Therapeutic diminution of Interleukin-10 with intranasal theophylline administration in hyposmic patients.

OBJECTIVE

To determine changes in nasal mucus Interleukin-10 (IL-10) before and after intranasal theophylline treatment in hyposmic patients, and the relationship of these changes to orally administered theophylline treatment.

DESIGN

IL-10 was measured in nasal mucus samples of 17 normal subjects and 39 patients with hyposmia of multiple etiologies by use of a sensitive spectrophotometric ELISA assay. Hyposmia is defined clinically by standardized evaluation of impaired olfactometry, as well as subjectively self reported by the patient.

RESULTS

Prior to treatment, IL-10 levels in nasal mucus were increased in hyposmic patients compared to controls. Following intranasal theophylline administration, over half of treated patients experienced a decrease of nasal mucus IL-10 toward control levels, correlated with a significant improvement in taste and smell function. Patients who increased with intranasal administration, similar to previously reported oral administration, showed no significant improvement in taste or smell function.

CONCLUSIONS

Nasal mucus IL-10 decreased in patients treated with intranasal theophylline. Mechanisms of action include phosphodiesterase and nuclear factor kappa-B inhibition, correlated with an improvement in both olfaction and gustation. IL-10 is induced by therapeutic and systemic administration of theophylline as with oral dosage, but reduced by lower and localized treatment.