HYPERSENSITIVITY RXN Micro LE2 Flashcards
Which type of hypersensitivity involves IgE antibodies reacting to allergens?
a) Type I
b) Type II
c) Type III
d) Type IV
a) Type I
Rationale: Type I hypersensitivity, also known as immediate/anaphylactic hypersensitivity, involves IgE antibodies reacting to allergens, binding to mast cells and eosinophils via the Fc receptor.
Which cell undergoes degranulation upon subsequent exposure to the allergen in Type I hypersensitivity?
a) T-cells
b) Neutrophils
c) Mast cells
d) B-cells
c) Mast cells
Rationale: In Type I hypersensitivity, upon subsequent exposure to the allergen, fixed IgE becomes cross-linked, causing mast cells to undergo degranulation.
Histamine primarily contributes to which effect during an allergic reaction?
a) Platelet aggregation
b) Vasodilation
c) Antibody production
d) Phagocytosis
b) Vasodilation
Rationale: Histamine is the primary mediator for Type 1 reactions and causes vasodilation, increased capillary permeability, and smooth muscle contraction.
Which drug can be used to counteract the effects of histamine during an allergic reaction?
a) Ibuprofen
b) Epinephrine
c) Antihistamine
d) Insulin
c) Antihistamine
Rationale: Antihistamine drugs can block histamine receptor sites, thereby counteracting the effects of histamine during an allergic reaction.
Which substance promotes platelet aggregation during Type I hypersensitivity reactions?
a) Histamine
b) Prostaglandin
c) Thromboxane
d) Epinephrine
c) Thromboxane
Rationale: Thromboxanes, during Type I hypersensitivity reactions, promote platelet aggregation.
Which type of hypersensitivity is most prevalent?
a) Type I
b) Type II
c) Type III
d) Type IV
a) Type I
Rationale: Type I hypersensitivity is mentioned as the most prevalent type of allergy.
What is the main goal of treatment for Type I hypersensitivity reactions?
a) Stimulate immune response
b) Increase antibody production
c) Counteract the mediators’ effects
d) Promote mast cell degranulation
c) Counteract the mediators’ effects
Rationale: The main goal of treatment for Type I hypersensitivity reactions is to counteract the effects of mediators like histamine.
Which is NOT a treatment for Type I hypersensitivity reactions?
a) Epinephrine
b) Antihistamines
c) Corticosteroids
d) Vitamin C
d) Vitamin C
Rationale: The treatments for Type I hypersensitivity reactions include epinephrine, antihistamines, and corticosteroids. Vitamin C is not mentioned as a treatment.
What is the genetic predisposition towards certain allergic reactions called?
a) Hypoactivity
b) Atrophy
c) Atopy
d) Anaphylaxis
c) Atopy
Rationale: Atopy refers to the strong genetic predisposition towards certain allergic reactions.
Which allergic reaction is characterized by high IgE levels?
a) Atopy
b) Anaphylaxis
c) Eczema
d) Urticaria
a) Atopy
Rationale: Atopy is associated with elevated IgE levels and a genetic predisposition towards certain allergies.
Which is a symptom of atopy?
a) Bronchospasm
b) Hay fever
c) Thrombocytopenia
d) Anemia
b) Hay fever
Rationale: Hay fever is one of the symptoms of atopy, along with other allergic reactions like asthma, eczema, and urticaria.
Which pathway does prostaglandin originate from?
a) Arachidonic acid via the lipoxygenase pathway
b) Arachidonic acid via the cyclooxygenase pathway
c) Glycolysis
d) Krebs cycle
b) Arachidonic acid via the cyclooxygenase pathway
Rationale: Prostaglandin is derived from arachidonic acid via the cyclooxygenase pathway.
How are most allergens in Type I hypersensitivity identified?
a) Blood tests
b) MRI scans
c) Skin tests
d) Urine tests
c) Skin tests
Rationale: Allergens causing Type I hypersensitivity reactions are often identified using skin tests, such as injection, patch, or scratch tests.
