| Abstract [eng] |
The aim of the study To investigate relationship between inflammation of the airways (bronchi) and pulmonary function. Objectives 1. To examine the levels of peripheral blood cytokines of patients suffering from COPD during exacerbation and remission, in order to detect non-invasive marker/markers of COPD that will enable us to differentiate infectious origin of exacerbation from non-infectious. 2. To investigate relationship between radiology changes of the lungs and respiratory function in patients suffering from chronic obstructive pulmonary disease. 3. To find out whether it is possible to evaluate changes of airway inflammation using classical inflammation and bacterial markers in patients suffering from COPD. To evaluate dependence of these markers on COPD clinical phase. 4. To evaluate the count of regulatory T lymphocytes (CD4+CD25+), as cells, possibly decreasing inflammation, in blood of the patients suffering from COPD and compare the results with results obtained from the group of patients who are not suffering from COPD. 5. To examine the amount of cells with CD25+ marker in mucosa of bronchi of patients suffering from COPD and compare this result with the result obtained in the control groups of non-smokers and smokers who are not suffering from COPD. Scientific novelty In practical work, the problem of timely diagnosis of exacerbation of the disease remains still important, despite significant achievements in research and treatment of COPD. The search of potential non-invasive markers enabling to diagnose the exacerbations of COPD timely and to determine the origin of exacerbation (bacterial vs. immune) is ongoing. From the point of possible markers of COPD, cytokines are promising. Although the blood levels of IL-10 and TNF-α were examined in patients suffering from COPD in several studies, the results of these studies were contradictory. Unlike other researchers, we tried to detect relationship between exacerbation of the disease, bacterial colonisation of the airways and blood cytokines levels; therefore, we had compared the patients suffering from COPD both during remission and exacerbation. For this purpose, we used a novel method of investigation and examined intracellular cytokines instead of extracellular ones. We found no publications concerning application of NBT and NFA examinations for diagnosis of COPD exacerbations or origin of these exacerbations, nevertheless these examination were available in clinical practice. We were the first researchers who used these tests for examination of the patients suffering from COPD. In accordance with the hypothesis stating that relative deficiency of regulatory T cells causing uncontrolled autoimmune inflammation in organisms of some smokers may be one of the causes of development of COPD, we have examined the amount of regulatory T cells in the blood and bronchial mucosa of the patients suffering from COPD. The results of our study had confirmed this hypothesis. MATERIALS AND METHODS The material studied was collected since February, 2009 till April, 2012 at the Centre of Pulmonology and Allergology of Vilnius University Hospital Santariškių Clinics. A total of 99 subjects were enrolled into the study, including 73 patients suffering from COPD (all stages) and 26 healthy persons (controls). All 99 subjects underwent comprehensive examination of lung function (spirometry with bronchodilation test, plethysmography, and gas diffusion examination). Blood samples to examine activity of inflammation (WBC count, CRP, ESR, fibrinogen, NFA and procalcitonin) were obtained from 32 patients. Blood NBT test was performed for 73 COPD patients and 26 control subjects, also. All 99 study subjects underwent bronchoscopy; for 43 patients and 26 control subjects the biopsy of bronchial mucosa was performed, all these patients provided blood samples for examination of CD4+CD25+ (Treg) cells. The bronchoscopy revealed endobronchial tumor and confirmed the diagnosis of lung cancer in one patient suffering from COPD. This patient was directed for surgery and discontinued participation in our study. Computed tomography imaging was performed for 38 patients. The samples for examination of blood cytokines were obtained from 24 subjects suffering from COPD. RESULTS The level of the majority of cytokines showed no difference while comparing remission and exacerbation phases We have found out that in comparison with remission, the level peripheral blood IL-10 is statistically reliably higher in patients who suffer from exacerbation. This study included 38 subjects suffering from COPD; in accordance with severity of the disease, the patients were distributed into 2 groups (the group I