[Airway neutrophils apoptosis in children with severe asthma].
OBJECTIVE
To investigate the changes of neutrophils in airway inflammation in children with severe asthma.


METHODS
Children with mild to moderate asthma (n=23), severe asthma (n=16) and healthy control subjects (n=16) underwent lung function tests and sputum induction. The sputum specimens were assayed for cellular differential count, the supernatant and peripheral blood were assayed for the concentrations of IL-8 by "sandwich" enzyme linked immunosorbent assay (ELISA). Sputum supernatant, IL-8 and mifepristone were assessed for their abilities to prolong the in vitro survival of blood-derived neutrophils.


RESULTS
The percentage of sputum neutrophils was significantly higher in severe asthmatics [59.54 (41.99-74.65)%] than mild-moderate asthmatics [30.03 (15.94-47.71)%] and healthy control subjects [29.72(16.53-45.74)%] (P < 0. 01); the level of IL-8 in sputum was significantly higher in severe asthmatics [2907.78 (331.67 - 3457.93) ng/L] than mild-moderate asthmatics [287.58 (130.75-656.84) ng/L] and healthy control subjects [179.2 (58.55-346.59) ng/L] (P < 0.01); the percentages of neutrophilic apoptosis respectively cultured with LPS [(10.57 +/- 1.97)%], severe asthmatics supernatant [(11.82 +/- 2.96)%], IL-8 [(10.47 +/- 1.93)%], dexamethasone [(9.93 +/- 1.95)%], severe asthma supernatant + mifepristone [(12.15 +/- 2.86)%] in vitro were lower than that cultured with PBS [(17.98 +/- 2.27)%], healthy control supernatant [(17.37 +/- 2.50)%], mild-moderate asthmatics supernatant [(16.35 +/- 3.26)%], mifepristone [(17.89 +/- 2.38)%], and dexamethasone + mifepristone [(17.06 +/- 2.59)%] (P < 0.01).


CONCLUSIONS
Suppression of neutrophilic apoptosis seems to play a potential role in airway neutrophilic inflammation in severe asthmatics, and the level of IL-8 in sputum was significantly higher in patients with severe asthmatics.
Liao
Jing
J
Department of Pediatrics, the First Affiliated Hospital, Guangxi Medical University, Nanning 530021, China.
Nong
Guang-min
GM
Jiang
Min
M
Zhang
Yu-xian
YX
Liang
Xiu-an
XA
Liu
Jing
J
D000293:Adolescent; D017209:Apoptosis; D001249:Asthma / Q000378:metabolism* / Q000473:pathology* / Q000503:physiopathology; D016022:Case-Control Studies; D002648:Child; D005260:Female; D006801:Humans; D007249:Inflammation; D016209:Interleukin-8 / Q000378:metabolism; D007958:Leukocyte Count; D008297:Male; D009504:Neutrophils / Q000166:cytology*; D012137:Respiratory System / Q000378:metabolism / Q000473:pathology; D013183:Sputum / Q000378:metabolism
D016209:Interleukin-8