Frigen II improves the reliability of measurement of interleukin-1 relatedsubstances in amniotic fluid

Background. To investigate the role of interleukin-1 related substances in amniotic fluid in normal term labor without intrauterine infection. Methods. Amniotic fluid samples were collected from forty-one patients with various backgrounds. A novel pre-assay treatment using Frigen II was intro duced to improve the recovery rates of cytokines, i.e., interleukin-1 alpha interleukin-1 beta and interleukin-1 receptor antagonist, prior to ELISA a ssay. Urine samples From newborn infants were also tested. Results. The concentrations of interleukin-1 alpha, interleukin-1 beta and interleukin-1ra were significantly higher in samples from normal vaginal de livery. The higher levels of interleukin-1 alpha were also observed in samp les from preterm labor without infection. Preterm infants produced more of interleukin-1 receptor antagonist in urine compared with term infants. Conclusions. This study provides evidence of the possible involvement of in terleukin-1 related substances in labor without signs of infection. The dat a From newborn urine suggests that amniotic interleukin-1ra originates from the fetus. However, amniotic fluid interleukin-1 alpha and interleukin-lp may be derived from maternal tissue, such as decidua.