Inflammatory markers in COPD

Chronic obstructive pulmonary disease (COPD) is identified as an inflammatory disorder characterised by airway and lung inflammation and destruction with systemic involvement of multiple organ systems. The inflammatory reaction could be monitored not only in the airways by the use of bronchoalveolar lavage (BAL), sputum, exhaled air, and exhaled breath condensate but also in blood and urine as well as in tissue obtained at surgery or autopsy. There is a large number of cytokines, chemoattractants and other mediators that are of importance for the interplay of inflammatory mechanisms in COPD. Neutrophilic granulocytes are key players in the inflammatory reaction and the most important chemoattractants for these cells seem to be IL-8 (CXCL8) and leukotriene B(4) (LTB(4)). Also, the macrophages and chemoattractants for mononuclear cells (CCL2, CCL3) are of importance as are T-lymphocytes, predominantly of the cytotoxic subtype (CD8+). Analyses in exhaled breath condensates and exhaled air have not been tremendously encouraging but there is a clear space for further development in this field within the near future. Blood markers, such as IL-6, CRP, and fibrinogen, have attracted interest during recent years, and further studies in this area will probably increase the understanding of systemic manifestations in COPD, in particular, regarding co-morbidity with cardiovascular disease.