PHOTOPHERESIS, A POSSIBLE THERAPY FOR AIRWAY HYPERREACTIVITY

Airway hyperreactivity is an almost universal feature of asthma. The e xact origin of this phenomenon is poorly understood. However, there is increasing evidence that T cells play an important role in the pathog enesis of this disorder. This fact makes it challenging to photopheres is to suppress the pulmonar hyperreactivity response. Photopheresis is a therapy for T cell mediated diseases aiming at specific suppression of the pathogenic clone of T cells involved. The use of photopheresis for the treatment of airway hyperreactivity was investigated in this study. We performed experiments in a murine model for airway hyperreac tivity. In short, mice were sensitized by cutaneous application of 2,4 ,6-trinitrochlorobenzene. The immune system was challenged by an intra tracheal injection of 2, 4,6-trinitrobenzenesulfonic acid and a bronch oalveolar lavage was performed. In this lavage the total number of leu kocytes was established and the number of macrophages was determined. It was found that photopheresis treatment was capable to suppress the airway hyperreactivity response for about 80%. In addition, the genera ted suppression proved to be transferable by splenocytes of treated an imals. We conclude that photopheresis can be an interesting therapy fo r airway hyperreactivity (and perhaps also for asthma) especially when one takes into account that photopheresis induces specific immune sup pression and has hardly any adverse effects.