[Reversed changes of the 15-lipoxygenase product lipoxin A₄ and the 5-lipoxygenase product leukotriene C₄ in children with asthma].
OBJECTIVE
To investigate the expressions of 15- and 5-lipoxygenases in leukocytes and the changes of the levels of blood lipoxin A₄ (LXA₄) and leukotriene C₄ (LTC₄) in children with asthma.


METHODS
The mRNA levels of 15- and 5-lipoxygenases in leukocytes were assessed by RT-PCR, and the levels of blood LXA₄ and LTC₄ were determined by ELISA, in 106 children with mild, moderate and severe asthma. Forty healthy children served as the controls.


RESULTS
In children with mild, moderate and severe asthma, the relative mRNA levels of 15-lipoxygenase in leukocytes were 1.78 ± 0.56, 1.28 ± 0.45 and 0.58 ± 0.22 (F = 16.72, P < 0.01), respectively, and all were higher than that of the controls (0.26 ± 0.12, P < 0.05). The levels of blood LXA₄ were (5.52 ± 1.97), (1.86 ± 0.72) and (0.81 ± 0.36) µg/L (F = 22.59, P < 0.01), respectively, decreasing with the severity of asthma, and all were higher than that of the controls [(0.04 ± 0.01) µg/L, P < 0.05]. There was a positive correlation between PEF, FEV(1) and blood LXA₄. The relative levels of 5-lipoxygenase mRNA in leukocytes were 0.26 ± 0.12, 0.79 ± 0.34 and 1.21 ± 0.52, respectively in children with asthma of mild, moderate and severe degree (F = 18.64, P < 0.01), which showed an increase with the severity of the disease, and all of which were higher than that of the controls (0.12 ± 0.05, P < 0.05). The levels of blood LTC₄ were (22.4 ± 8.2), (54.6 ± 28.4) and (118.7 ± 41.1) ng/L (F = 25.91, P < 0.01), respectively, also showing an increase with the severity of asthma, and were higher than that of the controls [(6.8 ± 2.5) ng/L, P < 0.05]. There was a negative correlation between PEF, FEV₁ and blood LTC₄.


CONCLUSIONS
The reversed changes of 15-lipoxygenase product LXA₄ and 5-lipoxygenase product LTC₄ in children with asthma of mild, moderate and severe degree suggests that insufficiency of LXA₄, an physiological antagonist to leukotrienes, and an overproduction of LTC₄, may be involved in the pathogenesis of worsening of asthma in children.
Yin
Pei-ling
PL
Department of Pediatrics, Nanjing First Hospital Affiliated to Nanjing Medical University, Nanjing 210006, China.
Wu
Sheng-hua
SH
Yao
Wen-jiang
WJ
Wu
Hong-mei
HM
Jiang
Hong-mei
HM
Su
Hong-ping
HP
Xu
Dan
D
Ye
Xiao-lei
XL
D001093:Arachidonate 15-Lipoxygenase / Q000097:blood*; D001094:Arachidonate 5-Lipoxygenase / Q000097:blood*; D001249:Asthma / Q000097:blood*; D016022:Case-Control Studies; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D007223:Infant; D007962:Leukocytes / Q000378:metabolism; D044045:Lipoxins / Q000097:blood*; D008297:Male
D044045:Lipoxins; C040527:lipoxin A4; D001093:Arachidonate 15-Lipoxygenase; D001094:Arachidonate 5-Lipoxygenase