S in their sputum, indicated that these patients were classified into eosinophilic, neutrophilic, and mixed granulocytic groups. The NE group had more patients with bacterial infection 10781694 and produced more sputum, accompanied by higher levels of MedChemExpress Nafarelin sputum and serum inflammatory mediators. As a result, some patients took significantly longer time for recovery and hospital stay and more patients required intensification of drug therapy, particularly for those who had been infected with drug-resistant bacteria. Apparently, the NE group of patients SIS3 custom synthesis usually displayed severe AECOPD and responded poorly to standard therapies. Because control of bacterial infection in the lung is crucial for the recovery of lung function [21,22], it is important to determine the infected bacteria and their susceptibility to antibiotics to eliminate the infection effectively. Given that many patients in the NE group had higher levels of inflammatory mediators, regular treatment with antibiotics may be valuable for preventing the development of AECOPD patients. The MC group of patients displayed elevated numbers of sputum neutrophils and eosinophils, more severe impairment of lung function and disease severity, accompanied by higher levels of sputum and serum inflammatory mediators. Like patients in the NE group, some patients in the MC group also had evidence of bacterial infection and responded poorly to the standard therapies, accompanied by higher levels of sputum and serum inflammatorymediators at their stable stage. As a result, they had the longest time for recovery and hospital stay. In contrast, the EO group of patients with predominant eosinophil infiltrates in the lungs had lower levels of sputum and serum inflammatory mediators and responded well to the standard therapies, accompanied by shorter time of recovery and hospital stay. However, patients in the EO group, like those in the MC group, usually had severe impairment of lung function. Apparently, elevated eosinophil infiltration in the lungs is associated with severe impairment of lung function. Indeed, eosinophilic inflammation is present in about 20 ?0 of patients with COPD [2,4,5]. Increased number of eosinophils were detected even in patients with stable COPD [23]. Hence, characterisation of eosinophils in the lungs of AECOPD patients may be valuable for the design of therapies for AECOPD [2]. We are interested in further investigation of how eosinophil infiltration contributes to the impairment of lung function. Currently, functional criteria, clinical symptoms, and measurements have been used for the classification of AECOPD patients [1]. Although sputum neutrophil counts and the levels of serum CRP are good biomarkers for evaluating the severity of AECOPD [8,9], other biomarkers, such as serum cytokines and SAA, are also important for the identification and management of AECOPD [10]. We employed a range of mediators and sputum inflammatory cells to classify AECOPD patients into four groups and found that patients in individual groups had unique clinical characteristics, similar to that of a previous report [3]. We found that the levels of serum CRP, IL-6, and SAA and sputum MMP-9, CRP, and IL-6, together with the predominant type of inflammatory cells, were excellent biomarkers for judging the severity of AECOPD in this population. Our initial observations suggest that in an inflammatory exacerbation of COPD, like in an acute exacerbation of asthma, both the intensity and the pattern of the inf.S in their sputum, indicated that these patients were classified into eosinophilic, neutrophilic, and mixed granulocytic groups. The NE group had more patients with bacterial infection 10781694 and produced more sputum, accompanied by higher levels of sputum and serum inflammatory mediators. As a result, some patients took significantly longer time for recovery and hospital stay and more patients required intensification of drug therapy, particularly for those who had been infected with drug-resistant bacteria. Apparently, the NE group of patients usually displayed severe AECOPD and responded poorly to standard therapies. Because control of bacterial infection in the lung is crucial for the recovery of lung function [21,22], it is important to determine the infected bacteria and their susceptibility to antibiotics to eliminate the infection effectively. Given that many patients in the NE group had higher levels of inflammatory mediators, regular treatment with antibiotics may be valuable for preventing the development of AECOPD patients. The MC group of patients displayed elevated numbers of sputum neutrophils and eosinophils, more severe impairment of lung function and disease severity, accompanied by higher levels of sputum and serum inflammatory mediators. Like patients in the NE group, some patients in the MC group also had evidence of bacterial infection and responded poorly to the standard therapies, accompanied by higher levels of sputum and serum inflammatorymediators at their stable stage. As a result, they had the longest time for recovery and hospital stay. In contrast, the EO group of patients with predominant eosinophil infiltrates in the lungs had lower levels of sputum and serum inflammatory mediators and responded well to the standard therapies, accompanied by shorter time of recovery and hospital stay. However, patients in the EO group, like those in the MC group, usually had severe impairment of lung function. Apparently, elevated eosinophil infiltration in the lungs is associated with severe impairment of lung function. Indeed, eosinophilic inflammation is present in about 20 ?0 of patients with COPD [2,4,5]. Increased number of eosinophils were detected even in patients with stable COPD [23]. Hence, characterisation of eosinophils in the lungs of AECOPD patients may be valuable for the design of therapies for AECOPD [2]. We are interested in further investigation of how eosinophil infiltration contributes to the impairment of lung function. Currently, functional criteria, clinical symptoms, and measurements have been used for the classification of AECOPD patients [1]. Although sputum neutrophil counts and the levels of serum CRP are good biomarkers for evaluating the severity of AECOPD [8,9], other biomarkers, such as serum cytokines and SAA, are also important for the identification and management of AECOPD [10]. We employed a range of mediators and sputum inflammatory cells to classify AECOPD patients into four groups and found that patients in individual groups had unique clinical characteristics, similar to that of a previous report [3]. We found that the levels of serum CRP, IL-6, and SAA and sputum MMP-9, CRP, and IL-6, together with the predominant type of inflammatory cells, were excellent biomarkers for judging the severity of AECOPD in this population. Our initial observations suggest that in an inflammatory exacerbation of COPD, like in an acute exacerbation of asthma, both the intensity and the pattern of the inf.