Page 352 - Clinical Immunology_ Principles and Practice ( PDFDrive )

332 Part two Host Defense Mechanisms and Inflammation

X-linked carriers of CGD but cannot differentiate autosomal oN tHE HorIZoN
carriers from normal subjects.
An alternative to the NBT test is a flow cytometric assay, in • Early recognition and molecular diagnosis of all phagocyte defects,
which the dye, dihydrorhodamine-1,2,3 is used. Neutrophils are leading to prophylactic antimicrobial treatment, where indicated
loaded with the nonfluorescent dye and then stimulated with • Improvement in bone marrow transplantation technology to allow for
early, safe, successful, fertility-preserving transplantation in all cases
PMA for 15 minutes at 37°C. The H 2 O 2 produced oxidizes the • Understanding the mechanisms of the hepatic complications of chronic
dye and results in increased fluorescence, detectable with a flow granulomatous disease (CGD) that correlate with mortality
cytometer. Catalase is added to prevent cell-to-cell diffusion of • Characterizing the pathways that converge on signal transducer and
H 2 O 2 . Since dye is localized to the cytoplasm, and catalase is activator of transcription 3 (STAT3) signaling causing the complex
present in the extracellular fluid, the dihydrorhodamine-1,2,3 somatic and immune disorder, hyper-IgE recurrent infection syndrome
assay detects the intracellular production of reactive oxygen (HIES).
metabolites. Stimulation of normal neutrophils with PMA results
in a two-log shift in the fluorescence intensity. Neutrophils from ACKNOWLEDGMENT
an X-linked carrier of CGD exhibit mosaicism with a negatively
stained (abnormal) population and a brightly stained positive This work was supported by the intramural program of the
population. Neutrophils from a patient with X-linked CGD that National Institute of Allergy and Infectious Diseases.
lack gp91 phox express little increase in fluorescence, whereas
neutrophils from a patient with a deficiency in p47 phox exhibit a Please check your eBook at https://expertconsult.inkling.com/
slight increase in fluorescence. The major advantages of the for self-assessment questions. See inside cover for registration
dihydrorhodamine-1,2,3 assay are the sensitivity, the signal-to- details.
noise ratio, and the ease of counting a large number of cells.
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