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Updated: Jul 16, 2026

Flow Cytometry-based Assay for the Monitoring of NK Cell Functions
Published on: October 30, 2016
Natural killer cell functional activity suppression by intravenous immunoglobulin, intralipid and soluble human
Roumen G Roussev1, Siu Chui Ng, Carolyn B Coulam
1Millenova Immunology Laboratories, Chicago, IL 60611, USA. rgroussev@yahoo.com
Problem:
The purpose of this study was to compare the ability of intravenous immunoglobulin (IVIg), intralipid and soluble human leukocyte antigen (sHLA)-G to suppress natural killer (NK) cell cytotoxicity in an in vitro assay.
Method Of Study:
Blood samples taken from 275 women experiencing reproductive failure were analyzed for NK cytotoxicity and the suppression of NK cytotoxicity by IVIg 4 and 2 mg/mL (n = 275), intralipid 18 and 9 mg/mL (n = 275) and sHLA-G 70 and 35 ng/mL (n = 50) using immunofluorescent labeled K562 cells as targets and flow cytometry.
Results:
Natural killer cytotoxicity was suppressed in all samples. Among patients with normal NK cell activity, IVIg suppressed NK cytotoxicity by 44.9 +/- 8.1%, intralipid suppressed NK killing by 45.2 +/- 8.3% and sHLA-G suppressed by 49.0 +/- 9.2%. When specimens with abnormal NK activity were observed for suppression of cytotoxicity, IVIg suppressed by 38.9 +/- 5.4%, intralipid suppressed by 39.8 +/- 6.2% and sHLA-G suppressed by 39.9 +/- 5.0%.
Conclusion:
Intravenous immunoglobulin, intralipid and sHLA-G suppressed NK cell cytotoxicity with equal efficacy in an in vitro assay.
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