Cord blood levels of cytokines as predictors of early neonatal sepsis.

Aim: To investigate whether cord blood levels of C-reactive protein, interleukin-1beta, interleukin-6, interleukin-8, tumour necrosis factor-alpha 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-1beta, tumour necrosis factor-alpha 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.