Characterisation of the cytokine inflammatory response in LPS stimulated full-term cord blood.

OBJECTIVE

Abnormal inflammatory responses are implicated in the pathogenesis of neonatal disease. This study aimed to describe the neonatal cytokine response using an in vitro model of stimulated cord blood.

METHODS

Cord blood samples (n = 12) were incubated in RPMI 1640 medium with and without lipopolysaccharide. Concentrations of tumor necrosis factor (TNF)-alpha, interleukin (IL)-6, IL-8, interferon (IFN)-gamma and IL-10 were determined by multiplex immunoassay at 0, 1, 3, 6 and 24 hours of incubation. The difference between stimulated and control response was defined as the potential secretory capacity (mean +/- S.E.M.; pg/million white cells). Analysis included a Kruskal-Wallis test and post-hoc Mann-Whitney U test.

RESULTS

All cytokine capacities increased rapidly by 1 hour (p<0.001), except IL-10 (p=0.04). TNF-alpha peaked between 3-6 hours (1581 +/- 377 pg/million WC), declining by 24 hours. Similarly, IFN-gamma peaked at 3 hours. Capacity ascended throughout the incubation period for IL-6, IL-8 (631 +/- 75 pg/million WC) and IL-10 (311 +/- 37 pg/million WC). Overall, IFN-gamma capacity was lowest (72 +/- 10 pg/million WC) and IL-6 capacity was greatest (61489 +/- 7059 pg/million WC).

CONCLUSION

The neonatal inflammatory response is chronologically similar to that determined in adults. Immature neonatal T-cell function may account for the lower IFN-gamma production. These results may expand our knowledge of neonatal disease, etiology and management.