Table 2 Controlled human exposure studies in patients with obstructive airway diseases.
From: Controlled human exposures to ambient pollutant particles in susceptible populations
Study | Subject (number) | Design | Particles | Results |
|---|---|---|---|---|
Gong et al [26] | Healthy volunteers (12) Patients with mild asthma (12) | Crossover | Filtered air, Fine CAPS (174 μg/m3) | CAPS induced modest and similar increases in parasympathetic stimulation of HRV in both groups |
Gong et al [42] | Healthy elderly, age (6) Elderly patients with COPD (13) | Crossover | Filtered air, Fine CAPS (200 μg/m3) | Decrease in HRV in healthy elderly but not in COPD patients |
Frampton et al [40] | Healthy volunteers (40), Patients with asthma (16) | Crossover | Filtered air Ultrafine carbon particles (10, 25 and 50 μg/m3) | In healthy subjects, reduced CD54 and CD18 on monocytes; decreased CD18 and CD49d on granulocytes; decreased CD25 in blood monocytes, basophils, and eosinophils; increased lymphocyte expression of CD25. In asthma, reduced CD11b on monocytes and eosinophils, CD54 on granulocytes, the percentage of CD4+ T cells, basophils, and eosinophils |
Piatropaoli et al [41] | Healthy volunteers (40), Patients with asthma (16) | Crossover | Filtered air Ultrafine carbon particles (10, 25 and 50 μg/m3) | No changes in airway eNO and total cell count/differentials in induced sputum; Increased percentage macrophages in the sputum of asthmatics; No changes in IL-6 and IL-8 in the sputum |
Gong et al [67] | Healthy volunteers (4) Patients with mild asthma (12) | Crossover | Filtered air Coarse CAPS (157 μg/m3) | Decrease HR and PNN50 4 hours post-exposure |
Stenfors et al [43] | Healthy volunteers (25) Patients with mild asthma (15) | Single-blind randomized crossover | Filtered air Diesel exhaust (PM10, 108 μg/m3) | Increased neutrophils, IL-8 and IL-6 in BAL fluid and P-selectin and VCAM-1 in bronchial biopsy, no difference between normal and asthmatics |
Gong et al [44] | Healthy volunteers (14) Patients with mild asthma (17) | Crossover | Filtered air Ultrafine CAPS (100 μg/m3 or 145,000/cm3 particle counts | Decreased O2sat, FEV1 and low frequency power; no differences between normal and asthmatics |