ASCP Immunology and Serology 2

Question 1

Which complement pathway is initiated by antibody-antigen complexes?

Accepted Answer

Classical pathway

Answer

The classical complement pathway is activated by IgG or IgM antibodies bound to antigen, triggering C1q binding.

Question 2

The Western blot test for HIV confirmation detects antibodies against which viral proteins?

Accepted Answer

p24 core, gp41 envelope, and gp120/160 envelope proteins

Answer

HIV Western blot detects antibodies to viral core (p24, p17) and envelope (gp41, gp120, gp160) proteins separated by electrophoresis.

Question 3

Anti-CCP (anti-cyclic citrullinated peptide) antibodies are most specific for:

Accepted Answer

Rheumatoid arthritis

Answer

Anti-CCP antibodies have >90% specificity for rheumatoid arthritis and can appear years before clinical symptoms.

Question 4

The indirect fluorescent antibody (IFA) test for ANA uses which substrate?

Accepted Answer

HEp-2 (human epithelial) cells

Answer

HEp-2 cells are the standard substrate for ANA IFA because their large nuclei display multiple patterns (homogeneous, speckled, nucleolar, centromere).

Question 5

Which marker is used to diagnose infectious mononucleosis caused by Epstein-Barr virus?

Accepted Answer

Monospot test (heterophile antibodies) plus EBV-specific antibodies

Answer

The monospot detects heterophile antibodies that agglutinate horse/sheep RBCs; EBV-specific tests (VCA-IgM, EA, EBNA) confirm diagnosis.

ASCP Practice Test

ASCP Practice Test

ASCP Immunology and Serology 2