Bacterial colonization and granulocyte activation in chronic maxillary sinusitis in asthmatics and non-asthmatics

The impact of bacterial colonization on the severity and pattern of chronic inflammation in rhinosinusitis is not clear. In this study, it was hypothesized that bacterial colonization of the sinus mucosa would have a greater impact on inflammatory response modulation in asthmatic patients than in non-asthmatic patients with chronic rhinosinusitis. In order to test this hypothesis, granulocyte activation was measured and related to bacteria identified in the sinus lavage. Lavages from the maxillary sinuses of 21 asthmatic and 19 non-asthmatic patients with chronic rhinosinusitis (CRS) were microbiologically examined for aerobic and anaerobic growth. Eosinophil cationic protein (ECP), an eosinophil activation marker, and myeloperoxidase (MPO), a neutrophil activation marker, were measured in the sinus lavages. Bacteria were recovered in 20/32 samples from the asthmatics and in 21/33 samples from the non-asthmatics. Gram-positive aerobes and anaerobes were slightly more common than Gram-negative bacteria. A different bacterial profile was found when comparing Gram-negatives between the groups. Concentrations of MPO were significantly higher in samples with bacterial recovery from asthmatic patients, compared to sterile samples of both groups. Concentrations of ECP in the samples from asthmatic patients were significantly higher than in the controls, with no significant difference related to bacterial colonization. Bacterial colonization in chronically inflamed sinuses may have an impact on neutrophil granulocyte activation in patients with bronchial asthma, which was not confirmed for patients with CRS without asthma.