Circulating Levels of Immunoreactive Cytokines in Women with Preeclampsia

PROBLEM: Circulating inflammatory cytokines have been implicated in the pathogenesis of preeclampsia. To test this hypothesis, we measured plasma levels of immunoreactive tumor necrosis factor (TNF)‐α and ‐β, interleukin (IL)−1α and ‐β, and IL‐6 and −10 in women with preeclampsia, in women with transient gestational hypertension, and throughout normal pregnancy.

METHOD OF STUDY: Enzyme‐linked immunosorbent assays were used and subjected to extensive validation studies.

RESULTS: The median concentration of plasma TNF‐α was increased by twofold in women with preeclampsia compared with that in normal third‐trimester pregnancy (P < 0.001) and in women with gestational hypertension (P < 0.04). The median concentration of plasma IL‐6 was increased by threefold in women with preeclampsia compared with that in normal third‐trimester pregnancy (P < 0.001) and increased twofold compared with that in women with gestational hypertension (P < 0.1). There were no significant differences observed in the levels of plasma IL‐1β and IL‐10 between the preeclamptic and other subject groups. The level of IL‐1β, but not the levels of IL‐10, TNF‐α, or IL‐6, was significantly changed during normal pregnancy compared with the nonpregnant condition manifesting an overall decline (P < 0.04). TNF‐β and IL‐1α were not detected in any samples, possibly because of the low sensitivity of these particular immunoassays.

CONCLUSION: Elevated levels of TNF‐α and IL‐6 may contribute to the putative endothelial dysfunction of preeclampsia.