CMLA Immunology & Serology 3

Question 1

Which method is most commonly used to detect rheumatoid factor (RF) in serum?

Accepted Answer

Latex agglutination or nephelometry

Answer

Rheumatoid factor (IgM antibody against the Fc portion of IgG) is detected by latex agglutination or nephelometry, where RF causes agglutination of IgG-coated particles.

Question 2

A positive antinuclear antibody (ANA) test with a high titer is most strongly associated with:

Accepted Answer

Systemic lupus erythematosus (SLE)

Answer

A positive ANA, especially in high titers with specific patterns (homogeneous, speckled), is most characteristic of systemic lupus erythematosus.

Question 3

The direct antiglobulin test (DAT/direct Coombs) detects:

Accepted Answer

Antibodies or complement already coating the patient's red blood cells in vivo

Answer

The DAT adds antihuman globulin reagent directly to the patient's washed red blood cells to detect IgG or complement already bound to the cells in vivo.

Question 4

Which test is used as a confirmatory test for HIV infection following a positive ELISA screen?

Accepted Answer

Western blot immunoassay

Answer

Western blot is the standard confirmatory test for HIV, detecting specific viral protein bands (p24, gp41, gp120/160) that indicate true HIV infection.

Question 5

Heterophile antibodies detected by the monospot test are most associated with which disease?

Accepted Answer

Infectious mononucleosis (EBV)

Answer

Infectious mononucleosis caused by Epstein-Barr virus (EBV) stimulates production of heterophile antibodies that agglutinate horse or sheep red blood cells.

(CMLA) Certified Medical Laboratory Assistant Practice Test

(CMLA) Certified Medical Laboratory Assistant Practice Test

CMLA Immunology & Serology 3