[Change in airway anaphylatoxin-complement factors C3a of sputum in patients with chronic obstructive pulmonary...

To investigate the possible role of anaphylatoxin(C3a) in chronic obstructive pulmonary disease (COPD).

Sixty-four elderly patients with COPD (including 51 males, 13 females, 31 with acute exacerbation of COPD and 33 with stable COPD) and 25 healthy controls were recruited in the study. The levels of C3a in the serum of centrifugated induced sputum and cell differential count in sendiment were determined.

The level of C3a [44.2 (13.2-48.5) μg/L] in induced sputum in acute exacerbation of COPD was significantly higher than those in the stable COPD [5.5 (3.6-20.7) μg/L, Z=-2.974, P=0.003] and the controls [1.7 (0.1-5.9) μg/L, Z=-3.145, P=0.002]. The level of C3a in the stable COPD was higher than that in the healthy subjects, but the statistical difference was not significant. The C3a levels in smokers and non-smokers of the healthy controls were 1.97 (0.12-6.27) μg/L and 1.36 (0.09-5.57) μg/L, respectively, and had no difference (P>0.05). The level of C3a in induced sputum was positively correlated with the number of total leukocytes (r=0.543, P<0.05).

C3a in induced sputum is significantly increased in COPD, and its high level correlates with the advanced stage of the disease, which suggests a possible role of C3a in the pathogenesis of COPD.