CD56/CD16 Expression on Mononuclear Cells and Concentration of Serum TNF-α in Recurrent Spontaneous Abortion

Abstract

Recurrent spontaneous abortion (RSA) is defined as the occurrence of three or more consecutive spontaneous abortion before 20 gestational weeks. But, 40-50% of RSA still remain "unex-plained". Cytokines seem to play a critical role in the pathogenesis of unexplained RSA, and Th1 cytokines have been shown to exert deleterious effects on pregnancy. NK cytotoxicity has been reported to be predictive of subsequent abortion in women who had unexplained recurrent abortions. The aim of this study was to investigate immunophenotypic characteristics of peripheral blood mononu-clear cells and evaluate Th1 cytokine (TNF-alpha) production in women with RSA. The study group comprised 93 women with RSA, and the control group consisted of 40 healthy pregnant women. The population of CD56/CD16 cells was observed by using a two-color scattergram in FACScan (Becton Dickinson, San Jose CA, USA). Concentration of TNF-alpha was measured by an enzyme-linked immunoabsorbant assay (ELISA) using commercial kits (NEOGEN corporation, Lexington KY, USA). The percentage of CD56+/CD16-cells were significantly higher (P<0.05) in the patients with RSA (13.40+/-7.95%) than in the pregnant control group (9.12+/-3.93%). We observed a significantly higher level of TNF-alpha (medians: 85.59+/-8.29 pg/mL versus 44.80+/-9.78 pg/mL; P<0.05) in RSA women compared to controls. This study indicates that an increased proportion of CD56+/CD16-mononuclear cells and increased level of serum TNF-alpha are related to RSA. Thus, the two factors could be used as an indicator of subsequent successful implantation and maintenance of gestation.