Increased T helper 1 cytokine responses by circulating T cells are present in women with recurrent pregnancy losses and in infertile women with multiple implantation failures after IVF

BACKGROUND: We aimed to study T‐helper 1 (Th1) and Th2 intracellular cytokine expression in peripheral blood lymphocytes of women with recurrent spontaneous abortions (RSA) or infertility with multiple implantation failures after IVF cycles. METHODS: Twenty‐six women with three or more RSA and 23 with two or more IVF failures (14 with no history of spontaneous abortion (SAB) and nine with more than one SAB) comprised the two study groups. Twenty‐one non‐pregnant healthy multiparous women served as controls. Proportions (%) of lymphocytes containing IFN‐γ, TNF‐α, IL‐4 and IL‐10 and the Th1/Th2 ratios of IFN‐γ/IL‐4, IFN‐γ/IL‐10, TNF‐α/IL‐4 and TNF‐α/IL‐10 in CD3+, CD3+/CD8– (T helper) and CD3+/CD8+ (T suppressor) cells were measured by 4‐colour flow cytometry. RESULTS: RSA women demonstrated significantly higher Th1/Th2 ratios of IFN‐γ/IL‐4 (P < 0.01), TNF‐α/IL‐4 and TNF‐α/IL‐10 (P < 0.05 each) in CD3+/CD8– T helper cells than those of controls. The proportion of TNF‐α producing CD3+/CD8– cells (P < 0.05), and the Th1/Th2 ratios of TNF‐α/IL‐4 (P < 0.05) and TNF‐α/IL‐10 (P < 0.005) in CD3+/CD8– cells were significantly higher in women with multiple IVF failures without SAB as compared with those of controls. CONCLUSIONS: The prevalence of dominant Th1 immune responses in peripheral blood lymphocytes may reflect the systemic contribution of Th1 cytokines to RSA or multiple implantation failures in IVF cycles.