Immunity Disorders and Dysfunctions

These vocabulary flashcards cover classifications of immune deficiencies, specific types of hypersensitivity reactions, and clinical terms related to white blood cell counts and diagnostic testing.

Primary immune dysfunction

Immune deficiency that is genetic or congenital in origin.

Secondary immune dysfunction

Acquired immune deficiency caused by factors such as disease, medications, malnutrition, surgeries, or chemotherapy and radiation.

Leukopenia

A condition characterized by a white blood cell count between $1000 - 4000\,\text{cells/mm}^3$.

Neutropenia

A condition where the neutrophil count is less than $1000\,\text{cells/mm}^3$, increasing the risk for infection, sepsis, and death.

Nadir

The lowest absolute neutrophil count (ANC) reached after a patient undergoes chemotherapy.

Neupogen (filgrastim)

A medication used in the medical management of patients with neutropenia.

Hypersensitivity

An immune response to an antigen that is exaggerated, leading to tissue damage.

Autoimmunity

An initiated immune response that creates antibodies against normal healthy cells and tissues.

Type I: Immediate Hypersensitivity

A humoral immunity response where IgE antibodies attach to mast cells and release chemicals causing smooth muscle contraction, vasodilation, and edema.

Atopic reaction

A local Type I allergic reaction associated with pollens, dust mites, or animal dander, manifesting as nasal discharge, itching, and watery eyes.

Anaphylaxis

A systemic, rapidly life-threatening Type I reaction characterized by urticaria, angioedema, bronchial obstruction, and vascular collapse.

Type II: Cytotoxic Hypersensitivity

Humoral immunity involving the activation of complement and forming IgG or IgM antibodies against normal cells, leading to cell lysis and phagocytosis.

Type III: Immune Complex-Mediated Hypersensitivity

Humoral immunity characterized by the formation of IgG or IgM antigen-antibody complexes that are deposited in tissues and small blood vessels.

Arthus’ reaction

The specific term for a localized Type III immune complex-mediated hypersensitivity reaction.

Type IV: Delayed Hypersensitivity

Cell-mediated immunity involving an exaggerated T-cell response without antibodies that occurs 24-72 hours after exposure.

Radioallergosorbent test (RAST)

A diagnostic blood study utilized in the medical plan of care for evaluating hypersensitivity reactions.