Temporal patterns of mediator release during developing cutaneous late-phase reactions


Zweiman University of Pennsylvania School of Medicine, 512 Johnson Pavilion, Philadelphia, PA 19104, USA



Several inflammatory mediators have been found released in sites of cutaneous late phase reactions (LPR). However, the temporal pattern of their release during LPR development has not been characterized.


Determine hourly accumulation of mediator release in comparison with gross and inflammatory cell responses during developing LPR.


Skin chamber appended to sites of allergen and diluent control challenge with hourly collections. Then, study of exuding leucocytes in chamber bases.


In the allergen-challenged sites, histamine release peaked in the first hour, then low level release over the next 5 h. Lactoferrin release from neutrophils started by the second hour, likely associated with released IL-8. Eosinophil cationic protein levels started increasing slightly later. The percentage of exuding leucocytes which were activated was significantly higher in the allergen challenge sites than in the control challenge sites


Both gross LPR and local inflammatory cell responses in the skin start soon after the immediate mast cell activation in IgE-mediated responses. Such inflammatory responses include leucocyte activation and mediator release.