Micro 205 (Raj) Chapter 18 Notes

Inappropriate operation of immune system can lead to

Disease

exaggerated immune response that damages host tissue

hypersensitivity

Misdirected immune response that attacks host tissues

autoimmune disease

lack of adequate immune responses

immunodeficiency

Immune response that injures

hypersensitivity

Found in skin tissue

Basophils and mast cells

Found in the blood

Eosinophils

Involves IgE; commonly called an allergic reaction, or allergy

Type I hypersensitivity

a rapid immune response to a usually harmless substance

Allergen

Common substances that trigger allergies include

~Inhaled substances (pollen, pet dander, mold)

~injected substances (venom, penicillin)

~Ingested substances (peanuts, seafood)

Occur only in those who are sensitized by prior exposure to allergen

Allergic reactions

Begins when helper T cells activate naive B cells

Sensitization

release of inflammatory mediators

degranulation

Skin condition characterized by wheal and flare

hives

teary eyes, sneezing, runny nose following inhalation of airborne antigen to upper respiratory tract

hay fever

due to mast cells in lower respiratory tract

asthma

Alters immune response

Immunotherapy

Causes immune system to produce IgG against allergen

Desensitization

recombinant humanized monoclonal antibody

rhuMab

Response destroys cells

Cytotoxic hypersensitivity

Examples of type II hypersensitivity: cytotoxic

hemolytic transfusion reactions and hemolytic disease of the newborn, some autoimmune diseases

Occur when natural antibodies bind to antigens on transfused cells

Transfusion reactions

Used to prevent hemolytic disease

RhoGam