Significance of the ratio interferon-γ/interleukin-4 in early diagnosis and immune mechanism of unexplained recurrent spontaneous abortion

Objective To investigate the significance of T helper type 1 (Th1)/Th2 cytokines in the pathogenesis of unexplained recurrent spontaneous abortion (URSA), and reveal the value of single cytokines and their proportions in early diagnosis. Methods A total of 44 URSA patients (URSA group), 51 patients with adverse pregnancy history (ad-pregnancy group), and 42 healthy volunteers with normal pregnancy (pregnancy group) were recruited for a cross-sectional study from July 2018 to April 2019 in the Second Xiangya Hospital. Pregnancies involving chromosomal abnormalities, infection, autoimmune diseases, and anatomical abnormalities were excluded. Flow cytometry was used to determine the level of Th1/Th2 cytokines in peripheral blood. Results The level of interleukin-6 (IL-6) in the peripheral blood of the ad-pregnancy group was significantly higher than in the other two groups. The ratio of interferon-gamma (IFN-gamma)/IL-4 in the URSA group was significantly higher than that of the pregnancy group. The area under the curve for IFN-gamma/IL-4 was 0.821, with high diagnostic efficiency, and sensitivity as high as 84.09%. Conclusion Laboratory testing for IL-6 is not recommended for the diagnosis or monitoring of URSA. The variable IFN-gamma/IL-4 can be used for the initial diagnosis of URSA to reduce the rate of missed diagnosis. This ratio was more important than the expression of a single cytokine in the Th1/Th2 immune response.

Automated summary

The study found that the level of IL-6 in the peripheral blood of the ad-pregnancy group was significantly higher than in the other two groups, and the ratio of IFN-gamma/IL-4 in the URSA group was significantly higher than that of the pregnancy group. The IFN-gamma/IL-4 ratio had high diagnostic efficiency with a sensitivity of 84.09%.