No abstract

Tonsil hyperplasia is the most common cause of pediatric obstructive sleep apnea (OSA). Despite the growing knowledge in tissue immunology of tonsils, the immunopathology driving tonsil hyperplasia and OSA remains unknown. Here we used multi-parametric flow cytometry to analyze the composition and phenotype of tonsillar innate lymphoid cells (ILCs), T cells, and B cells from pediatric patients with OSA, who had previous polysomnography. Unbiased clustering analysis was used to delineate and compare lymphocyte heterogeneity between two patient groups: children with small tonsils and moderate OSA (n = 6) or large tonsils and very severe OSA (n = 13). We detected disturbed ILC and B cell proportions in patients with large tonsils, characterized by an increase in the frequency of naïve CD27-CD21hi B cells and a relative reduction of ILCs. The enrichment of naïve B cells was not commensurate with elevated Ki67 expression, suggesting defective differentiation and/or migration rather than cellular proliferation to be the causative mechanism. Finally, yet importantly, we provide the flow cytometry data to be used as a resource for additional translational studies aimed at investigating the immunological mechanisms of pediatric tonsil hyperplasia and OSA.

Background: The management of chronic rhinosinusitis (CRS) in patients with cystic fibrosis (CF) and primary ciliary dyskinesia (PCD) is still a challenge. At our institution we have used gentamycin nasal spray, extemporaneously produced, for prophylactic treatment of moderate-to-severe CRS. The aim of this study was to investigate the gentamycin susceptibility of bacteria in sputum samples in CF and PCD patients treated for CRS. Methodology: Patients with CF and PCD who were prescribed gentamycin nasal spray for CRS and had sputum bacterial cultures taken pre-treatment and followed-up at least once after ≥6 months were retrospectively included. Microbiological data were descriptively analysed in terms of bacterial species and resistance to gentamycin. Results: A case series of 17 CF and 12 PCD patients passed the inclusion criteria. Of those cases, three (18%) CF patients and one (8%) PCD patient developed resistance to gentamycin during treatment with gentamycin nasal spray. In all four cases, the resistant bacterial isolates were <i>P. aeruginosa</i>. Additionally, two CF patients already had <i>P. aeruginosa </i> isolates resistant to gentamycin in the pre-treatment culture. In further two CF patients, the multi-resistant <i>Burgdorferi cepacia </i>complex, including gentamycin resistance, was identified. <i>P. aeruginosa </i> and <i>S. aureus </i> in CF and <i>P. aeruginosa</i> and <i>H. influenza </i> in PCD were the predominant bacterial species. Conclusions: The study showed that there was moderate incidence of gentamycin resistance in CF and PCD patients at our institution. However, further prospective studies are needed to confirm the outcomes.