ASCP Immunology and Serology 3

Question 1

Which test is the gold standard for confirming Lyme disease seropositivity after a positive ELISA?

Accepted Answer

Western blot (IgM and IgG bands to B. burgdorferi proteins)

Answer

The two-tier testing algorithm for Lyme disease uses ELISA screening followed by Western blot confirmation for IgM and IgG band criteria.

Question 2

C-reactive protein (CRP) is an acute-phase reactant synthesized primarily by which organ?

Accepted Answer

Liver

Answer

CRP is synthesized by hepatocytes in response to IL-6 and IL-1 during acute inflammation, rising within 4–6 hours of insult.

Question 3

A patient with recurrent Neisseria infections (meningitis, gonorrhea) likely has a deficiency in:

Accepted Answer

Terminal complement components (C5–C9, MAC)

Answer

Terminal complement (C5–C9) forms the membrane attack complex essential for killing encapsulated gram-negative bacteria like Neisseria species.

Question 4

Serum protein electrophoresis showing an M-spike in the gamma region indicates:

Accepted Answer

Monoclonal gammopathy (myeloma or MGUS)

Answer

A monoclonal spike (M-protein) in the gamma zone indicates clonal plasma cell proliferation, seen in multiple myeloma or monoclonal gammopathy of undetermined significance.

Question 5

The latex agglutination test for cryptococcal antigen in CSF detects:

Accepted Answer

Cryptococcal polysaccharide capsular antigen

Answer

The cryptococcal antigen (CrAg) test detects capsular polysaccharide with >99% sensitivity and specificity in CSF and serum.

ASCP Practice Test

ASCP Practice Test

ASCP Immunology and Serology 3