Hypoperfusion causes increased production of interleukin 6 and tumor necrosis factor alpha in the isolated, dually perfused placental cotyledon.

OBJECTIVE: Our purpose was to determine whether exposure of the isolated, perfused human placental cotyledon to different fetal circuit perfusion rates, and to concomitant pressure differences, alters placental production of interleukin 6 and tumor necrosis factor alpha. STUDY
DESIGN: The maternal and fetal circulations of 2 cotyledons from 5 placentas were perfused for 4 hours. The fetal circulation of 1 cotyledon was perfused at a low rate of 1 mL/min, and the other at a high rate of 10 mL/min. The maternal circulation of each cotyledon was perfused at 10 mL/min. Effluents from the fetal circulation were collected at hourly intervals, and concentrations of interleukin 6 and tumor necrosis factor alpha were determined by enzyme-linked immunosorbent assay. Concentrations of interleukin 6, obtained from a prior study with an estimated physiologic fetal circulation rate of 4 mL/min, were compared with the low and high perfusion rate results.
RESULTS: Concentrations of interleukin 6 and tumor necrosis factor alpha were greater at the perfusion rate of 1 mL/min, in comparison with the perfusion rate of 10 mL/min, with statistically significant differences achieved at 2 and 4 hours for interleukin 6 and at 4 hours for tumor necrosis factor alpha. Concentrations of both cytokines increased exponentially with time. Placental perfusion pressures were significantly greater at the perfusion rate of 10 mL/min.
CONCLUSION: Placental hypoperfusion results in an increased production of both interleukin 6 and tumor necrosis factor alpha. This finding links placental perfusion abnormalities to the myriad of disorders associated with elevated concentrations of inflammatory cytokines, including cerebral palsy.