Autoimmune diseases arise from an overactive immune response that attacks the body's own tissues and organs. Common symptoms include fatigue, joint/muscle pain, and organ dysfunction. There are two main types - organ-specific diseases that target a single organ, like Hashimoto's thyroiditis; and systemic diseases like lupus that can affect multiple body systems. Treatment focuses on immunosuppression to reduce the immune response and prevent further damage.

1. AUTOIMMUNE DISEASES
PRESENTED BY-
HASNAHANA CHETIA

2. DEFINITION
Autoimmune diseases are diseases that arise
from an overactive immune response of the
body against substances and tissues normally
present in the body. The immune system
mistakes some part of the body as
a pathogen and attacks it. This may be
restricted to certain organs or involve a
particular tissue in different places. The
treatment of autoimmune diseases is typically
with immunosuppression—a medication which
decreases the immune response.

3. SYMPTOMS
The symptoms of autoimmune disease vary depending on
the disease as well as the person's immune system. Common
symptoms include:
 Anxiety or depression
 Blood sugar changes
 Digestive or gastrointestinal problems
 Dizziness
 Elevated fever and high body temperature
 Extreme sensitivity to cold in the hands and feet
 Fatigue
 Infertility
 Inflammation
 Irritability

4.  Low or high blood pressure
 Malaise
 Weakness and stiffness in muscles and joints
 Weight Changes
And depending on the type of autoimmune
disease:
 Destruction of an organ or tissue
 Increase in the size of an organ or tissue

5. Autoimmune diseases can be classified
into 2 broad categories-
1. Organ-specific
2. Systemic

6. ORGAN-SPECIFIC AUTOIMMUNE DISEASES
In this type, the immune response is directed
to a target antigen unique to a single organ
or gland. The cells of the organ may be
damaged directly by humoural or cell-
mediated effector mechanisms. Alternatively,
the antibodies may overstimulate or block the
normal functions of the target organ.
Eg- Hashimoto’s thyroiditis

7. Organ-specific Auto-immune diseases are
mediated by-
A. Direct Cellular Damage where
lymphocytes or antibodies bind to cell-
membrane antigens, causing cellular lysis
and/or an inflammatory response in the
organ as a result of which the damaged
cellular structure is replaced by connective
tissue (scar tissue) and the function of the
organ declines.
Diseases caused by this are-

8. HASHIMOTO’S THYROIDITIS
Hashimoto's thyroiditis or chronic
lymphocytic thyroiditis is an autoimmune
disease in which the thyroid gland is gradually
destroyed by a variety of cell and antibody
mediated immune processes due to production
of auto-antibodies and sensitized Th1 cells for
thyroid antigens. It was the first disease to be
recognized as an autoimmune disease and was
discovered by Dr. Hashimoto Hakaru.

10. AUTOIMMUNE ANEMIAS
An individual with this disease makes auto-antibody
to RBC antigens, triggering complement-mediated
lysis or opsonization and phagocytosis of RBCs.
These are of 3 types-
1. Pernicious anemia
2. Autoimmune hemolytic anemia
3. Drug-induced hemolytic anemia
These are usually detected by Coomb’s test where
RBCs are incubated with anti-human IgG serum.

11. GOODPASTURE’S SYNDROME
Here auto-antibodies specific for certain
basement membrane antigens bind to the
basement membranes of kidney glomeruli
and alveoli of lungs. Subsequent
complement activation leads to cellular
damage and an ensuing inflammatory
response. Death is ensued within several
months of onset of symptoms.

12. Fig. Lung diagnosed with Goodpasture’s syndrome

13. INSULIN-DEPENDENT DIABETES MELLITUS
Diabetes mellitus type 1 (Type 1 diabetes, IDDM,
or, formerly, juvenile diabetes) is a form of diabetes
mellitus that results from autoimmune destruction
of insulin-producing beta cells of the pancreas. The
subsequent lack of insulin leads to increased blood
and urine glucose. The classical symptoms
are polyuria (frequent
urination), polydipsia (increased
thirst),polyphagia (increased hunger), and weight
loss.
Type 1 diabetes is fatal unless treated with insulin.

