[Study on relationship between detection of interleukin-6 and its mRNA and pregnancy induced hypertension]

To investigate the effect of Interleukin-6 (IL-6) on pathogenesis of pregnancy induced hypertension (PIH) and to confirm the derivation of IL-6 and relationship between IL-6 and growth of placenta and fetus.

Pregnant women without infection and uterine contraction are divided into two groups: (1) PIH group (n = 57), (2) Normal pregnancy group (n = 15), reverse transcription-polymerase chain rection (RT-PCR) is used to detect IL-6 mRNA expression in leucocyto of peripheral blood and in placenta; Enzyme-linked immunosorbent assay (ELISA) is used to detect IL-6 level of peripheral blood and amniotic fluid.

(1) The level of IL-6 and its mRNA in peripheral blood has a increasing trend as PIH degree. In moderate and severe PIH, IL-6 and its mRNA level are significantly higher than that of normal pregnancy. In each degree of PIH, IL-6 mRNA expression in placeata is significantly lower than that of normal pregnancy. In moderate and severe PIH, IL-6 level in amniotic fluid is significantly lower than that in normal pregnancy (P < 0.001). (2) In moderate and severe PIH, IL-6 level has high correlation to the IL-6 mRNA in peripheral blood (r = 0.67, P < 0.01). The IL-6 level in amniotic fluid has significant correlation to IL-6 mRNA in placenta (r = 0.79, P < 0.01). IL-6 and its mRNA in peripheral blood has no high correlation to IL-6 in amniotic fluid. (3) In severe PIH, the IL-6 mRNA in placenta and IL-6 level in amniotic fluid in the group of pregnancy with intrauterine growth retardation (IUGR) are both lower than that of the group without IUGR (P < 0.05).

In PIH, the immune activity is rising, the IL-6 is overproduced by activated immune cells and it may involve in immune respond of organism and damage of vasicular endothelium. Decrease of IL-6 mRNA in placenta and IL-6 in amniotic fluid showes that the capability of production and transport of IL-6 decline in placenta of PIH patient, and these result in ischemia of placenta trophoblast and disturbance of the growth and development of placenta and fetus.