pathophys podcast 12 ch

Immune disorders

conditions resulting from dysfunctional immune responses

Hypersensitivity

inappropriate or exaggerated immune response damaging host tissues (Types I–IV)

Type I hypersensitivity

IgE‑mediated allergic reactions (e.g., anaphylaxis, hay fever, asthma)

Type II hypersensitivity

antibody‑mediated cytotoxic reactions targeting cells or tissues (e.g., hemolytic anemia)

Type III hypersensitivity

immune complex–mediated inflammation from antigen‑antibody complexes (e.g., lupus nephritis)

Type IV hypersensitivity

T cell–mediated delayed hypersensitivity (e.g., contact dermatitis, TB skin test)

Autoimmunity

immune response directed against self-antigens resulting in tissue damage (e.g., rheumatoid arthritis)

Self‑tolerance

immune system’s ability to avoid attacking the body’s own cells

Autoantibody

antibody that mistakenly targets self-antigens

Primary immunodeficiency

congenital (genetic) defects in one or more components of the immune system (e.g., SCID)

Secondary immunodeficiency

acquired deficiency due to external factors (e.g., HIV, chemotherapy, malnutrition)

Allograft

tissue transplanted between genetically non-identical members of same species

Graft rejection

immune-mediated destruction of transplanted tissue

Graft-versus‑host disease (GVHD)

donor immune cells attack recipient tissues after transplantation

Immunosuppression

therapeutic reduction of immune response to prevent rejection or treat autoimmunity

Immunotherapy

modulation of immune response using biologics like monoclonal antibodies or cytokines

Immune latency

period where pathogen persists dormant and reactivates later (e.g., herpesviruses)

Chronic inflammation in immune disorders

ongoing inflammation causing organ damage (e.g., autoimmune hepatitis)

Tolerance induction

therapeutic strategies to reprogram immune system to accept self-antigens or transplanted tissue

Complement deficiency

failure of complement proteins increases susceptibility to infection and immune complex disease

Polyclonal activation

activation of multiple B cell clones leading to broad antibody production, sometimes self‑reactive

Idiotype network

theory describing regulation of immune response by antibodies recognizing other antibodies

Therapeutic plasma exchange

removal of pathogenic antibodies from circulation in autoimmune diseases (e.g., myasthenia gravis)