Natural killer cell functional activity suppression by intravenous immunoglobulin, intralipid and soluble human leukocyte antigen-G.

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.

Expression of intracellular Th1 and Th2 cytokines in women with recurrent spontaneous abortion, implantation failures after IVF/ET or normal pregnancy.

PROBLEM: We aimed to investigate absolute counts of intracellular T helper 1 (Th1) and Th2 cytokine expressing T-cell subpopulations in women with three or more recurrent spontaneous abortions (RSA), multiple implantation failures after in-vitro fertilization and embryo transfer (IVF/ET) (three or more) or during normal pregnancy. METHOD OF STUDY: Absolute cell counts and percentages of CD3+, CD3+/CD4+, and CD3+/CD8+ T-cell populations expressing intracellular cytokines [interferon-gamma (IFN-gamma), tumor necrosis factor-alpha (TNF-alpha), interleukin (IL)-4 and IL-10] was studied by four-color flow cytometry in 15 RSA and 13 implantation failure patients. Eighteen fertile non-pregnant and 47 normal pregnant women were also compared with regard to intracellular cytokine expression. RESULTS: Interleukin-10 producing CD3+/CD8+ T-cell counts were significantly lower in women with RSA (P < 0.05) and implantation failures (P < 0.05), and TNF-alpha producing CD3+/CD4+ T-cell counts were higher in women with RSA (P < 0.05) and implantation failures (P < 0.005) than those of non-pregnant fertile controls. During normal pregnancies, first trimester IL-4 expressing CD3+, CD3+/CD4+ T-cell counts (P < 0.05) and IFN-gamma expressing CD3+ T-cell counts (P < 0.05) were significantly higher than those of third trimester (P < 0.05). First trimester TNF-alpha expressing CD3+/CD8+ T-cell counts were significantly higher than those of second and third trimester women (P < 0.05). However, there are no differences in cytokine expression between non-pregnant and first trimester pregnant women. CONCLUSION: Absolute counts of IFN-gamma, IL-4, and TNF-alpha expressing T cells decrease with the progress of gestation (third trimester) during normal pregnancies. In women with implantation failures, absolute cell counts of TNF-alpha expressing CD3+/ 4- cells reflects the presence of dominant Th1 immune response. A significantly increased Th1 cytokine expression may be the underlying immune etiology for reproductive failures.