title: Measurement of amniotic fluid interleukin-6 using commercial kits.
abstract: OBJECTIVE
  The association between increased amniotic fluid interleukin-6 (IL-6) concentrations and preterm labor has received increasing attention. Several research groups have evaluated this association using commercial IL-6 kits, which principally use the sandwich-enzyme-immunoassay method, and were originally created to measure IL-6 in plasma, serum, or culture media. We evaluated commercial kits for the determination of IL-6 in amniotic fluid.
  
  
  METHODS
  Seven commercial kits were used to determine IL-6 concentrations in three amniotic fluid samples which were obtained from patients with clinical chorioamnionitis during labor and five from normal pregnancies at mid-trimester.
  
  
  RESULTS
  Amniotic fluid IL-6 values differed significantly with some having over a 50-fold discrepancy and the recovery of known IL-6 added to amniotic fluid ranged from 12 to 123%. However, by all kits we were able to identify that amniotic fluid from patients with chorioamnionitis contained significantly higher IL-6 concentrations than those from normal mid-trimester pregnancies.
  
  
  CONCLUSIONS
  Our data indicate that standardization of the method for measuring IL-6 in amniotic fluid is desirable for the comparison of values from various laboratories.
authors.affiliation: Department of Nutrition Sciences 218 Webb Building University of Alabama at Birmingham Birmingham AL USA.
authors.forename: T
authors.initials: T
authors.lastname: Tamura
authors.forename: W W
authors.initials: WW
authors.lastname: Andrews
authors.forename: K E
authors.initials: KE
authors.lastname: Johnston
authors.forename: G P
authors.initials: GP
authors.lastname: Hemstreet
authors.forename: R L
authors.initials: RL
authors.lastname: Goldenberg