Auto-immune diseases Flashcards
auto immunity
The immune response of auto Ab against self Ag
Humoral or cell-mediated immune response against the components of the own cells/tissues.
Auto antibody
An antibody made against substances formed by a person’s own body
Auto/self- antigens
Normal antigens mistakenly attacked by the immune system, leading to autoimmune diseases
Antigens present in one’s own cells
Autoimmune diseases
group of disorders in which tissue injury is caused by humoral (by auto-antibodies) or cell-mediated immune response (by auto-reactive T cells) to self-antigens.
what immune response is involved in autoimmune disease
adaptive (B-cells (humoral immunity) & T-cells (cellular immunity))
develop immunological memory
4 Causes of Autoimmune Diseases
Sequestered or Hidden antigens
Neo antigens
Molecular mimicry
Loss of Immunoregulation
what are neo antigens
Altered or Modified Antigens – by physical (irradiation), chemical (drugs) or microbial agents (intracellular viruses)
Molecular mimicry
Similarities between foreign and self-peptides favour the activation of autoreactive T or B cells by a foreign-derived antigen in a susceptible individual.
what causes loss of immunoregulation
over activity or lowered activity of T and B- cells
most common autoimmune disease (over 3% adult women)
thyroid diseases (Graves/ Hashimoto’s thyroiditis)
1% of general population have what autoimmune disease
rheumatoid arthiritis
brain autoimmune diseases
myasthenia gravis
Lambert-eaton syndrome
skin autoimmune diseases
psoriasis
vitiligo
pemphigus vulgaris
blood autoimmune diseases
haemolytic anaemia
thrombocytopenic purpura
endocrine autoimmune diseases
graves disease
Hashimoto thyroiditis
type I diabetes
what do autoantibodies do in type I diabetes
Target insulin, glutamic acid decarboxylase and specific β-cell proteins, so CD8+ T cells mediate cell destruction
what does graves disease commonly causes
hyperthyroidism (thyroid enlargement due to thyroid hormone overproduction)
what levels are increased in graves disease
- T3 (triiodothyronine)
- T4 (thyroxine)
- Persistent TSHr stimulation
2 treatments for graves disease
- Thyroidectomy
- Anti-thyroid drugs (carbimazole)
- Radioiodine-131
what does thyroid do in Hashimoto’s thyroiditis
not make enough thyroid hormone
what is thyroid like in Hashimoto’s thyroiditis
enlarged, inflamed, underactive
what levels are increased in Hashimoto’s thyroiditis
TSH
treatment for Hashimoto’s thyroiditis
Replacement therapy (Lthyroxine/ Liothyronine)
Natural desiccated thyroid (NDT)
symptoms of myasthenia Gravis
Weakness of the eye muscles (ocular myasthenia)
facial muscles affects (Speech/vision)
lambert-eaton syndrome
immune system attacks the connections between nerves and muscles.
what influx do ab’s in lambert-eaton syndrome decrease
Decreases Ca2+ influx into the nerve terminal as antibodies go to the voltage-gated Ca2+ channels
lambert-eaton syndrome symptoms
ataxia
Proximal & distal muscle weakness (Legs, arms, eyes, throat)
lambert-eaton syndrome treatment
3,4-diamino pyridine to block efflux of potassium ions, prolonging depolarisation (keeps calcium channels open longer) - so acetylcholine vessels fuse and release neurotransmitter better.
Haemolytic anaemia
IgG and IgM autoantibodies bind to RBCs and activate complement
RBCs become spherocytic and are phagocytosed by macrophages (haemolysis)
Haemolytic anaemia symptoms
fatigue
paleness
jaundice
fever
Thrombocytopenic purpura
the immune system mistakenly attacks and destroys platelets
Antibodies (IgG) to platelet surface glycoproteins
Thrombocytopenic purpura symptoms
Bleeding, bruising, rash (pupuric)
what are haematomas in Thrombocytopenic purpura
small lumps underneath the skin made of clotted blood
3 features of systemic AI diseases
IgG auto-antibodies formed against cellular components
Periods of intense inflammation followed by periods of relative calm (remissions)
Immune complexes (e.g. Rheumatoid factors) form when IgM, IgG and IgA autoantibodies bind to the Fc region of human IgG
what do autoantibodies attack in multiple sclerosis
myelin sheath
Dermatomyositis
autoimmune inflammation of the skin and underlying muscle tissue (symmetrical muscle weakness)
what cells infiltrate into muscle in dermatomyositis
T cells
what are Gottron’s papules in dermatomyositis
red areas overlying the knuckles
Rheumatoid Arthritis
a systemic autoimmune disorder that usually affects the joints of wrists, hands, elbows, shoulders, knees and ankles symmetrically
synovial membranes (synovium) of the joints become inflamed and produce excess fluid, which accumulates in the joint
Cartilage becomes rough and pitted, and bones often become eroded
Multiple Sclerosis (MS)
an autoimmune condition affecting the brain and nerves
Destruction of the myelin sheath
Sensory and visual disturbances
Systemic Lupus Erythematosus
Autoimmune disease in which the immune system attacks its tissues, causing widespread inflammation and tissue damage in joints, skin, brain, lungs, kidneys or blood vessels.
Systemic Lupus Erythematosus symptoms
fatigue, pain (muscle/joint),
weakness, facial rash (butterfly rash)
What test do 98% of all people with systemic lupus test positive in when diagnosing
ANA test (ab’s produced by immune system)
Sjӧgrens syndrome
autoimmune disease that affects the body’s moisture-producing (lacrimal and salivary) glands and some other organs (muscles, kidneys,lungs)
Immune cells target glands
Sjӧgrens syndrome symptoms
dry eye and mouth
headaches
difficulty concentrating
swelling and pain in your joints
heartburn
swollen glands
numbness or tingling