Which cell contains histamine in a preformed state?
a) Neutrophils
b) Lymphocytes
c) Platelets
d) Monocytes
c) Platelets
Rationale: Histamine exists in a preformed state in platelets as well as in the granules of mast cells and eosinophils.
Which secondary mediator is involved in Type I hypersensitivity reactions?
a) Hemoglobin
b) Insulin
c) IL-4
d) Progesterone
c) IL-4
Rationale: Alongside cytokines like TNF-a, IL-4 acts as a secondary mediator in Type I hypersensitivity reactions.
Which type of hypersensitivity involves cell surface antigens reacting with antibodies?
a) Type I
b) Type II
c) Type III
d) Type IV
b) Type II
Rationale: Type II hypersensitivity, also known as antibody-mediated hypersensitivity, involves cell surface antigens reacting with antibodies.
Which antibody is primarily involved in binding to cell surface antigens in Type II hypersensitivity?
a) IgA
b) IgE
c) IgG
d) IgM
c) IgG
Rationale: In Type II hypersensitivity, IgG antibodies play a significant role by binding to cell surface antigens.
What can the interaction of antibodies with cell surface antigens in Type II hypersensitivity activate?
a) Phagocytosis
b) Complement system
c) Natural killer cells
d) B-cell proliferation
b) Complement system
Rationale: In Type II hypersensitivity, the interaction of antibodies with cell surface antigens can activate the complement system, potentially leading to complement-mediated lysis.
Which drug, when bound to red blood cell surfaces, can trigger antibody formation leading to hemolysis?
a) Aspirin
b) Ibuprofen
c) Penicillin
d) Metformin
c) Penicillin
Rationale: Penicillin can bind to proteins on red blood cell surfaces, triggering the formation of antibodies that can lead to hemolysis.
Which pathogen induces antibodies that cross-react with red cell antigens, causing hemolytic anemia?
a) Escherichia coli
b) Staphylococcus aureus
c) Mycoplasma pneumoniae
d) Salmonella typhi
c) Mycoplasma pneumoniae
Rationale: Mycoplasma pneumoniae can induce antibodies that cross-react with red cell antigens, resulting in hemolytic anemia.
In Rheumatic Fever, antibodies against which bacteria cross-react with cardiac tissue?
a) Group A streptococci
b) Group B streptococci
c) Group C streptococci
d) Group D streptococci
a) Group A streptococci
Rationale: In Rheumatic Fever, antibodies generated against group A streptococci cross-react with cardiac tissue, potentially causing damage.
In which syndrome are antibodies formed against the basement membranes of the kidney and lung?
a) Sjögren’s Syndrome
b) Goodpasture’s Syndrome
c) Guillain-Barré Syndrome
d) Turner Syndrome
b) Goodpasture’s Syndrome
Rationale: In Goodpasture’s Syndrome, antibodies target the basement membranes of both the kidney and lung, potentially causing severe damage.
In Graves’ Disease, an autoantibody binds to which receptor leading to hyperthyroidism?
a) Insulin receptor
b) Adrenaline receptor
c) Thyroid-stimulating hormone (TSH) receptor
d) Growth hormone receptor
c) Thyroid-stimulating hormone (TSH) receptor
Rationale: In Graves’ Disease, an autoantibody binds to the TSH receptor, which results in the stimulation of the thyroid and consequently, hyperthyroidism.
What is the primary result of complement-mediated lysis in Type II hypersensitivity?
a) Vasodilation
b) Antibody formation
c) Cell death
d) Inflammation
c) Cell death
Rationale: Complement-mediated lysis, which can occur in Type II hypersensitivity, leads to the destruction or death of cells.
Which condition involves antibodies cross-reacting with cardiac tissue?
a) Rheumatoid Arthritis
b) Rheumatic Fever
c) Osteoarthritis
d) Myasthenia Gravis
b) Rheumatic Fever
Rationale: In Rheumatic Fever, antibodies against group A streptococci cross-react with cardiac tissue, which can cause damage.
