Laboratory Science Immunology and Serology 2

Question 1

What does a positive monospot (heterophile antibody) test indicate?

Accepted Answer

Infectious mononucleosis (Epstein-Barr virus)

Answer

HIV infection

Answer

Cytomegalovirus infection

Answer

Streptococcal pharyngitis

Question 2

Which CD marker is used to identify T helper lymphocytes, and its count monitors HIV/AIDS progression?

Accepted Answer

CD4

Answer

CD8

Answer

CD19

Answer

CD56

Question 3

What is the ELISA test principle used in serology?

Accepted Answer

Enzyme-linked antibody detecting antigen-antibody reactions via color change

Answer

Agglutination of red blood cells

Answer

Electrical migration of proteins in gel

Answer

Radioactive labeling of antigens

Question 4

Which complement pathway is activated by antigen-antibody complexes (IgG or IgM)?

Accepted Answer

Classical pathway

Answer

Alternative pathway

Answer

Lectin pathway

Answer

Regulatory pathway

Question 5

A Western blot test in HIV diagnosis detects antibodies to which viral proteins?

Accepted Answer

Structural proteins: gag (p24, p17), pol (p31, p51, p66), and env (gp41, gp120/160)

Answer

Only envelope proteins gp120 and gp41

Answer

Core protein p24 only

Answer

Reverse transcriptase only

Question 6

What does the C-reactive protein (CRP) test measure?

Accepted Answer

An acute-phase protein produced by the liver in response to inflammation or infection

Answer

Complement C1 levels

Answer

Antibodies to streptococcal antigens

Answer

Red blood cell turnover rate