IL-1 beta protein in human skin lymph does not discriminate allergic from irritant contact dermatitis

Recent data suggest a key rôle for IL-1 beta in the induction phase of allergic contact dermatitis. In the present study, the protein levels of IL-1 beta were measured in skin lymph derived from normal untreated skin as well as from irritant and allergic (induction and elicitation phase) contact dermatitis. IL-1 beta increased in the course of both types of contact dermatitis, displaying the highest levels in irritant CD. Using a reverse transcriptase-polymerase chain reaction, low signal strength of IL-1 beta mRNA was demonstrated in lymph cells derived from normal skin and allergic CD. In lymph cells collected 2 x daily during the induction phase of allergic contact dermatitis, no upregulation of the IL-1 beta mRNA signal was found. Isolated CD1a+ lymph cells derived from normal skin as well as from the induction and elicitation phase of allergic contact dermatitis did not express IL-1 beta mRNA. Our results demonstrate that in human skin lymph, the IL-1 beta profiles do not discriminate between irritant and allergic contact dermatitis and that besides resident epidermal and dermal cells, circulating lymph cells may also contribute to IL-1 beta protein production.