Which of the following diseases is NOT related to Type II hypersensitivity?
a) Graves’ Disease
b) Goodpasture’s Syndrome
c) Rheumatic Fever
d) Celiac Disease
d) Celiac Disease
Rationale: Celiac Disease is related to an immune response to gluten ingestion and is not directly related to the mechanisms of Type II hypersensitivity, unlike the other options provided.
Which hypersensitivity type is often associated with transfusion reactions?
a) Type I
b) Type II
c) Type III
d) Type IV
b) Type II
Rationale: Type II hypersensitivity reactions include ABO transfusion reactions, where the wrong blood type is transfused, leading to an immune response against the mismatched blood.
What can penicillin potentially cause when attached to red blood cells?
a) Vasoconstriction
b) Hemolysis
c) Increased platelet count
d) Leukopenia
b) Hemolysis
Rationale: When penicillin attaches to red blood cell surfaces, it can trigger antibody formation leading to hemolysis or destruction of the red blood cells.
Which organ is primarily affected by the autoantibody binding in Graves’ Disease?
a) Liver
b) Pancreas
c) Thyroid
d) Kidney
c) Thyroid
Rationale: In Graves’ Disease, an autoantibody binds to the TSH receptor, stimulating the thyroid and leading to hyperthyroidism.
In Type II hypersensitivity, what is the result of the antibody binding to cell surface antigens?
a) Activation of T-cells
b) Stimulation of B-cells
c) Activation of the complement system
d) Suppression of the immune response
c) Activation of the complement system
Rationale: In Type II hypersensitivity, when antibodies bind to cell surface antigens, it can activate the complement system, potentially leading to complement-mediated lysis.
- Type III hypersensitivity reactions are primarily driven by:
a) T-cell mediated reactions
b) Immediate IgE responses
c) Persistent antigen-antibody complexes
d) Direct antibody-mediated cellular damage
c) Persistent antigen-antibody complexes
Rationale: Type III hypersensitivity is caused by antigen-antibody immune complexes that are not promptly removed, leading to their deposition in tissues and subsequent damage.
- In the context of Acute Post Streptococcal Glomerulonephritis, which component is notably deposited at the glomerular basement?
a) IgA
b) IgE
c) C3
d) C5
c) C3
Rationale: The disease features lumpy deposits of immunoglobulins and the complement component C3 in the glomerular basement.
- The Arthus Reaction is characterized by:
a) A delayed inflammatory response peaking in weeks
b) Erythema and edema peaking within 3-8 hours
c) Immediate respiratory distress
d) Chronic joint pain
b) Erythema and edema peaking within 3-8 hours
Rationale: The Arthus reaction involves a localized inflammatory response characterized by skin erythema and swelling that intensifies within 3-8 hours.
- Serum sickness historically arose from passive immunization using serums derived from:
a) Pigs
b) Sheep
c) Horses
d) Goats
c) Horses
Rationale: Serum sickness was a result of passive immunization using animal serums, especially from horses or cows.
- In Rheumatoid Arthritis, which antibody is prominently involved?
a) Anti-DNA
b) Anti-M protein
c) Rheumatoid factor
d) Anti-nucleosome
c) Rheumatoid factor
Rationale: Rheumatoid Arthritis features the antibody known as the “rheumatoid factor” that targets IgG.
- The main organ affected in SLE due to immune complex deposition is:
a) Liver
b) Heart
c) Kidney
d) Lung
c) Kidney
Rationale: Though SLE can impact multiple organs, the kidneys face the most significant damage due to immune complex deposition.
