Active immunity types Correct Answers Natural: infection;
Acquired: vaccination.
Acute cellular rejection hallmark Correct Answers CD8 T-cell
cytotoxicity.
Acute GVHD symptoms Correct Answers Rash, jaundice,
diarrhea, GI bleeding.
Acute HIV infection features Correct Answers High viral load;
mild symptoms; rapid replication.
Acute humoral rejection hallmark Correct Answers Newly
formed antibodies → complement → neutrophils.
Acute inflammation cardinal features Correct Answers Rubor,
calor, tumor, dolor, functio laesa.
Acute phase reactants induced by IL-6 Correct Answers CRP,
MBL, serum amyloid A, fibrinogen.
Acute rejection cause Correct Answers CD8 cytotoxicity + CD4
inflammation; new antibodies.
Acute rejection hypersensitivity type Correct Answers Type IV.
Acute urticaria mechanism Correct Answers Local mast cell
activation → wheals and hives.
,Adaptive anti-tumor effector cells Correct Answers CD8 CTLs,
Th1 CD4 T cells, IgG via ADCC.
Adaptive anti-tumor mediators Correct Answers CD4 Th1 cells,
CD8 cytotoxic T cells, IgG antibodies via ADCC.
Adaptive immune recognition receptors Correct Answers MHC
I, MHC II, BCR, TCR.
ADCC-mediating antibody Correct Answers IgG (via NK
CD16).
Affinity definition Correct Answers Strength of a single
antibody-antigen binding site.
Affinity maturation definition Correct Answers Selection of B
cells producing higher-affinity antibodies.
Agammaglobulinemia characteristics Correct Answers Low
serum Ig; decreased B cells; defect at first B-cell checkpoint
(pre-BCR).
Agglutination definition Correct Answers Antibody
crosslinking of pathogens → enhances clearance.
AIRE defect results in Correct Answers Autoimmune
polyendocrine syndrome (APS-1).
AIRE function Correct Answers Presents tissue-specific
antigens in thymus to eliminate self-reactive T cells.
,AIRE function in negative selection Correct Answers Expresses
tissue-specific antigens for deletion of self-reactive T cells.
Allograft definition Correct Answers Transplant between
genetically different individuals of same species.
Allograft vs isograft difference Correct Answers Allograft =
genetically different individuals; Isograft = identical twins.
Alpha chain gene segments Correct Answers V and J.
Alternative C3 convertase Correct Answers C3bBb.
Alternative C5 convertase Correct Answers C3bBbC3b.
Alternative complement deficiency results in Correct Answers
Susceptibility to Neisseria and pyogenic infections.
Alternative pathway deficiency (Factor D/P) Correct Answers
Susceptibility to pyogenic infections and Neisseria.
Alternative pathway spontaneous activation Correct Answers
"Tick-over" hydrolysis of C3.
Anaphylatoxins in complement Correct Answers C3a, C4a, C5a
(C5a strongest).
Ankylosing spondylitis HLA Correct Answers HLA-B27.
, Anti-CD20 monoclonal antibody role Correct Answers
Eliminates autoreactive B cells; reduces autoantibody
production.
Anti-CD3 monoclonal antibody role Correct Answers Blocks T-
cell activation; used in DM1.
Anti-CTLA-4 monoclonal antibody role Correct Answers
Blocks autoreactive T-cell inhibition pathways; increases T-cell
activation.
Anti-TNF-α monoclonal antibody role Correct Answers Blocks
TNF-α from binding receptors.
Antibodies generated against HIV Correct Answers IgG, IgA,
IgM.
Antibody generated in sensitization phase of Type I Correct
Answers IgE.
Antibody mediating primary immune response Correct Answers
IgM.
Antibody mediating secondary immune response Correct
Answers IgG.
Antibody promoting antiparasitic responses Correct Answers
IgE.
Antibody that potently activates classical complement Correct
Answers IgM.