Innate and adaptive nasal mucosal immune responses following experimental human pneumococcal colonization.

Streptococcus pneumoniae (Spn) is a common cause of respiratory infection, but also frequently colonizes the nasopharynx in the absence of disease. We used mass cytometry to study immune cells from nasal biopsy samples collected following experimental human pneumococcal challenge in order to identify immunological mechanisms of control of Spn colonization. Using 37 markers, we characterized 293 nasal immune cell clusters, of which 7 were associated with Spn colonization. B cell and CD8+CD161+ T cell clusters were significantly lower in colonized than in non-colonized subjects. By following a second cohort before and after pneumococcal challenge we observed that B cells were depleted from the nasal mucosa upon Spn colonization. This associated with an expansion of Spn polysaccharide-specific and total plasmablasts in blood. Moreover, increased responses of blood mucosal associated invariant T (MAIT) cells against in vitro stimulation with pneumococcus prior to challenge associated with protection against establishment of Spn colonization and with increased mucosal MAIT cell populations. These results implicate MAIT cells in the protection against pneumococcal colonization and demonstrate that colonization affects mucosal and circulating B cell populations.

Evaluating the use of Floseal haemostatic matrix in the treatment of epistaxis: a prospective, control-matched longitudinal study.

Epistaxis is a common cause of emergency admissions in ENT. The use of Floseal haemostatic matrix in the treatment of epistaxis has been investigated in a number of studies in North America. We aimed to report a UK-based experience in the context of the current UK management paradigm. The study was designed as a prospective, unrandomised, control-matched longitudinal study. Cases were matched to controls in order to reduce the risk of bias. The overall treatment success rate for Floseal was 75 %, similar to the rates reported by studies based in North America. Nasal packing carried a success rate of 85 % and there was no statistically significant difference between the success rates of both treatments. Anecdotally Floseal can also be used successfully in thrombocyctopenic patients. There was a trend towards a shorter length of stay in the Floseal group, but this was not statistically significant. The 7-day readmission rate was 10 % for both the groups. This controlled study demonstrates that Floseal has a similar treatment success rate to nasal packing and that there may be a trend towards a shorter length of stay.