Canadian Health&Care Mall: Results of Airway Inflammation During Severe Exacerbations of COPD
We studied 1 female and 11 male COPD patients (mean ± SD; FEV1 40 ± 14% predicted; mean age, 69 ± 7 years) who were ex-smokers with a mean smoking history of 68 ± 23 pack-years (Table 1). All patients had negative results of skin-prick reaction tests and radioallergosorbent tests for a battery of common allergens. Patients’ exacerbation and stable-state characteristics are given in Table 1. A clear deterioration in cough, sputum, and blood gas analysis was observed in all subjects during an exacerbation. In addition, patients were unable to perform acceptable spirometry during an exacerbation. All patients showed acute respiratory failure at the time of the exacerbation (Po2, < 60 mm Hg) [Table 1]. Five patients had positive sputum culture results during exacerbations (for Streptococcus pneumoniae, three patients; for Pseudomonas aeruginosa, two patients). Chest radiographs at the time of exacerbation did not reveal pneumonia or pneumothorax in any patient.
The median viability of cells recovered by sputum processing was 89% (range, 59 to 99%) during exacerbation and 89% (range, 63 to 98%) in the stable state. The percentage of squamous epithelial cells among total cells was 0.2% (range, 0.04 to 1%) during exacerbation and 1.3% (range, 0.1 to 4.7%) in the stable state. No statistically significant difference was observed in cell viability or squamous cell contamination between samples obtained from patients during an exacerbation and while in the stable state, The volume of sputum obtained from COPD patients during an exacerbation was greater than that taken while in the stable state. However, this does not affect our analysis, because the results were expressed as the number of cells per gram of sputum, and levels of mediators were expressed per gram of sputum. Table 2 shows sputum cellularity in both states. The percentages of neutrophils were significantly higher during exacerbations (p = 0.002), and the percentages of macrophages were significantly higher in the stable state (p = 0.003). No statistically significant difference was observed in total nonsquamous cell count, eosinophil count, or lymphocyte count.
Fluid-Phase Inflammatory Mediators, and Cellular iNOS, Nitrotyrosine, and HO-1 Expressions
Levels of soluble mediators during exacerbation and in the stable state are shown in Table 3. MPO and IL-8 levels were increased during exacerbation (p = 0.005) when compared to the stable state (p = 0.028) [Table 3, Fig 1]. The mean values of GM-CSF (p > 0.09) and ECP (p > 0.16) were also increased, although not significantly (Table 3). We will be glad to greet you at our web site – http://healthcaremall4you.com/ Canadian health&care mall news website.
Percentages and absolute counts of iNOS, nitroty-rosine, and HO-1 positive (+ve) polymorphonuclear cells and macrophages are shown in Table 4. The percentages of nitrotyrosine +ve (p = 0.001) and HO-1 +ve (p = 0.004) inflammatory cells were significantly increased during exacerbations (Fig 2). When absolute counts of immunoreactive cells were compared, increased numbers of nitrotyrosine +ve inflammatory cells (p = 0.028) and marginally increased numbers of HO-1 +ve inflammatory cells (p = 0.05) were found during exacerbations compared to those found in the stable state (Fig 2). Total percentages and absolute counts of sputum iNOS +ve inflammatory cells were not significantly increased on exacerbation.
Changes in the level of soluble markers and in immunopositive cell counts did not differ between patients with documented bacterial infection during exacerbation (n = 5) or not (n = 7). No significant correlation was found between changes in absolute cell counts and changes in levels of cell chemoattrac-tants (ie, IL-8 and GM-CSF) during exacerbation.
Figure 1. Sputum MPO and IL-8 levels in samples obtained from patients in an exacerbation state (ES) and in stable state (SS).
Figure 2. Top: percentages of nitrotyrosine +ve inflammatory cells (ie, polymorphonuclear cells and macrophages) and HO-1 +ve inflammatory cells in samples obtained from patients in the exacerbation state and in the stable state. Bottom: absolute number of nitrotyrosine +ve inflammatory cells and HO-1 +ve inflammatory cells in samples obtained from patients in the exacerbation state and in the stable state (SS). See Figure 1 for abbreviations not used in the text.
Table 1—Characteristics of the Subjects During Exacerbation and in the Stable State
|FEV1, % predicted||40 ± 14|
|FEVj/FVC, % predicted||53 ± 11|
|AFEVj, %||4 (-4, 9)i|
|Pao2, mm Hg||51 ± 7||72 ± 11Л|
|Paco2, mm Hg||53 ± 8||39 ± 5Л|
|Purulent sputum, No.||6/12||0/12|
|Dyspnea at rest, No.||11/12||3/12|
Table 2—Total Nonsquamous Cell Count, Neutrophil, Macrophage, Eosinophil, and Lymphocyte Count
|Total cell count, X106 cells/g||38 (6, 100)||23.5 (6, 77)|
|ac X 106 cells/g||35.9 (14.9, 95)||18 (5.9, 68.5)|
|%||98 (90, 100)||83.5 (56, 99)i|
|ac X 106 cells/g||0.5 (0, 5)||2.9 (0, 18.9)i|
|%||1 (0, 8)||13.5 (0, 42)i|
|ac X 106 cells/g||0 (0, 0.5)||0.03 (0, 2.5)|
|%||0 (0, 2)||0.25 (0, 4)|
|ac X 106 cells/g||0.2 (0, 0.9)||0.15 (0, 1.3)|
|%||0.75 (0, 2)||1 (0, 2)|
Table 3—Sputum ECP, MPO, IL-8, and ECP Levels
|ECP Mgg||6.3 (1, 15.9)||3.5 (0.2, 9.4)|
|MPO, JLXg/g||39.9 (4.5, 64)||11.9 (1, 21.7)t|
|IL-8, ng/g||24.8 (1.5, 49)||4.9 (2.2, 37)t|
|GM-CSF, pg/g||110 (0, 1,010)||35.8 (0, 142)|
Table 4—Sputum iNOS +ve, Nitrotyrosine +ve, and HO-1 +ve Inflammatory Cells During Exacerbation
|iNOS +ve MACR + PMN|
|%||80 (50, 98)||69 (20, 90)||NS|
|ac X106 cells/g||31 (3, 69)||13 (3, 70)||NS|
|Nit +ve MACR + PMN|
|%||77 (39, 99)||38 (13, 76)||0.001|
|ac X 106 cells/g||29 (3, 100)||7 (2, 27)||0.028|
|HO-1 +ve MACR + PMN|
|%||19 (0, 50)||12 (0, 25)||0.043|
|ac X 106 cells/g||6 (0, 30)||2 (0, 10)||0.05|
Tags: chronic bronchitis, emphysema, exacerbation, heme oxygenase, inducible nitric oxide synthase, inflammation, nitrotyrosine, oxidative stress, sputum