High prevalence of influenza specific antibody secreting cells in nasal mucosa

Secretory immunoglobulin A (SIgA) provides the first Line of defence agains t pathogens initiating infection via the mucosal route, e.g. the influenza virus. The aim of this study was to examine the basal level of influenza-sp ecific antibody-secreting cell (ASC) in the local mucosa of the upper respi ratory tract. Nineteen patients scheduled fur tonsillectomy were enrolled f or the study, and they had not experienced influenza during the previous ye ar. Tonsils, blood, oral fluid and a nasal biopsy were sampled, and the bas al levels of ASC and antibodies (Abs) were determined. We found low numbers of influenza-specific ASC in the blood and tonsils, but there were about 1 0-100 times higher numbers of specific ASC in the nasal mucosa tissue despi te no recent influenza exposure. Thus, the basal level of influenza-specifi c ASC in the mucosa of the respiratory tract may be important in the protec tion against influenza infection.