Fig. 6
A scheme of the potential inflammatory biomarkers of infectious PTB based on the results revealed in this study. Infectious PTB was an inflammation-related disease with maternal high levels of several inflammatory factors. The prioritization of the inflammatory factors in infectious PTB prediction is sTNFR2 > TNFα > IL-10 > IL-6 > CRP > IL-1β. CRP/IL-1β/IL-6 in gestational 27–34 weeks, and TNF/NGF family in gestational 25–33 weeks, were potential biomarker clusters that specific for infectious PTB prediction. (IL-1β indicated interleukin-1 beta, IL-2 indicated interleukin-2, IL-4 indicated interleukin-4, IL-6 indicated interleukin-6, IL-8 indicated interleukin-8, IL-10 indicated interleukin-10, IL-17A indicated interleukin-17A, IL-27p28 indicated interleukin-27p28, CRP indicated C-reactive protein, TNFα indicated tumor necrosis factor α, sTNFR indicated soluble tumor necrosis factor receptor, NGF indicated nerve growth factor, CXCL9 indicated C-X-C motif chemokine ligand 9, IFN-γ indicated interferon gamma, sCD14 indicated soluble CD14 molecule, and sCD163 indicated soluble CD163 molecule)