Natural Killer Cell Functional Activity Suppression By Intravenous Immunoglobulin, Intralipid and Soluble Human Leukocyte Antigen-G


Roumen G. Roussev, 233 East Erie St, Suite 510, Chicago, IL 60611, USA.



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.


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%.


Intravenous immunoglobulin, intralipid and sHLA-G suppressed NK cell cytotoxicity with equal efficacy in an in vitro assay.