Interleukin-1beta in the bronchoalveolar lavage fluid of premature neonates: a marker for maternal chorioamnionitis and predictor of adverse neonatal outcome.
OBJECTIVE
To determine whether the presence of the proinflammatory cytokine interleukin (IL)-1beta in the lungs of preterm infants immediately after birth was associated with maternal inflammation and could predict adverse neonatal outcome.


METHODS
Prospective evaluation of serially obtained tracheal aspirates for the presence of IL-1beta in 25 preterm infants (birth weight 595-1700 g; gestational age 24-32 weeks) with respiratory distress syndrome. The initial tracheal aspirate was obtained within 1 h after delivery.


RESULTS
An initial tracheal aspirate positive for IL-1beta had a highly significant correlation with documented maternal chorioamnionitis for the given patient. In addition, the presence of IL-1beta correlated significantly with elevated total cell count (2.62 vs. 0.96 x 10(6)/ml, p = 0.0097), granulocyte count (2.12 vs. 0.22 x 10(6)/ml, p = 0.001), macrophage count (0.28 vs. 0.01 x 10(6)/ml, p = 0.02) and the presence of proinflammatory cytokines IL-6, IL-8 and tumor necrosis factor (TNF)-alpha. Preterm neonates positive for IL-1beta in their initial sample were on prolonged assisted ventilation (38 vs. 16 days, p = 0.013) and oxygen supplementation (62 vs. 40.5 days, p = 0.0462) and required prolonged hospitalization (69 vs. 46 days, p = 0.0165).


CONCLUSIONS
The concentration of IL-1beta in the initial tracheal aspirate obtained from the lungs of preterm infants within the first hour of life may serve as a marker of antenatal/perinatal inflammation, probably due to maternal chorioamnionitis, and could predict an adverse clinical course and short-term outcome.
Cayabyab
R G
RG
Division of Neonatology and Allergy/Immunology, Department of Pediatrics, Women's and Children's Hospital, LAC and USC Medical Center, University of Southern California School of Medicine, Los Angeles, California 90033, USA.
Jones
C A
CA
Kwong
K Y C
KY
Hendershott
C
C
Lecart
C
C
Minoo
P
P
Ramanathan
R
R
D015415:Biomarkers / Q000032:analysis; D001992:Bronchoalveolar Lavage Fluid / Q000166:cytology*; D002585:Cesarean Section / Q000706:statistics & numerical data; D002821:Chorioamnionitis / Q000276:immunology*; D016207:Cytokines / Q000378:metabolism; D005260:Female; D006801:Humans; D007231:Infant, Newborn; D007234:Infant, Premature / Q000378:metabolism*; D007375:Interleukin-1 / Q000378:metabolism*; D007442:Intubation, Intratracheal; D007902:Length of Stay / Q000706:statistics & numerical data; D008297:Male; D017063:Outcome Assessment, Health Care; D010102:Oxygen Inhalation Therapy; D011247:Pregnancy; D011446:Prospective Studies; D012121:Respiration, Artificial; D012127:Respiratory Distress Syndrome, Newborn / Q000276:immunology / Q000378:metabolism
D015415:Biomarkers; D016207:Cytokines; D007375:Interleukin-1