Published in:
01-11-2021 | Letter to Editor
Undetectable NK Cells due to the FCGR3A Variant, L66H, Which May Not Be Directly Disease-Causing
Authors:
Neema Izadi, Miao Sun, Emily M. Mace, Maurice R. G. O’Gorman, Joseph A. Church
Published in:
Journal of Clinical Immunology
|
Issue 8/2021
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Excerpt
A baby girl born at 38 weeks of gestation with no perinatal complications was brought to our attention for possible severe combined immunodeficiency (SCID) because of low T cell receptor excision circles (TRECs) (11/mcL, reference range > 18) on newborn screen. Blood was collected for confirmatory flow cytometry and the absolute number of T cells was borderline low (2116/mcL, reference range 2500–5500) but sufficient to rule out SCID. However, her NK cell enumeration showed absent (< 1%) NK cells (CD3
− CD56
+ CD16
+ by BD Biosciences 6-color TBNK, San Jose, CA). Subsequent testing at a local laboratory identified normal numbers of NK cells (26%), but at this laboratory, NK cells were defined as (CD3
− CD56
+ by locally derived reagents). Complete laboratory values can be found in Supplementary Table E
1. We therefore pursued further testing to determine if CD16 was absent from the patient’s cells or if there was a lack of targeting by the specific anti-CD16 monoclonal antibody used. …