- What results from the lingering antigen-antibody complexes in Type III hypersensitivity?
a) Inhibition of polymorphonuclear cells
b) Attraction of polymorphonuclear cells leading to tissue damage
c) Enhanced B-cell production
d) Immediate mast cell degranulation
b) Attraction of polymorphonuclear cells leading to tissue damage
Rationale: In Type III hypersensitivity, the lingering antigen-antibody complexes attract polymorphonuclear cells to the deposition sites, causing tissue damage.
- Which infection can potentially lead to Acute Post Streptococcal Glomerulonephritis?
a) Group B streptococci
b) Nephritogenic E. coli
c) Group A hemolytic streptococci
d) Staphylococcus aureus
c) Group A hemolytic streptococci
Rationale: Onset of Acute Post Streptococcal Glomerulonephritis occurs post-infection by group A hemolytic streptococci, especially strains with nephritogenic properties.
- Which reaction involves a hemorrhagic necrotic lesion that might ulcerate?
a) Serum sickness
b) Rheumatoid Arthritis
c) Arthus Reaction
d) SLE flare
c) Arthus Reaction
Rationale: The Arthus Reaction leads to a localized inflammatory response with hemorrhagic, necrotic lesions that might ulcerate.
- In Systemic Lupus Erythematosus (SLE), the antibodies primarily target:
a) Cell wall M protein
b) DNA and nucleohistones
c) IgG
d) Glomerular basement
b) DNA and nucleohistones
Rationale: In SLE, the antibodies predominantly target DNA and nucleohistones found in most body cells.
- Type III hypersensitivity reactions are often linked with the deposition of immune complexes in:
a) Lymph nodes
b) Blood plasma
c) Tissues
d) Bone marrow
c) Tissues
Rationale: Type III hypersensitivity arises when lingering antigen-antibody immune complexes deposit in tissues, leading to subsequent damage.
- In Rheumatoid Arthritis, where does immune complex deposition primarily occur?
a) Liver tissues
b) Inflamed joint membranes
c) Cardiac muscles
d) Lung alveoli
b) Inflamed joint membranes
Rationale: In Rheumatoid Arthritis, immune complexes mainly deposit in the membranes of inflamed joints.
- Maurice Arthus is best known for demonstrating which hypersensitivity reaction?
a) Serum sickness
b) Anaphylactic shock
c) Arthus Reaction
d) Post transfusion reaction
c) Arthus Reaction
Rationale: The Arthus Reaction is named after Maurice Arthus due to his experiments demonstrating this localized inflammatory response in rabbits.
- The primary mechanism of tissue damage in Type III hypersensitivity is through the activation and attraction of:
a) Macrophages
b) T-lymphocytes
c) B-lymphocytes
d) Polymorphonuclear cells
d) Polymorphonuclear cells
Rationale: In Type III hypersensitivity, the activated complement due to antigen-antibody complex deposition attracts polymorphonuclear cells, causing tissue damage.
- Which condition can be a result of a previous infection with certain strains of group A streptococcus containing M protein in their cell wall?
a) Serum sickness
b) Rheumatoid Arthritis
c) Acute Post Streptococcal Glomerulonephritis
d) Grave’s Disease
c) Acute Post Streptococcal Glomerulonephritis
Rationale: Acute Post Streptococcal Glomerulonephritis primarily affects individuals after respiratory infections caused by specific strains of group A streptococcus that contain M protein in their cell wall.
Which type of hypersensitivity involves specifically sensitized T lymphocytes?
A) Type I
B) Type II
C) Type III
D) Type IV
D) Type IV
Rationale: Type IV hypersensitivity is a cell-mediated response involving sensitized T lymphocytes that activate macrophages, leading to inflammation.
In contact hypersensitivity, what duration after contact with the antigen does the reaction typically begin?
A) Immediately
B) 6-8 hours
C) 12-48 hours
D) 2-3 days
C) 12-48 hours
Rationale: For contact hypersensitivity, the response typically begins 12-48 hours after contact with the offending agent.
Which test is utilized to identify the offending antigen in contact hypersensitivity?
