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What is Multiple Sclerosis?
• Most commonly defined as an autoimmune disease that affects the CNS
• Characterized by the loss and/or damage of the myelin sheath
• Loss of myelin sheath results in the inability of neurons to transmit neural signals properly, causing the many symptoms of MS
• Unpredictable and no known cures
Four Major Varieties of MS
• Relapsing/remitting (RRMS)– Characterized by periods of flare-ups and
remission– Accounts for 85% of MS patients
• Primary Progressive (PPMS)– Slow continuous worsening of disease from
onset– Only about 10%
Four Major Varieties of MS (cont.)
• Secondary Progressive (SPMS)– Initial period of relapsing-remitting, then steady
worsening of disease– 50% of patients diagnosed with RRMS develop into
this variety within 10 yrs without drug treatment
• Progressive Relapsing (PRMS)– Steady worsening with acute relapses– Different from RRMS in that disease progresses
during relapses– Only about 5 %
What Causes MS?
• Not exactly known
• Several theories
• Most common—myelin damage results from abnormal response in the immune system– T cells (type of white blood cell) attack myelin– Though to be triggered by environmental
and/or genetic factors
Many other theories
• MS is pathogen-mediated– Research suggests Chlamydia Pneumoniae
and other pathogens may trigger MS
• Genetics– Identical twin studies-> one has MS, other has
30% chance– No specific gene/s found yet
• Most likely involves a combination
MS Geography
• Typical onset between ages 20-50• Reduces life expectancy by about 10-15 yrs• About ½ patients survive 30+ yrs from onset• Affects 2-3 times as many women than men• Research suggests that genetic factors play a
role• More common among people of European
descent• About 400,000 Americans have MS
Symptoms of MS
• Wide variety due to nature of disease• Different classifications of symptoms
– Visual– Motor– Sensory– Cognitive– Coordination/Balance– Bowel, Bladder, and Sexual– Others
Diagnosis of MS
• No single test for diagnosing MS
• Usually diagnosed when all other possibilities ruled out
• Many tests – Medical history– Nervous system functioning– MRI, Evoked potential tests, spinal tap
Basic “Rule” for Diagnosis
• Est. by committee sponsored by NMSS in 1965
• Must have BOTH of the following:– Evidence of myelin loss in at least 2 areas
occurring in different places at different times– Any other diseases that could account for the
above have been ruled out
• Revised in 1983 by Poser to take into account advances in MRI technology
Treatments for MS
• No known cure
• Treatments involve relieving the symptoms or slowing the progression of the disease
• These are mostly drug treatments
• Also CAM’s- Complementary and Alternative Medicine
CAM’s
• Used with or instead of conventional drug treatments
• Some include– Acupuncture– Herbal medicine– Yoga– Relaxation techniques– Hypnosis
Conventional Drug Treatments
• Disease-modifying drugs*– ABC Treatments– Chemotherapeutic Agents– Corticosteroids & ACTH
• Drugs that help with symptoms– Wide variety from anti-depressants
(depression) to laxatives (bowel dysfunction) to anti-convulsants (pain/altered sensations)
ABC Treatments
• Most popular drug treatments for modifying course of disease
• Work by regulating aspects of the immune system
• ABC refers to the 3 major brand names of this category of drugs: Avonex, Betaseron/Betaferon, and Copaxone
• Also now added Rebif and Novantrone
ABC Treatments Cont.
• Interferon beta-1a– Avonex, Rebif
• Interferon beta-1b– Betaseron/Betaferon
• Glatiramer acetate– Copaxone
• Mitoxantrone– Novantrone
What are Interferons?
• Occur naturally in human body
• Proteins that prevent viral multiplication by stimulating the production of antiviral proteins in normal cells
• Interferon-alpha, Interferon-beta, and Intereron-gamma
Avonex
• Interferon-beta-1a
• Used for RRMS and SPMS w/relapses
• Produced by recombinant DNA technology using genetically engineered Chinese Hamster Ovary cells into which the human interferon beta gene has been introduced
• The resulting amino acid sequence is identical to human interferon-beta
Avonex
• Mechanisms by which it exerts it effects not fully understood
• Pharmacokinetics in MS patients not evaluated• Recommended dosage of 30 mcg to be
injected intramuscularly one weekly– Not recommended subcutaneously- adverse
reactions mainly at site of injection*
• No known interactions with other drugs• Safety of doses above 60 mcg has not been
evaluated-> do not know lethal dose
Current Avonex Research
• Avonex fairly new– Lots of research being done, few consistent
findings yet
• Most research with Avonex focuses on:– Comparison with other drugs of its type– Testing properties of the drug by altering
dosages,etc.– Seeing how well drug modifies disease
course in placebo studies
Future Research on MS
• Finding the cause
• Stopping/slowing progress of disease
• Repairing damage already done– Remyelination
• Better ways of treating symptoms
• Focusing on the social implications
Recommended Websites to Learn More
• http://www.avonex.com
• http://www.nationalmssociety.org