Increased levels of tumor necrosis factor alpha (TNF-alpha) and interleukin 1 beta (IL-1 beta) in tracheal aspirates of newborns with pneumonia.

Pneumonia is one of the major sites of infection in ventilated newborns. We investigated whether the cytokines IL-1 beta and TNF-alpha are detectable in tracheal aspirates of newborns with pneumonia as a diagnostic marker. All 12 infants with pneumonia had elevated levels of IL-1 beta (range 30-300 pg/ml) and TNF-alpha (range 60-680 pg/ml), whereas control infants (n = 21; respiratory distress syndrome, very low birth weight or infants intubated preoperatively) had no detectable levels of IL-1 beta or TNF-alpha. In vitro investigations with mononuclear cells of umbilical cord blood were performed to rule out that exogenously added surfactant influences IL-1 beta and TNF-alpha production. It is concluded that IL-1 beta and TNF-alpha are important and specific mediators of neonatal pneumonia which may be of diagnostic importance.