Plomp JJ et al, Ann Neurol, 1999; 45:189). However, it is not clear whether these antibodies are the cause of the disease or its symptoms. Treatment methods are similar to that proposed for Guillain barre syndrome; intravenous immunoglobulin (IVIG) and plasmapheresis are used. It is reported that recurrence of Miller-Fisher syndrome may occur (Kuitwaard et al, J Neurol Neurosurg Psychiatry. 2009;80:3). An expert neurologist may be required to diagnose Miller Fisher syndrome. Additional Reading: JB Winer. Bickerstaff's encephalitis and the Miller Fisher syndrome. J Neurol Neurosurg Psychiatry. 2001 October; 71(4): 433–435 Plomp JJ, Molenaar PC, O'Hanlon GM, Jacobs BC, Veitch J, Daha MR, van Doorn PA, van der Meché FG, Vincent A, Morgan BP, Willison HJ. Miller Fisher anti-GQ1b antibodies: alpha-latrotoxin-like effects on motor end plates. Ann Neurol. 1999 Feb;45(2):189–199. Schabet M. Miller Fisher syndrome. Pract Neurol. 2009 Oct;9(5):289-91. | ||
| This article is relevant to the following subject areas | ||
| •Medicine •Neurology •Immunology | ||
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