Objectives: Our goal was to assess in a longitudinal study of uncomplicated pregnancy the course of maternal plasma concentrations of the bioactive cytokine tumor necrosis factor-alpha, the soluble tumor necrosis factor-alpha receptors sTNFRI and sTNFRII, the soluble cell adhesion molecule sVCAM-1, and circulating fibronectin.
Study design: Blood was collected from 22 healthy pregnant women at 7 to 17, 18 to 22, 23 to 28, and 30 to 36 weeks' gestation and post partum. Plasma samples were measured by bioassay for bioactive tumor necrosis factor-alpha, by immunoassay for sTNFRI, sTNFRII, and VCAM-1, and by radial immunodiffusion for circulating fibronectin, and data were statistically analyzed.
Results: Plasma concentrations of all variables were significantly linked with gestational age. Levels of bioactive tumor necrosis factor-alpha and sTNFRII showed a parallel rise in the second trimester and a decrease thereafter. Values for sTNFRI and sTNFRII and for these receptors and VCAM-1 were correlated, a weak correlation between bioactive tumor necrosis factor-alpha and sTNFRII was observed, and no correlation between circulating fibronectin and other variables was apparent.
Conclusions: All variables studied exhibited a characteristic pattern depending on gestational age, which supports the concept of a physiologic role of tumor necrosis factor-alpha in pregnancy.