Cord blood levels of cytokines as predictors of early neonatal sepsis

Aim: To investigate whether cord blood levels of C‐reactive protein, interleukin‐1β, interleukin‐6, interleukin‐8, tumour necrosis factor‐α and the soluble receptor of interleukin‐2, are useful markers in the diagnosis of early neonatal sepsis. Design: Umbilical cord blood samples were obtained at birth from 261 neonates, but 5 of these newborns were excluded from the study. Group I included 10 newborns that developed early neonatal sepsis with a positive blood culture; Group II included 11 newborns with non‐infectious perinatal diseases; Group III, which served as the control group, included 10 randomly selected patients, matched for gestational age, among the 235 healthy newborn babies. Results: There were no differences among the three study groups in levels of C‐reactive protein, interleukin‐1 β, tumour necrosis factor‐α and the soluble receptor of interleukin‐2. Interleukin‐6 was significantly elevated in Group I (360.4 ± 157.8 pg/ml) and Group II (158.8 ± 122.3 pg/ml), when compared with Group III (8.6 ± 3.12 pg/ml) (p < 0.01), whereas interleukin‐8 was significantly elevated in Group I (389.3 ± 115.9 pg/ml) compared with Groups II (30.2 ± 5.1 pg/ml) (p < 0.05) and III (33.9 ± 8.6 pg/ml) (p < 0.05). A cut‐off of 100.8 pg/ml for interleukin‐6 obtained by the ROC (receiver operating characteristic) method gave a sensitivity of 50% and a specificity of 87%, and a cut‐off of 111.7 pg/ml for interleukin‐8 showed a sensitivity of 78% and a specificity of 91%. Conclusion: While cord blood levels of interleukin‐6 appear to be related to pathological conditions in the perinatal period (infectious and non‐infectious), interleukin‐8 seems to be a good predictor of early bacterial neonatal infection.