The modulatory effect of lipids and glucose on the neonatal immune response induced by Staphylococcus epidermidis.

BACKGROUND: Parenteral nutrition is an important risk factor for late onset sepsis in neonates. This may be caused by the long-term need of central venous access but also through a potentially modulating effect of lipids and glucose on the immune function. OBJECTIVE: It was the aim of this study to characterize the effect of lipids and glucose on the neonatal immune response in an in vitro Staphylococcus epidermidis sepsis model using whole cord blood of healthy term infants and preterm infants. RESULTS: At the single cell level, IL-6, IL-8 and TNF-α expression of CD14+ cells was significantly increased upon addition of 1% lipids, while the addition of clinically meaningful lipid concentrations had no remarkable effect. When glucose was added to whole cord blood cultures, a dose-dependent effect was demonstrated for IL-8 expression but not for other cytokines. CONCLUSIONS: These in vitro data suggest that the proinflammatory cytokine response to S. epidermidis may be modulated by lipids and glucose. Further studies are needed to investigate whether these findings are applicable to clinical settings and to evaluate the role of cytokine monitoring in infants receiving long-term parenteral nutrition.

Does the enteral feeding advancement affect short-term outcomes in very low birth weight infants?

BACKGROUND AND OBJECTIVES: Controversy exists regarding the optimal enteral feeding regimen of very low birth weight infants (VLBW). Rapid advancement of enteral feeding has been associated with an increased rate of necrotizing enterocolitis. In contrast, delaying enteral feeding may have unfavorable effects on nutrition, growth, and neurodevelopment. The aim is to compare the short-term outcomes of VLBW infants in tertiary care centers according to their enteral feeding advancement. PATIENTS AND METHODS: We prospectively studied the influence of center-specific enteral feeding advancement in 1430 VLBW infants recruited from 13 tertiary neonatal intensive care units in Germany on short-term outcome parameters. The centers were post hoc stratified to "rapid advancement to full enteral feeds" (median duration of advancement to full enteral feeds < or =12.5 days; 6 centers), that is, rapid advancement (RA), or "slow advancement to full enteral feeds" (median duration of advancement to full enteral feeds >12.5 days; 7 centers), that is, slow advancement (SA). RESULTS: VLBW infants born in centers with SA (n = 713) had a significantly higher rate of sepsis compared with VLBW infants born in centers with RA (n = 717), which was particularly evident for late-onset sepsis (14.0% vs 20.4%; P = 0.002). Furthermore, more central venous lines (48.6% vs 31.1%, P < 0.001) and antibiotics (92.4% vs 77.7%, P < 0.001) were used in centers with SA. CONCLUSIONS: Center differences in enteral feeding advancement occur and may have a significant impact on short-term outcomes such as nosocomial sepsis. Large, multicenter, prospective trials are required to further elucidate the optimal feeding strategy for VLBW infants.

Thrombopoietin production in human hepatic cell cultures (HepG2) is resistant to IFN-alpha, IFN-beta, and IFN-gamma treatment.

Thrombocytopenia is an important complication of interferon (IFN) therapy for chronic viral hepatitis. To study whether IFN interferes with hepatic thrombopoietin (TPO) synthesis, we used the human hepatoma cell line HepG2. Our results show that IFN-alpha, IFN-beta, or IFN-gamma did not impair TPO mRNA expression, as determined by quantitative RT-PCR, even when high IFN doses (up to 5000 U/ml) or long-term incubations (up to 14 days) were applied. Neither was the rate of secretion of immunoreactive TPO reduced on IFN treatment. These findings support the concept that IFNs primarily mediate effects on megakaryocytic cells and platelets rather than on TPO-producing hepatocytes.