THEOPHYLLINES EFFECT ON THE CELL-DYNAMICS OF THE CUTANEOUS HYPERSENSITIVITY REACTION IN PATIENTS ALLERGIC TO GRASS POLLENS

Theophylline, at plasma levels lower than that required for bronchodil ation, has steroid-sparing as well as additional anti-inflammatory pro perties in asthmatic patients. We have investigated the effects of the ophylline on eosinophils, circulating and recruited to the area of ant igen (AG) administration. Eleven atopic volunteers were randomised (an d crossed-over) to three regimens i.e. (a) placebo or (b) theophylline (200 mg sustained-release formulation, ED), both with ID (intradermal ) AG on day 3, or (c) theophylline with no AG. Peripheral blood counts were examined before therapy and at 6 h and 24 h after the first drug dose. Cellular dynamics at the area of AG administration were studied qualitatively, using the skin blister technique. Theophylline reduced circulating eosinophils, irrespective of AG administration (mean of 1 7% at 6 h and 15% at 24 h after AG, as compared to 47% and 38% with th eophylline only). Contrary to expectations theophylline increased eosi nophil vacuolisation at the area of AG administration (mean of 400% at 6 h and 182% at 24h). However, it had no effect on the area of indura tion. The state of cell activity during administration could explain t he dichotomy of its effect on eosinophil response.