Laryngeal secretions. An immunochemical and immunohistological study

This study was designed to investigate properties of laryngeal secretion and secretory activity of IgA in the larynx. Laryngeal secretions were collected by adsorption method on filter paper during laryngomicrosurgery from 20 patients having an inflammatory lesion in the larynx. Contents of IgG, IgA, IgE, secretory component (SC), and lactoferrin in the laryngeal secretions were determined and compared with results of those in nasal secretions, tracheobronchial washings, and serum samples obtained from the same subjects. The laryngeal mucosae of 8 laryngectomized materials for cancer lesion were subjected to immunofluorescence studies including the cytoplasmic SC affinity test. Results of this study indicate that laryngeal secretions are characterized by exocrine secretion, resembling nasal and tracheobronchial secretions in the electrophoretic pattern and immunoglobulins content. The immunofluorescence studies and SC affinity test found that the larynx possesses secretory activity of IgA, particularly in the ventricle and subglottis.