Interleukin 16 (IL-16) in asthma and allergic rhinitis. A comparison between upper and lower airways.

Asthma is a chronic inflammatory disease of bronchial mucosa, in which mast cells, eosinophils and activated T cells are of considerable importance. The increased chemotactic activity for T cells in patients with asthma is mainly attributable to IL-16. A strong association between asthma and allergic rhinitis exists from a clinical and epidemiologic standpoint of view. Although it is clear that the condition of the upper airways has impact on the lower airway physiology, the precise mechanisms underlying this relation are far from being resolved. This work was assessed the role of interleukin 16 (IL-16) in bronchoalveolar lavage (BAL) fluid in both diseases using quantitative sandwich enzyme immuno-assay, and the effect on ventilatory function. The results showed abnormally increased levels of IL-16 (294.4 +/- 15.24 pg/ml), serum eosinophils with absolute count (510.0 +/- 93.57, P>0.05), and total serum IgE (287.9 +/- 61.22 IU/ml) using ELFA in patients of combined asthma and rhinitis, than in each of them alone. There was reduction in FEV1 (forced expiratory volume in the first second) in the same group (81.6 +/- 2.01%). There was a negative correlation between BAL IL-16 and FEV1. In conclusion IL-16 may be considered as a marker of severity of airway inflammation.