Interleukin-16 in tracheal aspirate fluids of newborn infants.
BACKGROUND
It is currently unknown if interleukin (IL)-16 exists in the lungs of ventilated infants, and because the predominant cells in the airways of infants with CLD are CD4+ macrophages, we hypothesized that IL-16 plays a role as a pro-inflammatory mediator in lung inflammation.


OBJECTIVE
To examine if IL-16, a chemoattractant for CD4+ cells, is detectable in airway secretions of ventilated newborns. Its presence may be associated with lung inflammatory responses.


METHODS
Cohort cross-sectional study.


METHODS
Thirty-four mechanically ventilated newborn infants.


METHODS
Tracheal fluid (TF) specimens collected during the first month of life were examined for cell differentials determined from cytospin slides and supernatant was analyzed by ELISA for IL-16.


RESULTS
Eighty-three cross-sectional tracheal fluid (TF) specimens were analyzed. Eleven of the 27 preterm but none of the 7 term infants developed chronic lung disease (CLD). IL-16, ranging from 203 to 42,073 pg/ml, was detected in 16 of the 46 specimens obtained from CLD infants, 1 of the 30 specimens from 16 non-CLD preterm and 2 of the 7 specimens from 7 term infants (p<0.001). Leukocyte counts (median 16.6 vs. 2.0 x 10(-9)/l, p<0.0001) and percentage neutrophils (median 93% vs. 73%, p<0.001) were higher in IL-16 positive specimens.


CONCLUSIONS
IL-16 is detectable within the airway secretions of ventilated newborn infants and its presence is associated with a neutrophilic infiltration. Further studies are required to investigate its role in chronic inflammation in CLD.
Wang
He
H
School of Women's and Children's Health, University of New South Wales, Kensington, NSW, Australia.
Oei
Julee
J
Lui
Kei
K
Henry
Richard
R
D001826:Body Fluids / Q000737:chemistry / Q000166:cytology / Q000378:metabolism; D015331:Cohort Studies; D003430:Cross-Sectional Studies; D004797:Enzyme-Linked Immunosorbent Assay; D006801:Humans; D007231:Infant, Newborn; D007234:Infant, Premature; D019410:Interleukin-16 / Q000032:analysis / Q000378:metabolism*; D007958:Leukocyte Count; D009504:Neutrophils / Q000473:pathology; D010865:Pilot Projects; D029424:Pulmonary Disease, Chronic Obstructive / Q000209:etiology / Q000378:metabolism / Q000473:pathology; D012123:Pulmonary Ventilation; D012121:Respiration, Artificial; D014132:Trachea / Q000378:metabolism* / Q000473:pathology
D019410:Interleukin-16