14. B. Stimulating or Blocking Auto-antibodies
where antibodies act as agonists, binding to
hormone receptors in lieu of the normal ligand
and stimulating inappropriate activity. This
usually leads to an over-production of mediators
or an increase in cell growth.
Conversely, antibodies may act as antagonists,
binding hormone receptors but blocking
receptor function. This generally causes
impaired secretion of mediators and gradual
atrophy of the affected organ.
Diseases caused by this are-

15. GRAVE’S DISEASE
Graves' disease is an autoimmune disease
where the thyroid is overactive, producing an
excessive amount of thyroid hormones (a
serious metabolic imbalance known
as hyperthyroidism and thyrotoxicosis. This is
caused by autoantibodies (TSHR-Ab) that
activate the TSH-receptor (TSHR), thereby
stimulating thyroid hormone synthesis and
secretion, and thyroid growth (causing a
diffusely enlarged goiter. The resulting state
of hyperthyroidism can cause a dramatic
constellation of neuropsychological and
physical signs and symptoms.

16. FIG. GRAVE’S DISEASE PATIENT

17. MYASTHENIA GRAVIS
Myasthenia gravis is an autoimmune
neuromuscular disease leading to fluctuating muscle
weakness and fatiguability. It is an autoimmune
disorder, in which weakness is caused by
circulating antibodies that block acetylcholine
receptors at the postsynaptic neuromuscular
junction, inhibiting the stimulative effect of
the neurotransmitter
acetylcholine. Myasthenia is treated medically with
cholinesterase inhibitors or
immunosuppressants, and, in selected
cases, thymectomy.

18. FIG. SHOWING THYMOMA AND PARIAL PTOSIS CHARACTERISTIC OF
MYASTHENIA GRAVIS

19. SYSTEMIC AUTOIMMUNE DISEASES
In this type, the immune response is not
directed to a target antigen unique to a single
organ or gland, rather it is directed to any
different organs, tissues, and cells of the
body.
Eg- Systemic lupus erythematosus

20. SYSTEMIC LUPUS ERYTHEMATOSUS
 Systemic lupus erythematosus is
a systemic autoimmune disease that can affect
any part of the body. Affected individuals
produce auto-antibodies to a vast array of tissue
antigens, such as DNA,histones,
RBCs,platelets, leukocytes etc often through
excessive complement activation. The treatment
of SLE involves preventing flares and reducing
their severity and duration when they occur &
treatment can include corticosteroids and anti-
malarial drugs.

21. Fig. A baby suffering from SLE

22. MULTIPLE SCLEROSIS
Multiple sclerosis is
aninflammatory disease in which the
fatty myelin sheaths around the axon of
the brain and spinal cord are damaged,
leading to demyelination and scarring as well
as a broad spectrum of signs and symptoms.
Affected people’s cerebrospinal fluid contains
activated T-cells that infiltrate brain tissue
and cause characteristic inflammatory
lesions, destroying myelin leading to
neurological dysfunctions.

23. RHEUMATOID ARTHRITIS
Rheumatoid arthritis (RA) is a chronic, systemic inflammatory
disorder that may affect many tissues and organs, but
principally attacks synovial joints. The process produces an
inflammatory response of the synovium (synovitis) secondary
to hyperplasia of synovial cells, excess synovial fluid, and the
development of pannus in the synovium. The pathology of the
disease process often leads to the destruction of articular
cartilage and
ankylosis of the joints. Rheumatoid arthritis can also produce
diffuse inflammation in the lungs, pericardium, pleura,
and sclera, and also nodular lesions, most common
insubcutaneous tissue. Although the cause of rheumatoid
arthritis is unknown, autoimmunity plays a pivotal role in both
its chronicity and progression, and RA is considered a systemic
autoimmune disease.

24. Fig. Hand of a person infected with RA

25. GENDER DIFFERENCES IN AUTOIMMUNITY
Women are more susceptible to Autoimmune
diseases than men. This is because it has
been deduced that women produce higher
titer of antibodies than men and so, in
general, mount more vigorous immune
responses. Women generally tend to have
higher levels of CD4+ T cells and
significantly higher levels of serum IgG.

26. TREATMENT
Current therapies for autoimmune diseases
include-
1.Immunosuppressive drugs
2.Thymectomy
3.Plasmapherisis
4.Vaccination with T cells specific for an
auto-antigen
5.Usage of Synthetic Blocking Peptides
6.Usage of Monoclonal Antibodies

27. REFERENCES
 Immunology by Kuby
 Wikipedia
 www.ncbi.nlm.nih.gov
 www.medconnect.in