Secretory immunoglobulin A in the human endolymphatic sac. An immunohistochemical study

Presence of immunoglobulin A (IgA) and of secretory component in epithelial cells and in the lumen of the human endolymphatic sac was demonstrated by two different immunohistochemical methods. IgA was also detected in perisaccular plasma cells. The findings connote the existence of a local immune system of the inner ear.