The relationship between inflammation and dipalmitoyl phosphatidycholine in induced sputum of children with asthma.
BACKGROUND
Animal studies have shown elevated surfactant production in response to lung injury. In human airways, the contribution of surfactant to the airway epithelial barrier and importance of eosinophilic inflammation is increasingly appreciated. The relationship between blood and sputum inflammatory indices of childhood asthma to surfactant levels is unknown. In this study we hypothesized that the degree of inflammation influences the level of dipalmitoyl phosphatidycholine (DPPC) in airways of children with asthma.


METHODS
Sixteen children with asthma (ages 5.5-16 years) underwent venipuncture, skin prick test, spirometry, hypertonic saline challenge, and induced sputum during a nonacute phase. Sputum (sp) and blood (se) markers of inflammation (eosinophils, neutrophils, eosinophilic cationic protein [ECP]), were related to sputum DPPC levels and several markers of asthma severity (airway hyperresponsiveness, quality of life, FEV1).


RESULTS
On multiple regression, sp-DPPC significantly correlated to sp-ECP (r=0.53, P=0.0048). Se-ECP, se-Eo, sp-eosinophils, sp-neutrophils, se-neutrophils, and inhaled steroids dose did not significantly influence sp-DPPC. Exposure to smoke did not influence inflammatory markers. FEV1 and quality of life data did not relate to any blood or sputum variable. A significant association between AHR and se-eosinophils, but not between AHR and se-ECP, sp-eosinophils, or sp-ECP was found.


CONCLUSIONS
Elevated DPPC levels occur in the presence of chronic eosinophilic inflammation in airways of children with stable asthma. Whether this represents an inherent lung mechanism for epithelial protection remains to be elucidated.
Chang
Anne B
AB
Flinders University Northern Territory Clinical School, Alice Springs Hospital, Northern Territory, Australia. abchang@mac.com
Gibson
P G
PG
Masters
I B
IB
Dash
P
P
Hills
B A
BA
D015060:1,2-Dipalmitoylphosphatidylcholine / Q000378:metabolism*; D000293:Adolescent; D001249:Asthma / Q000378:metabolism* / Q000473:pathology; D001798:Blood Proteins / Q000378:metabolism; D002648:Child; D002675:Child, Preschool; D047091:Eosinophil Granule Proteins; D004804:Eosinophils / Q000378:metabolism; D005260:Female; D006801:Humans; D018836:Inflammation Mediators / Q000097:blood*; D008297:Male; D012260:Ribonucleases; D012882:Skin Tests; D013183:Sputum / Q000737:chemistry*
D001798:Blood Proteins; D047091:Eosinophil Granule Proteins; D018836:Inflammation Mediators; D015060:1,2-Dipalmitoylphosphatidylcholine; D012260:Ribonucleases