[A study on the relevance of airway inflammatory indices in induced sputum and airway hyperresponsiveness in asthmatics].
OBJECTIVE
To analyze the correlations between NO(3)(-)/NO(2)(-), eosinophil counts in induced sputum and airway hyperresponsiveness (AHR) and therefore to explore the clinical significance of these parameters in severity assessment and medication adjustment in patients with mild to moderate asthma.


METHODS
From February 2003 to June 2004, 35 outpatients with mild to moderate persistent asthma (mild: 9, moderate: 26) from Huaxi Hospital asthma clinic were treated with combined medications of inhaled corticosteroids (ICS) plus long-acting beta(2) agonist (LABA) for one year. The symptom scores were recorded, and AHR (represented by PC(35)sGaw), eosinophil counts and NO(3)(-)/NO(2)(-) concentrations in induced sputum were measured at regular intervals. Fifteen healthy volunteers served as control and eosinophil counts and NO(3)(-)/NO(2)(-) concentrations in induced sputum were measured.


RESULTS
A total of 35 subjects were enrolled, of whom 26 completed one-year or longer follow-up. PC(35)sGaw of 26 subjects before treatment was 0.08 g/L, which became 1.40 g/L at the third months, and then maintained at a very low level (2.64 g/L) after the seventh month. NO(3)(-)/NO(2)(-) decreased from [(734 +/- 72) x 10(-3) g/L] to [(230 +/- 41) x 10(-3) g/L] by the third month (q = 6.26, P < 0.05), and [(137 +/- 27) x 10(-3) g/L] by the seventh month, which showed no significant difference with normal control (136 +/- 20) x 10(-3) g/L, q = 3.77, P > 0.05). Eosinophil counts decreased from (0.016 +/- 0.008) to (0.014 +/- 0.007) by the third month, which was not significantly different from normal control (q = 2.94, P > 0.05). In the first fifth months the concentration of NO(3)(-)/NO(2)(-) in induced sputum exhibited a significant negative correlation with PC(35)sGaw (r(1) = -0.872, r(2) = -0.653, r(3) = -0.639, r(4) = -0.656, all P < 0.05). But eosinophil counts had no correlation with PC(35)sGaw in the first three months (r(1) = 0.237, r(2) = 0.536, r(3) = 0.675, all P > 0.05).


CONCLUSIONS
The parameters related to airway inflammation including PC(35)sGaw and sputum NO(3)(-)/NO(2)(-) may be useful in assessing asthma severity, evaluating the efficacy of treatment and adjusting medication regimens.
Pang
Ya-min
YM
Department of Respiratory Medicine, West China Hospital, Sichuan University, Chengdu 610041, China.
Liu
Chun-tao
CT
Tan
Cheng-wu
CW
Wang
Gang
G
D000293:Adolescent; D000328:Adult; D001249:Asthma / Q000503:physiopathology*; D016022:Case-Control Studies; D004804:Eosinophils; D005260:Female; D006801:Humans; D007249:Inflammation; D008297:Male; D008875:Middle Aged; D009566:Nitrates / Q000032:analysis; D009573:Nitrites / Q000032:analysis; D012137:Respiratory System; D013183:Sputum / Q000737:chemistry*; D055815:Young Adult
D009566:Nitrates; D009573:Nitrites