Clinical application of maternal serum cytokine determination in prematurerupture of membranes - interleukin-6, an early predictor of neonatal infection?

Background In cases of premature rupture of membranes (PROM), an early dete ction of fetal infection is necessary in order to weigh infectious complica tions against prematurity. As routine parameters (leukocytes, C-reactive pr otein (CRP), fever, and fetal tachycardia) lack satisfactory sensitivity an d specificity, this study evaluates whether the determination of interleuki n-6 (IL-6), interleukin-8 (IL-8) or soluble interleukin-2 receptor (IL-2R) in maternal serum could supplement or replace routine inflammation paramete rs. Methods. In this prospective study results of clinical and laboratory param eters were investigated with respect to neonatal infection in 71 patients w ith FROM. IL-6, IL-8 and IL-2R were determined by enzyme immunoassays. Results. Best specificity and sensitivity could be demonstrated for CRP and IL-6. Both elevation of CRP and IL-6 correlated significantly (p<0.01 and p <0.001, respectively) with the onset of neonatal infection. At a cutoff o f 11 pg(ml, IL-6 reaches a sensitivity of 81% and a specificity of 76% CRP a specificity of 76% (cutoff 1.2 mg/dl) and a sensitivity of 56%. In 4/ 16 (25%) cases developing neonatal infection, IL-6 increased earlier than CRP. IL-8 and IL-2R results showed a less significant correlation with fetal ou tcome. Conclusions. Determination of IL-6 in maternal serum can significantly cont ribute to an earlier detection of fetal infection in patients with PROM.