Secretory leukocyte protease inhibitor and lung inflammation in developing bronchopulmonary dysplasia.
OBJECTIVE
To investigate secretory leukocyte protease inhibitor (SLPI) concentrations in tracheal lavage fluids of neonates with an endotracheal tube in place during the first month of life, and to evaluate the relationship of SLPI to neutrophil counts and elastase activity in patients in whom bronchopulmonary dysplasia (BPD) developed versus those in whom it did not.


METHODS
A prospective, inception cohort study.


METHODS
University children's hospital neonatal intensive care unit.


METHODS
Fifty-three neonates who weighed < 2000 gm at birth, and who had an endotracheal tube in place, were enrolled. Forth-one patients survived to 28 days; BPD developed in 24 but not in 17 patients.


METHODS
Tracheal lavage was performed on days 1, 2, 4, 7, 14, 21, and 28, and analyzed for neutrophils, elastase activity, and SLPI. Results were evaluated longitudinally for 28 days, and were compared between BPD and no-BPD groups during the first week.


RESULTS
SLPI concentrations increased significantly for all patients during the study period. During the first week, SLPI concentrations were similar between BPD and no-BPD groups; neutrophil counts and elastase activity were higher in the BPD group.


CONCLUSIONS
Patients in whom BPD ultimately developed had early evidence of increased pulmonary inflammation and a significantly less favorable protease-antiprotease balance. If elastase-induced injury contributes to the development of BPD, early therapy with recombinant SLPI might be beneficial by increasing the antielastase capacity of epithelial lining fluid.
Watterberg
K L
KL
Department of Pediatrics, Milton S. Hershey Medical Center, PA 17033.
Carmichael
D F
DF
Gerdes
J S
JS
Werner
S
S
Backstrom
C
C
Murphy
S
S
D001992:Bronchoalveolar Lavage Fluid / Q000276:immunology; D001997:Bronchopulmonary Dysplasia / Q000201:enzymology* / Q000276:immunology; D006801:Humans; D007230:Infant, Low Birth Weight; D007231:Infant, Newborn; D007958:Leukocyte Count; D007962:Leukocytes / Q000201:enzymology*; D008168:Lung / Q000201:enzymology / Q000276:immunology*; D009504:Neutrophils; D010196:Pancreatic Elastase / Q000378:metabolism; D011014:Pneumonia / Q000201:enzymology / Q000276:immunology; D011446:Prospective Studies; D053491:Proteinase Inhibitory Proteins, Secretory; D011506:Proteins; D053481:Secretory Leukocyte Peptidase Inhibitor; D015842:Serine Proteinase Inhibitors / Q000032:analysis*; D000515:alpha 1-Antitrypsin / Q000032:analysis
D053491:Proteinase Inhibitory Proteins, Secretory; D011506:Proteins; C506814:SLPI protein, human; D053481:Secretory Leukocyte Peptidase Inhibitor; D015842:Serine Proteinase Inhibitors; D000515:alpha 1-Antitrypsin; D010196:Pancreatic Elastase