CLINICAL IMMUNOLOGY AND SEROLOGY
ACTUAL EXAM 2026 QUESTIONS AND
VERIFIED SOLUTIONS GRADED A+
◉ Active Immunity. Answer: individual produces antibody
-follows immunization of infection
memory (lasting)
◉ Passive immunity. Answer: antibody transferred to individual
example: gamma globulin injections, placental transfer
no memory (temporary)
◉ Cellular adaptive immunity. Answer: T cell/lymphokines
primary defense against viral/fungal infections (intracellular
organisms)
hypersensitivity type IV (delayed) (ex. transplant rejection)
,◉ humoral adaptive immunity. Answer: B cell (plasma
cell)/antibody
defense against bacterial infections (extracellular organisms)
hypersensitivity type I (immediate)
hypersensitivity type II (ADCC)
hypersensitivity type III (Immune complex)
◉ Characteristics of immunogens (antigens) that affect
immunogenicity. Answer: 1. large size molecule (molecular weight of
at least 10 KDa)
2. high complexity (simple repeating units do not make good
immunogens
3. chemical composition (proteins and polysaccharides are better
than carbohydrates, lipids, and nucleic acids)
4. foreignness (the more different from the host, the more
immunogenic)
, ◉ IgG. Answer: greatest concentration in serum
4 subclasses
activates complement (except for IgG4)
crosses placenta
75% of total antibody concentration
◉ IgM. Answer: largest antibody (pentamer)
fixes complexes best (multiple binding sites)
prominent in early immune response (indicates acute infection)
5-10% of total antibody concentration
◉ IgA. Answer: predominant antibody in body secretions (tears,
saliva, nasal mucosa)
serum IgA (monomer) & secretory IgA (dimer)
ACTUAL EXAM 2026 QUESTIONS AND
VERIFIED SOLUTIONS GRADED A+
◉ Active Immunity. Answer: individual produces antibody
-follows immunization of infection
memory (lasting)
◉ Passive immunity. Answer: antibody transferred to individual
example: gamma globulin injections, placental transfer
no memory (temporary)
◉ Cellular adaptive immunity. Answer: T cell/lymphokines
primary defense against viral/fungal infections (intracellular
organisms)
hypersensitivity type IV (delayed) (ex. transplant rejection)
,◉ humoral adaptive immunity. Answer: B cell (plasma
cell)/antibody
defense against bacterial infections (extracellular organisms)
hypersensitivity type I (immediate)
hypersensitivity type II (ADCC)
hypersensitivity type III (Immune complex)
◉ Characteristics of immunogens (antigens) that affect
immunogenicity. Answer: 1. large size molecule (molecular weight of
at least 10 KDa)
2. high complexity (simple repeating units do not make good
immunogens
3. chemical composition (proteins and polysaccharides are better
than carbohydrates, lipids, and nucleic acids)
4. foreignness (the more different from the host, the more
immunogenic)
, ◉ IgG. Answer: greatest concentration in serum
4 subclasses
activates complement (except for IgG4)
crosses placenta
75% of total antibody concentration
◉ IgM. Answer: largest antibody (pentamer)
fixes complexes best (multiple binding sites)
prominent in early immune response (indicates acute infection)
5-10% of total antibody concentration
◉ IgA. Answer: predominant antibody in body secretions (tears,
saliva, nasal mucosa)
serum IgA (monomer) & secretory IgA (dimer)
