MLPAO Immunology and Serology Flashcards
7 cards from real MLPAO practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 MLPAO Immunology and Serology flashcards as text
Rheumatoid factor (RF) is typically an autoantibody of which immunoglobulin class directed against:
Answer: IgM directed against patient's own IgG
Rheumatoid factor is classically an IgM autoantibody that targets the Fc region of the patient's own IgG, forming immune complexes that contribute to inflammation in rheumatoid arthritis.
In flow cytometry, CD4:CD8 ratio is used clinically to monitor patients with HIV. A significantly decreased ratio (below 1.0) indicates:
Answer: Progressive immunodeficiency due to CD4+ T cell depletion
HIV selectively destroys CD4+ T helper cells, causing the CD4:CD8 ratio to fall below normal (normal ~2:1); a ratio below 1.0 indicates significant immune compromise and disease progression.
The Weil-Felix test uses Proteus vulgaris antigens to detect antibodies in patients suspected of having:
Answer: Rickettsial infections
The Weil-Felix test exploits cross-reactive antigens between Rickettsia species and certain Proteus strains; patient antibodies from rickettsial infections agglutinate Proteus OX-19, OX-2, and OX-K antigens.
Which principle underlies the fluorescent treponemal antibody absorption (FTA-ABS) test for syphilis?
Answer: Indirect immunofluorescence after absorption of non-specific antibodies
The FTA-ABS uses indirect immunofluorescence where patient serum is first absorbed with non-pathogenic treponemes to remove cross-reactive antibodies, then applied to Treponema pallidum on a slide and detected with fluorescent anti-human immunoglobulin.
In immunofixation electrophoresis (IFE) for serum protein analysis, a monoclonal band (M-protein) in the gamma region most commonly suggests:
Answer: A plasma cell dyscrasia such as multiple myeloma
A discrete monoclonal band (M-spike) on IFE indicates clonal proliferation of a single plasma cell line producing identical immunoglobulin, characteristic of plasma cell dyscrasias including multiple myeloma and Waldenström macroglobulinemia.
Which quality control measure is most important when performing agglutination serological tests to ensure reagent validity?
Answer: Running known positive and negative controls with each test batch
Running known positive and negative controls with every test batch validates reagent performance, detects lot-to-lot variation, and ensures the assay is functioning correctly before reporting patient results.
Serum protein electrophoresis (SPEP) separates proteins primarily based on:
Answer: Electrical charge and molecular size in an alkaline buffer
SPEP separates serum proteins in an alkaline buffer (pH ~8.6) where all proteins carry net negative charges; migration toward the anode is determined by charge density and molecular size, producing the characteristic albumin, alpha-1, alpha-2, beta, and gamma bands.