Hypersensitivity and Immune Response

These flashcards cover key concepts related to hypersensitivity, immune responses, autoimmune diseases, transplantation, immunotherapy for cancer, and immunodeficiencies, as discussed in lecture notes.

Hypersensitivity

An exaggerated immune response to an allergen that leads to tissue damage.

Antigen

Any substance, usually foreign, that the immune system recognizes and reacts to.

Allergen

A type of antigen that causes an allergic reaction.

Immunopathology

The study of disease caused by the immune response.

Hygiene Hypothesis

The theory that early exposure to germs increases immune tolerance to harmless antigens.

Type I Hypersensitivity

Anaphylactic reaction occurring minutes after re-exposure to an allergen.

IgE

A class of antibodies involved in allergic reactions.

Degranulation

The release of granules containing histamine from mast cells and basophils.

Systemic Anaphylaxis

A severe allergic reaction that leads to blood vessel dilation and may cause circulatory collapse.

Localized Anaphylaxis

An allergic reaction confined to a specific area of the body, like hives or hay fever.

Type II Hypersensitivity

Cytotoxic reaction involving IgG or IgM antibodies that cause cell lysis.

Hemolytic Disease of the Newborn

A condition caused by Rh incompatibility between mother and infant.

Rh Factor

A blood group antigen that can cause incompatibility issues during pregnancy.

Type III Hypersensitivity

Immune complex reaction where IgG antibodies bind soluble antigens.

Immune Complex

Antibody-antigen clumps that trigger inflammation and tissue damage.

Type IV Hypersensitivity

Delayed cell-mediated reaction involving T cells and cytokines.

Cytotoxic T Lymphocytes (CD8+)

T cells that kill cancer cells and infected cells.

Autoimmune Disease

A condition where the immune system attacks self-antigens.

Self-Tolerance

The ability of immune cells to discriminate between self and non-self.

Rheumatoid Arthritis

An autoimmune condition that causes chronic inflammation in joints.

Grave's Disease

An autoimmune disorder leading to overproduction of thyroid hormones.

Diabetes Mellitus Type I

An autoimmune condition where T cells destroy insulin-producing pancreatic cells.

Multiple Sclerosis

An autoimmune disease where the immune system attacks the myelin sheath of nerves.

Transplantation

The process of transferring cells, tissues, or organs from one body to another.

Autograft

A transplant from one part of the body to another in the same individual.

Isograft

A transplant between identical twins.

Allograft

A transplant between genetically different individuals of the same species.

Xenograft

A transplant from a different species.

Hyperacute Rejection

Immediate rejection of a xenograft due to the presence of nonhuman antigens.

Immunosuppression

Treatment to prevent an immune response against transplanted tissues.

Tumor-Associated Antigens

Markers on cancer cells that make them appear non-self, triggering immune response.

Immunotherapy

Treatment that utilizes the immune system to fight diseases like cancer.

Vaccines

Biological preparations that provide acquired immunity to certain diseases.

Monoclonal Antibodies

Antibodies produced by identical immune cells that are clones of a unique parent cell.

Immunodeficiency

A condition resulting in a decreased ability to fight infections and diseases.

Congenital Immunodeficiency

Immunodeficiency present at birth due to defective genes.

Acquired Immunodeficiency

Immunodeficiency that develops after birth, often due to infections or other factors.

AIDS

Acquired Immune Deficiency Syndrome caused by HIV, leading to a weakened immune system.

HIV Origin

HIV originated from chimpanzees and crossed into humans in the early 20th century.

CD4+ T Cells

A type of T cell that is crucial for the immune system, targeted by HIV infection.

Primary Transmission of HIV

The most common transmission route of HIV, primarily through sexual contact.

Symptoms of Phase 1 HIV Infection

Asymptomatic; swollen lymph nodes, and the person appears healthy.

Symptoms of Phase 2 HIV Infection

Gradual decline in CD4+ T cells with few serious symptoms.

Symptoms of Phase 3 HIV Infection

Severe immune weakness as CD4+ T cell counts fall below 200.

Contaminated Needles

A route of HIV transmission linked to sharing needles.

Breast Milk

A possible transmission route for HIV from mother to infant.

Challenges in HIV Vaccine Development

Include rapid mutation of the virus and lack of a natural immunity model.

Phase 1 HIV Infection Duration

Typically occurs within weeks of initial infection.

Phase 2 HIV Infection Duration

Can last several years as the immune response wanes.

Phase 3 HIV Infection Development

AIDS develops after prolonged CD4+ T cell decline.