Results

At present, over 300 children with DS are followed-up in our center by a multidisciplinary team. For 65 of them data on airway endoscopy are available. On average, a broncho- or laryngoscopy was performed at the age of 2.89 years, with a range from 2 months to 17 years. Most of the patients were male (63%). Our control group consists of 150 children with respiratory symptoms that warranted endoscopic evaluation, but without additional underlying conditions. They were matched in terms of age and sex with our DS group: the median age of endoscopy was 3.5 years (p = 0.418), 63% were boys (p = 0.971).
Samples for cultures and PCR testing were obtained in 47 of the DS patients (47/65 = 72%) and in 135 of our control patients (135/150 = 90%). In most of these patients, cultures showed multiple organisms (for example in 64% of the DS group). The encountered microorganisms were labeled as typical bacteria, atypical bacteria or other (mostly viruses) [table 1], based on experience and previous studies . We then attributed each patient to a category, depending on the microbiological data [table 2]: 1) sterile or only presence of commensals, 2) only typical bacteria present, 3) only atypical bacteria present, and 4) a combination of both typical and atypical bacteria. When comparing the DS to the control group, we found similar microorganisms. Also the percentages of encountered categories were comparable, no statistically significant differences were found [table 2].