Immune System Disorders

Flashcards about Immune System Disorders focusing on Immunodeficiencies, Autoimmunity, and Hypersensitivities.

Immunodeficiencies

Lack of a properly functioning immune system

Autoimmunity

Immune responses directed toward “self”

Hypersensitivities

Excessive or inappropriately directed immune responses, sometimes including a component of autoimmunity

Primary Immunodeficiencies

Immunodeficiencies present from birth and genetic in nature.

Secondary Immunodeficiencies

Acquired immunodeficiencies resulting from infections, chronic illnesses, medications & treatments, environmental factors or aging.

Autoimmune Disorders

Failure of self-tolerance that leads to immune responses against tissues, resulting in chronic conditions.

Managing Autoimmune Disorders

Immunosuppressive drugs, replacement therapies, and monoclonal antibodies used to dampen the autoimmune attack.

Hypersensitivities

Inappropriate, exaggerated immune response to harmless antigens, sometimes self-antigens, classified into 4 categories.

Type I Hypersensitivity

Commonly called “allergies,” involving IgE antibodies against harmless substances (allergens) and excessive histamine production.

Sensitization

Process where the first exposure to an allergen triggers excessive IgE production.

Systemic anaphylaxis

A system-wide allergic reaction that can be rapidly fatal, leading to throat swelling, fluid in the lungs, and shock.

Desensitization immunotherapy

Involves injecting a patient with an allergen in a controlled setting to trigger IgG production.

Type II Hypersensitivity

Starts with IgG binding to the surface of cells, triggering the complement system or NK cells to destroy the antibody-bound cells.

ABO Blood Types

Carbohydrate chains found on red blood cells that determine blood type (A, B, AB, O).

Hemolytic Disease of the Newborn

Triggered by Rh incompatibility between mother and fetus, where the mother's antibodies attack the fetus's red blood cells.

Type III Hypersensitivity

Soluble antigens + IgM/IgG antibodies aggregate together to form large complexes, which triggers complement and inflammation.

Type IV Hypersensitivity

Delayed hypersensitivity involving T cells reacting to a harmless substance or self. Onset occurs 12-72 hours after exposure.