Abstract
In COPD severity of disease is generally diagnosed by the GOLD guidelines. The GOLD stages, however, poorly correlate with disease progression. The extend of systemic inflammation in COPD patients plays a role in the progression of the disease Therefore, the severity of the systemic inflammatory response of COPD patients was characterized by phenotyping of blood neutrophils.
51 COPD patients (GOLD I – IV), and 14 healthy smokers were included in the study. The expression of activation epitopes on neutrophils was analyzed by flow cytometry. Responsiveness for fMLF was measured by analysis of cells in the presence or absence fMLF.
Responsiveness of neutrophils for fMLF, expressed as the ratio of CD11b in the presence and absence of fMLF, identified two distinct COPD patient populations. Phenotype 1 (55%) was comparable to the healthy smokers and phenotype II (45%), showed a significantly higher mean ratio of 17.24. ± 0.78 vs. 5.6±0.53, respectively: These two groups did not differ in FEV1, but a higher expression of CD181 was found in group II compared to group I: 207.5.± 10.24 vs. 154.5±8.9, respectively (p<0.001). Similar data were found for CD66b, CD33, CD64 and active FcγRII on neutrophils.
Two distinct groups of COPD patients were identified by determining the responsiveness of their neutrophils for fMLF. This was associated with differences in expression of several neutrophil activation markers. These findings demonstrate a higher systemic inflammation in patients with phenotype II. It is tempting to speculate that these patients will have a faster disease progression.
- © 2011 ERS