Resolution of bronchial inflammation is related to bacterial eradication following treatment of exacerbations of chronic bronchitis.
BACKGROUND
Recent studies of the role of bacteria in chronic bronchitis have shown that bacterial colonisation is associated with enhanced inflammation and that purulent acute exacerbations of chronic bronchitis (AECB) are associated with bacteria and characterised by increased inflammation. Changes in bronchial inflammation in response to the success or failure of bacterial eradication following AECB were therefore studied.


METHODS
Bacterial quantitative culture and sputum markers of inflammation (myeloperoxidase (MPO), neutrophil elastase, leukotriene B4 (LTB4), sol:serum albumin ratio, and secretory leukoprotease inhibitor) were measured in patients presenting with culture positive purulent AECB and repeated 10 days and 2 months later. 41 patients provided sputum sufficient for both bacteriology and assessment of inflammation at baseline and day 10, and 46 provided sufficient sample for bacteriology, 40 of which could also be analysed for inflammation at 2 months (when clinically stable).


RESULTS
At day 10, 17 of the 41 patient samples had a positive bacterial culture. In the stable state, 18 of the 46 samples had a positive culture, but with a significantly lower bacterial load than at presentation. Although there was no difference between the groups at presentation, the concentration of MPO was lower (p<0.05) in those in whom bacteria were eradicated by day 10 than in those with persisting bacteria. The LTB4 concentration was similarly lower (p<0.001) in those in whom bacteria were eradicated than in those with persistent bacteria. In the stable clinical state the concentrations of both MPO and LTB4 were lower in those in whom bacteria were eradicated than in patients with persisting bacteria.


CONCLUSIONS
Resolution of bronchial inflammation following AECB is related to bacterial eradication. Those in whom bacteria continue to be cultured in their sputum have partial resolution of inflammation which may reflect continued stimulation by the reduced bacterial load.
White
A J
AJ
Department of Respiratory Medicine, Queen Elizabeth Hospital, Birmingham B15 2TH, UK.
Gompertz
S
S
Bayley
D L
DL
Hill
S L
SL
O'Brien
C
C
Unsal
I
I
Stockley
R A
RA
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000900:Anti-Bacterial Agents / Q000627:therapeutic use*; D001424:Bacterial Infections / Q000188:drug therapy*; D015415:Biomarkers / Q000032:analysis; D029481:Bronchitis, Chronic / Q000188:drug therapy* / Q000382:microbiology; D002444:Cefuroxime / Q000031:analogs & derivatives* / Q000627:therapeutic use*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D013183:Sputum / Q000382:microbiology
D000900:Anti-Bacterial Agents; D015415:Biomarkers; D002444:Cefuroxime; C040738:cefuroxime axetil