Tumor necrosis factor-alpha, interleukin-6, and interleukin-10 levels are altered in preeclampsia: a systematic review and meta-analysis.

PROBLEM Published reports testing the association between cytokine levels and preeclampsia are conflicting. This comprehensive systematic review and meta-analysis aimed at testing the association between preeclampsia and maternal circulating tumor necrosis factor-alpha (TNF-α), interleukin (IL)-6, and IL-10. METHOD OF STUDY A systematic literature search of studies reporting maternal circulating TNF-α, IL-6, and IL-10 in women with preeclampsia and normotensive pregnant women was conducted yielding 41, 28, and 12 eligible reports, respectively. RESULTS Both mild preeclampsia and severe preeclampsia were associated with elevated TNF-α [mean difference (MD) = 7.34 pg/mL, 95% CI 5.02-9.66 and MD = 7.91 pg/mL, 95% CI 4.72-11.10, respectively] and IL-6 (MD = 61.01 pg/mL, 95% CI 14.24-107.77 and MD = 28.54 pg/mL, 95% CI 15.90-41.17, respectively) in the third trimester. Preeclampsia was also associated with elevated levels of IL-10 (MD = 5.54, 95% CI 0.69-10.38). The systematic review of studies reporting median data was in consensus with the parametric data. CONCLUSION This systematic review and meta-analysis with accompanying summary of non-parametric data shows elevated maternal circulating TNF-α, IL-6, and IL-10 levels in preeclampsia.