Natural killer (NK) cell subsets and NK cell cytotoxicity in women with histories of recurrent spontaneous abortions.
OBJECTIVE
Natural Killer (NK) cell measurement and NK cytotoxicity are two measurements for assessing the cellular immune response. Both of the techniques have been reported to be prognostic for women with recurrent spontaneous abortion (RSA). We evaluated the two methods to determine the relationship of the two assays. Because both methods portend to evaluate the same process, the previous clinical data suggested that the methods evaluate the same phenomena. We undertook these studies to determine whether simple NK cell counts may be sufficient in the evaluation of NK activity in RSA.


METHODS
The NK cell cytotoxicity at effector-to-target ratios of 50:1 and 25:1 was determined using a flow cytometric NK cell cytotoxicity assay. These values were then correlated with the percentages and absolute counts of three peripheral blood NK cell subsets.


RESULTS
The data indicate that the flow cytometric assay is reproducible and precise and can be successfully used to evaluate patient samples. Linear regression analysis indicated a lack of correlation between peripheral blood NK cell cytotoxicity and percentages or absolute counts of CD56+CD16+, CD56+CD16- or CD3+CD56+ lymphocyte subsets (range of correlation coefficients, 0.1-0.3).


CONCLUSIONS
NK cell cytotoxicity and peripheral blood NK cell values measure different aspects of NK cells and do not correlate. These data indicate that simple enumeration of NK cells may not be sufficient in the evaluation of NK cells in RSA.
Gilman-Sachs
A
A
Clinical Immunology Laboratory, Finch University of Health Sciences, Chicago Medical School, IL, USA.
DuChateau
B K
BK
Aslakson
C J
CJ
Wohlgemuth
G P
GP
Kwak
J Y
JY
Beer
A E
AE
Beaman
K D
KD
D000022:Abortion, Spontaneous / Q000276:immunology*; D019002:CD56 Antigen / Q000276:immunology; D003602:Cytotoxicity, Immunologic; D005260:Female; D005434:Flow Cytometry; D006801:Humans; D016130:Immunophenotyping; D007694:Killer Cells, Natural / Q000166:cytology / Q000276:immunology*; D016131:Lymphocyte Subsets / Q000276:immunology; D011247:Pregnancy
D019002:CD56 Antigen