A) Blood test
B) Urine test
C) Patch testing
D) Intradermal test
C) Patch testing
Rationale: Patch testing is used to determine the specific antigen causing the reaction in contact hypersensitivity.
Which type of hypersensitivity has a delayed response, beginning 2-3 days after antigen contact?
A) Type I
B) Type II
C) Type III
D) Type IV
D) Type IV
Rationale: Type IV hypersensitivity is characterized by a delayed response, starting 2-3 days post-antigen contact.
Which cell functions as the antigen-presenting cell in contact hypersensitivity?
A) Neutrophil
B) B lymphocyte
C) Langerhans cell
D) Macrophage
C) Langerhans cell
Rationale: In contact hypersensitivity, the Langerhans cell in the epidermis acts as the antigen-presenting cell.
Which of the following can cause erythema, itching, vesication, or eczema within 12-48 hours upon skin contact in sensitized individuals?
A) Tuberculin
B) Nickel
C) Blood transfusion
D) Intradermal injection
B) Nickel
Rationale: Nickel is one of the agents listed under contact hypersensitivity that can trigger skin reactions in sensitized individuals.
A negative TST test in the context of leprosy suggests:
A) Tuberculoid leprosy
B) Lepromatous leprosy
C) Active tuberculosis
D) Past tuberculosis exposure
: B) Lepromatous leprosy
Rationale: A negative test in leprosy indicates lepromatous leprosy, which is characterized by weak cell-mediated immunity.
Which type of hypersensitivity reaction is initiated by T lymphocytes that activate macrophages?
A) Type I
B) Type II
C) Type III
D) Type IV
D) Type IV
Rationale: Type IV hypersensitivity involves T lymphocytes that activate macrophages, leading to inflammation.
A positive TST test in leprosy is indicative of:
A) Lepromatous leprosy
B) Tuberculoid leprosy
C) Past tuberculosis exposure
D) Current tuberculosis
B) Tuberculoid leprosy
Rationale: In leprosy, a positive TST points to tuberculoid leprosy, indicating active cell-mediated immunity.
Which chemical is NOT associated with contact hypersensitivity?
A) Formaldehyde
B) Sulfonamides
C) Tuberculin
D) Nickel
C) Tuberculin
Rationale: Tuberculin is associated with the tuberculin skin test (TST) for tuberculosis exposure or infection, not contact hypersensitivity.
Which of the following statements about Type IV hypersensitivity is true?
A) It involves antibody-antigen reactions.
B) It is an immediate hypersensitivity reaction.
C) It is mediated by T lymphocytes.
D) It begins immediately after antigen contact.
C) It is mediated by T lymphocytes.
Rationale: Type IV hypersensitivity is cell-mediated and involves specifically sensitized T lymphocytes.
The antigen-presenting cell in contact hypersensitivity interacts primarily with:
A) CD8 T cells
B) CD4 TH1 cells
C) B cells
D) Natural Killer cells
B) CD4 TH1 cells
Rationale: In contact hypersensitivity, the antigen-presenting Langerhans cell in the epidermis interacts with CD4 TH1 cells to trigger a response.
In which hypersensitivity type is the response usually delayed, starting 2-3 days after antigen exposure?
A) Type I
B) Type II
C) Type III
D) Type IV
D) Type IV
Rationale: Type IV hypersensitivity is characterized by a delayed response, which typically starts 2-3 days post-antigen contact.
Poison ivy can lead to which type of hypersensitivity?
A) Type I
B) Type II
C) Type III
D) Type IV
D) Type IV
Rationale: Contact with agents like poison ivy can trigger Type IV hypersensitivity, causing skin reactions in sensitized individuals.
Which of the following reactions typically peaks within 3-8 hours of antigen exposure?
A) Arthus reaction
B) Tuberculin reaction
C) Serum sickness
D) Rheumatoid arthritis
A) Arthus reaction
Rationale: The Arthus reaction is characterized by erythema and edema that peak within 3-8 hours after antigen exposure.
