Download Autoimmune Disease

What is meant by
“A case of
mistaken identity”?
Give an example.
The Immune System
Makes Mistakes
attacks harmless
foreign substances
allergies
attacks the body’s own
tissues and organs
autoimmune disease
Allergies
What are the symptoms of an allergic reaction?
Allergy
Symptoms
What foreign
substances
cause allergies?
Allergens – allergy-causing antigens
Pollen
Dust
Mites
Foods
Animal
Hair
Allergy
a rapid overreaction to an antigen
(allergen) that is not normally harmful
What is
Histamines
causing
all these
part of the inflammatorysymptoms?
response
released by cells stimulated by
antigen (allergen)
dilates blood vessels
increases the permeability of the capillaries to white blood
cells and some proteins
allows them to engage pathogens in the infected tissues
Histamines
How do Antihistamines Work?
What is
blocks
it
histamine
doing?
receptor
receptor
cell
Autoimmune
Disease
•
condition in which the immune
system mistakenly attacks the
body’s own organs and tissues
Autoimmune Diseases
• juvenile diabetes
• rheumatoid arthritis
• multiple sclerosis (MS)
• lupus
• rheumatic fever
Why would the body attack
itself?
What is the mistake made
by the immune system?
Hint: In order for the immune system to be
successful in defending the body, what two
things must it be able to distinguish?
The basis of immunity
is in the body’s ability to
distinguish between its own
substances (“itself”) and foreign
substances (“nonself”)
“Self
molecules”
(“I.D. tags”)
Autoimmune Disease
immune system fails to recognize
some of the body’s tissues as “self”
- Like a “case of mistaken identity”
Why does this happen?
Hypothetical Factors Influencing
Autoimmune Disease
• infections
• aging
• chronic stress
• hormones
Rheumatic fever
•
caused by a bacteria (strep)
• triggers an immune
response against heart and joint
tissues
individual produces antibodies to
antigens of strep bacteria
strep antigens are structurally
similar to antigens of the heart
anti-strep antibodies attack sites on
the heart, damage the heart muscle
and heart valves.
Rheumatoid
Arthritis
Rheumatoid Arthritis
White blood cell attack leads to
the destruction of cartilage and
bone in the joint
Rheumatoid Arthritis
white blood cells attack cells inside
joint capsule producing
inflammation
inflammation causes cells of capsule
to grow and divide abnormally
abnormal cells destroy cartilage and
bone in the joint
Pancreatic cells
Islets of
Langerhans
Pancreatic cells
under attack by
white blood cells
Juvenile Diabetes
(Type I diabetes mellitus)
Antibodies destroy insulin-producing
cells of pancreas
Normal
nerve
fiber
MS
nerve
fiber
Multiple Sclerosis (MS)
• White blood cells attack and damage nerve
cells
• Damage interferes with messages between
nerves and the body
Lupus
Lupus
antibodies attack nucleic acids
and cell organelles such as
ribosomes and mitochondria
Lupus
• virus might trigger the disease in
genetically susceptible individuals
• inflammation and damage to various
body tissues
joints, skin, kidneys, heart,
lungs, blood vessels, brain
Vaccine
– a weakened or dead pathogen
put into the body to stimulate
the production of antibodies and
the primary immune response
How might a vaccine
induce an autoimmune
disease?
antigen similar to substance in body?
Treating Autoimmune Disease
immunosuppressive drugs and steroids
Problems
• infections
• not specific
Autoimmunity
vs.
Immunodeficiency
What is
this?
Antibody
Active Immunity
Passive Immunity
You make
the antibodies
You don’t make
the antibodies
Exposure to
antigen
- injection
- vaccine
- infection
- breastfeeding
In some cultures it is normal
for babies to be breast-fed
for up to 4 years!
Benefits of Breastfeeding
Breast milk:
http://www.webmd.com
• provides ideal nutrients for infants (vitamins, protein,
and fat) in a form more easily digested than infant
formula
• contains antibodies that help your baby fight off
viruses and bacteria
• lowers the baby's risk of having asthma or allergies
• babies who are breastfed exclusively for the first 6
months, without any formula, have fewer infections
(ear infections, respiratory illnesses, bouts of diarrhea,
hospitalizations and trips to the doctor.)
Benefits of Breastfeeding
• Breastfeeding has been linked to higher
IQ scores in later childhood in some studies.
• Physical closeness, skin-to-skin touching,
and eye contact all help baby bond with
mother
• Infants are more likely to gain the right amount of
weight as they grow rather than become overweight
children.
• May also plays a role in the prevention of SIDS
(sudden infant death syndrome).
• May lower the risk of diabetes, obesity, and cancer
Benefits of Breastfeeding
Breastfeeding:
• burns extra calories, so it can help mom lose
pregnancy weight faster.
• releases the hormone oxytocin, which helps the
mother’s uterus return to its pre-pregnancy size and
may reduce uterine bleeding after birth.
• lowers mother’s risk of breast and ovarian cancer.
• may lower mother’s risk of osteoporosis
• saves time and money
(you don't have to buy and measure
formula, sterilize nipples, or warm bottles)
Active immunity
Passive Immunity
When the boy got infected the first time
his primary immune response was
activated and he made antibodies to attack
the antigen. His immune cells divided and
left behind memory cells. When he got
infected the second time his memory cells
made the secondary immune response
fight the disease faster and stronger, so he
didn’t even get sick.
myelinated
demyelinated
Multiple Sclerosis (MS)
Myelin protein surrounding
nerve cells is attacked and
destroyed
nerve impulses are slowed or
blocked
Rheumatic fever
• can occur following untreated
streptococcus (strep) infection
• most often affects children
causing painful, inflamed joints
• in some cases, permanent
damage to heart valves.