CLINICAL IMMUNOLOGY AND
SEROLOGY - UNIT 4 (QUESTIONS
AND 100% VERIFIED ANSWERS) 2026.
Hypersensitivity - ANS -an exaggerated response by the immune system to a particular
substance
T/F During hypersensitivity the immune system causes damage to the host - ANS -True
What are the four categories of classification of hypersensitivity? - ANS -Type I-IV
What type of hypersensitivity is mediated by IgE? - ANS -Type I Hypersensitivity
What are the stimuli of type I Hypersensitivity? - ANS -Pollen Venom Drugs Food
What are the stimuli of type II Hypersensitivity? - ANS -Incompatible red cells
What are the stimuli of type III Hypersensitivity? - ANS -Heterologus serum, self antigen
What are the stimuli of type IV Hypersensitivity? - ANS -
Mechanism of Type I Hypersensitivity - ANS -cell bound antibodies react with antigen to release
physiologically active substances
,Mechanism of Type II Hypersensitivity - ANS -free antibody reacts with antigen associated with
cell surfaces
Mechanism of Type IV Hypersensitivity - ANS -not seen until 24-48 hours - different from other
three in that sensitized T-cells not antibody
Mechanism of Type III Hypersensitivity - ANS -antibody reacts with soluble antigen to form
complexes that participate in tissues.
Which types of Hypersensitivity are immediate? - ANS -Type I,II, III
Type V Hypersensitivity - ANS -
Atopy - ANS -inherited tendency to respond to naturally occurring, inhaled and ingested
allergens with continual production of IgE
Which researchers discovered that serum factor was responsible for Type I Hypersensitivity -
ANS -Prausnitz and Kustner
Passive Cutaneous Anaphylaxis - ANS -Serum from allergy individual transferred to a nonallergic
individual presets as an allergic skin reaction in the non allergic individual.
(How Kraus and Kustner figured out Type I Hypersen)
Where is IgE synthesized - ANS -Lymphoid tissue of the respiratory and gastrointestinal tracts
What cells regulate IgE production? - ANS -Type 2 Helper cells.
, What are the principle effector cells of immediate hypersensitivity? - ANS -Mast Cells
What regions of the body are mast cells most prominent? - ANS -Skin, Upper and lower
respiratory tract, and gastrointestinal tract
What is a difference between basophil and mast cell? - ANS ---Mast cell leaves bone marrow
immature and migrates to peripheral tissues
--Basophils are circulating cells
Name two types of an in vivo testing for type I hypersensitivity - ANS -
Type II Hypersensitivity - ANS -cytotoxic- formation of IgG and IgM directed against cells in CT.
In transfusion reaction cellular destruction resulting from hetero - ANS -
Which hypersensitivity reaction type is characterized short time lag (seconds to minutes)
between exposure to antigen and clinical symptoms? - ANS -Type I
B Blood type has what type of antigen and which antibody? - ANS -B antigen and Anti-A
Antibody
O blood type has what type of antigen and what type antibody? - ANS -No antigen. Both Anti A
and Anti B antibody
What portion of the US population is estimated to exhibit allergic or immediate hypersensitivity
reactions? - ANS -30%
SEROLOGY - UNIT 4 (QUESTIONS
AND 100% VERIFIED ANSWERS) 2026.
Hypersensitivity - ANS -an exaggerated response by the immune system to a particular
substance
T/F During hypersensitivity the immune system causes damage to the host - ANS -True
What are the four categories of classification of hypersensitivity? - ANS -Type I-IV
What type of hypersensitivity is mediated by IgE? - ANS -Type I Hypersensitivity
What are the stimuli of type I Hypersensitivity? - ANS -Pollen Venom Drugs Food
What are the stimuli of type II Hypersensitivity? - ANS -Incompatible red cells
What are the stimuli of type III Hypersensitivity? - ANS -Heterologus serum, self antigen
What are the stimuli of type IV Hypersensitivity? - ANS -
Mechanism of Type I Hypersensitivity - ANS -cell bound antibodies react with antigen to release
physiologically active substances
,Mechanism of Type II Hypersensitivity - ANS -free antibody reacts with antigen associated with
cell surfaces
Mechanism of Type IV Hypersensitivity - ANS -not seen until 24-48 hours - different from other
three in that sensitized T-cells not antibody
Mechanism of Type III Hypersensitivity - ANS -antibody reacts with soluble antigen to form
complexes that participate in tissues.
Which types of Hypersensitivity are immediate? - ANS -Type I,II, III
Type V Hypersensitivity - ANS -
Atopy - ANS -inherited tendency to respond to naturally occurring, inhaled and ingested
allergens with continual production of IgE
Which researchers discovered that serum factor was responsible for Type I Hypersensitivity -
ANS -Prausnitz and Kustner
Passive Cutaneous Anaphylaxis - ANS -Serum from allergy individual transferred to a nonallergic
individual presets as an allergic skin reaction in the non allergic individual.
(How Kraus and Kustner figured out Type I Hypersen)
Where is IgE synthesized - ANS -Lymphoid tissue of the respiratory and gastrointestinal tracts
What cells regulate IgE production? - ANS -Type 2 Helper cells.
, What are the principle effector cells of immediate hypersensitivity? - ANS -Mast Cells
What regions of the body are mast cells most prominent? - ANS -Skin, Upper and lower
respiratory tract, and gastrointestinal tract
What is a difference between basophil and mast cell? - ANS ---Mast cell leaves bone marrow
immature and migrates to peripheral tissues
--Basophils are circulating cells
Name two types of an in vivo testing for type I hypersensitivity - ANS -
Type II Hypersensitivity - ANS -cytotoxic- formation of IgG and IgM directed against cells in CT.
In transfusion reaction cellular destruction resulting from hetero - ANS -
Which hypersensitivity reaction type is characterized short time lag (seconds to minutes)
between exposure to antigen and clinical symptoms? - ANS -Type I
B Blood type has what type of antigen and which antibody? - ANS -B antigen and Anti-A
Antibody
O blood type has what type of antigen and what type antibody? - ANS -No antigen. Both Anti A
and Anti B antibody
What portion of the US population is estimated to exhibit allergic or immediate hypersensitivity
reactions? - ANS -30%
