Hypersensitivity Reactions Flashcards
Type I Hypersensitivity reactions are mediated by ___________ antibodies
IgE
How are IgE levels increased in a type I hypersensitivity reaction?
Exposure to antigen, ie. Bee stings, pollen, and shellfish
What cells does IgE bind to to cause degranulation in a type I hypersensitivity reaction?
Basophils and mast cells
What cell-derived mediators of inflammation are released when IgE antibodies bind to basophils and mast cells?
Histamine, leukotrienes, and eosinophilic chemotactic factor
What does the release of histamine cause in a type I hypersensitivity reaction at the vascular level?
Vascular leakage in venules and arteriole dilation leading to hypotension
A type I hypersensitivity reaction causes (Bronchodilation/Bronchoconstriction) via leukotrienes?
Bronchoconstriction
What pathologies are associated with a type I hypersensitivity reaction?
Hay fever, asthma, hives, anaphylactic shock, physical urticaria
What is a type I hypersensitivity reaction also called?
Immediate, IgE mediated, or anaphylactic
What is an emergency treatment for a type I hypersensitivity reaction?
Epipen (Epinephrine)
What are the effects of an epipen on a patient suffering from anaphylactic shock?
Vasoconstriction, bronchodilation, increased blood pressure, and increased heart rate
A type II hypersensitivity reaction involved ______ and ______ antibodies?
IgG, IgM
What do IgM and IgG antibodies bind to in a type II hypersensitivity reaction?
Self antigens
What occurs when IgM and IgG antibodies bind to “self” antigens?
Triggering of the complement system via classic pathway and tissue damage
- Infiltration of WBC via chemotaxis
- Opsonization via C3b
- Lysis via C5b-C9
What are type II hypersensitivity reactions also called?
Cytotoxic reactions
What pathologies are associated with a type II hypersensitivity reaction?
Goodpasture syndrome
Hemolytic anemia
Myasthenia gravis
Graves’ disease
Hachimoto’s thyroiditis
Rheumatic fever
Hyperacute graft rejection
Erythroblastalis fetalis
What is the etiology and pathogenesis of Goodpasture syndrome?
Autoimmune type II hypersensitivity reaction where the body produces anti-glomerular basement membrane (kidney) antibodies
What are the symptoms of Goodpasture syndrome?
Hematuria, hemoptysis, kidney failure
What is the etiology of myasthenia gravis?
Autoimmune type II hypersensitivity reaction where the body produces antibodies against acetylcholine receptors on muscles (LMNs)
What are the symptoms of myasthenia gravis?
Flaccid paralysis beginning with small muscles of the face, muscle fatigue, lid lag of eyes, winded stair walking
What is the etiology of Grave’s disease?
Autoimmune type II hypersensitivity reaction where the body produces antibodies against thyroid stimulating hormone (TSH)
Graves’ disease is (Hypothyroid/Hyperthyroid)?
Hyperthyroid
What type II hypersensitivity pathology is unique in that it binds to a receptor and increases its productivity?
Grave’s disease
Hachimoto’s thyroiditis is (Hypothyroid/Hyperthyroid)?
Hypothyroid
What is the etiology of Hachimoto’s thyroiditis?
Autoimmune type II hypersensitivity reaction where the body produces antibodies against thyroglobulin and thyroid peroxidase (TPO)
What is the etiology of rheumatic fever?
Autoimmune type II hypersensitivity reaction where the body produces antibodies against streptococcus M proteins
What can untreated streptococcus infection lead to?
Rheumatic fever or heart disease
What is the etiology of a hyperacute graft rejection?
Autoimmune type II hypersensitivity reaction where the body produces antibodies in the host against a skin graft post surgery
What is erythroblastalis fetalis also known as?
Rh disease
What occurs in erythroblastalis fetalis?
Antibodies against fetal Rh+ blood made by the birthing mother due to differences in blood type
What type of hypersensitivity reaction is erythroblastalis fetalis?
Type II
In a type III hypersensitivity reaction the antibodies involved are ______ and ______
IgG, IgM
What unique structure forms when IgG and IgM bind to a circulating antigen in a type III hypersensitivity reaction?
Immune complex
A type III hypersensitivity reaction is when an antibody is made against a _________________ in _________________?
Soluble antigen, blood plasma
What is activated when an immune complex gets stuck in a capillary bed during a type III hypersensitivity reaction?
Complement system
What pathologies are associated with a type III hypersensitivity reaction?
Local Arthus reaction
Systemic Lupus Erythematosus
Serum Sickness
Glomerulonephritis
What is an arthus reaction?
Localized type III hypersensitivity reaction that occurs after a vaccine or injection where the toxoid generates an immune complex to bring in WBCs
What are the most commonly affected tissues in systemic lupus erythematosus? Why?
Kidneys, skin, and liver due to larger populations of capillary beds
What are symptoms of systemic lupus erythematosus?
Butterfly rash on the face, fatigue, joint pain, anemia
What is serum sickness?
Type III hypersensitivity reaction to a horse serum injection where the body forms immune complexes against horse proteins
What is glomerulonephritis?
Type III hypersensitivity reaction where the body forms immune complexes in the glomerulus of the kidney leading to inflammation and filtration issues
What are type III hypersensitivity reactions also called?
Immune complex mediated reactions
What are symptoms of glomerulonephritis?
Proteinuria, hematuria, hypertension, fever, low back pain; Increased BUN (blood urea nitrogen) and blood creatinine, decreased GFR
What hypersensitivity reaction does not require the presence of antibodies?
Type IV
What lymphocyte is primarily involved in a type IV hypersensitivity reaction?
CD4+ Helper T cells
What cell mediated cytokines are involved in a type IV hypersensitivity reaction?
IL-1, IL-6, IL-12
What causes the release of cytokines from CD4+ helper T cells in a type IV hypersensitivity reaction?
Presence of a foreign antigen
A type IV hypersensitivity reaction is (Instant/Delayed)?
Delayed
A type IV hypersensitivity reaction requires at least __________ exposures to an antigen?
Two
What pathologies are associated with a type IV hypersensitivity reaction?
Allergic sensitivities to cosmetics and detergents
Poison ivy and sumac
Granulomatous diseases such as tuberculosis, leprosy, sarcoidosis, and Crohn’s disease
Treponema pallidum spirochete diseases such as syphilis
Deep fungal infections such as histoplasmosis
What are type IV hypersensitivity reactions called?
Delayed type/ T cell mediated reaction
What type of hypersensitivity reaction is tuberculosis, leprosy, sarcoidosis, and Crohn’s disease?
Type IV
What type of hypersensitivity reaction is syphilis?
Type IV
