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

Antinuclear antibody (ANA) testing

Answer

Western blot electrophoresis

Answer

VDRL flocculation test

Question 2

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

Accepted Answer

Systemic lupus erythematosus (SLE)

Answer

Rheumatoid arthritis

Answer

Multiple sclerosis

Answer

Lyme disease

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

Free antibodies circulating in the patient's serum

Answer

Antinuclear antibodies in serum

Answer

Cold agglutinins at low temperatures

Question 4

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

Accepted Answer

Western blot immunoassay

Answer

Quantitative PCR viral load assay

Answer

CD4+ T cell count

Answer

p24 antigen capture ELISA

Question 5

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

Accepted Answer

Infectious mononucleosis (EBV)

Answer

Cytomegalovirus (CMV) infection

Answer

Hepatitis B infection

Answer

Toxoplasmosis

Question 6

A positive indirect antiglobulin test (IAT/indirect Coombs) indicates that:

Accepted Answer

The patient's serum contains antibodies capable of binding to red blood cell antigens

Answer

Complement is already bound to the patient's red blood cells

Answer

Red blood cell destruction is actively occurring in the spleen

Answer

Antibodies have coated the patient's red blood cells in circulation

Question 7

According to CDC guidelines, which test is used to confirm a positive ELISA result in the two-tier testing approach for Lyme disease?

Accepted Answer

Western blot (immunoblot)

Answer

Polymerase chain reaction (PCR)

Answer

Bacterial culture of blood

Answer

Complement fixation test