Table 3: Changes of EBC biomarkers in chronic obstructive pulmonary disease (COPD).

BiomarkersStable COPDAECOPD

pH [132], and after treatment [145]
[57, 132, 134], correlated with FEV1 [57]
, correlated with GOLD stage, IC/TLC, RV/TLC, and CO diffusing capacity, only in ex-smokers [134]

H2O2 [135137] , and after treatment [146]

Aldehydes
 (MDA, hexanal, heptanal) [138, 139]
[140]

8-Isoprostane [136, 141, 142] , and after treatment [146]
High variability within day and between days [143]

LTs
 LTB4 [16, 141, 152], correlated with CO diffusing capacity [146, 147], and after treatment [146]
, and after recovery [152]
 LTE4Undetectable [16]
High variability within day and between days [143]
 Cys-LTs [3]

PGs
 PGE2, PGF2 (compared to asthmatic patients) [16]

Acute phase response
 AAT, MMP-9, TIMP-1 [150, 151]
Neutrophilic inflammation
 IL-1β, IL-12 [52]
 IL-1a, IL-1β, Dominant protein type (62%) [144]
 IL-2, IL-12a, IL-1β, IL-6,
 IL-12β, IL-15,IL-8, IL-10,   [52, 148, 149]
 INF-α, INF-γ, IL-12, TNF-a
 TNF-a, C3
 NCA, GRO-a, and after treatment (only in outpatients) [152]

Nitrites [149]

α1-antitrypsin,
SP-A1, SP-A2,
S-100 calgranulins
Detected in COPD, but not in A1AD patients [144]

IL-1α,
lysozyme-C
Detected in A1AD, but not in the other COPD patients [144]

sHLA-1, sCD95,
SLP-1, MPO
[153, 154]

Nucleic acids of
 influenza virus, RSV, L. pneumophila Detected [155]

= increase, = reduction, = no significant change, and [] = corresponding reference.
AECOPD = acute exacerbation of COPD, FEV1 = forced expiratory volume at 1 sec, IC = inspiratory capacity, TLC = total lung capacity, RV = residual volume, CO = carbon monoxide, MDA = malondialdehyde, H2O2 = hydrogen peroxide, LTs = leukotrienes, PGs = prostaglandins, ILs = interleukins, INF = interferon, TNF-a = tumour necrosis factor-a, C3 = complement fraction 3, NCA = neutrophil chemotactic activity, AAT = a1-antitrypsin antiprotease, MMP-9 = metalloproteinase-9, TIMP-1 = metalloproteinase-1 inhibitor, SPs = surfactant proteins, s = solute, SLP-1 = secretory leukocyte protease inhibitor-1, MPO = myeloperoxidase, RSV = respiratory syncytial virus, and L. pneumophila = Legionella pneumophila.