Re: Fw: [JJ World] Do Bacteria or Viruses Cause MS?

[Guest guest]



[JJ World] Do Bacteria or Viruses Cause MS?Do Bacteria or Viruses Cause MS? by C. Article Date: 07-08-05The origins of multiple sclerosis apparently lie in an abnormal assault bythe body's immune system against certain parts of the central nervous system,which include the brain and spinal cord.1Similar Proteins Targeted?Though it hasn't been clear as to the cause of this immune system miscue, anew study from Switzerland suggests that a certain bacterium or virus may bethe culprit.2 These bacterial infections, the Swiss study team claims,induce a kind of self-recognition that may contribute to some autoimmune diseasessuch as MS and Guillain-Barre syndrome (GBS).These organisms produce an infection that may stimulate the production ofantibodies that make up the immune system, as well as immune cells known asT-cells. The theory is that the immune cells target bacterial proteins thatclosely resemble the body's own proteins, leading to crossreactivity with healthytissues.Alternative TheoryHowever, in the latest study, Gennaro de Libero, MD, at University Hospitalin Basel, Switzerland, and his associates identified another possiblemechanism. In this case, bacterial infections may promote activation of T cells thatrecognize special molecules present in bacteria and humans known asglycosphingolipids (gly-koh-sfin-goh-LIH-pids), or GSL. The research team showedthat infection with some bacteria or even exposure to pieces of the outer wallof the bacteria results in an increase in T-cell response to these molecules."This stimulation may contribute to inflammatory responses during bacterialinfections and may predispose individuals to autoimmune diseases," deLibero's team wrote. It's an important mechanism that leads to autoreactive T-cellactivation in the immune system, and may take part in the origins of manyother autoimmune diseases, de Libero explained.The investigators theorize that although autoreactive T-cells may play abeneficial role in promoting the response to infection in the body, in theabsence of infection, these T-cells might instead seek out the abundant GSLmolecules found in the central nervous system, resulting in the damage to tissuein that part of the body seen in people with _MS_(http://www.msneighborhood.com/content/understanding_ms/what_is_ms.aspx) .Another disease in which this mechanism may be found includes Guillain-Barrsyndrome (GBS), "in which the anti-GSL T-cell response may be important," deLibero explained.No Definite Conclusions YetOther research has focused on the possible role of disease-causing organismsas an underlying source of MS. For instance, in 2003, Spanish researchersassessed the levels of antibodies that were associated with three pathologicalorganisms in the blood samples taken from a group of people with MS.3The study team found "a strong association" between antibodies against humanherpesvirus type 6 (anti-HHV-6), one of the many herpesviruses, and theearly stages of _multiple sclerosis_(http://www.msneighborhood.com/content/understanding_ms/what_is_ms_1421.aspx) , particularly in those with the relapsingform of the disease. Antibodies against Epstein-Barr virus were also linkedwith MS in these patients, the study team noted.In a review paper on the subject,4 doctors at Wayne State University inDetroit reviewed previous studies that suggested a link between MS and certainbacterial or viral infections. However, they found many inconsistentobservations, writing that "no conclusion is possible at this point".1. National Multiple Sclerosis Society. What is Multiple Sclerosis?Available at: http://www.nationalmssociety.org/What%20is%20MS.asp.2. De Libero G, Moran AP, Gober HJ et al. Bacterial infections promote Tcell recognition of self-glycolipids. Immunity 2005 Jun;22(6):763-72.3. Villoslada P, Juste C, Tintore M et al. The immune response againstherpesvirus is more prominent in the early stages of MS. Neurology 2003 Jun24;60(12):1944-8.4. Swanborg RH, Whittum-Hudson JA, Hudson AP. Infectious agents and multiplesclerosis—are Chlamydia pneumoniae and human herpes virus 6 involved? JNeuroimmunol 2003 Mar;136(1-2):1-8. is a long-time health journalist and an editor for PriorityHealthcare. His credits include overseeing health news coverage for the websiteof Fox Television's The Health Network, and articles for the New York Post andother consumer and trade publications._What is MS?_(http://www.msneighborhood.com/content/understanding_ms/what_is_ms.aspx)_How MS Makes You Sick_(http://www.msneighborhood.com/content/understanding_ms/what_is_ms_1421.aspx)_Disease Course and Progression_(http://www.msneighborhood.com/content/understanding_ms/what_is_ms_1926.aspx)_More on Bacteria/Viruses' Possible Role in MS_(http://www.nationalmssociety.org/Sourcebook-Etiology.asp)_National Institutes of Health_(http://www.ninds.nih.gov/disorders/multiple_sclerosis/multiple_sclerosis.htm)