Figure 1.

The concentration of sHLA-I molecules in blood serum and exhaled breath condensate in COPD patients during the exacerbation and in the stable period. Data are presented as mean ± SD. Control: healthy nonsmoking volunteers, II: moderate COPD, III: severe COPD, ex: exacerbation, and st: stable phase. ∗p < 0.05 versus healthy nonsmokers, #p < 0.05 versus patients with moderate COPD during the exacerbation, ∨p < 0.05 versus patients with moderate COPD in the stable phase, and ^p < 0.05 versus patients with severe COPD during the exacerbation.