EFFECT OF SLOW-RELEASE THEOPHYLLINE ON NASAL ANTIGEN CHALLENGE IN SUBJECTS WITH ALLERGIC RHINITIS

It has been recognized recently that theophylline possesses anti-infla mmatory effects that could be of clinical interest in patients with ai rway inflammatory diseases such as asthma and allergic rhinitis (AR), The aim of the present study was to explore the effect of theophylline on the nasal eosinophilic inflammatory response following allergen ch allenge in patients with AR. Fourteen subjects suffering fi om seasona l rhinitis with an early reaction after nasal allergen provocation wer e challenged outside the pollen season after pretreatment for 3 weeks with placebo or slow-release theophylline (Euphylong(R)) in a randomiz ed double-blind, cross-ol er study, Nasal blocking index (NBI), nasal airway resistance and symptoms were recorded before, and 1 and 5 h aft er challenge; additionally, nasal lavage fluid was collected before, a s well as 1 and 5 h after challenge. Eosinophil cationic protein (ECP) was measured in the lavage as well as the number of eosinophils befor e, and 1 h and 5 h after allergen challenge. After 3 weeks of treatmen t, baseline concentrations of ECP in nasal lavage amounted to 826+/-32 9 ng.L-1 (placebo) and 936+/-351 ng LI (theophylline). The ECP levels did not increase during the early phase response. Five hours after cha llenge, ECP in the placebo group increased markedly (p<0.01), whereas no significant increase was observed during theophylline treatment. In parallel, the number of eosinophils in the nasal lavage fluid was lon er during theophylline treatment. Additionally, theophylline therapy a lso significantly reduced the nasal symptoms and had some protective e ffect against nasal obstruction following allergen challenge. These re sults confirm the anti-inflammatory effects of theophylline and sugges t that these effects may be of clinical benefit in patients with aller gic rhinitis.