included patients with severe and very severe COPD and the group II consisted of the patients suffering from moderate and mild COPD). There were no statistically reliable differences in CTI changes between the groups of mild and severe bronchial obstruction (according to GOLD) stage. During remission, there were no statistically significant differences between the groups in pulmonary volumes, values of blood gases and gas diffusion, also. However, the values of TLC, RV, and capillary pCO2 in patients with more severe stage of bronchial obstruction suffering from COPD exacerbation were markedly higher and DLco, pO2, sO2 were markedly lower, in comparison with these of patients with less severe stage (p<0.05). We have found out linear correlations between bronchiectasis, emphysema and the rate of exacerbations (r=0.4; p=0.014; Fig.10), between pulmonary fibrosis and presence of bronchiectasis (r=0.4; p=0.014); the value of DLco correlated negatively with the extent of pulmonary fibrosis and the rate of exacerbations of the disease (r = – 0.4; p=0.02; Fig. 11). We have also found negative correlation between TLC, RV and pO2, sO2 (r = –0.4, p=0.009) and positive correlation between TLC, RV and pCO2 (r =0.4, p = 0.027). The study included a total of 73 patients. It was found out that the levels of CRP, fibrinogen, WBC and ESR values in the blood of patients suffering from COPD differed markedly during remission and exacerbation. We found out no increase in blood procalcitonin levels in patients suffering from COPD exacerbation. There was no significant increase in either NBT, or in NFA, during COPD exacerbation. There were no differences of NBT and NFA between patients with COPD and healthy ones; however, there was a good correlation between these values themselves. The comparison of COPD and control groups demonstrated no statistically significant difference either in total number of CD4+CD25+ cells, or in CD4+CD25+bright( Treg). However, in the group of patients suffering from severe and very severe COPD, the count of these cells was found to be significantly lower, in comparison with healthy smokers. The difference between smoking and non-smoking controls was found to be statistically significant, also: the count of CD4+CD25+ lymphocytes was markedly higher in healthy smokers than in non-smokers. The biopsies of bronchial mucosa were examined for the same 69 subjects who underwent assessment of CD25+ blood cell count. The same groups of study subjects were compared, including the group of patients with severe and very severe COPD, mild and moderate COPD, healthy smokers and non-smokers. A reliable difference between COPD and controls was found out: in the group of COPD patients the count of CD25+ cells was markedly lower (100.9±50.4 vs 131.4±64.1). CONCLUSIONS 1. The levels of blood markers of inflammation activity depend on clinical phase of COPD. During exacerbation, the intensification of inflammation of the airways is well reflected by classic blood markers of inflammatory activity, including CRP, ESR, fibrinogen, white blood cell count and, as well, the results of bronchial aspirate examination. NBT, NFA and procalcitonin tests, from the points of view of diagnosis of inflammation of the airways and treatment of exacerbation, are not important in patients suffering from COPD. 2. The changes of the levels of blood cytokines, including increased IL-10 and decreased TNF-α level, reflect an exacerbation of COPD. It is very possible that these cytokines may be valuable laboratory markers of COPD clinical phase, enabling one to differentiate bacterial exacerbation of COPD from non-bacterial. 3. The classification of the patients suffering from COPD into stages taking into account only FEV1 value reveals the entirety of structure and functional changes of the lungs insufficiently. The relationship between radiology and functional changes of the lungs is not unambiguous. The worsening of gas diffusion index reflects the development of pulmonary fibrosis. The more frequent exacerbations of COPD are related to more severe changes of pulmonary structure (i.e., bronchiectasis and emphysema). The patients with poorer functional condition during remission (III and IV groups of severity of bronchial obstruction according to GOLD) experience markedly greater impairment of functional condition of respiratory system during exacerbation, in comparison with that of the patients in mild to moderate severity stages of COPD. 4. The dysfunction of immune system of the body plays the role in development of COPD, also, as the inflammation of the airways (possibly autoimmune) may be supressed inadequately due to insufficiency of CD4+CD25+ (T regulatory) lymphocytes. |
