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The mass lesion in the patient's lung is evaluated with fiberoptic bronchoscopy with transbronchial biopsy. Sputum collected after the
procedure demonstrates acid-fast bacteria with a "beaded" appearance. Giant cells found in the biopsy material would be likely to express
which of the following membrane markers?
A. CD4
B. CD8
C. CD14
D. CD16
E. CD19
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hey nickmle ...nice to see u ....
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way to goooo leen and sage... corrrect ans is C....
hi leen hows prep...yeah i remember abt pahrm i will try to post couple of q;s too....
The correct answer is C. CD14, the endotoxin receptor, is a standard marker for macrophages and cells of their lineage. The giant cells in a TB granuloma are histiocytes, which are modified macrophages, so they would bear macrophage cell markers.
CD4 (choice A) is a cell marker for helper T lymphocytes that would be found in the halo of lymphocytes surrounding the Langerhans giant cells, but would not be on the giant cells themselves.
CD8 (choice B) is a cell marker for cytotoxic T lymphocytes that would be present in the halo of lymphocytes surrounding the giant cells, but would not be on the giant cells themselves.
CD16 (choice D) is a cell marker for NK cells, which would not be on the giant cells in a TB granuloma.
CD19 (choice E) is a cell marker for B-lymphocytes, which are not likely to be present in a TB granuloma, a reaction mediated exclusively by cell-mediated immunity.