Immunology and Serology Flashcards
7 cards from real Medical Laboratory Technician Exam practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Immunology and Serology flashcards as text
Which test is considered the gold standard confirmatory test for HIV infection?
Answer: Western blot / immunoblot
Western blot (or newer HIV-1/HIV-2 differentiation immunoassay) is used to confirm a repeatedly reactive HIV screen result.
A latex agglutination test for Cryptococcus neoformans detects which antigen?
Answer: Polysaccharide capsular antigen
The cryptococcal antigen test detects polysaccharide capsular antigen of C. neoformans in serum or CSF.
Secretory IgA differs from serum IgA primarily in that secretory IgA:
Answer: Contains a J chain and secretory component
Secretory IgA is a dimer joined by a J chain and protected by a secretory component added during transcytosis across epithelial cells.
In immunofluorescence testing for ANA, a homogeneous (diffuse) pattern is most commonly associated with antibodies against:
Answer: dsDNA and histones
A homogeneous ANA pattern reflects antibodies to dsDNA and histones that bind uniformly throughout the nucleus.
Which immunoglobulin class is the first to be produced during a primary immune response?
Answer: IgM
IgM is synthesized first during a primary immune response because it requires no class-switch recombination.
A patient with recurrent Neisseria infections and low CH50 but normal C3 levels most likely has a deficiency of:
Answer: Terminal complement components (C5–C9)
Terminal complement deficiency (C5–C9) impairs membrane attack complex formation, predisposing to Neisseria bacteremia, with low CH50 but normal C3.
The Weil-Felix test uses Proteus OX strains to detect antibodies in which infection?
Answer: Rocky Mountain spotted fever (Rickettsia)
The Weil-Felix test exploits cross-reactive antigens between Proteus OX strains and Rickettsia species to detect rickettsial antibodies.