Evidence of the local immune status in the human larynx.

We have studied the presence of local immunity in the larynx and its role and development of laryngeal glands in the human larynx. The local immune status in laryngeal secretion or related tissue specimens from the laryngeal ventricle was examined and the results were analyzed between individuals with or without head and neck cancer. Laryngeal secretions or mucosal tissue specimens were obtained during the microscopic laryngeal surgery or at the time of the surgery of the larynx. The laryngeal secretion contained immunological factors such as IgG, IgM, IgA or secretory IgA (SIgA). The mean level of SIgA of the mucosal tissue was low in patients with the benign laryngeal disease and considerably decreased in patients with previous radiation therapy. The level of SIgA in the laryngeal secretion closely correlated to the level of SIgA in the mucosal tissue. From the present study, we confirmed the actual presence of local immune function in the human larynx. Furthermore, the local immune status is affected by either the presence of malignancy or the treatment to the larynx such as radiation.

Age related changes in the distribution of laryngeal glands in the human adult larynx.

OBJECTIVE: To understand the defense status of glandular tissue in the human adult larynx, we examined the glandular distribution, concentration and the ratio of the mucous glands in the subglottic and supraglottic larynx. METHODS: One-hundred and seven adult larynges were examined. The area of the mucosa and glands were measured using an image analyzing system. The correlations of the concentration as well as the ratio of the mucous glands with age were analyzed. RESULTS: The ratio of the areas occupied by the glandular acini of the subglottis was almost equal to that of infants as we reported earlier. The concentration of the laryngeal glands decreased in higher-aged adults at the level of the supraglottis, but not at the level of the subglottis. CONCLUSIONS: In comparison to infants, the ratio of laryngeal glands of the human subglottic larynx is rather constant in human adults. However, the supraglottic larynx seems to be influenced by increasing age. The changes deserved in the laryngeal glands predominantly occur in the supraglottic larynx.

Radiotherapy of the neck influences the distribution of laryngeal secretory glands.

To elucidate the influence of radiation therapy on the larynx in patients who receive radiotherapy to the neck, we observed the changes in the distribution of the laryngeal glands. Human adult larynges from patients with either laryngeal or hypopharyngeal cancer were histopathologically examined, and the changes in the glandular distribution as well as in the ratio of serous or mucous type cells were surveyed using an image analysis system. The mean ratio of the area occupied by glandular acini in the subglottic larynx was 0.182 in the non-radiation group and 0.098 in the radiation group (p < 0.001). Although no statistical difference was observed, the average density of the glands decreased and the average ratio of serous-type/mucous-type glandular cells decreased in the irradiated larynx. The glandular acini are often replaced with fibrous connective tissue and the ratio of serous-type glandular cells decreases. These results indicate that not only the voice function but also the local defence function of the larynx might be impaired after radiotherapy.