Medical Immunology - Autoimmune Diseases

What is the essential feature of an autoimmune disease?

Tissue injury is caused by the immunologic reaction of the organism against its own tissues

What type of hypersensitivity reactions are autoimmune diseases?

Type II and III

Production of what antibodies is associated with autoimmune diseases?

Autoantibodies

What sex is more likely to have an autoimmune disease?

Females

What do HLA genes encode?

MHC I and MHC II proteins

What are possible causes of autoimmune diseases?

Molecular mimicry, defective T-suppressor cells, cytokine imbalance/overproduction, expression of HLA gene products, complement deficiencies, failure of immunologic tolerance

What is an example of molecular mimicry?

Streptococcus produces surface antigens that resemble heart valve and neuronal tissues

What is immunologic tolerance?

Prevention of an immune response against a particular antigen

What kind of antigens does the immunologic tolerance develop an immune response to?

Self-antigens

What is central tolerance?

Early development within the thymus or bone marrow, T and B-cells with high affinity for self antigens undergo apoptosis

What are the two types of immunologic tolerance?

Central and peripheral

What is peripheral tolerance?

Responsible for maintaining tolerance in secondary lymphoid tissues created by anergy, regulatory T-cells, and deletion

What is anergy in relation to lymphocytes?

Lymphocytes that recognize self-antigens do not become activated when they encounter self-antigens.

What is anergy in relation to T-cells?

T cells expressing self-antigens do not express costimulatory proteins, which means they do not activate.

What is anergy in relation to B-cells?

Presence of self-antigens without activated T-cells leads to B-cell anergy

How do regulatory t-cells aid in peripheral tolerance?

They inhibit self reactive T-helper cells, release TGF-beta and IL-10

How does deletion aid in peripheral tolerance?

Autoreactive T-cells underego apoptosis

What is multiple sclerosis?

Demyelination disturbs neuron conduction and leads to various symptoms, mostly patients between 20-40 that live in the north

What is myasthenia gravis?

Anti-cholinergic receptor antibodies and abnormal thymus leads to antibodies produced against cholinergic receptors. ACh is prevented from reaching receptor and receptors are destroyed. This leads to muscle weakness

What type of hypersensitivity reaction is myasthenia gravis?

Type II

What is the treatment for myasthenia gravis?

Cholinesterase inhibitors

What is Systemic Lupus Erythematosus?

Associated with the production of antibodies that react with nuclear materials such as DNA and histones, symptoms of butterfly rash and rash on hands and chin, seizures, depression, renal failure, arthritis, morbidity

What type of reaction is lupus?

Type III

How is lupus treated?

NSAIDS, aspirin, corticosteroids, antimalarial drugs

What is rheumatoid arthritis?

Attack on joints with an unknown cause, enzymes in synovial fluid degrade cartilage

What is celiac disease?

Chronic disease caused by a gluten intolerance, autoantibodies to enzyme that breaks down gluten, gluten gets stuck in small intestine which triggers an immune response

What is immunodeficiency?

Absence or failure of normal function of one or more elements of the immune system

What are the two types of immunodeficiency?

Congenital/primary, acquired/secondary

What is the more common type of immunodeficiency disorder?

Acquired

Primary immunodeficiency is commonly _-linked.

X

Primary immunodeficiency occurs more often in _____.

Males

What is severe combined immunodeficiency disease?

Patient lacks both B and T-cells, failure of lymphocytes to develop

What is Bruton’s X-linked Agammaglobulinemia?

B-cells fail to mature and therefore cannot make antibodies, defect in gene BTK required for B-cell maturation, small lymph nodes/no tonsils/no adenoids

True/False: Individuals with Bruton’s X-linked Agammaglobulinemia do not respond to vaccines.

True

What is chronic granulomatous disease?

Genetic disorder in which phagocytes are unable to kill certain types of bacteria and fungi, defect in NADP oxidase therefore unable to make reactive oxygen species to kill bacteria, often fatal

How is chronic granulomatous disease treated?

Use of antimicrobial that can kill intracellular infections or bone marrow transplant

How is CGD diagnosed?

Nitroblue tetrazolium test

What type of immunodeficiency is Diabetes?

Secondary

How are secondary immunodeficiencies treated?

Immunosuppressants, chemotherapeutic drugs, steroids

What is the human immunodeficiency virus?

Sexual/parenteral/perinatal infection that deplete CD4 cells

How is HIV treated?

3 medications from a minimum of two drug classes